Desempenho, síntese de proteína microbiana e comportamento ingestivo de novilhas leiteiras alimentadas com casca de café em substituição à silagem de milho

• Autor(a) principal: Teixeira, Rafael Monteiro Araújo
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5856
• topic: Bovino de leite; Alimentação e rações; Silagem; Milho; Casca de café; Recria; Nutrição animal; Dairy cattle; Feeds and feeding; Silage; Corn; Coffee hulls; Reproduction; Animal nutrition; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

The nutrients intakes and total apparent digestibility, performance, ingestive behavior, economic use of diet, ruminal parameters, nitrogen balance and microbial protein synthesis and ingestive behavior of dairy heifers under replacement of corn silage by coffee hulls were evaluated in this research. Twenty-four dairy Holstein heifers, purebred and crossbred, were assigned to a randomized block design, with four treatments and six replicates, according to the animal initial weight. The treatments were four coffee hulls levels: 0.0, 10.7, 20.7, and 30.7% as-fed basis, in replacement of corn silage, resulting in average replacements of 0.0, 7.0, 14.0 and 21.0% in dietary total dry matter, respectively. A 2.0 kg concentrate mix was daily fed to each animal. The intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), calcium (Ca), potassium (K) and sodium (Na), expressed in kg/day showed linear (P<0.05) increase as the coffee hulls levels increased. The intakes of ether extract (EE), total carbohydrates (CHO), nonfiber carbohydrates (NFC), phosphorus (P), magnesium (Mg) and total digestible nutrients (TDN), expressed in kg/day, showed no effect as the dietary coffee hulls levels increased. The digestibility of DM, OM, CP, CHO, NDF and the dietary NDT concentration linearly decreased (P<0.05) under replacement of corn silage by coffee hulls. It was observed linear decrease (P<0.05) for weight gain, as the dietary coffee hulls levels increased, and a reduction of 5.51 g/unity added hulls was estimated, but wither and hip growth in cm/day were not affected by the coffee hulls levels increase. Regarding the ingestive behavior, no difference among diets for average time spent in eating, ruminating and idling were detected. However, it was observed that DM and NDF feeding efficiency showed linear increase (P<0.05), as the dietary coffee hulls levels increased. The nitrogen compounds intakes and urinary and fecal N excretion linearly increased (P<0.05) as the dietary coffee hulls levels increased, that resulted in N positive balance for all treatments. However, absorbed N percentage compared to the intaked linearly decreased (P<0.05). The ruminal ammonia concentrations and the plasma urea concentration (NUS) did not vary as the dietary coffee hulls levels increased. The excretions of uric acid, allantoin and purine derivatives, the absorbed purines, the microbial nitrogen compounds and the microbial efficiency linearly decreased (P<0.05) as the dietary coffee hulls levels increased. It was concluded that the replacement of corn silage by coffee hulls, uo to 30.7% as-fed basis, increased DM intake, but reduced the nutrients digestibility and the microbial efficiency and, consequently, animal performance. The use of coffee hulls in the dairy heifers diets is viable up to 14% dietary total dry matter, and it depends on its availability and financial resources, although the highest economic return was obtained at 7% dietary total dry matter, considering intake and weight gain and also a coffee hull cost approximately 20% corn silage cost.