Doctor of Philosophy / Department of Animal Sciences and Industry / Michael E. Dikeman / Two experiments were conducted to evaluate the effects of dietary vitamin A on growth, carcass characteristics, and meat quality of ruminants. In Experiment 1, 40 crossbred wethers (BW = 28.7 kg) were assigned to 1 of 4 treatments: backgrounding (BG) and finishing (FN) with no vitamin A (LL); BG with no vitamin A, FN with high vitamin A (6,600 IU[dot in middle of line]kg [superscript-1] diet) (LH); BG with high vitamin A and FN with no vitamin A (HL); and BG and FN with high vitamin A (HH). During BG (d 1 to 56), intake was restricted to achieve 0.22 kg ADG. During FN (d 57 to 112), lambs consumed the same diet ad libitum. Lambs were humanely slaughtered after 112 d. There were no treatment differences (P > 0.05) in feed intake, ADG, or final BW. Carcasses from the HH group had higher (P < .05) marbling scores (514 vs. 459), and 25.8 % more extractable intramuscular lipid (IMF) than LL (3.88 vs. 3.08 % for HH and LL, respectively, P < .05); the LH and HL treatments were intermediate. The was a negative correlation (r = -0.38) between serum fatty acid content and %IMF. Experiment 1 data suggest that increased marbling may be achieved with high vitamin A for 112 d in lambs. In Experiment 2, Angus crossbred steers (n = 48), were either early-weaned (EW) at 137[plus or minus]26 d of age or weaned at a traditional age (TW) 199[plus or minus]26 d and allotted to either 42,180 IU vitamin A[dot in middle of line]hd[superscript-1][dot in middle of line]d[superscript-1] (HA) or no vitamin A (NA). Early- and TW steers consumed treatments for 235[plus or minus]17 and 175[plus or minus]18 d, respectively. Serum and liver retinol content diverged dramatically (both, P < 0.01) by the end of the experiment and TW steers tended (P > 0.10) to have higher ADG than EW steers (1.31[plus or minus]0.2 and 1.48[plus or minus]0.2 kg[dot in middle of line]hd[superscript-1][dot in middle of line]d[superscript-1], respectively). Steers were humanely slaughtered at 1.02 cm fat. Weights tended (P = 0.08) to be heavier and carcasses were fatter (P < 0.05) for HA than NA. Marbling score and % IMF were higher (P < 0.05) for EW-NA than other treatments. Percentage of USDA Choice and Prime carcasses doubled (P < 0.05) for NA than HA. Yield grades increased (P < 0.05) with EW-HA and were similar (P > 0.10) among other treatments. Feeding NA was effective for increasing marbling without increasing fat; EW enhanced these effects. Reasons for the contradictory results in these 2 experiments are unclear. Species differences in the ability to metabolize retinol are implicated.

Orientadores: Rosana de Fátima Possobon, Sérgio Tadeu Martins Marba / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T19:02:32Z (GMT). No. of bitstreams: 1 Almeida_AnaClaudiaGomesde_M.pdf: 1687313 bytes, checksum: 7f13d9f93644fa6d3554ca2c564fb984 (MD5) Previous issue date: 2015 / Resumo: Esta dissertação, em formato alternativo, com a apresentação de um capítulo, aborda a temática do desmame precoce. O desmame precoce traz inúmeras desvantagens para a criança e para a mãe, sendo associado ao aumento da morbi-mortalidade infantil. Estima-se que 1,5 milhões de lactentes vão a óbito devido à alimentação inadequada, introduzida antes do sexto mês de vida. O objetivo deste estudo foi avaliar a associação entre desmame precoce, as variáveis pré e pós-natal e o locus de controle das mães. Foi realizado um estudo retrospectivo de coorte, utilizando instrumentos que investigaram os aspectos socioeconômicos e demográficos, as variáveis pré e pós-parto, e a escala multidimensional de locus de controle de Levenson. A amostra foi composta por 410 mães de crianças com idade entre 0 a 5 anos, que estiveram presentes no dia da campanha nacional de vacinação infantil contra a Poliomielite, realizada no mês de junho de 2013, pela Secretaria de Saúde do Município de Piracicaba-SP. A análise estatística foi realizada por meio de regressão logística múltipla hierárquica, avaliando a associação entre a variável dependente, o desmame precoce e as seguintes variáveis independentes sócio-demográficas: renda familiar, número de pessoas no lar, habitação, grau de instrução materno e paterno, chefe de família e profissão dos pais. As variáveis relacionadas ao desmame precoce e ao pré e pós-parto foram: idade materna e paterna, estado civil, idade e gênero da criança, paridade, experiência em aleitar e informações sobre o início do pré-natal, tipo de parto, problemas durante o parto com a mãe e/ou com a criança, permanência em alojamento conjunto, início da amamentação, acesso à informações sobre amamentação e manejo da lactação, vontade de amamentar, gravidez planejada, intercorrências mamárias, uso de chupeta e mamadeira, retorno ao trabalho e participação da avó. A escala de Levenson, composta por três subescalas - internalidade, externalidade outros poderosos e externalidade ao acaso. Estas variáveis foram divididas em blocos, sendo o primeiro composto por características maternas, o segundo por características do nascimento do bebê e o terceiro envolvendo características do bebê e assistenciais. Desta maneira, foram testadas no modelo multinível as variáveis com p?0,20 de cada bloco, permanecendo no modelo aquelas que continuaram associadas ao desmame com p?0,05, após o ajuste, para as variáveis do mesmo bloco e finalizando com as hierarquicamente superiores. Os resultados encontrados demonstraram que a prevalência do desmame precoce foi de 40%. Encontrou-se associação estatisticamente significativa entre desmame precoce e a variável baixa escolaridade materna (IC95% = 1,18-3,22; p= 0,0131), ausência de experiência prévia em amamentar (IC95% = 3,76-9,75; p= <0,0001) e uso de chupeta (IC95% = 1,78-4,17; p= <0,0001). Não houve associação entre o tipo de locus de controle e o desmame precoce. Concluiu-se que ter maior nível de escolaridade materna, ter experiência prévia em aleitamento e não oferecer chupeta à criança são fatores de proteção ao aleitamento materno / Abstract: This dissertation, in alternate format, with the presentation of a chapter addresses the theme of early weaning. Early weaning has numerous disadvantages for the child and the mother, being associated with increased infant morbidity and mortality. It is estimated that 1.5 million infants will die due to inadequate nutrition, introduced before the sixth month of life. The objective of this study was to evaluate the association between early weaning, pre and postnatal variables and Mother's locus of control. A retrospective cohort study was performed using instruments that investigated the socioeconomic and demographic indicators, pre variables and postpartum, and the multidimensional scale of Levenson's locus of control. The sample consisted of 410 mothers of children aged 0-5 years who were present on the day of national childhood immunization campaign against polio, held in June 2013, the Health Department of the city of Piracicaba-SP . Statistical analysis was performed using hierarchical multiple logistic regression, evaluating the association between the dependent variable, early weaning and the following socio-demographic independent variables: family income, number of people in the home, housing, degree of maternal and paternal education , householder and profession of parents. The variables related to early weaning and pre and post-delivery were maternal and paternal age, marital status, age and child gender, parity, breastfeeding experience and information on the initiation of prenatal care, type of delivery, problems during childbirth with the mother and / or with the child, remained in the accommodation, initiation of breastfeeding, access to information on breastfeeding and lactation management, desire to breastfeed, unplanned pregnancy, breast complications, pacifier use and bottle, return to work and grandmother participation. The scale Levenson, composed of three subscales - internality, other powerful external and external to chance. These variables were divided into blocks, the first composed of maternal characteristics, the second by Baby Birth characteristics and the third involving baby characteristics and care. In this way, were tested in the multilevel model variables with p?0,20 of each block, remaining in the model those who remained associated with weaning with p = 0.05 after adjustment for the variables of the same block and ending with the hierarchically superior. The results showed that the prevalence of early weaning was 40%. Statistically significant association between early weaning and the variable low maternal education (95% CI = 1.18 to 3.22; p = 0.0131), no previous experience in nursing (95% CI = 3.76 to 9, 75, p = <0.0001) and pacifier use (95% CI = 1.78 to 4.17; p = <0.0001). There was no association between the type of locus of control and early weaning. It was found to have higher levels of maternal education, previous experience in breastfeeding and not offer child pacifiers are protective factors for breastfeeding / Mestrado / Saude da Criança e do Adolescente / Mestra em Saúde da Criança e do Adolescente

Investigamos a distribuição de ghrelina e de seu receptor (GHS-R) na mucosa gástrica de ratos durante a terceira semana de vida pós-natal e avaliamos o efeito do desmame precoce sobre estas moléculas. Estudamos também a participação da ghrelina no controle da proliferação celular do epitélio gástrico, e para tanto utilizamos a administração de um antagonista. Detectamos o aumento do número de células imunomarcadas para ghrelina nos animais desmamados precocemente e observamos que nem a expressão de GHS-R nem a concentração proteica deste receptor foram alteradas pela mudança da dieta. O uso do antagonista [D-Lys-3]-GHRP-6 resultou na diminuição do índice de síntese de DNA no epitélio gástrico. Concluímos que a ghrelina e o GHS-R estão distribuídos no estômago durante a terceira semana de vida pós-natal e que o desmame precoce aumenta os níveis de ghrelina no epitélio gástrico, sem comprometer seu receptor. Por fim, sugerimos que esta modulação pode estar envolvida no controle da proliferação celular que é fundamental para o desenvolvimento do estômago. / In the present study, we investigated the distribution of ghrelin and growth hormone secretagogue receptor (GHS-R) in the rat gastric mucosa during the third postnatal week, and evaluated the effects of early weaning on these molecules. In addition, we studied whether ghrelin is part of cell proliferation control in gastric epithelium, and to that we used an antagonist. We detected an increase of ghrelin immunolabelled cells in animals submitted to early weaning and observed that GHS-R expression and protein levels of this receptor were not altered by dietary change. The antagonist [D-Lys-3]-GHRP-6 reduced DNA synthesis index. We concluded that ghrelin and GHS-R are distributed in the gastric mucosa during the third postnatal week and that early weaning increases hormone levels in the gastric epithelium, without changing its receptor. We can suggest that such modulation might be involved in the control of cell proliferation, which is essential for stomach development.

O desmame precoce (DP) consiste na abrupta substituição do leite pela dieta sólida e este padrão de alimentação pode ter impacto sobre o crescimento do estômago. Esta situação é também estressante para os filhotes e eleva os níveis de corticosterona que age ligando-se ao receptor de glicocorticoide (GR). Estudamos a expressão e a distribuição do GR na mucosa gástrica de ratos amamentados (C) e em DP. A expressão de GR foi maior aos 17 dias no grupo C e aumentou do 17º para o 18º dia no grupo em DP (p<0,05). O DP diminuiu o nível de GR, principalmente aos 18 dias (p<0,05), porém não alterou sua distribuição tecidual. Em termos de localização subcelular o GR, ficou mais concentrado no citoplasma no C (p<0,05), enquanto no DP, a distribuição foi similar entre os compartimentos, com uma redução no citoplasma (p<0,05), e um sutil aumento no núcleo. Sugerimos que a resposta de GR ao DP indica a alteração um elemento essencial na atividade da corticosterona, e essa modificação pode ser importante na coordenação do crescimento da mucosa gástrica durante o desmame precoce. / Early weaning (EW) is the abrupt change from suckling (S) to solid food and it can impair stomach development. This is a stressful situation for pups and it augments corticosterone levels, which acts through glucocorticoid receptor (GR). We studied GR expression, tissue and subcellular distribution in the gastric mucosa of S and EW pups. GR expression was higher at 17 d in S pups (p<0,05), whereas in EW group, it increased from the 17th to 18th d (p<0,05). GR protein levels decreased throughout EW, mainly at 18 d (p<0,05). However, EW did not alter tissue distribution of GR along the gastric gland. As for GR subcellular distribution, we found that in S group GR was more concentrated in the cytoplasm, (p<0,05), whereas in EW pups, GR was similarly distributed between compartments, though we detected a decrease in the cytoplasm (p<0.05) and a slight increase in the nucleus. We suggest that GR response to EW indicates the change of an essential element of corticosterone cascade, and such alteration might be important in the coordination of gastric mucosa growth.

The objectives of this thesis were: 1) to assess the iron status of piglets, 2) to thoroughly evaluate the blood profile, growth performance, and tissue mineral concentration of young pigs during the pre and postweaning periods after receiving various dosages of iron (0, 50, 100, 200, and 300 mg iron) at birth, 3) as well as evaluate the effects of an additional iron injection before weaning on hematological measures, growth performance, and tissue mineral concentration postweaning. In the initial experiment, there was a 60% incidence of iron deficiency at weaning after administration of a 150 mg iron injection at birth. Also at weaning, hemoglobin concentration was negatively correlated with BW and BW gain (r = -0.53, P < 0.0001, and r = -0.60, P < 0.0001 respectively). In the second experiment, pigs that were not injected with iron at birth had a major reduction in hematological measures, growth performance, and tissue iron concentration until d 52 where iron status was recovered but growth was not. Overall, ADG was improved in a linear and quadratic manner (P = 0.02 and P = 0.01 respectively) as the iron dosage increased with the largest improvement from the 0 mg to 50 mg iron treatment. The improvement observed in ADG let to similar increases (P = 0.02 and P = 0.01 respectively) in final BW as iron dosage treatments increased. Hemoglobin (Hb) concentration improved (P = 0.01) with increasing injectable iron as early as d 1 and continued to d 38, thereafter (d 52) no differences in Hb concentration were observed. Iron concentration for all tissues (liver, spleen, heart, and kidneys) at weaning was greater (P ≤ 0.01) as the iron dosage increased. In the third experiment, pigs that were supplemented with an additional iron injection 4 days before weaning had an increased ADG for the overall experimental period (31 to 34 d). The improved ADG during the experiment led to a heavier (P < 0.001) final BW (~1 kg) for pigs injected with an additional iron injection. At weaning, pigs injected with a second iron injection had higher (P < 0.001) hemoglobin concentration and other complete blood count measures. The improved Hb concentration observed at weaning continued 14 days later (P ≤ 0.02). Additionally, liver iron concentration was greater (P = 0.02) at weaning for the pigs receiving an additional iron injection. In summary, the initial iron injection administered at birth may not be adequate to satisfy all individual iron requirements of piglets before weaning, however, hematological measurements and tissue iron concentration do improve as the iron dosage increases at birth. Furthermore, injecting an additional iron injection before weaning improves nursery growth performance.

Background: The withdrawal of invasive mechanical ventilation (MV) within the context of withdrawal of life-sustaining measures (WLSM) is common in the intensive care unit (ICU). The method by which invasive MV is withdrawn during WLSM remains an ongoing topic of discussion and research; two methods are terminal weaning (TW) and terminal extubation (TE). Aims: To statistically describe and compare the processes of TW and TE as undertaken in two ICUs. Study Design: A secondary data analysis using data from a longitudinal retrospective chart audit. Results: A total of 78 patient charts were included. MV was withdrawn in 88.5% of patients undergoing WLSM. TW was used in 62.3% of the cases while TE was used in 37.7%. Patients who underwent TW were on average younger, had a longer ICU stay, higher respiratory support requirements, a longer duration of invasive MV, and shorter period from first change in MV parameters to patient death. Conclusion: This study highlights the nuances and complexities within MV withdrawal and WLSM in the ICU.

This study evaluated the changes in body composition, glycogen tissue reserves, visceral organ growth, and small intestine morphology in the young pig. A total of 96 crossbred pigs were euthanized at birth (pre-suckle), days 1, 2, 3, 5, 7, 14 postpartum, weaning at day 21, and days 1, 2, 3, 5, 7, 14, 28, and 42 post-weaning. Body composition of the pig had increasing dry matter and fat, decreasing ash, calcium and phosphorus, and relatively static protein percentage over the course of the study. Liver and muscle glycogen was greatest at birth. Following birth and weaning there was a distinct decrease in the amount of liver glycogen, while there was only a clear decrease in muscle glycogen at birth. Absolute measures of the visceral organs increased in a variety of manners (linear, quadratic and/or cubic); relative measures of visceral organs responded in different manners to increasing age. In the suckling period, villous height, villous height:crypt depth ratio, and goblet cell count was greater than in the post-weaning period. Crypt depth continued to increase through the entire study. Villi measurements of the middle and distal portion of the small intestine taken via scanning electron microscope, revealed different responses to increasing age, but numerically, villi width increased, villi density, enterocyte width, and microvilli density decreased, and microvilli diameter was relatively static. Villi, on average, increased the absorptive area of the small intestine 18 fold and microvilli increased the surface area on average 400 fold. This study provided a vast amount of biometric information on the development of the young pig from birth to 42 d post weaning.

Bakgrund: Mekaniskt ventilationsstöd används till patienter för att säkerställa ett tillfredsställande gasutbyte mellan koldioxid och syre. Avvänjningsprocessen från mekaniskt ventilationsstöd är påfrestande för patienten. Sjuksköterskor som arbetar med denna patientkategori ställs in för utmaningar som fodrar stor kunskap.Syfte: Belysa sjuksköterskors upplevelser av att vårda patienter vid avvänjning av mekaniskt ventilationsstöd. Metod: En systematisk litteraturöversikt med kvalitativa artiklar. Resultat: Ur analysen identifierades tre kategorier som var lära känna patienten, beslutsprocessen och optimera förutsättningarna. Konklusion: Kontinuitet och kommunikation i vården av patienten upplevdes som grundläggande för att lära känna patienten och för att bedöma patientens tillstånd. Vidare framkom det svårigheter att använda standardiserade strategier i arbetet med att avvänja patienter från mekaniskt ventilationsstöd. / Background: Mechanical ventilation support is used for patients to ensure a satisfactory gas exchange between carbon dioxide and oxygen. The weaning process from mechanical ventilation support is stressful for the patient. Nurses who work with this patient category are set for challenges that require a great deal of knowledge. Purpose: To shed light on nurses' experiences of caring for patients when weaning mechanical ventilation support. Method: A systematic literature review with qualitative articles. Results: From the analysis, three categories were identified to get to know the patient, the decision-making process and optimize the conditions. Conclusion: Continuity and communication in the care of the patient was perceived as fundamental for getting to know the patient and for assessing the patient's condition. The study described that there were difficulties in using standardized strategies in the work of weaning patients from mechanical ventilation support.

In recent years, U.S. swine producers have received pressure from consumers to reduce antibiotic usage. With the increased consumer pressure, pork producers have sought out other technologies, including feed additives, to reduce antibiotic usage in commercial pork production. Therefore, the objective of Chapter 2 was to determine whether supplementing L-glutamine at cost-effective levels can replace dietary antibiotics to improve pig welfare and productivity following weaning and transport. Based on previous research, we hypothesized that withholding dietary antibiotics would negatively affect pigs while diet supplementation with 0.20% L-glutamine (GLN) would have similar effects on pig performance and health as antibiotics. Mixed sex pigs (N = 480; 5.62 ± 0.06 kg BW) were weaned (18.4 ± 0.2d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pigs were blocked by BW and allotted to 1 of 3 dietary treatments [n = 10 pens/dietary treatment/replicate (8 pigs/pen)]; antibiotics [A; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)], no antibiotics (NA), or GLN fed for14 d. On d 15 to 34, pigs were provided common antibiotic free diets in two phases. Data were analyzed using PROC MIXED in SAS 9.4. Day 14 BW and d 0 to 14 ADG weregreater (P = 0.01) for A (5.6% and 18.5%, respectively) and GLN pigs (3.8% and 11.4%, respectively) compared to NA pigs, with no differences between A and GLN pigs. Day 0 to 14 ADFI increased for A (P < 0.04; 9.3%) compared to NA pigs; however, no differences were detectedcomparing GLN to A and NA pigs. Once dietary treatments ceased, no differences (P > 0.05) in growth performance amongdietary treatments were detected. On d 13, plasma tumor necrosis factor alpha (TNF-α) was reduced (P = 0.02) in A (36.7 ± 6.9 pg/ml) and GLN pigs (40.9 ± 6.9 pg/ml) versus NA pigs (63.2 ± 6.9 pg/ml). Aggressive behavior tended to be reduced overall (P = 0.09; 26.4%) in GLN compared to A pigs, but no differences were observed between A andGLN versus NA pigs. Huddling, active, and eating/drinking behaviors were increased overall (P < 0.02; 179, 37, and 29%, respectively) in the spring replicate compared to the summer replicate. A subset of pigs from Chapter 2 were utilized, in Chapter 3, toevaluate the dietary treatment effects on intestinal morphology and gene expression. On d 33, mast cells/mm2were increased (P= 0.05) in GLN and NA pigs vs. A pigs (22.2% and 19.7%, respectively). On d 33, villus height:crypt depth tended to be increased(P= 0.07; 7.0%) in GLN and A pigs vs. NA pigs.On d 33, glucagon-like peptide 2 (GLP-2)mRNA abundance was decreased (P= 0.01; 50.3%) in GLN and NA pigs vs. A pigs.Crypt depth was increased (P= 0.01; 16.2%) and villus height:crypt depthratiowas reduced (P= 0.01; 9.6%)during the spring replicate compared to the summer replicate on d 33. On d 13, TNF-α and occludin mRNA abundance wereincreased (P≤0.04; 45.9%and 106.5%, respectively)andzonula occludens-1(ZO-1)mRNA abundance tended to be increased (P= 0.10; 19.2%) in the spring replicate compared to the summer replicate. Previous research and the results of Chapter 2 indicates that supplementing nursery diets with 0.20% GLN provides similar growth and health benefits as dietary antibiotics, but it is unknown whether greater inclusion levels will provide additional benefits. Therefore, the objectiveof Chapter 4 was to evaluate the impact of replacing dietary antibiotics with increasing levels ofGLNon growth performance, health status, and production costs in pigs following weaning and transport. We hypothesized that diet supplementation with 0.20% to 1.00% GLNwould incrementally improvepig health and productivity compared to dietary antibiotics. Mixed sex pigs (N = 308; 5.64 ± 0.06 kg BW) were weaned (19.1 ± 0.2 d of age) and transported in central Indiana during the autumn of 2017. Pigs were blocked by BW and allotted to 1 of 7 dietary treatments (n = 8 pens/dietary treatment); A[chlortetracycline (441 ppm)+ tiamulin (38.6 ppm)], NA, 0.20% GLN, 0.40% GLN, 0.60% GLN, 0.80% GLN, or 1.00% GLNfed for 14 d. On d 15 to 35, pigs were provided NA diets in two phases. Data were analyzed using PROC MIXED in SAS 9.4. Overall, ADG (P= 0.04; 6.4%) and ADFI (P= 0.04; 6.9%) were reduced in NA pigs vs. 0.40% GLN or A pigs. Increasing GLN in the diet tended to increase (linear;P= 0.10) ADG. Overall, increasing GLN in the diet tended to increase (linear; P= 0.08) d 35 BW. Day 35 BW was greater (P= 0.01) in 0.80%GLN and A pigs compared to NA, 0.20% GLN, and 0.60% GLN pigs, but no BW differences were detected between 0.80% GLN and A and 0.40% GLN and 1.00% GLN pigs. In addition, d 35 BW was greater (P= 0.01) for 0.40% GLN and 1.00% GLN compared to 0.20% GLN. Overall income over feed and therapeutic injectable antibiotics cost for enteric and unthrifty challenges was greater (P= 0.02) in 0.80% GLN pigs compared to NA, 0.20% GLN, and 0.60% GLN pigs, but no income over feed and therapeutic injectable antibiotics cost for enteric and unthrifty challenges differences were detected between 0.80% GLN pigs and 0.40% GLN, 1.00% GLN, and A pigs. Health challenges in swine herds negatively impact swine growth rate and performance. Therefore,utilizing the pigs from Chapter 2, the study objective for Chapter 5 was to quantifythe impact of differences in rearing conditions through post hoc analysis on growth performance, tissue accretion rates, and production economics in pigs during different replicates(summer or spring). We hypothesized that pigs reared under health challenged conditions would have decreased growth performance and tissue accretion rates resulting in increased production costs compared to pigs reared with less health challenges. Data were analyzed using PROC MIXED and PROC NLMIXED in SAS 9.4. Therapeutic injectable antibiotics cost was reduced(P= 0.01; 246.7%) in the spring replicate compared to the summer replicate. Income over feed and therapeutic injectable antibiotics cost was greater (P= 0.01; 23.1%; $16.62/pig) in the spring replicate compared to the summer replicate.Predicted ADG was greater (P≤ 0.05) in spring replicate barrows compared to thesummer replicate barrows during the ranges of 22 to 38 and 119 to 177 days of age, respectively. Spring replicate gilts had greater ADG (P≤ 0.05) compared to summer replicate gilts during the ranges of 22 to 47 and 112 to 177 days of age, respectively. The maximum predicted empty body protein accretion rate for the summer replicate gilts and the spring replicate gilts is 145 and 156 g/d, respectively. In conclusion, GLN supplementation improved pig performance and health after weaning and transport similarly to A across studies and GLN shows promise as an antibiotic alternativewith 0.40% GLN appearing to be the optimal level. Health challenges in pigs can have profound negative impacts on tissue accretion ratesand key economic drivers for pork producers such as poorer feed efficiency and reduced hot carcass weight. The adverse health effects resulting in reduced growth performance, increased production costs($16.62/pig), and negatively impact producer profitability.<p> </p>

Objetivo: Analizar y determinar mediante una revisión sistemática el impacto que tiene el método BLW sobre la salud nutricional en bebés de 6 a 12 meses. Método: La metodología que se desarrollará está basado en el artículo de Tricco A, et al del a2018 y el de Peters MD,et al del año 2015. En el artículo de Peters, et al, mencionan que en una revisión sistemática exploratoria se debe realizar una búsqueda rigurosa y extensa de la literatura internacional. Así como definir los objetivos, los métodos y detallar los planes propuestos. Los artículos primarios investigados deben ser clasificados por el tipo de intervención, población, duración de la intervención, palabras clave. Asimismo, mencionan que las revisiones sistemáticas exploratorias son útiles para reunir evidencia, ya que, son adecuadas para abordar preguntas más allá de la efectividad o la experiencia en una intervención.