Fatty acid composition of milk from Holstein cows fed fish oil, canola oil, or their combination in early lactation (original) (raw)

2010, Advances in Animal Biosciences

Tropical pasture is the main source of cattle feed, but in the dry season it is deficient in protein, which is essential for microbial growth. The search for technology to increase animal performance may be a feasible alternative to reduce costs with dairy cattle nutrition. This work aimed to compare the performance and the efficiency of lactating cows on pasture, supplemented with concentrate containing 16% crude protein (CP) on dry matter basis using cottonseed meal with 38% CP as protein source, with or without a feed additive containing branched chain volatile fatty acids (Nutricattle). Twenty-four lactating Holstein × Gir crossbred cows were evaluated (average body weight = 436.5 kg, days in milk = 119, body condition score = 2.75, and average milk yield = 7.55 L/day). Animals were offered 1.0 kg/animal/day of concentrate in 2 milking times. In the first week, cows were fed the same diet. After the adaptation period, each lot was randomly assigned to feed the concentrate with or without 24 g of additive/cow/day. Data were analyzed in a randomized blocks design, including milk production and body condition score as covariates, using F test. Although there was a reduction in supplement intake in the fourth week, average milk yield of the additive treatment (8.3 L) was higher (P = 0.01) than the average milk yield of the control (7.3 L). There was no difference in the final body condition score between treatments (P = 0.48), but the additive increased 0.5 units during the experimental period. In relation to milk quality, no difference was observed in milk fat (P = 0.21) and cryoscopy (P = 0.71) between treatments. Therefore, although pastures usually have good quality during the rainy season, according to this result, the inclusion of Nutricattle additive was nutritionally efficient, increasing milk production by 12%.