Characterization of Straightbred and Crossbred Rabbits for Milk Production and Associative Traits

Abstract

Two hundred twenty-five lactation and litter performance records from 82 does representing four genetic groups and two diets were analyzed to quantify breed, heterosis, reciprocal F1 cross and diet effects for milk production and associative traits. Doe genetic groups were New Zealand White (NN) and Californian (CC) straightbred and Californian X New Zealand White (CN) and New Zealand White X Californian (NC) reciprocal crossbreds. Pelleted diets fed to does and litters were either a commercial control or a 74% alfalfa diet. Three sire breeds of litters included NN, CC and Flemish Giant (FG) straightbreds. Doe genetic group and diet were important sources of variation (P less than .05) for all traits examined except for litter milk efficiency (litter gain/milk intake) and doe feed efficiency (milk yield/feed intake). The sire breed of litter effect did not influence (P greater than .05) lactational performance of does nor associative preweaning traits. Straightbred NN does were heavier at kindling, yielded more milk, reared a heavier litter by 21 d and were more efficient in converting feed into milk than were straightbred CC does (P less than .01). Significant heterosis was detected for milk production and for litter size and weight at 21 d. Reciprocal differences between crossbred doe groups were observed (P less than .05) for litter milk efficiency and doe feed intake. The 74% alfalfa diet was superior to the commercial control diet for effects on milk production and litter size and weight at 21 d, although doe feed intake was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Rabbit milk: A review of quantity, quality and non-dietary affecting factors

“…The highest correlations reported are for the period between birth and 21 days of age and amount to 0.90 (Lebas, 1969), 0.91 (Fortun-Lamothe andSabater, 2003) or even 0.99 (Lukefahr et al, 1983). Weight gain of the litter at a later stage is much less correlated with the milk yield in the corresponding period (Lebas, 1969).…”

“…Lukefahr et al (1983) demonstrated that New Zealand White does are superior (+ 30%) to Californian does and that crossbred rabbits of both breeds are superior than the pure breeds. However, in another study, the same team determined a comparable milk production for the 4 breeds tested (Calfornian, New Zealand White, Palomino and White Satin) (McNitt and Lukefahr, 1990), which indicate that the genetic background of the particular populations is perhaps more important than the breed itself.…”

Genetic comparison of milk production and composition in three maternal rabbit lines

“…Lukefahr et al (1983) detected a strong positive association within breed between milk production of the doe and both litter size and weight at 21 d of age. In intensive rabbit meat production, it is common to use crossbred does from lines selected for litter size and thereby indirectly improve milk yield (Garreau et al, 2004).…”

“…An increase in litter size by one kit born alive increased weekly milk yield by 49.21 g/wk; this confirmed the positive relationship between litter size and milk production in maternal rabbit lines already reported in the literature. Lukefahr et al (1983) reported a correlation coefficient of 0.78 between total 21 d lactational yield and litter size at 21 d. Iraqi and Youssef (2006) estimated that an increase in litter size by one kit resulted in an increase by 42.9, 84.4, 102.4, 84.6 and 306.9 g of milk for the 1 st , 2 nd , 3 rd , 4 th week and total milk yield, respectively. Other studies confirmed this positive phenotypic relationship between litter size and milk production in rabbits.…”

“…No records were conducted in the fourth week of lactation, so differences between lines in the persistency of milk production could not be studied. Milk yield was measured using the weigh-suckle-weigh method described by Lukefahr et al (1983). This method basically consisted of weighing the dam before and after suckling, so on control days it is only necessary to allow access to the dams once per day for about 5-10 min.…”