Feed processing can affect rumen development in new born calves, and potentially define animal performance. Two feed management systems, extruded starter (Ruter) with possible early weaning and ground starter (control), were evaluated in thirty-two Holstein calves (16 females and 16 males). Animals were randomly assigned to the treatments using a randomized block design with birth weight as a covariate. They were weaned when starter intake reached 800 g for two consecutive days. Twenty-one days after the weaning, males were slaughtered and the stomach compartments were isolated. Rumen and omasum fragments were processed for morphological evaluation. Animal performance, clinical condition and stomach compartment weight did not differ between the treatments (P> 0.05), despite weaning weight of animals receiving extruded starter being 5.68% higher than the control animals. Extruded starter stimulated cell proliferation of the ruminal epithelium (P <0.05), but did not affect the dimensions of the papillary rumen and omasum mitotic index (MI). The Ruter feeding system was potentially beneficial for weight gain and morphofunctional rumen development in lactating animals; however, this treatment did not allow early weaning as proposed by the feeding system.

Avaliou-se o efeito de diferentes formas de processamento da casca de mandioca na alimentação sobre o desempenho e as características de carcaça, a morfologia ruminal e a viabilidade técnico-econômica da criação de ovinos. Foram utilizados 20 ovinos machos da raça Santa Inês, desmamados, com peso inicial de 19,02±0,21 kg e 90 dias de vida. O delineamento experimental foi inteiramente casualizado com cinco repetições por dieta. Durante o período experimental de 84 dias, incluindo 14 dias de adaptação, os animais foram mantidos em sistema de semiconfinamento em pastagem de Brachiaria decumbens. Foram avaliadas quatro formas de processamento da casca de mandioca: desidratada triturada em peneira de 12 ou de 5 mm; úmida triturada e ensilada; e úmida triturada e hidrolisada com 0,5% de cal virgem (óxido de cálcio - CaO). O peso médio ao abate foi 30,72±1,46 kg. Não houve influência do tipo de processamento da casca sobre as características de desempenho analisadas, as características quantitativas de carcaça e a morfologia ruminal, sendo influenciado somente o rendimento de paleta. A casca de mandioca hidrolisada foi a que promoveu melhor eficiência econômica. Os tipos de processamento da casca de mandioca não alteram o desempenho, as características de carcaça, os rendimentos de corte e a morfologia ruminal dos ovinos Santa Inês.

The objective of this trial was to evaluate the effect of different forms of processing of cassava peel in sheep feeding on performance traits, carcass, morphology and rumen and economic technical feasibility. Twenty non-castrated male Santa Ines lambs of 19.02±0.21 kg of initial body weight and 90 days of age at the beginning of the study were used in this trial. The design was completely randomized design with five replications per treatment. During the experimental period of 84 days, including 14 days of adaptation, animals were kept in semi-confinement on Brachiaria decumbens. Four forms of cassava peel processing were evaluated: dried cassava peel ground through 12-mm sieve; dried cassava peel ground through 5-mm sieve; ground and ensiled cassava peel, and wet, ground hydrolyzed with 0.5% lime (calcium oxide - CaO). The average weight at slaughter was 30.72±1.46 kg. There was no influence of the type of processing on the performance variables analyzed, quantitative carcass characteristics or ruminal morphology; only the values of width and leg yield palette were influenced. Hydrolyzed cassava peel showed the best economic efficiency between treatments. The different methods of processing cassava peel do not affect performance, carcass characteristics, yield cuts or rumen morphology of Santa Ines sheep.

Os objetivos deste trabalho foram determinar a funcionalidade do sulco do retículo em bovinos adultos e avaliar técnicas alternativas para preparação, infusão e coleta de marcadores da dinâmica ruminal. Quatro vacas com cânulas ruminais foram utilizadas em três ensaios experimentais. No ensaio 1 a porcentagem de água que passou diretamente ao omaso (27,39 %) tendeu a ser menor (P = 0,14) que a porcentagem de água que atingiu o ruminorretículo (72,61 %), indicando funcionamento ineficiente dessa estrutura em bovinos adultos. No ensaio 2, as taxas fracionais de passagem de fluido determinadas simultaneamente por Cr-EDTA (14,79 % h-1) e Co-EDTA preparado por técnica alternativa (14,76 % h-1) não diferiram (P = 0,96) e as regressões exponenciais tiveram alto coeficiente de determinação (r² = 0,90). A relação Co:Cr no fluido ruminal não diferiu ao longo das quatro horas de coleta de amostras (P = 0,68). Não houve variação entre a relação Co : Cr na urina e nas fezes. A técnica de fácil execução, proposta para preparação do Co-EDTA, mostrou-se efetiva. No ensaio 3, em que os marcadores foram infundidos à digesta sem homogeneização, a melhor plotagem (r² = 0,88; P < 0,001) da regressão exponencial foi obtida excluindo-se os cinco primeiros tempos de coleta (1,67 h após infusão) e dobrando-se os intervalos até as 5,33 h após infusão. Nesse padrão de coleta, os coeficientes de determinação das regressões exponenciais não diferiram (P = 0,17) de curvas padrões (r² = 1), quando comparados hipoteticamente. As técnicas alternativas propostas para infusão e amostragem são viáveis, mas requerem validação.

The objectives of this work were to determine the functionality of the reticular groove in adult cattle and to evaluate alternative techniques for preparation, infusion and collection of ruminal dynamics markers. Four cows with rumen cannulas were used in three experimental assays. In the first assay the water percentage that passed directly to the omasum (27.39 %) tended to be lower (P = 0.14) than the water percentage that reached the reticulorumen (72.61 %), indicating inefficient functioning of the reticular groove in adult bovines. In assay 2, the fractional rates estimated simultaneously by Cr-EDTA (14.79 % h-1) and Co-EDTA prepared for an alternative technique (14.76 % h-1) did not differ (P = 0.96). The exponential regressions had a high determination coefficient (r² = 0.90). The Co : Cr ratio in the ruminal fluid did not differ during the four hour sampling period (P = 0.68). There was no variation in the Co : Cr ratio in urine or feces. The simple technique proposed for the preparation of Co-EDTA, was effective. In assay 3, markers were infused into digesta without homogenization. The best plotting (r² = 0.88; P < 0.001) of the exponential regression was obtained by excluding the five initial collection times (1.67 h after infusion) and by doubling the sampling intervals until 5.33 h after infusion. Under this collection pattern, the exponential regression determination coefficients did not differ (P = 0.17) from the standard curves (r² = 1), when hypothetically compared. The alternative techniques proposed for infusion and sampling are viable, but require validation.