Influence of feeding intensity on corporeal development, body composition and sexual maturity in female rabbits

Abstract

Twenty-six 6-week old female New Zealand White rabbits were divided into two groups: ad libitum (AL) and 70% restricted (RS) feeding. At the beginning of the experiment the liveweights were practically the same: 0.99 +/- 0.08 vs. 1.01 +/- 0.08 kg in group AL and RS, respectively. At 18 weeks of age the body weight of Group RS rabbits was 84.7% (3.14 +/- 0.24 kg) of the group AL (3.71 +/- 0.31 kg). The apparent digestibility of crude protein was significantly (p < 0.001) higher in Group RS than in Group AL (76.5 +/- 1.4 vs. 73.0 +/- 2.7%). The daily water consumption was significantly (p < 0.05) higher (3.5 ml/g DM intake) in Group RS as compared to Group AL (1.9 ml/g DM). Since the average body weight in Group RS at 18 weeks was the same as that of Group AL at 14 weeks of age (3.14 kg), the comparison of the live body measures and indices was based on these ages. Animals fed ad libitum or restricted show no differences at the defined age in most live body measurements except in heart girth and rump width, which were significantly (p < 0.05) shorter in Group AL than in Group RS (29.3 +/- 0.8, 5.7 +/- 0.5 and 30.7 +/- 1.0, 6.2 +/- 0.3 cm, respectively). Body capacity was significantly (p < 0.05) smaller in Group AL, as the head capacity-body capacity proportion was significantly (p < 0.05) higher in Group AL than in Group RS (1653.1 +/- 134.5, 22.0 +/- 2.5 and 1913.7 +/- 168.7, 17.7 +/- 1.9, respectively). Due to restricted feeding the growth of the head proved to be less intensive than that of the body at the same body weight. The body in these does tended to be wider. Since the head in comparison to length or capacity of the body was smaller in does fed 70% of ad libitum, it could be concluded that the development of body parts of restricted-fed does was unequal (allometric growth). The effect of feed restriction reflected in lower dry matter and fat, and a higher ash and protein content both in total body and in dry matter composition of rabbits at 18 weeks of age. Restricted feeding delayed sexual maturity (69 vs. 92% of rabbits) with later starting ovarian activity, weaker ovarian responsiveness, and a smaller number of tertiary follicles on the ovarian surface.

Feed intake limitation strategies for the growing rabbit: effect on feeding behaviour, welfare, performance, digestive physiology and health: a review

“…An increase in protein digestion was often observed in growing rabbits (Xiccato et al, 1992;Gidenne and Feugier, 2009) and adults (Lebas, 1979;Xiccato and Cinetto, 1988;Fodor et al, 2001). Similarly, in these studies the authors found in R animals a better digestive efficiency for energy, but few improvements in lipid or fibre digestion.…”

Influence of feeding intensity on the growth, body composition and sexual maturity of male New Zealand White rabbits

“…In the late-maturing 24-week-old Hungarian Giant rabbits the corresponding figures were 89.7% for body weight and 87.5% for average body weight gain. In the New Zealand White breed, restricted feeding delayed sexual maturity with later starting ovarian activity, weaker ovarian responsiveness, and a smaller number of tertiary follicles on the ovarian surface (Fodor et al, 2001a). This shows that the degree of optimal feed restriction considerably depends on the genotype in female rabbits.…”

“…One of the most important objectives of the prospective development is to achieve sexual maturity at an optimum age. The growth of organs at a different rate that depends on feeding (nutritional allometry) is currently known in heifers, dogs and cats (Rivers and Burger, 1989) and in different rabbit breeds such as the 'Pannon' White, Danish White and crossbred varieties (Kenessey et al, 1998) as well as the New Zealand White and Hungarian Giant female rabbits (Fodor et al, 2000(Fodor et al, , 2001b. Fekete and Gippert (1981) studied the effects of different levels of feed restriction in broiler rabbits.…”

“…They found that a 15% and 25% reduction of the daily feed intake resulted in a 19% and 35% decrease in the body weight gain, respectively; on the other hand, the digestibility of nutrients improved. Fodor et al (2000Fodor et al ( , 2001aFodor et al ( , 2001b studied the effect of feeding intensity in female New Zealand White rabbits of early sexual maturity and Hungarian Giant rabbits of late sexual maturity. In female New Zealand White rabbits subjected to restricted feeding, the growth of the head was less intensive as compared to that of the body at a constant body weight; in addition, the body had grown wider by the time of reaching sexual maturity.…”

“…The objective of this experiment was to determine changes in body weight, body measurements, body composition and sexual maturity as a function of feeding intensity in male New Zealand White rabbits as a continuation of similar studies performed on New Zealand White does previously (Fodor et al, 2001a).…”