Pre-mating plasma prolactin profile affects California doe rabbit reproductive performance

Abstract

Ovulation failure was associated with a reduction in pre-mating concentrations of oestradiol-17β and prolactin (PRL). The present study aimed to evaluate whether pre-mating PRL levels have a role in the reproductive efficiency of doe rabbits. A total of 78 multiparous California does (2nd parity) were divided, according to plasma pre-mating PRL, into five categories, >20-25, >25-30, >30-35, >35-40, and >40-45 ng/ml. Does in all categories were naturally mated and kindled, then their reproductive measurements and progesterone (P4) levels were determined. Results show that pre-mating PRL averaged 23.60 ± 0.78, 28.00 ± 0.83, 33.46 ± 0.43, 38.17 ± 0.49 and 41.98 ± 0.68 ng/ml in five categories (p < 0.05), respectively, representing the highest distribution (38.5%) in the 3rd-category. Live body weight of doe rabbits, at mating, pregnancy, and parturition increased (p < 0.05) with increasing pre-mating PRL level. The number of services, litter size, and pregnancy rate increased (p < 0.05) by increasing PRL levels. Reproductive traits and P4 level at mid-pregnancy of does, and the average weight of kits at birth increased (p < 0.05) by increasing PRL levels. The pre-mating PRL profile is important for the identification of reproductive performance in doe rabbits.

Keywords: Litter size; Pregnancy; Progesterone; Prolactin; Rabbits.

Fig. 1

Change in live body weight of doe rabbits from mating up to kindling. (a,b,c: significant category differences at p < 0.05).

Fig. 2

Correlation coefficients between PRL level and doe live body weight at different reproductive stages. (*** significant at p < 0.001).

Fig. 3

Kit viability rate at birth and weaning as affected by PRL category. (a,b: significant category differences at p < 0.05).

Fig. 4

The concentration of progesterone in the blood plasma of does in different PRL categories at mid-and late pregnancy. (a,b,c: significant category differences at p < 0.05.