Lucas Silveira Ferreira

Desempenho e desenvolvimento do trato digestório superior de bezerros leiteiros alimentados com concentrado de diferentes formas físicas

The physical form of concentrate on the performance and rumen development on dairy calves was evaluated in this experiment. Twenty-two Holstein male calves, with 42.3 kg initial body weight, were individually housed, fed 4 L/d of liquid diet and starter concentrate in two physical forms (pelleted or coarsely ground). Starter concentrate intake was monitored daily and calves were weighted weekly, always after the morning liquid diet feeding. After 10 weeks, four calves from each treatment were slaughtered and rumen samples were taken for pH, rumen short chain fatty acids (SCFA) and N-NH3 concentration. Morphometric measurement of the forestomach was also evaluated. There was no effect of the physical form on starter concentrate intake, body weight, and daily gain. The physical form of the concentrate also had no effects on pH, SCFA or N-NH3 rumen concentration, nor on the morphometric measurements of the forestomach, except for rumen capacity and abomasum weight, which were higher for animals fed pelleted starter concentrate. Coarsely ground starter concentrate may be an alternative to reduced production costs since the physical form of the concentrate had no effect on performance or in the development of forestomach of dairy calves.

Efeito da adição de butirato de sódio, propionato de cálcio ou monensina sódica no concentrado inicial sobre parâmetros ruminais e de desenvolvimento do rúmen de bezerros leiteiros

O objetivo neste trabalho foi avaliar o efeito da inclusao de butirato de sodio, monensina sodica ou propionato de calcio no concentrado inicial sobre parâmetros ruminais e de desenvolvimento do trato digestorio superior de bezerros leiteiros. Quinze bezerros holandeses recem-nascidos foram fistulados no rumen e alojados em baias individuais ate a decima semana de vida, com livre acesso a agua, alimentados com leite (4 L/dia), em duas refeicoes, e concentrado a vontade contendo butirato de sodio (0,15%), monensina sodica (30 ppm) ou propionato de calcio (0,15%). A partir da quarta semana de vida dos animais, antes e 2 horas apos a alimentacao da manha, foram realizadas colheitas semanais de fluido ruminal para determinacao do pH, da concentracao de acidos graxos de cadeia curta (AGCC) e N-amoniacal. Ao completar 10 semanas, os animais foram abatidos para avaliacao do crescimento do trato digestorio superior. O pH ruminal apresentou diferencas, tanto entre horarios quanto entre os aditivos utilizados no concentrado inicial. As concentracoes de AGCC totais, bem como de cada acido graxo, nao foram afetadas pelos aditivos. Entretanto, o horario de colheita teve efeito sobre todos os parâmetros, exceto a concentracao molar de acido acetico. O peso total do trato digestorio superior, assim como o peso medio de cada compartimento e a capacidade maxima do reticulo-rumen, nao foram afetados pelos aditivos fornecidos no concentrado. Tambem nao foram observados efeitos dos aditivos sobre a altura, a largura e o numero de papilas do epitelio ruminal. A inclusao desses aditivos no concentrado inicial nao afeta os parâmetros ruminais ou de desenvolvimento do trato digestorio de bezerros em aleitamento.

Evaluation of mannan-oligosaccharides offered in milk replacers or calf starters and their effect on performance and rumen development of dairy calves

The objective of this study was to evaluate the route of administration of mannan-oligosaccharides in the diet of dairy calves and their effects on performance and plasma parameters indicative of rumen development. Following birth, twenty-four male Holstein calves were used in a completely randomized design and assigned to the following treatments: Control; 4 g/d Bio-Mos® (Alltech Biotech.) added to starter concentrate; and 4 g/d Bio-Mos® mixed into milk replacer. Animals were housed in individual hutches with free access to water, and fed 4L/d of milk replacer until weaning at six weeks. Calves also received 23g/kg crude protein of starter concentrate ad libitum. Fecal scores were evaluated daily. Body weights, growth measurements and blood samples for glucose, urea-N and β-hidroxibutyrate analyses were taken weekly until 8 weeks of age. There were no significant effects of treatment or treatment × age interactions for mean starter concentrate intake, weight gain or body growth. However, there was a significant age effect for all parameters. Fecal scores were not affected by treatments. Also, plasma concentration of glucose, urea-N or β-hidroxibutyrate were not affected by treatment or the treatment × age interaction. However, urea-N and β-hidroxibutyrate concentrations significantly increased with age, suggesting adequate rumen development. Under the conditions of this study, there were no calf performance benefits when mannan-oligosaccharides were incorporated into milk replacer or calf starter concentrate.

Desempenho e parâmetros sanguíneos de bezerros leiteiros que receberam sucedâneo lácteo ou silagem de colostro

O objetivo deste estudo foi avaliar o desempenho e os parâmetros sanguineos de bezerros que consumiram colostro bovino fermentado sob condicoes anaerobias. Apos o nascimento, 18 bezerros da raca Holandes foram alojados em abrigos individuais e passaram a receber 4L da dieta liquida, sucedâneo lacteo ou silagem de colostro, divididos em duas refeicoes. O consumo de concentrado inicial e o escore fecal foram registrados diariamente, enquanto a pesagem e as colheitas de amostras de sangue para a determinacao das concentracoes plasmaticas de glicose, nitrogenio ureico, acidos graxos livres, β-hidroxibutirato e proteinas totais sericas foram realizadas semanalmente. Os animais alimentados com silagem de colostro apresentaram menores consumo de concentrado, ganho de peso diario e peso vivo. Todos os parâmetros sanguineos avaliados foram afetados pelos tratamentos, exceto a concentracao plasmatica de proteinas totais. O escore fecal foi afetado pelos tratamentos durante a segunda semana de vida, com animais alimentados com silagem de colostro apresentando fezes anormais e secas. O fornecimento de silagem de colostro como dieta liquida exclusiva nao resultou em desempenho animal adequado, nao sendo uma boa alternativa de substituto de leite.

Desempenho e desenvolvimento ruminal em resposta ao fornecimento de substâncias húmicas para bezerros leiteiros em sistema de desaleitamento precoce - doi: 10.4025/actascianimsci.v33i4.10907

The objective of this work was to evaluate the inclusion of humic substances in starter concentrate on the performance of dairy calves and rumen development. Twenty Holstein calves were used in a completely randomized block design and distributed in two treatments according to inclusion of humic substances in concentrate: 1) Control; 2) Humic substances. Animals received 4 L d -1 liquid diet and starter concentrate ad libitum . Fecal score analyses were carried out daily, and calves were weighed weekly and growth measurements and blood samples for glucose, urea-N and β-hidroxibutyrate (BHBA) were taken. The calves were weaned at eight weeks of age and slaughtered for evaluation of forestomach development. There were no effects (p > 0.05) between treatments or treatment x age interaction for concentrate intake, weight gain, growth measurements or blood parameters. Fecal scores and rumen development were not affected (p > 0.05) by the inclusion of humic substances. There were no benefits from the inclusion of humic substances in starter concentrate on performance or rumen development of dairy calves