Effect of controlled nursing with one-day fasting on rabbit doe performance

Abstract

This work studied whether the expected better subsequent reproduction for permanent controlled nursing versus free nursing could be further improved by a caloric biostimulation with temporary fasting and re-feeding of does before artificial insemination (AI) and how it influences the development of current litters. A total of 240 females were randomly assigned at first day of lactation to one of three groups each with 80 does in a balanced manner according to the number of kits, litter weight, newborn kit weight after adjusting to 8 rabbits per litter, doe body weight and parity. Rabbits in the control group (C) were fed ad libitum and nursed freely up to weaning at 35 days of age. In the group of local farm practice (F) females also received a diet ad libitum but controlled nursing was used. That meant once a day nursing for the first 14 days of lactation (8 am to 9 am) with using a metal-sheet for doe–litter separation and free nursing afterwards. In the biostimulated group (B) does were subjected to a 24-h fasting between days 8 and 9 (i.e. only drinking was possible between 10 am Monday and 10 am Tuesday) with a 48–50 h ad libitum re-feeding before AI (at 11 days, between 10 am and 12 am Thursday) and similar controlled nursing regime to F group. This biostimulation reduced the ratio of does having turgid vulva by 16.9% (46.7 vs. 63.6 and 48.1% for the B, F and C groups, respectively; P < 0.05) and the kindling rate by 6.8% (78.7 vs. 85.5 and 71.1%; P < 0.05) when compared with merely controlled nursing (F). However, biostimulation tended ( P = 0.152) to increase the total-born by one kit per litter (11.2 vs. 10.2 and 10.3). Individual kit weights and litter weights at weaning were reduced in response to controlled nursing (944, 966 vs. 1033 g; P = 0.001 and 7179, 7451 vs. 7900 g; P = 0.001). Biostimulation led to 17% lower total weight of 70-day-old rabbits per doe (14.54 vs. 17.53, 17.51 kg; P = 0.009) compared to F and C groups due to poorer 35–70 day growth (36.1 vs. 40.5, 40.8 g/day; P = 0.001) and higher mortality than for C group (12.3 vs. 7.9%; P < 0.01). In conclusion, this biostimulation worsened the subsequent reproductive performance of does and the development of current litter. Further research is required about the presumable interaction between the nursing system and feeding strategy of does.