Efeito de diferentes fontes lipídicas sobre variáveis nutricionais, de produção e composição do leite de cabras localmente adaptadas

Abstract

The experiment was conducted to evaluate the effects of dietary lipid sources in the intake and digestibility of nutrients, in the balance of nitrogen compounds, purine derivative excretion, milk production and composition of indigenous goats. Four females goats at 109 days of lactation, with an initial average body weight (BW) of 47.10 ± 5.86 kg were used in a Latin square design with four periods and four treatments. The experimental diets consisted of a control diet (CON) without supplemental lipids and four test diets with different lipid sources: oil (OL) composed of 60% castor and 40% sunflower oil, cashew nut meal (CNM) and coconut meal (COCO). Experimental diets were formulated in order to meet the requirements of lactating goats producing one kg/day of milk and 40 g of fat. The experimental period lasted 60 days and was divided into four periods of 15 days each, comprising 10 days of adaptation to the experimental diets and five days of sampling. The variables were analyzed by linear model with diet effects, Latin square, period and animal. The difference between treatments was analyzed using Tukey's test (P = 0.05). Dry matter intake and non-fibrous carbohydrate intake were lower (p < 0,05) to the COCO diet compared to CON diet, whereas ether extract intake was higher (p < 0,01) to the COCO diet and lower to the CON. Ether extract digestibility coefficient was higher with COCO diet, followed by OL and CNM diets, when compared to control diet. Milk production, 4% fat - corrected milk and lactose synthesis (g/day) were higher (p < 0,05) for goats fed with CON diet and lower for goats fed with COCO diet. The different lipid sources did not affect nitrogen balance (NB) (p > 0.05). A lower milk allantoin excretion (P <0.05) was observed for goats supplemented with COCO diet (p < 0.01) compared to the CNM and CON diet. The utilization of oil and cashew nut meal may be a strategy in dietary plan of goat milk production system.