GENETIC AND SOME PHYSIOLOGICAL EVALUATIONS OF DOE AND BODY CONDITION TRAITS FOR THE APRI RABBITS

This study was conducted on 330 records from 110 does of APRI rabbits to make a genetic evaluation for some doe traits included litter traits (litter size at birth; LSB, and at weaning; LSW, Litter weight at birth; LWB, and at weaning; LWW), milk yield traits during (the 1 st week; MY7, the 2nd week; MY14, the 3 rd week; MY21, the 4 th week; MY28 of lactation, and total milk yield; TMY), and body condition score traits (body condition score at mating; BCSM, and after kindling; BCSK). This was besides the physiological evaluation for does body condition through some blood parameters which were taken at mating and after kindling as indicators for does body condition and health. Heritability estimates for litter traits were relatively low ranged from 0.08 to 0.14. Estimates of h 2 for milk yield traits were low ranged from 0.03 to 0.12. Values of h 2 for BCSM, and BCSK were low 0.03 and 0.01 respectively. Repeatability estimates for litter traits were low to moderate ranged from (0.09 to 0.15). Repeatability estimates for milk yield traits were low ranged from (0.03 to 0.12). Genetic correlations between LSB and LSW, LSB and LWB, LWB and LWW were positive and (0.89, 0.31, and 0.37) respectively. Positive genetic correlations among milk yield at the 2 nd , 3 rd , 4 th week of lactation and total milk yield were detected. A negative strong genetic correlation (0.78) was detected between milk yield during the 1 st and 3 rd weeks of lactation. The genetic trend for litter traits had fluctuations with year-season levels. A high value of genetic trend for LSW was detected which increases with the Spring season. Milk yield at the 1 st , 2 nd , 3 rd , 4 th weeks of lactation and total milk yield increased 74.66, 98.99, 110.24, 90.54, and 370.84 (g), respectively by the increasing of litter size at lactation week with one bunny. Total protein, albumin, and globulin levels were significantly (P≤0.001) decreased after kindling. But, the albumin/globulin ratio was significantly (P≤0.001) increased after kindling. Glucose and urea levels were insignificantly decreased by increasing the parity; the estradiol hormone was insignificantly increased by increasing the parity. Conclusively,Low estimates of h 2 for doe litter, milk, and body condition score traits in APRI rabbits reflected that these rabbits were highly affected by non-additive genetic effects. Achieving high progress in such traits requires improving management and environmental conditions. The moderate estimate of repeatability for LSW (0.15) indicated that this trait could be improved through selection depending on little records. Milk yield traits at the 2 nd week could be effective to improve total milk yield in these rabbits and accordingly improving litter weight at weaning. The high value of genetic trend for LSW which increases with the Spring season in the two years of study reflects the improvement of the performance of APRI rabbits does. Litter size at the week of lactation had a significant (P <0.01) effect on all milk yield traits under study. Total protein, globulin, and albumin levels are good indicators for does body condition and health.