Abstract
An experiment of one-year duration was conducted on sixteen adult male German Angora rabbits under sub-temperate Himalayan conditions, to assess the effect of seasons on their body weight, wool production and quality, plane of nutrition and the digestibilities of nutrients. The daily meteorological attribute viz. minimum and maximum temperature; relative humidity and rainfall were recorded during winter (October to March), summer (April to June) and rainy (July to September) seasons. Biological parameters viz. body weight at the time of shearing, wool yield of individual rabbit, quality attributes of wool, fortnightly dry matter intake, chemical composition of feed and fodder and digestibilities of nutrients were recorded. Average minimum and maximum ambient temperature during winter, summer and rainy seasons were 4.6${\pm}$1.9 and 21.4${\pm}$2.8; 13.6${\pm}$2 and 30.3${\pm}$2; and 20.0${\pm}$1.4 and $31.0{\pm}1.8^{\circ}C$, respectively. The average relative humidity and total rainfall during winter, summer and rainy season were 69.5${\pm}$2.9% and 74.7${\pm}$21.8 mm; 58.6${\pm}$2.2% and 38.1${\pm}$18.1 mm; and 69${\pm}$4.2% and 104.0${\pm}$43.7 mm, respectively. The body weight of rabbits increased during all seasons, however, the maximum average daily weight gain of 3.47${\pm}$0.1 g was observed during the rainy season. The wool yield differed significantly (p$\leq$0.05) among different seasons with highest (140.4${\pm}$10 g) and lowest (108.5${\pm}$6.9 g) during winter and summer, respectively. The wool yield during the rainy season was 123.3${\pm}$5.2 g. The wool quality attributes revealed non-significant differences for staple length, fiber diameter, medulation percent, percent pure fibers and percent guard hairs. Plane of nutrition revealed significant (p$\leq$0.05) differences for concentrate intake. The concentrate intake was highest during winter (124.4${\pm}$2.6 g) followed by summer (86.8${\pm}$8.9 g) and rainy (80.7${\pm}$11.8 g) seasons. The reverse trend was observed in roughage intake with significantly (p${\leq}$0.05) lower intake during winter and highest during summer months. As a result total dry matter intake during different seasons was similar. Significant differences (p${\leq}$0.05) were observed for digestibilities of crude protein, crude fiber, ether extract, acid detergent fiber and cellulose. Digestibility of crude protein was highest during winter whereas the digestibilities of crude fiber, ether extract, acid detergent fiber and cellulose remained higher during the rainy season. During the winter season, the dry matter used for producing 100 g of wool was substantially lower than during other seasons and was concluded to be the best season for production of Angora wool under subtemperate Himalayan conditions.