Effects of feeding programme on the performance and energy balance of nulliparous rabbit does

Abstract

A total of 190 rabbit females were used to evaluate five feeding programmes from 9 weeks of age to the first parturition: CAL, fed ad libitum with a control diet (C: 11.0 MJ digestible energy (DE) and 114 g digestible protein (DP)/kg dry matter (DM)) until first parturition; CR, fed ad libitum with C diet until 12 weeks of age and then C diet restricted (140 g/day) until first parturition; F, fed ad libitum with a low-energy, high-fibre diet (F: 8.7 MJ DE and 88 g DP/kg DM) until first parturition; FC, fed with F diet ad libitum until 16 weeks of age, and C diet ad libitum until first parturition; FCF, fed with F diet ad libitum until 16 weeks of age, then C diet ad libitum until 20 weeks and then F diet ad libitum until first parturition. The rabbits were artificially inseminated at 18 weeks of age. CAL group had a higher mortality rate compared with the other groups between 9 and 12 weeks of age (34% v. 3%; P , 0.05) and during the last 3 weeks of first pregnancy (14% v. 3%; P , 0.05). The CAL and FC females presented higher BW and perirenal fat thickness (PFT) than CR females at 11 days of pregnancy (10.41 kg and 10.6 mm; P , 0.05), with F females showing medium values. The type of feeding procedure did not affect the fertility rate of young females at first artificial insemination. Differences in BW disappeared at parturition, when only CAL females presented a greater PFT than CR and FC females (10.3 mm; P , 0.05). In comparison with FCF, CAL females had smaller and thinner live born litters (22.5 kits and 2139 g, respectively; P , 0.05), with CR, F and FC females showing medium values. The low number of kits born alive for CAL females was because of their lesser total number of kits born (21.7 kits; P , 0.05) and the greater mortality of their litters at birth (113.9%; P , 0.05) compared with FCF females. Non-esterified fatty acid was higher in the blood of females fed C diet (CAL and CR) than in others at partum day (on average 10.15 mmol/l; P , 0.05). In conclusion, the ad libitum use of diets for lactating rabbit does throughout the rearing period could lead young rabbit females to present a higher risk of early death and smaller litter size at first parturition. Feed restriction or earlier use of suitably fibrous diets led females to achieve the critical BW and fat mass at first mating to ensure reproduction.

Effects of rearing feeding programme on the young rabbit females’ behaviour and welfare indicators

“…The data on body weight, feed intake, blood metabolites and hormones were similar to those obtained by other authors (Rommers et al, 2004;Brecchia et al, 2006;García-García et al, 2011;Rebollar et al, 2011;Menchetti et al, 2015a;Martínez-Paredes et al, 2012), except for blood glucose and insulin concentrations at 20 th wk of age, which were very low in all groups. Compared with values at 13 th wk of age, blood glucose fell in mid gestation, as a result of its increased metabolic demand by foetal and maternal tissues (Fortum-Lamothe, 2006) and, accordingly, circulating insulin concentration also decreased.…”

“…However, T3 concentration was higher at 13 th wk, as required in a growing animal due to the function of T3 in animal growth. Martínez-Paredes et al (2012) found an increase in T3 values from 9 to 18 wk of age.…”

“…Compared with values at 13 th wk of age, blood glucose fell in mid gestation, as a result of its increased metabolic demand by foetal and maternal tissues (Fortum-Lamothe, 2006) and, accordingly, circulating insulin concentration also decreased. This fall in blood insulin level should be even greater if compared with that recorded by Martínez-Paredes et al (2012) at insemination (18 wk of age). However, insulin blood concentration at mid gestation was very low compared to that provided by Menchetti et al (2015a), but this discrepancy could be due to differences in the sampling protocol, in our case in the morning and after four hours of fasting.…”

“…It can be hypothesised that the 3 feeding programmes allowed us to achieve the leptin threshold and body maturity level necessary for reproductive activity of young rabbit does (Arias-Alvarez et al, 2009;Martínez-Paredes et al, 2012). On the other hand, Martínez-Paredes et al (2012) also observed that a higher energy intake achieved during late gestation by using a low energy/high fibre diet did not affect litter performance at partum. Blood concentration of NEFA varied with the feeding programme, being higher for those females receiving diet C (both ad libitum and restricted) compared to F females.…”

Metabolic and biochemical changes in plasma of the periparturient rabbit does with different litter size

“…There is also a considerable fatty deposition in the liver so intense that it may interfere with the liver function (Bruss, 1997). Episodes of pregnancy toxaemia can be surmised in rabbit does, which lead females to higher mobilization of reserves in late pregnancy (Rommers et al, 2004;Martínez-Paredes et al, 2012). Subsequently, body reserves are recovered during the first stage of lactation and reach a maximum around day 10 in lactation (Quevedo et al, 2007).…”