Performance of Holstein x Gyr dairy cows fed hydrolyzed sugarcane-based diets

Semina: Ciências Agrárias

Carlos Giovani Pancoti¹  Fernando César Ferraz Lopes²  Mariana Magalhães Campos³  Ricardo Reis e Silva⁴  Ana Luiza da Costa Cruz Borges⁴  Tainá Silvestre Moreira⁵ 

[1] Agroceres Multimix;Embrapa Gado de Leite;Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA Gado de Leite;Escola de Veterinária, Universidade Federal de Minas Gerais;Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo;

关键词: Alcali;    Bovine;    Calcium oxide;    Digestibility;    Feeding behavior;    Saccharum officinarum.;   

DOI  :  10.5433/1679-0359.2019v40n2p807

来源: DOAJ

【 摘 要 】

Twelve multiparous 7/8 Holstein x Gyr dairy cows were fed diets based on chopped sugarcane supplied in natura (control) or after being hydrolyzed (fresh matter basis) for 24 h with 0.5%, 1% or 2% calcium oxide (CaO). The voluntary consumption and digestibility of dietary nutrients, milk production and composition, and feeding behavior of cows were evaluated. A switchback design with three periods, four treatments and three blocks was used. The linear and quadratic effects of the treatments were analyzed using orthogonal contrasts, and the effects were considered significant when P ? 0.05. Compared to the that in the control treatment, the Ca concentration increased by 297%, 570% and 1,083% in the diets including sugarcane hydrolyzed with 0.5%, 1% and 2% CaO, respectively, while the respective Ca:P ratios were 6.58:1, 10.70:1 and 19.77:1 (control Ca:P ratio: 1.55:1). The hydrolysis of sugarcane with increasing amounts of CaO promoted a linear reduction (P < 0.01) in the intake of dry matter (DM), nonfibrous carbohydrates, crude protein (CP), organic matter (OM), neutral detergent fiber corrected for ash and protein (NDFap) and ether extract. The intake of total digestible nutrients, acid detergent fiber (ADF), lignin, hemicelluloses and cellulose presented quadratic behavior (P < 0.01) in response to increasing CaO concentrations used for sugarcane hydrolysis. Increases in the amount of CaO used for sugarcane hydrolysis had no effect on the digestibility of NDFap (P > 0.05), but there were linear reductions (P < 0.05) in the digestibility of DM, OM and ADF; the production of milk corrected or not corrected to 4% fat; and the content of protein, lactose and total solids. Linear reductions (P < 0.05) were also observed in the production of all milk components. Only the milk fat content was not altered (P > 0.05) in response to the inclusion of hydrolyzed sugarcane in the diets. There was no effect (P > 0.05) of sugarcane hydrolysis with increasing amounts of CaO on the time the cows spent idle, ruminating and feeding, but there was a linear increase (P < 0.05) in the minutes spent ruminating 1 kg of DM and NDF. Chopped sugarcane hydrolyzed for 24 h with 0.5% to 2.0% CaO should not be used as exclusive roughage in diets for Holstein x Gyr dairy cows with an average milk production of 10 kg day?1.

【 授权许可】

Unknown