Assessment Of Some Factors Affecting The Reproductive And Productive Performance Of Tagger Goats Under Dryland Farming

Two experiments were conducted in Taggar goats to evaluate the effect of two supplements varying in protein and energy, litter size and season of birth and their interactions on some reproductive and productive traits. Forty seven (47) mature Taggar goats were used in experiment one, while in the second experiment the female kids were monitored continuously through a complete reproductive cycle, whereas male kids were monitored up to weaning age. The results indicated that supplemented does secured higher conception rates, kidding rates, litter size and lower mortalities. The season of birth significantly (P<0.05) affected litter size in favour of the rainy season, and conception rates in favour of the cool dry season. Both supplementation and rainy season kidding favoured kids birth weight. Supplementation favoured high litter size and rainy season kidding, favoured short kidding intervals and service periods. The season of kidding did not affect milk yield. Litter size exerted a significant (P<0.05) effect on milk yield favouring dams with triplet kids. The supplemented groups produced higher milk with significance (P<0.05) in fat and lactose. The results of the second experiment showed that kids born to supplemented groups were heavier at birth (2.16±0.09 and 2.11±0.07 versus 1.84±0.07 kg). There was no significant effect of season of birth. In contrast to litter size effect which exerted a significant (P<0.05) effect on birth weights favouring small litter size. The birth weight of single born, twin and triplets were 2.10±0.06 and 2.02±0.05 and 1.79±0.16 kg respectively. The kids born to supplemented dams maintained their superiority throughout the different growth periods. The season of birth did affect neither birth weight nor subsequent growth rates, thereafter. The sex of the kid however significantly influenced (P<0.05) both birth weight and weaning weight favouring male compared with female kids. Litter size demonstrated a similar pattern to sex since single born kids were heavier at birth and weaning than twins and which were superior to triplets. The body weight gain up to weaning was significantly 13 (P<0.05) higher in males (6.17±0.27 kg) versus (5.20±0.25 kg) for female kids. Conception rates were not affected by either supplementation or season of birth although the cool dry season kidders secured a higher conception rate than the rainy season. The kidding rate was higher among the supplemented groups compared with the control and was higher in the rainy season 92 versus 90% in the cool dry season. The results highlighted that body weight at puberty; conception and first kidding were higher in the supplemented groups whereas the season of kidding did not affect these traits. The litter size on other hand affected only pubertal weight and favouring single born kids. The body weight at conception and kidding were not affected by litter size. Supplemented dam attained age at puberty earlier than the unsupplemented groups (5.6, 6.3 and 7.4 months) for the two supplemented groups (A&B) and the control respectively. Like wise the supplemented groups secured first conception and first kidding at a earlier age than the control, (6.4, 7.4 and 8.5 month and 10.5, 12.4 and 13.8 months) as conception and first kidding ages respectively. The litter size on the other hand exerted a non-significant effect. Supplemented groups experienced less mortality rates than the control. The respective values were 20, 12.5 and 11.1%. Season of kidding did not influence preweaning mortality rates, but exerted a significant (P<0.05) role in post weaning mortality rates. The respective estimates were 16.7 versus zero percent for the cool dry season and rainy season respectively. The sex of kid also exerted a significant (p