Effects of replacing corn and Tifton hay with forage cactus on milk production and composition of lactating dairy cows

[摘要] The objective of this trial was to evaluate the effect of replacing Tifton hay and corn with forage cactus (Opuntia ficus indica Mill ) on milk production and composition and milk fatty acid profile in lactating Holstein cows. Animals averaged 583 ± 7.07 kg of body weight in the beginning of the trial and were fed diets containing (% of DM): 0, 12.0, 25.0, 38.0 or 51.0% of forage cactus. Five Holstein cows were randomly assigned to treatments in a 5 x 5 Latin square design. Each experimental period lasted 17 days with 10 days for diet adaptation and seven days for data and sample collection. Milk production, 3.5% fat corrected milk, and milk fat content and yield were not affected by increasing the levels of forage cactus in the diet and averaged 20.65 kg/d, 19.76 kg/d, 3.73% and 0.745 kg/d, respectively. Milk contents of capric, lauric, mirystic, linoleic, linolenic e arachydic acids were not changed when the levels of forage cactus were increased in the diet. However, milk contents of the medium-chain fatty acids palmytic and palmitoleic reduced linearly while the opposite was observed for the long-chain fatty acids estearic and oleic. Although milk production and composition were not affected by replacing corn and Tifton hay with forage cactus, significant changes were found in the milk profile of medium and long-chain fatty acids by increasing the proportion of forage cactus in the diet.

[学科分类] 兽医学

[关键词] fatty acids profile;mammary gland;milk quality    Introdução A zona semi-árida nordestina;apesar de possuir solo em sua maioria com fertilidade natural média a alta;tem como principal fator limitante ao crescimento das forrageiras o acentuado déficit hídrico na maioria dos meses do ano;associado a um regime pluviométrico inconsistente;conduzindo a ocorrência cíclica de períodos de estiagens prolongadas