A note on the effects of breed, stage of lactation and pregnancy status on milk composition of rabbits

Forty-five New Zealand White and 35 Californian doe rabbits, 8 months old and in the third parity of their 1st year of production were used in this study. Thirty-five does were concurrently pregnant and lactating, the remaining 45 does were non-pregnant. Milk samples were collected in colostrum and at the 7th, 14th, 21st, 28th and 35th days of lactation. Neither breed nor pregnancy status affected the does milk composition except for total phosphorus which was significantly lower ( P < 0·05) in the pregnant does' milk. However the major components of milk except lactose, were significantly affected by stage of lactation. Both moisture: total solids and calcium: phosphorus ratios were the same (2:1) throughout the lactation. The ratio between retinol concentration in colostrum and in the 5th week was about 10:1. Specific gravity was significantly ( P < 0·05) correlated with protein, lactose (positive) and fat (negative).