Effect of Different Seasons on the Performance of Grey Giant Rabbits under Sub-Temperate Himalayan Conditions

Abstract

An experiment was conducted on 190 progeny (winter -74; summer -59; rainy -57) of 12 Grey Giant rabbits (10 female +2 males), to assess the effect of different seasons in a year, on their reproductive, growth and productive performances along with feed efficiency, under sub-temperate Himalayan conditions. The daily meteorological attributes recorded during winter (October to March), summer (April to June) and rainy (July to September) seasons, and analysed were minimum and maximum temperature, relative humidity and rainfall. Various biological parameters recorded were doe weights at mating and kindling, litter size at birth, litter weight at birth, kit mortality, litter size at weaning, litter weight at weaning, weekly body weight up to 98 d and weaner mortality. Individual weight gains, dressing percentages, meat weights, liver weights, raw-pelt weights, processed pelt weights and processed pelt areas at slaughter on d 84 and 98, respectively were also recorded. The feed and fodder compositions and their nutritive values during different seasons were also analysed. Average ambient temperature during winter, summer and rainy seasons were 13.2±2.8, 22.4±3.7 and 24.8±2.3°C, respectively. The average relative humidity and total rainfall for winter, summer and rainy seasons were 68.9±1.5% and 48±26.6mm, 66.3±4.8% and 125.6±56.8 mm, and 77.3±1.3% and 116.3±90.4 mm, respectively. The weight of doe at mating and kindling, litter size at birth, litter weight at birth and litter size at weaning were comparatively higher whereas litter weight at weaning was significantly (p<0.05) higher during winter as compared to summer and rainy seasons. The kit mortality was significantly (p<0.05) higher during winter while the weaner mortality was significantly (p<0.05) higher during rainy season. At 84 d, the live weight per doe, slaughter weight, dressing percentage and liver weight were significantly (p<0.05) higher during winter than summer and rainy. Similarly, the gain in weight and meat weight at 84 and 98 d were significantly (p<0.05) higher during winter. The weight of raw pelt and processed pelt were recorded significantly (p<0.05) higher during winter while no difference in the area of processed pelts during different seasons could be observed. No difference in the biological performance could be observed between sexes in any of the seasons. Roughage analysis revealed comparatively higher crude protein percent and lower crude fibre percent during summer and rainy seasons than in winter. The roughage dry matter intake was comparatively higher during summer and rainy seasons vis-a-vis constant amount of concentrate supplied during all the three seasons. The digestibilities of dry matter was significantly (p<0.05) lower, whereas that of crude fiber, acid detergent fibre and cellulose were negative during winter. Interestingly, the feed:gain was exceedingly well during winter than in other seasons and it is concluded that it was the best season for production of rabbits under sub-temperate Himalayan conditions.

Investigation of Pre- and Post-Weaning Mortalities in Rabbits Bred in Egypt, with Reference to Parasitic and Bacterial Causes

“…Prevalence of preweaning mortality due to insufficient milk supply and large litter size was the highest in winter (45.28%) while the lowest was in autumn (26.6%). Similar results were obtained by [31,32]. The prevalence of preweaning mortality because of cannibalism was 26.38%.…”

Reproductive efficiency of female German Angora Rabbits under Indian sub-temperate climatic conditions.

“…Other authors have observed no significant effect of season on LSB, LWB and LSW (BHATT et al 2002). BELHADI et al (2002) also support our findings that spring is the best season for reproduction of rabbits.…”

Reproductive performance of different breeds of broiler rabbits under sub-temperate climatic conditions

“…In agreement with our results, Khalil and Mansour (1987) and El-Maghawry et al (1988) also noted higher values for litter size at weaning in spring, while Kumar et al (2005) reported a significant effect of season on gestation length in Angora rabbits. Similarly to our data, the absence of seasonal effects on fertility (Rodríguez and Fallas, 1999), litter size at birth and weaning (Bhatt et al, 2002) and sex ratio (Khalil and Mansour, 1987) has also been reported. In contrast, Ponce de Leon et al (2000) observed that the season had a significant effect on fertility, being higher in spring and lower in autumn.…”

“…The increasing day length, comfortable temperature and availability of quality fodder during spring season may contribute to the high reproductive efficiency of rabbits in this period of the year. The pasture during spring was lush, having higher nutritive value with more protein and carotene content as compared to other seasons (Bhatt et al, 2002) and it has been observed that higher feed intake during lactation increased both litter size and weight at weaning (Pascual et al, 2002). Fertility, prolificacy, litter weight at birth, gestation length, and sex ratio were higher in rabbit does over 2 yr of age, followed by females of less than 1 yr of age and 1-2 yr old.…”