Estratégias para utilização da cana-de-açúcar na alimentação de novilhas leiteiras: relações entre ureia, proteína verdadeira e amido

• Autor(a) principal: Abreu, Claudilene Lima de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1823
• topic: Alimentação animal; Digestibilidade dos nutrientes; Novilhas leiteiras; Animal feeding; Nutrient digestibility; Dairy heifers; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

This study aimed to evaluate intake, nutrient digestibility, nitrogen metabolism, degradability and rumen fill in dairy heifers fed cane sugar and urea relations, trueprotein and starch. Since the animals (eleven heifers with initial body weight of 250 ± 31 kg) were divided into two Latin squares, 6 x 6 and 5 x 5, for Experiments 1 and 2, respectively. The periods were made for 23 days, with 10 days for adaptation and 13 days of collection. We used cane sugar as a source for both bulky Experiments with added urea + ammonium sulfate (9:1) to correct the protein content being diluted and mixed with sugar before feeding the animals. In Experiment 1 we used two levels of urea, 10 and 14 g urea / kg MN cane, and for each level was made available to the animals 1.5 kg / day concentrates the basis of ground corn, soybean meal and mineral supplement, with different levels of crude protein: 180, 200 and 220 g / kg dry matter. In Experiment 2, we used relations starch: fiber in the concentrate: 80:20, 70:30, 60:40, 50:50 and 40:60 (urea + ammonium sulfate was added to the bulky 10 g urea / kg MN cane). Was offered 1.5 kg of concentrate containing ground corn, soybean meal, wheat bran and mineral supplement. The intake assessment was conducted from the 10 to 15th day of each period with daily weighing the amount of diet fed and orts for each treatment. The apparent digestibility was determined using the indirect method with chromic oxide indicator, provided the 1st to the 14th day of each experimental period. Stool samples were collected between the 10th and 15th day of each period at intervals of 26 hours. The estimation of kinetic parameters of particle passage through the gastrointestinal tract of the animals was determined from the adjustment compartment model (gamma exponential and a compartment to another), the data for Fecal excretion of Lanthanum indicator, set the cell wall cane -cane. From 17 ° to 23 days of each period stool samples were collected at times 0, 8, 16, 24, 30, 36, 42, 48, 54, 60, 66, 72, 84, 96, 120 and 144 hours after Incubation of labeled fiber. To estimate parameters of ruminal degradability of fiber from sugar cane and its various parts (top and stem bark)was adopted in situ technique, using three animals rumen. The samples were incubated at 0, 3, 6, 9, 12, 24, 36, 48, 72, 96, 120 and 144 hours, with three replicates for each food and every time. The increased levels of non-protein nitrogen as urea in diets with sugar cane as forage (10 to 14 g of urea / kg cane MN) for dairy heifers does not affect the utilization of nutrients by the animals, with intake, digestibility similar dry matter and lower values of effective degradability of fiber and rumen fill. The inclusion of starch in increasing levels and lower fiber diets with cane sugar more urea for dairy heifers shows no changes in NDF cane and rumen fill. The stem has a higher NDF compared to shell and tip of cane sugar.