Effect of restricted feeding and realimentation on compensatory growth, carcass composition and organ growth in rabbit

Abstract

SummaryThe effect of restricted feeding and realimentation on growth and carcass composition was studied in two experiments, each using 30 rabbits of the Swedish White Domestic Breed. The rabbits were slaughtered in groups of 5. The restricted feeding started at 1.0 or 1.6 kg live weight respectively, restriction lasting to 2.1 or 2.4 kg. The highest slaughter weight was 3.2 kg. The feed restriction was to 60 p. 100 of the ad libitum consumption of the litter mates at the same age or same weight and realimentation ad libitum or 100 p. 100 respectively. The nutritive value of the pelleted diet was determined in digestibility trials and carcass composition was studied by mincing and chemical analysis of soft tissue.Restricted feeding produced carcasses which, at the same weight, had a lower content of fat, a higher content of protein and the same content of water in the soft tissue. After realimentation, the carcasses had still a lower content of fat, the same content of protein and a higher content of water. There was a tendency to a higher feed consumption at ad libitum feeding during realimentation compared with continuous ad libitum feeding. The restriction had a significant effect on digestibility, which was better in the restricted animals, especially in expt. 1.The treatments had no effect on total feed consumption, total feed efficiency or protein retention. There was a tendency to better growth rates during realimentation and in expt. 2 also a tendency to a better daily carcass weight gain. However, the differences were not significant.Of the internal organs, weight of liver was the most affected by restriction and realimentation.

Effect of early feed restriction on performance and health status in growing rabbits slaughtered at 2 kg live-weight

“…Likewise, Szendro et al (1988) stated that it was possible to improve feed conversion up to 13% with time-restricted feeding. However, the results of the present work are consistent with those of other studies (Ledin, 1984;Perrier, 1998;Tumova et al, 2002) which found that feed conversion of restricted and then realimented rabbits was similar to that of rabbits continuously fed ad libitum when considering the entire fattening period. Finally, live weight at 63 d was lower for rabbits that had been restricted at the beginning of the trial (1989 vs. 1888 g; P=0.001).…”

“…In fact, the higher digestibility coefficients detected by Lebas (1979), Ledin (1984) and Szendro et al (1988) in restricted rabbits may lead to lower nutrient flows in the caudal part of the ileum. Moreover, Gidenne and Feugier (2009) found that a feed restriction of 20% increased the caecal concentration of volatile fatty acids (from 65.9 up to 84.8 mmol/L when feed restriction ranged from 0 to 40%), and acidified caecal contents (5.64 vs. 5.99, P<0.001) while enhancing bacterial fibrolytic activity (5.0 vs. 10.6 µmol reducing sugar/g DM per h, P<0.05).…”

“…Compensatory growth was observed in previously restricted rabbits in the realimentation period (49 to 63 d) since, in this period, the latter rabbits gained more weight than never restricted rabbits (44.8 vs. 54.8 g/d; P<0.001). Compensatory growth after a period of feed restriction is a constant feature in realimented rabbits (Ledin, 1984;Maertens and Peeters, 1988;Tumova et al, 2002). In the whole fattening period (35 to 63 d), feed restriction reduced both feed intake (112 vs. 104 g/d; P=0.003) and weight gain (44.0 vs. 40.4 g/d; P=0.001) so that FCR was not enhanced (2.56 on average).…”

“…Thus, Gidenne et al (2009a,b) found that live weight of restricted rabbits (restriction of 20 or 25%) at 70 d of age was respectively 3.84 or 6.01% (P<0.01) lower than that of rabbits continuously fed ad libitum. Furthermore, Ledin (1984) needed to postpone 15 d the end of the experiment to obtain the same live weight for all rabbits. Tumova et al (2002) were probably the only work where no a lower weight for restricted rabbits at the end of the fattening period was found.…”

Feed restriction strategy in the growing rabbit. 2. Impact on digestive health, growth and carcass characteristics

“…In addition, Maertens and Peeters (1988) reported a higher compensatory growth with a high-energy diet compared to a lower one. With a shorter restriction period, Ledin (1984) detected a weaker compensatory growth, suggesting that the importance of this phenomenon would be related to the level and to the duration of the intake restriction. But contrary to what was expected, here the compensatory growth was not associated with the behaviour of overeating in previously restricted animals, thus leading to an improved FC.…”