• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 8
  • 2
  • 1
  • 1
  • Tagged with
  • 33
  • 13
  • 10
  • 8
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Personality and the HPA-axis in Association with Postpartum Depression

Iliadis, Stavros I January 2016 (has links)
Postpartum depression is a psychiatric disorder affecting a substantial proportion of newly delivered women, and remains a significant cause of childbirth-related morbidity. The aim of the present thesis was to examine psychological, endocrine and genetic aspects of postpartum depression in a large, population-based sample of women in Uppsala, Sweden. All included studies were undertaken as parts of the BASIC-project, a longitudinal study on psychological wellbeing during pregnancy and the postpartum period. Study participants were screened for depressive symptoms in pregnancy week 17 and 32 as well as at six weeks and six months postpartum, mainly by use of the Swedish version of the Edinburgh Postnatal Depression Scale (EPDS). Furthermore, personality was assessed with the Swedish universities Scale of Personality (SSP) in pregnancy week 32. Evening cortisol levels in saliva were measured in pregnancy week 36 and at six weeks postpartum. Blood samples were obtained to measure corticotropin-releasing hormone levels (CRH) and to perform genetic analyses. The results of this thesis demonstrate that neuroticism is a strong and independent predictive factor of depressive symptoms at six weeks and six months postpartum, and has a significant mediatory role in the association between a single nucleotide polymorphism in the hydroxysteroid (11-beta) dehydrogenase 1 gene (HSD11B1) and postpartum depression. Furthermore, women with postpartum depressive symptoms present with a dysregulated hypothalamic-pituitary-adrenal axis activity in terms of elevated cortisol levels postpartum, as well as elevated CRH levels in mid-gestation. In conclusion, this thesis develops current knowledge on several attributes of postpartum depression. Further studies are required to replicate and expand on these results, which would further contribute to early identification of women at risk of postpartum depression and adoption of proper interventions that may moderate the short- and long-term consequences of the disorder.
22

Rastreamento de disfunção ventricular assintomática em puérperas : padrão ecocardiográfico evolutivo e comparativo a casos de miocardiopatia periparto

Vettori, Daniela Vanessa January 2008 (has links)
Objetivos: Determinar a prevalência de disfunção sistólica assintomática do ventrículo esquerdo no puerpério e comparar sua evolução com os casos de miocardiopatia periparto ocorridos no mesmo período. Pacientes e Métodos: Estudo transversal entre setembro de 2002 e abril de 2005, para determinar a prevalência de disfunção ventricular assintomática no puerpério imediato e a incidência de miocardiopatia periparto no mesmo período, e entre novembro de 2007 e janeiro de 2008 para verificar a evolução clínica e ecocardiográfica destas pacientes. Os parâmetros ecocardiográficos das puérperas com disfunção ventricular assintomática também foram comparados com os de puérperas normais. Disfunção sistólica do ventrículo esquerdo foi definida como diâmetro diastólico final ≥ 5,6 cm e/ou fração de ejeção < 53,0% + encurtamento fracional sistólico < 25%. Resultados: Foram rastreadas 1182 puérperas, sendo detectados 10 casos (0,85%) de disfunção ventricular assintomática, cujas características clínicas, como raça, superfície corporal, paridade, gemelaridade e uso de tocolíticos, não foram diferentes quando comparadas com 18 controles rastreados sem disfunção. A incidência de miocardiopatia periparto no período foi de 6 casos em 10866 partos (1/1811 partos de nascidos vivos). Após uma média de 4,0 anos (2,9-5,2 anos), 7 dos 10 casos de disfunção assintomática e 5 dos 6 casos de miocardiopatia clínica realizaram nova ecocardiografia, verificando-se significativo aumento da fração de ejeção e do encurtamento fracional médios nos dois grupos, sendo que a parcela de recuperação da função foi semelhante nos grupos (p interação > 0,05). Conclusões: Ocorre disfunção ventricular no puerpério sem os achados clínicos de insuficiência cardíaca cujos parâmetros ecocardiográficos evoluem de maneira semelhante aqueles de pacientes com miocardiopatia periparto ao longo do tempo. / Objective: To determine the prevalence of asymptomatic left ventricular systolic dysfunction in puerperium and to compare its progression with that of cases of peripartum cardiomyopathy that occurred in the same study period. Patients and Methods: Cross-sectional study conducted from September 2002 to April 2005 to determine the prevalence of asymptomatic ventricular dysfunction in early puerperium and the incidence of peripartum myocardiopathy, and from November 2007 to January 2008 to obtain clinical and echocardiographic follow-up data of the study patients. Echocardiographic parameters of puerperal women with asymptomatic ventricular dysfunction were also compared with those of normal puerperal women. The parameters to define left ventricular systolic dysfunction were end-diastolic diameter ≥ 5.6 cm and/or ejection fraction < 53.0%, and systolic fractional shortening < 25%. Results: A total of 1182 puerperal women were screened, and 10 cases (0.85%) of asymptomatic ventricular dysfunction were detected. Clinical characteristics, such as ethnicity, body surface, parity, multiple gestations, and tocolytic therapy, were not different from those of the 18 normal women used as controls. The incidence of peripartum cardiomyopathy was 6 cases out of 10866 deliveries (1/1811 live births). After a mean of 4.0 years (2.9-5.2 years), 7 of the 10 patients with asymptomatic dysfunction and 5 of the 6 with clinical cardiomyopathy underwent follow-up echocardiography. A significant increase was found in mean ejection fraction and fractional shortening in the two groups, and function recovery rates were similar in the two groups (p > 0.05). Conclusions: Ventricular dysfunction may occur in the puerperium without clinical signs of heart failure, and the long-term progression of echocardiographic parameters is similar to that found in cases of peripartum cardiomyopathy.
23

Rastreamento de disfunção ventricular assintomática em puérperas : padrão ecocardiográfico evolutivo e comparativo a casos de miocardiopatia periparto

Vettori, Daniela Vanessa January 2008 (has links)
Objetivos: Determinar a prevalência de disfunção sistólica assintomática do ventrículo esquerdo no puerpério e comparar sua evolução com os casos de miocardiopatia periparto ocorridos no mesmo período. Pacientes e Métodos: Estudo transversal entre setembro de 2002 e abril de 2005, para determinar a prevalência de disfunção ventricular assintomática no puerpério imediato e a incidência de miocardiopatia periparto no mesmo período, e entre novembro de 2007 e janeiro de 2008 para verificar a evolução clínica e ecocardiográfica destas pacientes. Os parâmetros ecocardiográficos das puérperas com disfunção ventricular assintomática também foram comparados com os de puérperas normais. Disfunção sistólica do ventrículo esquerdo foi definida como diâmetro diastólico final ≥ 5,6 cm e/ou fração de ejeção < 53,0% + encurtamento fracional sistólico < 25%. Resultados: Foram rastreadas 1182 puérperas, sendo detectados 10 casos (0,85%) de disfunção ventricular assintomática, cujas características clínicas, como raça, superfície corporal, paridade, gemelaridade e uso de tocolíticos, não foram diferentes quando comparadas com 18 controles rastreados sem disfunção. A incidência de miocardiopatia periparto no período foi de 6 casos em 10866 partos (1/1811 partos de nascidos vivos). Após uma média de 4,0 anos (2,9-5,2 anos), 7 dos 10 casos de disfunção assintomática e 5 dos 6 casos de miocardiopatia clínica realizaram nova ecocardiografia, verificando-se significativo aumento da fração de ejeção e do encurtamento fracional médios nos dois grupos, sendo que a parcela de recuperação da função foi semelhante nos grupos (p interação > 0,05). Conclusões: Ocorre disfunção ventricular no puerpério sem os achados clínicos de insuficiência cardíaca cujos parâmetros ecocardiográficos evoluem de maneira semelhante aqueles de pacientes com miocardiopatia periparto ao longo do tempo. / Objective: To determine the prevalence of asymptomatic left ventricular systolic dysfunction in puerperium and to compare its progression with that of cases of peripartum cardiomyopathy that occurred in the same study period. Patients and Methods: Cross-sectional study conducted from September 2002 to April 2005 to determine the prevalence of asymptomatic ventricular dysfunction in early puerperium and the incidence of peripartum myocardiopathy, and from November 2007 to January 2008 to obtain clinical and echocardiographic follow-up data of the study patients. Echocardiographic parameters of puerperal women with asymptomatic ventricular dysfunction were also compared with those of normal puerperal women. The parameters to define left ventricular systolic dysfunction were end-diastolic diameter ≥ 5.6 cm and/or ejection fraction < 53.0%, and systolic fractional shortening < 25%. Results: A total of 1182 puerperal women were screened, and 10 cases (0.85%) of asymptomatic ventricular dysfunction were detected. Clinical characteristics, such as ethnicity, body surface, parity, multiple gestations, and tocolytic therapy, were not different from those of the 18 normal women used as controls. The incidence of peripartum cardiomyopathy was 6 cases out of 10866 deliveries (1/1811 live births). After a mean of 4.0 years (2.9-5.2 years), 7 of the 10 patients with asymptomatic dysfunction and 5 of the 6 with clinical cardiomyopathy underwent follow-up echocardiography. A significant increase was found in mean ejection fraction and fractional shortening in the two groups, and function recovery rates were similar in the two groups (p > 0.05). Conclusions: Ventricular dysfunction may occur in the puerperium without clinical signs of heart failure, and the long-term progression of echocardiographic parameters is similar to that found in cases of peripartum cardiomyopathy.
24

Parâmetros clínicos e laboratoriais de vacas leiteiras no período de transição manejadas em free stall / Clinical and laboratory parameters of dairy cows in the transition period managed in free stall

Trajano, Haroldo Pimentel 24 May 2013 (has links)
Made available in DSpace on 2015-03-26T13:47:14Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1130934 bytes, checksum: 4f9cc3b6a64e9f7c3838baa5ce0d9079 (MD5) Previous issue date: 2013-05-24 / The aim of this study was to evaluate hematological and blood biochemical changes, in association with urinalysis and physical examination of dairy cows in puerperium as well as to verify the efficiency of protocols capable of monitoring the onset of metabolic and infectious diseases. The study was conducted using 22 Holstein cows, 11 primiparous and 11 multiparous, aged from two until seven years, belonging to the dairy herd of the Teaching, Research and Extension in Dairy Cattle Unit - UEPE/GL, of the Department of Animal Science of the Federal University of Viçosa. A total of 154 blood and urine samples were analyzed. The research consisted of clinical monitoring along with laboratory analysis (blood count, blood biochemistry and urinalysis). The following methodology was established in order to measure clinical variables along with blood and urine samples: fifteen days before calving (T-15), immediately after calving (T0), two days (T2), five days (T5), ten days (T10), fifteen days (T15) and thirty days after calving (T30). During physical examination a gradual loss of body condition score and postpartum infections were verified; leukocytosis with neutrophilia and lymphocytosis immediately after calving were also observed through blood count; blood biochemistry showed elevated levels of urea, hyperphosphatemia and hypochloremia during the transition period; urinalysis showed low values of urine pH shortly before calving. These results confirmed the efficiency of clinical and laboratory monitoring in the diagnosis of metabolic diseases in dairy cows during the puerperium period and the monitoring protocol used was accurate. / O objetivo do presente estudo foi avaliar as alterações hematológicas e a bioquímica sanguínea, em associação à urinálise e ao exame físico, de vacas leiteiras no período de transição e verificar a eficiência de protocolos de monitoramento para a ocorrência de doenças metabólicas e infecciosas. O estudo foi desenvolvido com 22 vacas da raça holandês PB, sendo 11 primíparas e 11 multíparas, com idade entre dois e sete anos, pertencentes ao rebanho leiteiro da Unidade de Ensino, Pesquisa e Extensão em Gado de Leite UEPE/GL, do Departamento de Zootecnia da Universidade Federal de Viçosa. Um total de 154 amostras de sangue e urina foi analisado. A pesquisa consistiu do monitoramento clínico e análises laboratoriais (hemograma, bioquímica sanguínea e urinálise). Foi estabelecida a seguinte metodologia para mensuração das variáveis clínicas e coletas de sangue e urina: quinze dias antes do parto (T-15); imediatamente após o parto (T0); dois dias (T2), cinco dias (T5), dez dias (T10), quinze dias (T15) e trinta dias após o parto (T30). Ao exame físico verificou-se perda gradativa do escore de condição corporal e infecções pós-parto; por meio da análise hematológica constatou-se leucocitose por neutrofilia e linfocitose ao parto; a analise bioquímica sanguínea evidenciou valores elevados de ureia sérica, hiperfosfatemia hipocloremia e decréscimo no colesterol total no período de transição; a urinálise apresentou baixos valores de pH da urina no pré-parto. Diante dos resultados obtidos a pesquisa confirmou a eficiência das avaliações clínicas e laboratoriais no diagnóstico de doenças metabólicas em vacas leiteiras no puerpério e o protocolo de monitoramento adotado foi correto.
25

Rastreamento de disfunção ventricular assintomática em puérperas : padrão ecocardiográfico evolutivo e comparativo a casos de miocardiopatia periparto

Vettori, Daniela Vanessa January 2008 (has links)
Objetivos: Determinar a prevalência de disfunção sistólica assintomática do ventrículo esquerdo no puerpério e comparar sua evolução com os casos de miocardiopatia periparto ocorridos no mesmo período. Pacientes e Métodos: Estudo transversal entre setembro de 2002 e abril de 2005, para determinar a prevalência de disfunção ventricular assintomática no puerpério imediato e a incidência de miocardiopatia periparto no mesmo período, e entre novembro de 2007 e janeiro de 2008 para verificar a evolução clínica e ecocardiográfica destas pacientes. Os parâmetros ecocardiográficos das puérperas com disfunção ventricular assintomática também foram comparados com os de puérperas normais. Disfunção sistólica do ventrículo esquerdo foi definida como diâmetro diastólico final ≥ 5,6 cm e/ou fração de ejeção < 53,0% + encurtamento fracional sistólico < 25%. Resultados: Foram rastreadas 1182 puérperas, sendo detectados 10 casos (0,85%) de disfunção ventricular assintomática, cujas características clínicas, como raça, superfície corporal, paridade, gemelaridade e uso de tocolíticos, não foram diferentes quando comparadas com 18 controles rastreados sem disfunção. A incidência de miocardiopatia periparto no período foi de 6 casos em 10866 partos (1/1811 partos de nascidos vivos). Após uma média de 4,0 anos (2,9-5,2 anos), 7 dos 10 casos de disfunção assintomática e 5 dos 6 casos de miocardiopatia clínica realizaram nova ecocardiografia, verificando-se significativo aumento da fração de ejeção e do encurtamento fracional médios nos dois grupos, sendo que a parcela de recuperação da função foi semelhante nos grupos (p interação > 0,05). Conclusões: Ocorre disfunção ventricular no puerpério sem os achados clínicos de insuficiência cardíaca cujos parâmetros ecocardiográficos evoluem de maneira semelhante aqueles de pacientes com miocardiopatia periparto ao longo do tempo. / Objective: To determine the prevalence of asymptomatic left ventricular systolic dysfunction in puerperium and to compare its progression with that of cases of peripartum cardiomyopathy that occurred in the same study period. Patients and Methods: Cross-sectional study conducted from September 2002 to April 2005 to determine the prevalence of asymptomatic ventricular dysfunction in early puerperium and the incidence of peripartum myocardiopathy, and from November 2007 to January 2008 to obtain clinical and echocardiographic follow-up data of the study patients. Echocardiographic parameters of puerperal women with asymptomatic ventricular dysfunction were also compared with those of normal puerperal women. The parameters to define left ventricular systolic dysfunction were end-diastolic diameter ≥ 5.6 cm and/or ejection fraction < 53.0%, and systolic fractional shortening < 25%. Results: A total of 1182 puerperal women were screened, and 10 cases (0.85%) of asymptomatic ventricular dysfunction were detected. Clinical characteristics, such as ethnicity, body surface, parity, multiple gestations, and tocolytic therapy, were not different from those of the 18 normal women used as controls. The incidence of peripartum cardiomyopathy was 6 cases out of 10866 deliveries (1/1811 live births). After a mean of 4.0 years (2.9-5.2 years), 7 of the 10 patients with asymptomatic dysfunction and 5 of the 6 with clinical cardiomyopathy underwent follow-up echocardiography. A significant increase was found in mean ejection fraction and fractional shortening in the two groups, and function recovery rates were similar in the two groups (p > 0.05). Conclusions: Ventricular dysfunction may occur in the puerperium without clinical signs of heart failure, and the long-term progression of echocardiographic parameters is similar to that found in cases of peripartum cardiomyopathy.
26

Depression With Peripartum Onset (Postpartum) and Mother’s Perceptions of Social Support and Self-Efficacy for Parenting

Ramsey, Shenetha Carmise 01 January 2019 (has links)
Depression with peripartum onset, which was previously called maternal depression, or postpartum depression, is common among many pregnant women. The condition increases impairment in maintaining relationships, self-esteem, and parenting skills. The purpose of this phenomenological qualitative study was to explore how mothers who have experienced peripartum onset (postpartum) depression perceive their social support and their ability to parent effectively. The conceptual framework was based on Albert Bandura’s self-efficacy theory. Convenience and snowball sampling were both used to obtain 6 research participants who were interviewed face-to-face or by telephone. Participants shared their experiences with depression, perceptions of social support, and how both influenced their parenting efficacy. Two cycles of coding were used: initial and focus coding. Key themes of this research study were mother’s age of onset with depression, symptoms, coping strategies, supports received, results of social supports, recommendations to other mothers, and effects of depression on parenting. The results were that mothers’ depression negatively affected parenting, which resulted in receiving social supports such as postpartum trainings, talk therapy, and psychotherapy (counseling). This study may help to close the gap and extend the literature by exploring the influence of peripartum onset (postpartum) depression on parenting. Implications for positive social change may include more direction in how human services professionals address mothers during their pregnancy or postpregnancy related to peripartum onset (postpartum) depression.
27

Trends in Characteristics and Outcomes of Peripartum Cardiomyopathy Hospitalizations in the United States Between 2004 and 2018

Ijaz, Sardar H., Jamal, Shakeel, Minhas, Abdul M., Sheikh, Abu B., Nazir, Salik, Khan, Muhammad Shahzeb, Minhas, Anum S., Hays, Allison G., Warraich, Haider J., Greene, Stephen J., Fudim, Marat, Honigberg, Michael C., Khan, Sadiya S., Paul, Timir K., Michos, Erin D. 01 April 2022 (has links)
Data are limited on contemporary temporal trends in maternal characteristics and outcomes in hospitalized patients with peripartum cardiomyopathy (PC). We used the National Inpatient Sample database from January 1, 2004, to December 31, 2018, to identify PC hospitalizations in women aged 15 to 54 years. Weighted survey data were used to derive national estimates for the United States population and examine trends. Between 2004 and 2018, there was a total of 23,420 weighted hospitalizations for PC in women aged 15 to 54 years. The mean (standard error) age of this hospitalized PC population was 30.3 (0.1) years, with 44.6% White, 39.3% Black, 9.0% Hispanics, and 7.1% "Other" racial/ethnic groups. There was a nonsignificant increase in the PC hospitalization per 100,000 live births from 33.6 in 2004 to 42.4 in 2018 (p-trend = 0.06) over the study period, driven by a statistically significant increase in the younger women age group 15 to 35 years (p-trend = 0.04). The PC hospitalizations per 100,000 live births for women aged 36 to 54 years were more than double that observed in women aged 15 to 35 years (77.6 vs 33.5). PC hospitalizations were more than threefold greater in Black versus White women (103.5 vs 32.0 per 100,000 live births). Overall, inpatient mortality was 0.8%; the adjusted inpatient mortality showed a nonsignificant overall decrease from 1.1% in 2004 to 0.5% in 2018 (p-trend = 0.15). The overall mean length of stay was 4.6 days; the adjusted mean length of stay decreased from 5.8 days in 2004 to 4.6 days in 2018 (p-trend <0.01). In conclusion, there has been a nonsignificant increase in hospitalizations for PC, driven by an increasing rate of hospitalizations in younger women. The older maternal age group and Black patients had a higher proportional hospitalization as compared with the younger age group and White patients. There was a nonsignificant decrease in inpatient mortality.
28

Long-Term Follow-Up of Mechanical Circulatory Support in Peripartum Cardiomyopathy (PPCM) Refractory to Medical Management: A Multicenter Study

Jawad, Khalil, Koziarz, Alex, Dieterlen, Maja-Theresa, Garbade, Jens, Etz, Christian D., Saeed, Diyar, Langer, Elena, Stepan, Holger, Scholz, Ute, Krause, Michael, Brenner, Paolo, Schulz, Uwe, Borger, Michael A., Eifert, Sandra 02 June 2023 (has links)
Background: Peripartum cardiomyopathy (PPCM) is a rare, life-threatening form of heart disease, frequently associated with gene alterations and, in some cases, presenting with advanced heart failure. Little is known about ventricular assist device (VAD) implantation in severe PPCM cases. We describe long-term follow-up of PPCM patients who were resistant to medical therapy and received mechanical circulatory support or heart transplant. Methods and results: A total of 13 patients were included with mean follow-up of eight years. Mean age of PPCM onset was 33.7 ± 7.7 years. All patients were initially treated with angiotensin-converting enzyme inhibitors and beta-blockers, and four received bromocriptine. Overall, five patients received VADs (three biventricular, two isolated left ventricular) at median 27 days (range: 3 to 150) following childbirth. Two patients developed drive line infection. Due to the short support time, none of those patients had a stroke or VAD thrombosis. In total, five patients underwent heart transplantation, of which four previously had implanted VADs. Median time to transplantation from PPCM onset was 140 days (range: 43 to 776), and time to transplantation from VAD implantation were 7, 40, 132, and 735 days, respectively. All patients survived until most recent follow up, with the exception of one patient who died following unrelated abdominal surgery two years after PPCM recovery. Conclusions: In patients with severe, life-threatening PPCM refractory to medical management, mechanical circulatory support with or without heart transplantation is a safe therapeutic option.
29

Flushing com gordura protegida ruminal sobre o retorno da atividade ovariana e produção de leite de cabras no pré e pós-parto / Flushing with bypass lipid on the return of ovarian activity and milk yield of preand post-parturition goat

Carneiro, Camila 26 February 2010 (has links)
Made available in DSpace on 2015-03-26T13:54:54Z (GMT). No. of bitstreams: 1 texto completo.pdf: 678757 bytes, checksum: 204336019a9dcf2b30eed986ade2d2a2 (MD5) Previous issue date: 2010-02-26 / The study was conducted from March to June 2009, the farm Clean water in the municipality of Piau - MG. Nineteen Toggenburg goats were used, primiparous (n=9) and multiparous (n=10), with an average weight of 50 kg and body condition score between 2,75 and 3,75, distributed in randomized blocks, in order to evaluate the flushing effect of long chain fatty acid protected ruminant lipids (bypass lipids; MEGALAC-E®) on the return of ovarian activity and milk yield and composition. Flushing was given from the 21st day before to the 21st day after parturition. Treatment 1 received flushing in the pre- and post-parturition (n=4); treatment 2 received flushing only on pre-parturition (n=5); treatment 3 received flushing only on the post-parturition (n=5) and treatment 4 (the control group) did not receive flushing (n=5). Goats were fed four times a day, receiving corn silage for volume and experimental rations as a concentrate (with or without MEGALAC-E®, at 2% of DM). Several reproductive parameters were evaluated, such as: interval from parturition to the first estrus (IPE - days), interval from parturition to first ovulation (IPO - days), diameter of ovulatory follicle (DIAMF - mm), number of ovulations (NUMOV) and follicle size on the day of estrus (FOLESTRUS - mm); as well as productive parameters such as: milk yield (MY - kg), corrected milk yield for 3.5% fat (CMY - Kg/day), body weight (Kg), body condition score (BCS), milk fat content (FAT - %), milk protein content (PTN - %), milk lactose content (LAC - %), total milk dry extract content (EST - %); and also the production of the following milk constituents: PGOR, PPTN, PLAC and PEST (kg/day). There was no observed interaction (P>0.05) between the used treatments and the productive parameters related to flushing, but a correlation was found (P<0.05) with the lactation week as well as with MY (r = 0.24), CMY (r = 0.25), PTN (r = -0.22), PLAC (r = 0.23), EST (r = -0.23), PGOR (r = 0.18), PPTN (r = 0.23) and PEST (r = 0.24). There was no observed interaction (P>0.05) between the used treatments and the studied reproductive parameters, but important correlations between these variables were found. The values of IPE (days) from the animals were 20.5±2.2 (T1), 30.0±17.4 (T2), 20.2±2.1 (T3) e 19.0±2.5 (T4), and those of IPO (days) were 26.3±4.0 (T1), 22.4±3.3 (T2), 24.4±1.1 (T3) and 24.2±3.6 (T4) (P>0.05). The DIAMF (mm) values were: T1 (7.21±0.30), T2 (6.86±0.31), T3 (6.66±0.27) and T4 (7.32±0.64) and NUMOV were T1 (1.5±0.3), T2 (1.2±0.2), T3 (1.4±0.2) and T4 (1.0±0.0). A negative correlation (r = -0.68) was observed between ECC at parturition and IPE, as well as to IPO (r = -0.48). A positive correlation (r = 0.47) was found between body weight at ovulation and the NUMOV. In conclusion, the use of MEGALAC-E® at (2% of DM) was not sufficient to promote alterations in milk yield and composition and on the evaluated reproductive parameters. So, there is a need for more studies related to the protected fat inclusion in order to establish values that may improve productive and reproductive parameters of dairy goats. / O experimento foi conduzido no período de Março a Junho de 2009, na granja Água limpa no município de Piau - MG. Foram utilizadas 19 cabras da raça Toggenburg, primíparas (n=9) e multíparas (n=10), com peso vivo médio de 50 kg e escore de condição corporal variando entre 2,75 e 3,75, sendo distribuídas em delineamento em blocos casualizados, com o objetivo de avaliar o efeito do flushing com gordura protegida ruminal de ácidos graxos de cadeia longa (MEGALAC-E®) sobre o retorno da atividade ovariana e a produção e composição do leite. O flushing foi oferecido do 21º dia pré-parto ao 21º dia pós-parto. O tratamento 1 recebeu flushing no pré e pós parto (n = 4); o tratamento 2 recebeu flushing somente no pré-parto (n = 5), o tratamento 3 recebeu flushing somente no pós-parto (n = 5) e o tratamento 4 não recebeu flushing (controle) (n = 5). As cabras foram alimentadas quatro vezes ao dia, recebendo como volumoso a silagem de milho e o concentrado (com ou sem MEGALAC-E®, a 2% da MS). Foram avaliados parâmetros reprodutivos, como: intervalo do parto ao primeiro estro (IPE - dias), intervalo do parto à primeira ovulação (IPO - dias), diâmetro do folículo ovulatório (DIAMF - mm), número de ovulações (NUMOV) e tamanho do folículo no dia do estro (FOLESTRO - mm) e parâmetros produtivos como: produção de leite (PL - kg), produção de leite corrigida para 3,5% de gordura (PLC - kg/dia), peso vivo (PV - kg), escore de condição corporal (ECC), teor de gordura do leite (GOR - %), teor de proteína do leite (PTN - %), teor de lactose do leite (LAC - %), teor de extrato seco total do leite (EST - %) e as produções destes constituintes no leite: PGOR, PPTN, PLAC e PEST (kg/dia). Não se observou interação (P>0,05) dos tratamentos utilizados e os parâmetros produtivos relacionados ao flushing, porém, houve efeito (P<0,05) da semana de lactação sobre estes mesmos parâmetros, também observado pelas correlações significativas com a PL (r = 0,24), a PLC (r = 0,25), a PTN (r = -0,22), a PLAC (r = 0,23), o EST (r = -0,23), a PGOR (r = 0,18), a PPTN (r = 0,23) e a PEST (r = 0,24). Não se observou interação (P>0,05) dos tratamentos utilizados e os parâmetros reprodutivos estudados, porém, observou-se correlações importantes entre estas variáveis. O IPE (dias) foi de 20,5±2,2 (T1), 30,0±17,4 (T2), 20,2±2,1 (T3) e 19,0±2,5 (T4), e o IPO (dias) foi de 26,3±4,0 (T1), 22,4±3,3 (T2), 24,4±1,1 (T3) e 24,2±3,6 (T4) (P>0,05). Os DIAMF (mm) foram: T1 (7,21±0,30), T2 (6,86±0,31), T3 (6,66±0,27) e T4 (7,32±0,64) e o NUMOV foi de T1 (1,5±0,3), T2 (1,2±0,2), T3 (1,4±0,2) e T4 (1,0±0,0). Correlação negativa (r = -0,68) foi observada entre ECC ao parto e IPE, bem como para IPO (r = -0,48). Correlação positiva (r = 0,47) foi encontrada entre o peso corporal à ovulação e o NUMOV. Conclui-se que o nível de MEGALAC-E® usado (2% da MS do concentrado) não foi suficiente para promover mudanças na produção e composição do leite e nos parâmetros reprodutivos avaliados. Sendo assim, existe a necessidade de mais estudos relacionados a níveis de inclusão de gordura protegida, a fim de se estabelecer valores que possam melhorar os parâmetros produtivos e reprodutivos de cabras leiteiras.
30

Nuove indagini sul metabolismo e la risposta immunitaria dalla messa in asciutta all'avvio di lattazione / NEW INSIGHT ON METABOLISM AND THE IMMUNE RESPONSE FROM DRY-OFF TO EARLY LACTATION

MEZZETTI, MATTEO 03 April 2019 (has links)
Il sistema immunitario è costituito da una varietà di cellule, molecole e processi biologici che interagiscono per prevenire le invasioni microbiche, riconoscere le molecole estranee ed eliminare le fonti esistenti di lesioni cellulari, ripristinando le normali funzioni tissutali una volta risolto il problema. L'immunità innata è la prima linea di difesa contro le invasioni di agenti patogeni. Nelle vacche da latte, il suo funzionamento subisce gravi alterazioni durante il periodo di transizione (TP). In questa fase è stata segnalata una compromissione delle funzioni delle cellule polimorfonucleate (PMN) correlate alla produzione di metaboliti reattivi dell'ossigeno (ROM), all’attività della mieloperossidasi (MPO), alla chemiotassi e alla fagocitosi. I PMN bovini hanno un alterata espressione dei geni codificanti per tali funzioni tra -1 e 2 settimane dal parto, rispetto al livello rilevato 4 settimane dopo il parto per gli stessi geni. La causa esatta delle disfunzioni immunitarie che si verificano nel periparto non è mai stata chiaramente identificata. In esse possono contribuire diversi fattori, principalmente imputati alle alterazioni metaboliche tipiche del periparto (cambiamenti nell’assetto ormonale, limitazione della risposta immunitaria materna al fine di mantenere la gravidanza, alterazioni nel bilancio energetico e stato di stress ossidativo). Tuttavia, la durata e l’entità delle disfunzioni immunitarie può aumentare qualora subentri uno stato di squilibrio fisiologico (PI). In tali condizioni, le alterazioni metaboliche del periparto sfuggono al controllo dei meccanismi omeostatici e omeoretici, ed una infiammazione sistemica è la conseguenza frequente di questo squilibrio. Lo stato infiammatorio sistemico è scatenato da un aumento dei livelli di citochine proinfiammatorie (PIC), che è collegato ad un aumento della temperatura corporea al parto, e che tipicamente inficia le funzionalità epatiche, modificando le priorità anaboliche dell'organo in fase di inizio lattazione. A seguito di tale slittamento, il fegato produce più α-globuline, note come proteine positive di fase acuta (+APP), cioè aptoglobina, ceruloplasmina e siero amiloide alfa (SAA). Al contrario, riduce la sintesi di albumina, retinol binding protein (RBP), paraoxonasi (PON) e lipoproteine, note come proteine negative di fase acuta (-APP), e sequestra minerali, quali zinco e ferro, dal flusso ematico. L'infiammazione porta all'attivazione dei PMN, mentre la ridotta competenza immunitaria comunemente riportata in TP è stata associata ad un effetto opposto sui leucociti. Pertanto, questi dovrebbero essere considerati come due fenomeni distinti, ma lo stato di PI potrebbe essere considerato un denominatore comune, direttamente correlato al rischio di patologie in avvio di lattazione. Le strategie nutrizionali per ottimizzare l'immunità delle vacche da latte durante il TP dovrebbero quindi essere focalizzate sulla riduzione del grado di PI correlato al parto. Tra tali strategie nutrizionali, dovrebbe essere presa in considerazione la corretta gestione delle fonti energetiche per adattarle alle variazioni dei fabbisogni. Inoltre, il profilo degli acidi grassi delle fonti lipidiche può contribuire nel modificare le funzioni immunitarie. Infine, la somministrazione di prodotti supplementari con attività antiossidanti o antinfiammatorie, così come di specie donatrici di gruppi metilici, potrebbero essere strategie utili a favorire la funzionalità immunitaria delle bovine durante il TP. In una prospettiva più ampia, sebbene strategie nutrizionali e supplementi possano talora mitigare le alterazioni immunitarie, possiamo concludere che l'adozione di pratiche volte a minimizzare il PI durante il periodo di transizione sia la strategia più efficace per prevenire le disfunzioni. Al fine di chiarire il legame tra le alterazioni che si verificano nel periparto e le disfunzioni immunitarie delle bovine da latte sono stati condotti tre esperimenti. Bovine di razza frisona sono state alloggiate in poste individuali a stabulazione fissa e monitorate regolarmente per le condizioni corporee (BCS), il peso (BW), l'assunzione di alimenti (DMI), la produzione di latte (MY) e il tempo di ruminazione. Campioni di sangue sono stati raccolti regolarmente per valutare un ampio profilo ematochimico e per testare le funzioni dei globuli bianchi mediante stimolazioni ex-vivo. Inoltre, la diapedesi dei PMN è stata testata in vivo mediante test della carragenina e sono stati raccolti campioni di rumine a 30 giorni dal parto (DFC). Il primo esperimento era volto a chiarire le cause dei cambiamenti metabolici che si verificano al momento della messa in asciutta, ed il contributo del livello produttivo in tali alterazioni. Infatti, i profondi cambiamenti nell’alimentazione, gli adattamenti gastrointestinali, del metabolismo e dei parametri immunitari che si verificano nelle bovine alla messa in asciutta sono note scatenare il rilascio di cortisolo, indurre segnali di infiammazione sistemica ed alterare il bilancio redox. Produzioni di latte elevate al momento della messa in asciutta hanno un ruolo nell'aggravare tali condizioni. Nel nostro studio, un gruppo di 13 bovine è stato asciugato a 55 giorni dalla data prevista per il parto. Gli animali sono stati divisi in due gruppi in base alla produzione media dell'ultima settimana di lattazione, assumendo un cut-off di 15 kg * d-1: bassa (LM; 6 animali) e alta produzione (HM; 7 animali). I dati sono stati sottoposti ad ANOVA utilizzando un modello per misure ripetute, assumendo il livello produttivo al termine della lattazione, il tempo e la loro interazione come effetti fissi. L'aumento delle quantità di fibra nella razione di asciutta ha ridotto la DMI e aumentato il tempo di ruminazione. La migrazione dei leucociti nella ghiandola mammaria per contribuire alla fase di involuzione ha ridotto la loro abbondanza nel sangue e aumentato la loro attività. Tale attivazione dei leucociti nella mammella ha aumentato l'abbondanza di specie reattive dell’azoto nel plasma e innescato un'infiammazione sistemica in tutti gli animali (aumento delle +APP e riduzione delle -APP). Tale infiammazione ha compromesso le funzioni epatiche (aumento delle concentrazioni di gamma-glutamil transferasi -GGT- bilirubina e fosfatasi alcalina -ALP-). Sia la produzione di specie dell’azoto che lo stato infiammatorio sistemico hanno contribuito all'esaurimento degli antiossidanti circolanti (gruppi tiolici -SHp-, tocoferolo, β-carotene, potere antiossidante ferrico riducente -FRAP- e capacità antiossidante contro specie reattive dell'ossigeno -ORAC-). Gli animali con una produzione più elevata alla messa in asciutta hanno mostrato la peggiore condizione, probabilmente per i più profondi cambiamenti metabolici che hanno affrontato dopo l'interruzione delle mungiture, e per la fase involutiva verosimilmente più dispendiosa. Questo studio evidenzia la messa in asciutta come una fase critica per gestire la salute delle vacche da latte, e suggerisce un potenziale legame della messa in asciutta con le alterazioni delle funzioni immunitarie che si verificano nel periparto. Nel secondo esperimento si sono cercati di identificare i cambiamenti del sistema immunitario che precedono l'insorgenza della chetosi, al fine di chiarire il loro ruolo nella comparsa della malattia. Pertanto, 13 bovine sono state monitorate tra -48 e 35 DFC e suddivise in due gruppi sulla base dei loro livelli plasmatici di beta idrossibutirrato (BHB): inferiore (CTR, 7 animali) o superiore a 1,4 mMol / L (KET; 6 animali). I dati sono stati sottoposti ad ANOVA utilizzando un modello per misure ripetute, assumendo lo stato di salute, il tempo e la loro interazione come effetti fissi. Le vacche KET hanno avuto una maggiore attivazione del sistema immunitario prima del parto (maggiori concentrazioni plasmatiche di PIC, MPO e specie ossidanti e maggiori produzione di interferone gamma in risposta alla stimolazione con Mycobacterium avium) alterazioni della funzionalità epatica (più alta concentrazione sanguigna di GGT) e minori minerali plasmatici. Elevati livelli plasmatici di NEFA, BHB e glucosio nelle vacche KET suggeriscono uno stato di insulinoresistenza e una marcata mobilizzazione del grasso corporeo durante il periodo di asciutta. Tali andamenti dei parametri relativi al metabolismo energetico durante l’asciutta sono stati associati alla riduzione della DMI al momento del parto e al peggioramento del bilancio energetico negativo ad avvio lattazione. Ciò ha causato a sua volta una riduzione di MY e accresciuto ulteriormente la mobilizzazione dei grassi in avvio di lattazione. Compromissione della funzionalità epatica e attivazione dei leucociti durante il periodo di asciutta hanno determinato una marcata risposta infiammatoria di fase acuta nelle vacche KET dopo il parto (maggiori concentrazioni di +APP minori concentrazioni di RBP), ed ulteriormente compromesso la funzionalità epatica (maggiori concentrazioni di glutammato-ossalacetato transaminasi -AST-GOT- e bilirubina). I leucociti delle vacche KET hanno mostrato ridotte funzioni infiammatorie dopo stimolazione ex-vivo con lipopolisaccaridi batterici (minore produzione di PIC e maggiore produzione di lattato). Queste alterazioni potrebbero essere guidate dall'azione combinata dei metaboliti legati alla mobilizzazione dei lipidi e delle azioni antinfiammatorie volte a prevenire un'infiammazione eccessiva. Ciò suggerisce che le alterazioni dei parametri immunitari osservate prima del parto siano altamente correlate con la probabilità di sviluppare chetosi in avvio di lattazione. Nel terzo esperimento è stato somministrato un prodotto immunostimolante dalla comprovata efficacia nel migliorare le funzioni leucocitarie degli animali immunodepressi e nel ridurre l'incidenza delle malattie infettive delle bovine ad inizio lattazione. La sua modalità di azione non è mai stata chiarita, e un’indagine approfondita sul suo effetto metabolico potrebbe evidenziarne l’efficacia anche nei confronti dei disordini metabolici del periodo di transizione. Pertanto, un gruppo di10 bovine è stato monitorato da -62 a 42 DFC. Il gruppo trattato (TRT, 5 animali) ha ricevuto 32,5 g di Omnigen-AF® (Phibro Animal Health Corporation) due volte al giorno (65 g d-1), mentre il gruppo di controllo (CTR, 5 animali) non ha ricevuto alcun supplemento. I dati sono stati sottoposti ad ANOVA utilizzando un modello per misure ripetute, assumendo il trattamento, il tempo e la loro interazione come effetti fissi. La somministrazione dell’immunostimolante alla messa in asciutta non ha influenzato BW, BCS, MY, composizione del latte e del fluido ruminale e nemmeno modificato la concentrazione di neutrofili del sangue. Tuttavia, ha aumentato il tempo di ruminazione e migliorato il metabolismo energetico dopo il parto (concentrazioni di NEFA e BHB inferiori). Le bovine TRT avevano maggiori concentrazioni ematiche di linfociti e i loro leucociti avevano una maggiore efficienza nel rispondere alla stimolazione con lipopolisaccaridi batterici (produzione di lattato inferiore e minore consumo di glucosio). Nonostante questi effetti positivi sulle cellule immunitarie, l'immunostimolante non ha influenzato le concentrazioni di +APP dopo il parto. Inoltre, l’immunostimolante ha ridotto le concentrazioni di albumina, PON e antiossidanti dopo il parto, suggerendo la compromissione di alcune funzioni epatiche negli animali trattati. Tuttavia, la mancanza di qualsiasi effetto sui biomarcatori di funzionalità (bilirubina) e danno epatico (GGT, AST-GOT, ALP) smentisce una reale compromissione delle attività epatiche a seguito del trattamento. Gli effetti positivi nel favorire il recupero delle funzioni del rumine, riducendo la mobilizzazione dei grassi corporei dopo il parto, suggeriscono che l'immunostimolante sia una strategia efficace nella prevenzione dei disturbi metabolici del periodo di transizione. / Immune system is made of a variety of cells, molecules and biological processes that interacts to prevent microbial invasions, recognize foreign molecules and eliminate existing sources of cellular injuries to restore tissues to their normal functions once problem has been solved. Innate immunity is the primary defense line against pathogens invasions. Its functioning typically undergoes severe alterations during transition period (TP) of dairy cows. An impairment of polymorphonuclear cells (PMN) functions related to reactive oxygen metabolites (ROM) production, myeloperoxidase (MPO) activity, chemotaxis and phagocytosis has been reported in this phase. Bovine PMN have an altered abundance in mRNA transcripts encoding for such functions between -1 and 2 weeks from calving, in comparison to the level found at 4 weeks after calving for the same genes. The exact cause of immune dysfunctions occurring in peripartum has never been clearly identified. Reduced immune competence could arise from the interaction of different factors affected from the typical peripartum trends (i.e. changes in endocrine asset, limitations of maternal immune responses against the allogeneic conceptus, alterations in energy balance and oxidative stress status). Nevertheless, its duration could be modified when peripartal changes exceed the control of homeorhetic and homeostatic mechanisms, leading to the physiological imbalance (PI) condition. Such a condition could also trigger the inflammatory-like status. It consists in a prepartal raise of pro-inflammatory cytokines (PICs) levels, that is linked to a raise in body temperature at calving, and that typically affects liver metabolism, implying severe losses in hepatic functions and a shift of anabolic priority of the organ in early lactation. The liver produces more α-globulins, known as positive acute phase proteins (APP), i.e. haptoglobin, ceruloplasmin and serum amyloid alpha (SAA). Conversely, it reduces the synthesis of albumin, retinol binding protein, paraoxonase (PON) and lipoproteins, known as negative APP and sequesters minerals, as zinc and iron, from blood flow. Inflammation lead to the activation of PMN, while the reduced immune competence commonly reported in TP has been associated to an opposite effect on leukocytes. Thus, these should be considered as two distinct phenomena, but they could arise from a common cause with a different magnitude and duration. Nutritional strategies to optimize dairy cow’s immunity during TP should be focused on reducing the PI degree related to calving, as this condition could be referred as a common denominator between immune dysfunction and diseases causes. Among such nutritional strategies, the correct management of energy sources to fit with altered requirements should be considered. Furthermore, fatty acids profile of lipid sources administered could also modify immune functions. Finally, the administration of supplementary products exerting antioxidant or anti-inflammatory activities, as well as methyl donors species, could be beneficial for dairy cows immunity in TP. In a wider perspective, although feed additives and nutritional strategy could be effective in mitigate immune alterations, we can conclude that adoption of proper management practices aimed to avoid PI condition in peripartal period of dairy cows could be the most effective strategy to prevent dysfunctions. Three experiments have been designed to elucidate the linkage between sudden changes occurring in peripartum and immune alterations in dairy cows. Throughout such experiments Holstein dairy cows were housed in tied stalls and monitored regularly for body condition score (BCS), body weight (BW), dry matter intake (DMI), milk yield (MY) and rumination time. Blood samples were collected regularly to assess a wide hematochemical profile and to test white blood cell functions through ex-vivo challenges. Furthermore, PMN diapedesis has been tested in-vivo through a carrageenan-skin test and rumen samples were collected at 30 days from calving (DFC). The first experiment was aimed in investigate the main causes of metabolic changes occurring at dry-off and the contribution of MY in such alterations. In fact, dry-off is related to deep changes in feeding behavior, gastro intestinal adaptations, metabolism and immune parameters in high-yielding cow’s career. Indeed, the release of cortisol, signals of systemic inflammation and altered redox balance have been reported immediately after milking interruption, and high MY have a role in aggravating such conditions. In our study, a group of 13 Holstein dairy cows were dried off at 55 days from expected calving day, and regularly monitored from -7 to 34 days from dry-off (DFD). Animals were retrospectively divided in two groups according to their average MY in the last week of lactation, assuming a cut-off of 15 kg*d-1: low MY (6 cows) and high MY (7 cows). Data were submitted to ANOVA using a mixed model for repeated measures including MY at dry-off, time and their interaction as fixed effects. Increased fiber amounts of dry ration reduced DMI and increased rumination time. Leukocytes migration into mammary gland to contribute in the involution phase decreased their abundance in blood at dry-off, and their activity. Such activation of leukocytes at mammary site increased the abundance of nitrogen species in plasma and triggered a systemic inflammation in all the animals, as reflected from increased concentrations of positive and reduced concentrations of negative APPs. Such inflammation impaired liver functions, as suggested from the increased gamma-glutamyl transferase (GGT), bilirubin and alkaline phosphatase (ALP) concentrations. Both the production of nitrogen species and the systemic inflammatory status contributed in the depletion of antioxidant system in blood (thiol groups -SHp-, tocopherol, β-carotene, ferric reducing antioxidant power -FRAP- and oxygen reactive antioxidant capacity -ORAC-). Animals with higher MY at dry-off showed the worst condition, likely for the deeper metabolic changes they faced at milking interruption, and to the greater amount of mammary parenchyma to be reabsorbed. This study highlights the dry-off as a thorny point to manage dairy cows’ health and depose for a relationship between dry-off and immune alteration that typically occurs at calving. The second experiment was aimed in investigate changes occurring in the immune system prior to ketosis onset to elucidate their role in disease occurrence. Thus, a group of 13 Holstein dairy cows were monitored from -48 to 35 DFC and retrospectively divided into 2 groups basing on their plasma BHB levels: lower (CTR; 7 cows) or higher than 1.4 mMol/L (KET; 6 cows). Data were submitted to ANOVA using a mixed model for repeated measures including health status, time and their interaction as fixed effects. KET cows had a greater activation of the immune system prior to calving (higher plasma concentrations of PICs, myeloperoxidase and oxidant species, and greater interferon gamma responses to Mycobacterium avium) impaired liver functions (higher blood concentration of GGT) and lower plasma minerals. High plasma NEFA, BHB and glucose levels in KET cows suggest an insulin resistance status and a marked mobilization of body fat occurring during dry period. They were also associated to reduced DMI around calving and worse negative energy balance in early lactation. This caused in turn reduced MY and increased fat mobilization in early lactation. Impairment of liver function and activation of leukocytes during the dry period accentuated the acute phase response in KET cows after calving (greater concentrations of positive APPs and lower concentration of retinol binding protein), further impairing liver function (higher blood concentrations of glutamate-oxaloacetate transaminase -AST-GOT- and bilirubin). Leukocytes of KET cows had reduced inflammatory functions after an ex vivo stimulation assay (lower production of PICs and greater production of lactate). These alterations on WBC could be driven by the combined action of metabolites related to the mobilization of lipids and of anti-inflammatory actions aimed to prevent over exuberant inflammation. This suggests that prepartal trends of immune parameters be highly related with the likelihood of developing diseases in early lactation. The third experiment consisted in the administration of Omnigen-AF (OAF), an immune stimulant that is effective in increasing leukocytes functions in immunosuppressed animals and in reducing incidence of infectious diseases in early lactating dairy cows. Its mode of action has never been elucidated, and a wider perspective of its metabolic effect could highlight its effectiveness in facing metabolic disorders of transition period also. Thus, a group of 10 Holstein dairy cows were divided into 2 groups: treated group (TRT; 5 cows) received 32.5 g of Omnigen-AF® (Phibro Animal Health Corporation) twice a day (65 g d-1) as top-dress on the morning and afternoon feeds, while control group (CTR; 5 cows) did not receive any supplementation. From -62 to 42 DFC animals were monitored regularly. Data were submitted to ANOVA using a mixed model for repeated measures including treatment, time and their interaction as fixed effects. Administration of OAF at dry-off did not affect BW, BCS, milk yield, milk and rumen fluid composition, and neither affected blood neutrophils concentrations. Nevertheless, it increased rumination time and improved the energy metabolism after calving (lower NEFA and BHB concentrations). TRT cows had an increased lymphocytes abundance at blood level, and their leukocytes had greater efficiency in facing biological stressors during the peripartum (lower lactate production and lower glucose consumption after a challenge with bacterial lipopolysaccharides). Despite these positive effects on immune cells, OAF did not affect the positive APPs concentrations after calving. A reduced abundance of albumin, PON and antioxidants also occurred with OAF after calving, suggesting some impairment of hepatic functions to occur. Nevertheless, the lack of any effect on main biomarkers related to liver function (bilirubin) and liver damage (GGT, AST-GOT, ALP) dismisses a real impairment of liver activities to occur with OAF. Positive effects in favoring the recovery of rumen functions, reducing mobilization of body fats after calving suggest OAF to be an effective strategy in preventing metabolic disorders of transition period.

Page generated in 0.0307 seconds