The influence of the nutritive plane on the early growth of the Holstein calf has been investigated. Particular attention has been given to near-maximal growth rates, and to the ability of calves to exhibit compensatory growth after nutrient restriction is removed. A whole milk feeding standard, intended to allow maximum consumption, was established and used as the plane of nutrition for a group of high-plane calves. A second group of calves was fed milk at a lower plane for a period, before being realimentated to the same high plane that their contemporaries had received. Metabolic rate measurements were made on all calves at regular intervals. The animals of both groups were slaughtered at a body weight of 113 kgm (250 lb) and various measurements were taken from the dissected carcasses. The high-plane feeding standard proved to be quite satisfactory and permitted weight gains from 1.09 to 1.34 kgm/ day for the calves reared continuously on this plane. Highly reproducible rates of gain were displayed by the low-plane calves, both during the periods of restriction and realimentation. The growth rates of the low-plane calves in the latter period exceeded those of the high-plane animals, being from 1.45 to 1.6l kgm/day. The possible reasons for this increased growth capability are discussed in relation to the studies of other workers on compensatory growth. Nutrient restriction depressed the metabolic rates of low-plane calves below those exhibited by their high-plane partners of equal weight. Upon realimentation, the metabolic rates of the previously-restricted calves rose quite rapidly to levels commensurate with the heat losses of the high-plane animals. The carcass dissection studies did not reveal extensive modifications in body composition that could be attributed to the treatments. The growth of certain visceral organs was retarded or accelerated by the nutritive planes imposed, but the musculature and skeleton were apparently unaffected by the pattern of growth. The yield of edible meat was essentially the same for both groups of animals, despite a lower consumption of milk by the calves whose growth had been interrupted. A model, for comparison of the relative efficiencies of restricted and unrestricted meat-producing animals, is suggested. / Land and Food Systems, Faculty of / Graduate

Orientador: José Jurandir Fagliari / Coorientador: Rinaldo Batista Viana / Coorientador: Daniela Gomes da Silva / Banca: Raimundo Souza Lopes / Banca: Annelise Carla Camplesi dos Santos / Resumo: A determinação do perfil bioquímico sérico é uma excelente ferramenta para identificar eventuais alterações fisiológicas pertinentes à saúde e ao bem-estar do bezerro, sobretudo no período neonatal. Deste modo objetivou-se com o presente estudo avaliar o perfil bioquímico sérico de bezerros bubalinos sadios no período neonatal. Foram examinadas amostras de soro sanguíneo de 50 animais da raça Murrah oriundos de fazenda produtora de leite situada no município de Alambari - SP. Os animais foram distribuídos em três grupos experimentais, de acordo com o número de parições de suas mães, sendo 15 bezerros filhos de búfalas primíparas (G1), 19 bezerros filhos de búfalas multíparas com duas a quatro parições (G2) e 16 bezerros filhos de búfalas multíparas com cinco a 14 parições (G3). As colheitas de amostras de sangue venoso foram realizadas nos seguintes momentos: ao nascimento, antes da ingestão do colostro (M0), às 24h (M1), 48h (M2) e 72h após o nascimento (M3) e aos 7 (M4), 14 (M5), 21 (M6) e 30 dias de idade (M7), para determinação das atividades séricas das enzimas gamaglutamiltransferase (GGT), fosfatase alcalina (ALP), aspartato aminotransferase (AST) e creatina quinase (CK) e das concentrações séricas de proteína total, albumina, globulinas, ferro, cálcio total, cálcio ionizado, fósforo, sódio e potássio. As concentrações séricas de imunoglobulina G (IgG), foram determinadas pela técnica de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The serum biochemical profile is an excellent tool to identify any relevant physiological changes to health and calf welfare, especially in the neonatal period. This study aimed to evaluate serum biochemical profile of healthy buffalo calves in the neonatal period. Serum samples from 50 Murrah animals from a milk farm in the city of Alambari - SP were examinated. The animals were divided into three groups according to the number of parities of their mothers, 15 calves born from primiparous buffaloes (G1), 19 calves born from multiparous buffaloes with two to four parities (G2) and 16 calves from multiparous buffaloes with five to 14 parities (G3). The venous blood samples were taken at the following times: at birth, before the ingestion of colostrum (M0) at 24h (M1), 48h (M2) and 72h after birth (M3) and 7 (M4), 14 (M5), 21 (M6) and 30 days of age (M7) for determination of serum activities of gamma glutamyl transferase enzymes (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), creatine kinase (CK), and serum concentrations of total protein, albumin, globulin, iron, total calcium, ionized calcium, phosphorus, sodium, potassium. Serum concentrations of immunoglobulin G (IgG) were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results were evaluated by analysis of variance (ANOVA) using the Tukey's test to compare means, significance was observed at 5% probability. The age factor influenced all biochemical parameters, ex... (Complete abstract click electronic access below) / Mestre

Calves infected with Babesia bovis or Babesia bigemina between 3 and 9 months of age can develop immunity without showing overt clinical signs. This transient immunity is not dependent on maternal immunity. After 9 months of age, they are fully susceptible to challenge. Dairy calves between 2 and 3 months of age were vaccinated with B. bigemina and B. bovis live frozen vaccines (Onderstepoort Biological Products®). Two months after vaccination, 90% of calves were serologically positive on IFA test to B. bigemina, and 70% were serologically positive to B. bovis. At this age, only 17% of the control group had seroconverted to B. bigemina and none of the calves had seroconverted to B. bovis. All experimental calves maintained positive serological status to both B. bovis</i. and B. bigemina for at least 5 months after vaccination. It is sound practice to vaccinate dairy calves against babesiosis at 2–3 months of age. Endemic stability is achieved before the period of natural resistance wanes. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Veterinary Tropical Diseases / unrestricted

<p>Calves raised in automated milk feeder (AMF) systems benefit from social interaction and having access to large amounts of milk, which they can consume in multiple small meals. Additionally, these systems record longitudinal feeding behavior measurements on each calf. However, if group size, composition, and disease detection are not optimal, the health and performance of calves can be compromised. The analysis of AMF data can provide information that may allow for improved disease detection and group management to maximize health and welfare of pre-weaned dairy calves. A proper understanding of the data generated by AMF and its context are essential to derive meaningful information about health status and group dynamics of dairy calves. Because the goal is that farmers can use this information to support decisions, six years of historical data from a commercial dairy farm were first collected, described, and stored in a research data ecosystem and then used to evaluate feeding and social behavior of calves. The first chapter evaluates the effect of environmental and biological factors on the feeding behavior of 9,737 calves. The results showed that reductions in milk consumption and drinking speed preceded the detection of bovine respiratory disease using farm protocols. In addition to health status, temperature humidity index, birth weight, and parity of the dam also influenced milk consumption and drinking speed. Therefore, including data on the traits of the individuals and the conditions of their environment can improve predictive models for sickness detection and performance assessment. The second chapter evaluates the use of AMF records and social network analysis. Interactions that occur at the autofeeder from 254 calves in five groups were used to rank individual animals and assess the groups’ stability. Enrollment order was associated with dominance rating, based on feeder displacements. Birth weight, however, had no influence on dominance rating. Social network analysis showed that although displacements are not constant over time, calves did not displace every other calf in their group, indicating some selectivity. This study demonstrates the possibility of using longitudinal data from precision technology to assess group dynamics.</p>

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Eight clinically normal calves of different breeds were used in this study. The animals were given daily doses of arsanilic acid (Pro-Gen Abbott) varying from 1.4 to 6 mgs/lb. of live body weight with subsequent individual increase up to 20 mg/lb. Daily physical examination were carried out on each animal. Samples of blood and urine were taken two or three times a week for analysis. After death, tissues were collected for histopathological examination. Following is a description of the most important findings: 1) Arsanilic acid, in this study, did not show the growth promoting properties for calves reported for poultry and swine. 2) The toxic level of arsanilic acid for calves is 8 mgs/lb. of body weight. 3) Bilirubinemia, bilirubinuria and albuminuria occurs on the last two or three days preceding death. 4) Prothrombin time is gradually increased from the first ingestion of arsanilic acid reaching the highest values two days before death. Increases in prothrombin time occurred even on low levels of arsanilic acid which produced no other clinical or clinical pathological changes. 5) Symptoms and pathologies-anatomical lesions are similar to those reported for other arsenic derivatives. 6) Principal organs injured are the liver and kidney. / Master of Science

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