Effect of body condition score and nutritional flushing on the reproductive performances of Spanish and Spanish x boer crossbred does

Abstract

The objective of this experiment was to evaluate the effect of body condition score (BCS) and short-term supplementation with high levels of energy and protein sources on the reproductive performance of 180 does consisting of 90 Spanish and 90 Spanish x Boer (60 ½ Boer = F1-cross; and 30 ¾ Boer = F2-cross) genotypes. Each of the 3 genotypes was equally distributed to treatments of 2 body condition groups (BCG, low and high) and 3 flushing treatments consisting of no supplementation (control), supplementation with protein mixture (PM) alone and PM + ground corn (PE) in a 2 x 3 x 3 factorial arrangement of treatments. The flushing period lasted 11 days, after which does were exposed to sexually active Boer bucks for 42 days. The results indicated that although not significant, flushing with PM and PE diets numerically increased the body weight and body condition score of all genotypes in high BCG. In low BCG, flushing with PM and PE diets significantly (p<0.05) increased the body weight of F1-cross and Spanish does, respectively. Moreover, in low BCG, flushing with PE diet significantly (p<0.05) increased the BCS values by 26.7%, 18.1% and 29% in Spanish, F1- and F2-crosses, respectively. Similarly, flushing with PM diet significantly (p<0.05) increased the BCS values in Spanish and F1 genotypes by 19.6% and 10.7%, respectively. In the high BCG, the Spanish and F1-cross does flushed with PE diet had significantly (p<0.05) higher pregnancy and multiple birth rates than F2 genotype. In the low BCG, the pregnancy and kidding rates of Spanish does flushed with PM diet was significantly (p<0.05) higher than those of F2-cross. The F2-cross supplemented with PM and PE diets had significantly (p<0.05) higher multiple birth rates than both Spanish and F1-cross. Litter size was significantly (p<0.05) higher for F1 and F2-crosses supplemented with PE diet. The progesterone concentration was significantly (p<0.01) lower in all genotypes before breeding than observed after mating. In conclusion, flushing with protein and energy sources for short period of time was found to be beneficial for improving the body weight and body condition score and subsequently, the reproductive efficiency of does under poor body condition.

Key words: Body condition score; Body weight; Nutritional flushing; Reproductive traits; Spanish x Boer crosses.