Effect of high fat diets on the performance, milk yield and milk composition of multiparous rabbit does

Experiment 1. One hundred and twenty-five lactations from 88 New Zealand X Californian does were used to study the influence of high fat diets on the performance and milk yield of multiparous rabbit does in two high productiv ity situations: housed in hot conditions (minimum temperature above 24 degr ees C) with eight pups (group H8), or housed in warm conditions (minimum te mperature under 21 degrees C) with 11 pups (group W11). Starting from a con trol diet (diet C) with 26 g ether extract (EE) per kg dry matter (DM), two isoenergetic diets were formulated adding fat from vegetable sources tip t o 99 g EE per kg DM (diet V) or animal sources up to 117 g EE per kg DM (di et A). The lactating does showed similar food daily intakes (similar or equ al to 105 g DM per kg), therefore digestible energy intake of does on high fat diets was significantly higher (P < 0.001). The addition of fat to the diets increased (P < 0.001) milk yield of does (+21 and 24 g/day for diets V and A, respectively) and lifter weight at weaning (P < 0.05), and decreas ed the number of pups replaced (P < 0.01) during lactation. Croup H8 does h ad significantly lower DM intakes, lifter growth rates and milk production levels than group W11 does (P < 0.001). Experiment 2. The effect of these diets on milk composition was determined in 62 lactations from 28 multiparous rabbit does, in which litter size was maintained at eight pups. Milk samples were collected manually on the 7th, 21st and 28th days of lactation. Milk of does given high fat diets, especia lly diet A, had higher fat and energy contents (P < 0.001) and a lower prot ein content (P < 0.001) than those given diet C. Milk of does given diet A had a greater DM content than those given the diets C or V (P < 0.001). The re was a correlation between the fatty acid composition of milk and dietary fat. The proportion of odd chain fatty acids in the milkfat was lower for does given diet V (P < 0.05) than those given diet A. In conclusion, high f at diets were related to a higher milk yield and Energy content of milk, al lowing a higher litter weight gain and a lower mortality of sucking pups.