Optimization of reproductive efficiency of both beef and dairy herds is critical for sustainability and profitability. Two separate experiments were performed to test the reproductive outcomes following early weaning of beef heifers and intrafollicular insemination in dairy cows. Early weaning is a proven way to induce precocious puberty in heifers. Heifers will experience more estrous cycles before breeding, which is associated with increased fertility. In this experiment, heifers were either subjected to early weaning and a high concentrate diet (EW; 106.5±3.4 days of age) or normal weaning (NW; 231.7±3.33 days of age) treatments. Despite no effect (P>0.15) of weaning treatment on age at puberty, EW heifers tended to have higher pregnancy rates than NW heifers. A progesterone clearance analysis revealed that EW heifers also have greater ability to metabolize progesterone. This altered progesterone metabolism could be a direct result of changes in metabolism caused by feeding a high concentrate diet after early weaning. Pregnancy rates in cattle are often lower than desired. New reproductive advances are constantly developed to improve reproductive function. A recently described possible technique is intrafollicular insemination (IFI). The objective of the second experiment was to investigate whether IFI can cause fertilization. Abattoir ovaries with dominant follicles injected with semen and incubated overnight displayed sperm in close association with granulosa cells. When synchronized cows were subjected to IFI, no pregnancies resulted. While other studies have demonstrated success with IFI, it is still unknown if fertilization is possible within the follicle of the ovary. / Master of Science

The thesis sets out the design of new feeding strategies in the current context of rabbit production, marked by the high prevalence of Epizootic Rabbit Enteropathy and the need of the systematical use of antibiotics as the only way to maintain the digestive health of growing rabbits, and, consequently, the economical viability of the farms. In this context, the study is focused in the use of weaning diets in combined feeding of rabbit does and litters. In the first experiment, eight weaning diet were tested; they were formulated in a factorial design 2Œ2Œ2 with the following factors: i) partial replacement of starch with acid detergent fibre, ii) partial replacement of starch with neutral detergent soluble fibre and iii) reduction in the crude protein content. The three strategies impaired milk yield and body condition of rabbit does and decreased litter weight at weaning; however, they decreased the post-weaning mortality of young rabbits, and those effects seem to be additive. In the second experiment, the effect of those strategies on caecal environment of growing rabbits was tested. The dietary changes modified the production of volatile fatty acids (which increased) and/or ammonial nitrogen (which decreased), creating a more favorable environment to maintain the stability of caecal microbial ecosystem and, consequently, the digestive health, which would explain the reduction of mortality observed in the previous experiment. In the third experiment, a factorial design 2Œ2 was carried out to compare two feeding systems (conventional or the one based in the use of a weaning diet in combined feeding formulating the most favorable feed to digestive health of young rabbits, according to the results obtained in the two previous studies) and two weaning ages (28 or 42 days) in the long term (5 cycles). The results showed once again the conflict of interests between rabbit does production and young rabbits health. In this context, the work has been focused in the use of weaning diets in combined feeding of rabbit does and litters. / Martínez Vallespín, B. (2011). Use of weaning diets in combined feeding of females and growing rabbits [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/14122

Yes / Objectives Studies of the carbon and nitrogen stable isotope ratios (δ13C and δ15N) of modern tissues with a fast turnover, such as hair and fingernails, have established the relationship between these values in mothers and their infants during breastfeeding and weaning. Using collagen from high-resolution dentine sections of teeth which form in the perinatal period we investigate the relationship between diet and physiology in this pivotal stage of life. Materials and Methods Childhood dentine collagen δ13C and δ15N profiles were produced from horizontal sections of permanent and deciduous teeth following the direction of development. These were from two 19th-century sites (n = 24) and a small number (n = 5) of prehistoric samples from Great Britain and Ireland. Results These high-resolution data exhibit marked differences between those who survived childhood and those who did not, the former varying little and the latter fluctuating widely. Discussion Breastfeeding and weaning behavior have a significant impact on the morbidity and mortality of infants and the adults they become. In the absence of documentary evidence, archaeological studies of bone collagen of adults and juveniles have been used to infer the prevalence and duration of breastfeeding. These interpretations rely on certain assumptions about the relationship between isotope ratios in the bone collagen of the adult females and the infants who have died. The data from this study suggest a more complex situation than previously proposed and the potential for a new approach to the study of maternal and infant health in past populations.

Yes / The carbon (δ13C) and nitrogen (δ15N) isotope ratios of human bone collagen have been used extensively over the last 40 years to investigate the diet of past populations. It has become apparent that bone collagen can give an unreliable temporal dietary signature especially in juveniles. With higher temporal resolution sampling of collagen from tooth dentine, it is possible to identify short‐term changes in diet previously invisible in bone. This paper discusses the inherent problems of using bone collagen for dietary studies and suggests better sample choices which can make our interpretations more robust, using breastfeeding and weaning as an example. / The modern data was collected and analysed using funding from the Rank Prize Funds New Investigator Award and sponsorship from DB Orthodontics, Bradford. The Tooth Fairy team acknowledges the support of the National Institute for Health Research Clinical Research Network (NIHR CRN). / Research Development Fund Publication Prize Award winner, February 2020.

Conventional techniques within the beef cattle industry involve weaning the calf from the dam when the calf is about 205 days of age. Weaning induces a stress-response that is implicated in reducing the health and productivity of newly weaned calves. Our goal was to evaluate the impact of weaning on the stress immune responses of beef calves. To that end, we 1) evaluated novel methods to quantify physiological markers of stress, 2) compared immune function and growth of calves grazing legume versus grass forages, and 3) compared the effects of abrupt versus two-stage weaning on calves. In study 1, calf, yearling, and adult beef cattle were used to assess the accuracy and precision of handheld glucometers in quantifying bovine blood glucose concentration. Precision Xtra® and ReliOn® glucometers were used chute side to quantify blood glucose concentrations in cattle and were compared to an accepted plasma glucose analysis on the same samples for validation. The Precision Xtra® glucometer was more accurate and precise than the ReliOn® glucometer. In study 2, weaned heifers were used to compare the immunomodulatory effects of grazing alfalfa versus fescue over a 30 day grazing period. No differences were detected in the interferon gamma (IFNγ) production and weight gain between the heifers on alfalfa and fescue. In study 3, effects of two-stage (fenceline) and abrupt weaning were compared. Calf weights, immune cell function, antibody production, blood glucose concentrations, fecal cortisol concentrations, and gene expression (FAS, IL-4,IL-10, and IFNγ) were measured pre- and post-weaning. On the day after weaning, the abruptly weaned calves had higher blood glucose concentrations than fenceline weaned calves. Fecal cortisol concentration and gene expression of FAS and IL-4 increased in both groups after weaning, but no differences were detected between the weaning treatments. Gene expression of IL-10 and IFNγ did not change over time. No date, treatment or treatment*date effect was detected for total weight gain or IFNγ production within the non-stimulated and the mitogen-stimulated whole blood samples. / Master of Science

No / The present study aimed to explore previously unreported ethnic differences in infant feeding practices during the introduction of solid foods, accounting for maternal and birth factors, and to determine whether these feeding patterns are associated with BMI at 3 years of age. An observational study using Poisson regression was carried out to investigate the relationship between ethnicity and infant feeding practices and linear regression was used to investigate the relationship between feeding practices and BMI at 3 years of age in a subsample of 1327 infants in Bradford. It was found that compared with White British mothers, mothers of Other ethnicities were less likely to replace breast milk with formula milk before introducing solid foods (adjusted relative risk (RR) – Pakistani: 0·76 (95 % CI 0·64, 0·91), Other South Asian: 0·58 (95 % CI 0·39, 0·86), and Other ethnicities: 0·50 (95 % CI 0·34, 0·73)). Pakistani and Other South Asian mothers were less likely to introduce solid foods early ( < 17 weeks) (adjusted RR – Pakistani: 0·92 (95 % CI 0·87, 0·96) and Other South Asian: 0·87 (95 % CI 0·81, 0·93)). Other South Asian mothers and mothers of Other ethnicities were more likely to continue breast-feeding after introducing solid foods (adjusted RR – 1·72 (95 % CI 1·29, 2·29) and 2·12 (95 % CI 1·60, 2·81), respectively). Pakistani and Other South Asian infants were more likely to be fed sweetened foods (adjusted RR – 1·18 (95 % CI 1·13, 1·23) and 1·19 (95 % CI 1·10, 1·28), respectively) and Pakistani infants were more likely to consume sweetened drinks (adjusted RR 1·72 (95 % CI 1·15, 2·57)). No association between infant feeding practices and BMI at 3 years was observed. Although ethnic differences in infant feeding practices were found, there was no association with BMI at 3 years of age. Interventions targeting infant feeding practices need to consider ethnicity to identify which populations are failing to follow recommendations.

O processo de envelhecimento promove mudanças morfológicas e fisiológicas em todo organismo, tornando-o frágil. Com o envelhecimento, o comprometimento anatômico e fisiológico do sistema respiratório pode promover alterações físicas e funcionais responsáveis por facilitar o surgimento da insuficiência respiratória, levando a internação em terapia intensiva e ventilação mecânica invasiva. Com objetivo de determinar quais variáveis estão associadas ao sucesso do desmame da ventilação mecânica em pacientes idosos e não idosos, foi delineada uma coorte retrospectiva com 331 pacientes, em três unidades de terapia intensiva do Hospital de Clínicas Niterói, Rio de Janeiro, Brasil. A prevalência de sucesso no desmame na amostra foi de 83,7%. Os resultados após análise multivariada demonstraram como variáveis independentes associadas ao desmame na amostra total e nos pacientes com idade < 70 anos o APACHE II e o índice integrativo de desmame (IWI). Nos pacientes com idade > 70 anos, o IWI foi a única variável respiratória independente encontrada para melhor prognóstico do desmame. O presente estudo concluiu que não houve influência da idade no resultado do desmame e o IWI demonstrou ser a principal variável preditora do desmame na população de pacientes idosos. / The ageing promotes morphological and physiological changes throughout the body, making it fragile. With ageing, the physiological and anatomical impairments of the respiratory system may promote physical and functional changes responsible for facilitating the development of respiratory failure, resulting in stays in intensive care and invasive mechanical ventilation. In order to determine which variables were associated to the successful weaning from mechanical ventilation in elderly and non-elderly patients, we evaluated 331 patients through a retrospective cohort in three intensive care units of the Hospital de Clínicas Niterói, Rio de Janeiro, Brazil. The Prevalence of the successful weaning in the entire sample evaluated was 83.7%. The results, after multivariate analysis, showed as independent variables associated with weaning in total sample and in patients aged < 70 years old, APACHE II and Integrative weaning índex (IWI). In patients aged > 70 years old, IWI was the single independent respiratory variable found related to the successful weaning. In conclusion, age presented no influence on weaning outcome. The IWI showed to be the main variable of weaning outcome in elderly patients.

Made available in DSpace on 2014-06-11T19:26:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-23Bitstream added on 2014-06-13T20:14:38Z : No. of bitstreams: 1 barrozo_d_me_jabo.pdf: 515290 bytes, checksum: 672a5fd2bc13656f7e2aa5b2c9cfe9ba (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo foi estudar a influência da idade da vaca ao parto (IVP), da idade do animal ao sobreano (IS) e do peso ao sobreano (PS) sobre os escores de conformação (C), precocidade (P), musculatura (M) e temperamento (T) ao sobreano de animais Nelore; estimar a herdabilidade (h²) destas características, empregando-se diferentes modelos estatísticos e estimar as co-variâncias e correlações entre T e as características reprodutivas perímetro escrotal (PE), idade ao primeiro parto (IPP) e idade ao segundo parto (ISP), de bovinos Nelore. A base de dados utilizada pertence ao PAINT®, CRV Lagoa LTDA. Foram realizadas análises de regressão após a absorção do efeito de grupo de contemporâneos (GC). As estimativas de h² foram obtidas por máximaverossimilhança restrita sob um modelo animal, considerando-se o efeito genético aditivo de animal como aleatório, incluindo diferentes efeitos fixos. IVP apresentou efeito quadrático sobre P e M, segmentado quadrático-quadrático sobre C e linear sobre T. A característica C comportou-se de modo similar ao PS e P e M foram semelhantes ao ganho de peso neste período. IS e PS apresentaram efeitos quadráticos sobre C, P e M e efeito cúbico e linear, respectivamente, sobre T. Estimativas de h² foram encontradas entre 0,13 á 0,38 (C, P e M) de acordo com o modelo utilizado, enquanto para PE, IPP e ISP, as estimativas foram iguais a 0,52; 0,13 e 0,03. As correlações genéticas entre T e PE, T e IPP e T e ISP foram de 0,16; -0,04 e -0,32. As correlações estimadas entre T e as características reprodutivas foram de pequena magnitude. A seleção para os escores visuais pode trazer ganhos genéticos moderados nas características de carcaça / The aims of this study were to study the effect of age at calving (IVP), age of yearling (IS) and yearling weight (PS) on the scores of conformation (C), precocity (P), muscle (M) and temperament (T) of yearling Nellore, to estimate heritability (h ²) of these traits, using different statistical models and to estimate the covariance and correlation between T and the reproductive traits scrotal circumference (SC), age at first calf (IPP) and age at second calf (ISP). The database used belongs to the breeding program PAINT ® of CRV Lagoa LTDA. Regression analysis were performed after the absorption of the effect of contemporary group (CG). Estimates of h² were obtained by restricted maximum likelihood method under an animal model, considering the genetic effect of animal as random, with different fixed effects. IVP showed a quadratic effect on P and M, segmented quadratic-quadratic and linear on C on T, respectively. C showed similar patter as PS while P and M were similar to weight gain in this period. IS and PS showed a quadratic effect on C, P and M and cubic and linear effects, respectively, on T. The estimates of h ² ranged from 0.13 to 0.38 (C, P and M) according to the model used, whereas for PE, IPP and ISP, the estimates were equal to 0.52, 0.13 and 0, 03. Genetic correlations between T and PE, T and IPP and T and ISP were 0.16, -0.04 and -0.32. The estimated correlations between T and the reproductive traits were small. Selection applied on visual scores could bring moderate genetic gains to the carcass traits

O processo de envelhecimento promove mudanças morfológicas e fisiológicas em todo organismo, tornando-o frágil. Com o envelhecimento, o comprometimento anatômico e fisiológico do sistema respiratório pode promover alterações físicas e funcionais responsáveis por facilitar o surgimento da insuficiência respiratória, levando a internação em terapia intensiva e ventilação mecânica invasiva. Com objetivo de determinar quais variáveis estão associadas ao sucesso do desmame da ventilação mecânica em pacientes idosos e não idosos, foi delineada uma coorte retrospectiva com 331 pacientes, em três unidades de terapia intensiva do Hospital de Clínicas Niterói, Rio de Janeiro, Brasil. A prevalência de sucesso no desmame na amostra foi de 83,7%. Os resultados após análise multivariada demonstraram como variáveis independentes associadas ao desmame na amostra total e nos pacientes com idade < 70 anos o APACHE II e o índice integrativo de desmame (IWI). Nos pacientes com idade > 70 anos, o IWI foi a única variável respiratória independente encontrada para melhor prognóstico do desmame. O presente estudo concluiu que não houve influência da idade no resultado do desmame e o IWI demonstrou ser a principal variável preditora do desmame na população de pacientes idosos. / The ageing promotes morphological and physiological changes throughout the body, making it fragile. With ageing, the physiological and anatomical impairments of the respiratory system may promote physical and functional changes responsible for facilitating the development of respiratory failure, resulting in stays in intensive care and invasive mechanical ventilation. In order to determine which variables were associated to the successful weaning from mechanical ventilation in elderly and non-elderly patients, we evaluated 331 patients through a retrospective cohort in three intensive care units of the Hospital de Clínicas Niterói, Rio de Janeiro, Brazil. The Prevalence of the successful weaning in the entire sample evaluated was 83.7%. The results, after multivariate analysis, showed as independent variables associated with weaning in total sample and in patients aged < 70 years old, APACHE II and Integrative weaning índex (IWI). In patients aged > 70 years old, IWI was the single independent respiratory variable found related to the successful weaning. In conclusion, age presented no influence on weaning outcome. The IWI showed to be the main variable of weaning outcome in elderly patients.

Thesis (M.A. Agricultural Management (Animal Production)) -- University of Limpopo, 2020 / The Nguni is indigenous multi-purpose cattle breed that plays an important role in both commercial and communal farming systems in South Africa (SA). Unfortunately, the breed is currently under threat of diminishing due to farmers’ preference for exotic breeds and cross breeding. In recognition of the above, the Industrial Development Corporation, the Mpumalanga Department of Agriculture, Rural Development, Land and Environmental Affairs and the University of Limpopo established the Nguni cattle breed preservation project. In this project, a herd of 30 Nguni heifers and 1 bull were allocated to 34 Communal Property Associations (CPA) and 40 private farming enterprises each. With its three distinct ecological zones (High, Mid and Low-veld), the Mpumalanga province poses a challenge to the Nguni preservation project since cattle have to adapt to different ecological zones in order to grow and reproduce efficiently. Knowledge of cattle herd productivity improves the understanding of the functional attributes and is useful in determining the constraints and the potential of communal beef cattle production systems. Significant differences between ecological zones were observed for age at first calving, weaning rate, calves’ birth weight and calves’ weaning weight (p < 0.05). Calving of heifers in the Mid-veld zone occurred earlier (24 months) on both ownership types compared to Highveld (28.09 months for private and 26.00 for CPA) and the Lowveld (28.35 months for both ownerships). Nguni cattle on the Highveld performed better in terms of weaning rate under both private and CPA ownerships, where the weaning rate were 93% and 80%, respectively. Calves birth weight was lower in both ownership types in the Midveld zone (22.17 kg), whereas in the CPA, the Lowveld zone had higher calves birth weights (26.80 kg). In the private ownership, the highest calves’ birth weight (25.35 kg) was on the Highveld. The calves weaning weight were significantly higher (p < 0.05) on Highveld in private ownership (190.16 kg) and lowest (160.39 kg) in the Midveld zone. For the CPA, the highest calves weaning weight was also on the Highveld (187.55) and lowest on Midveld (167.50 kg). A full range of backup services that are offered to the communities by stakeholders in the form of a beef package that includes veld and pasture management, nutrition management, beef performance, animal recording keeping, genetic evaluation and animal health management program needs thorough attention.