The value of trace minerals in a fattening ration.

This is the fourth in a series of experiments conducted to determine the value of trace minerals in a typical fattening ration. Three previous experiments, similar to this one, were reported in Kansas Agr. Exp. Sta. Cirs. 297, 308 and 335. Chemical analyses of feeds commonly used in cattle rations in this area show there is no deficiency in any of the trace minerals: cobalt, copper, iodine, iron, manganese and zinc. It is possible the minerals may not be adequately balanced or available to the animal at all times. The objective of this test is to determine if trace minerals, when fed at a commonly used level, will influence rate of gain and feed efficiency

Consumo, digestibilidade e balanço de nitrogênio em novilhos alimentados com cama de frango e suplemento à base de microbiota ruminal liofilizada Intake, digestibility and nitrogen balance of steers fed broiler litter and supplement based on lyophilized ruminal microbiota

Este experimento foi realizado para avaliar o efeito de dois níveis de cama de frango (15,0 e 30,0%), associada ou não a um suplemento à base de microbiota ruminal liofilizada de bovinos adultos (0 e 10 g/animal•dia), na alimentação de novilhos Holandês/Zebu. Quatro novilhos fistulados no rúmen e abomaso foram distribuídos em um quadrado latino 4 x 4 em arranjo fatorial e alimentados individualmente à vontade. O consumo e as digestibilidades totais e parciais dos nutrientes foram avaliados. Não houve efeito do nível de cama de frango sobre o consumo e os coeficientes de digestibilidade da matéria seca (MS), matéria orgânica (MO) e fibra em detergente neutro (FDN). O aumento do nível de cama de frango na dieta elevou o coeficiente de digestibilidade intestinal e total da proteína bruta (PB), porém, quando se adicionou o suplemento à dieta com 15,0% de cama de frango, a digestibilidade intestinal aumentou e àquela contendo 30,0% diminuiu. Quando se adicionou o suplemento à dieta com 15,0% de cama de frango, o coeficiente de digestibilidade total não sofreu efeito, mas diminuiu para a dieta com 30%. A ingestão diária de 10 g do suplemento, por animal, não alterou o consumo e os coeficientes de digestibilidade da MS, MO e FDN.<br>This experiment was conducted to evaluate the effect of two levels of broiler litter (15.0 and 30.0%), associated or not to a supplement based on bovine lyophilized ruminal microbiota (0 and 10 g/animal•day), in the Holstein Zebu steers feeding. Four steers with ruminal and abomasal fistulae were allotted to a 4 x 4 latin square in a factorial arrangement and individually fullfed. The intake and total and partial digestibilities were evaluated. There was no effect of broiler litter level on the intake and coefficients of digestibilities of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF). The increase of the level of broiler litter in the diet increased the total and intestinal crude protein (CP) digestibility coefficient, however, when the supplement was added to the diet containing 15.0% of broiler litter, the intestinal digestibility increased, and that of 30.0% decreased. When the supplement was added to the diet containing 15.0% broiler litter, the total digestibility coefficient did not show effect, but decreased for the diet with 30.0%. The daily intake of 10 g of supplement per animal did not affect the intake and the coefficient of digestibilities of DM, OM and NDF