EFFECT OF MODIFYNG ROUGHAGE /CONCENTRATE RATIO ON SEMEN QUALITY AND FERTILITY AS AFFECTED BY EXHAUSTIVE EJACULATION IN ZARAIBI BILLY GOATS

ABSTRACT
The objective of this study was to determine the effect of a specific proportion of concentrate feed mixture (CFM) to berseem hay (BH) on semen quality, sperm abnormalities and fertility of Zaraibi billy goats during exhaustion test. Six adult billy goats were equally divided into control group (G-A) and treated group (G-B). Semen quality and sperm abnormalities were evaluated with exhaustion test of epididymis (ETE). Semen collected three times daily at one hour interval among ejaculates for three successive weeks. The feeding system for G-A was 700 gm CFM supplemented with 500 gm BH daily / buck, while 500 gm CFM plus 750 gm BH were afforded to G-B daily / head. The fertility test was carried out with 48 healthy and sexual mature Zaraibi nanny goats without any significant difference among them in body weight, age and oestrous period. Nanny goats were divided into two equal groups (n=24) which mated with billy bucks in G-A and G-B. The obtained results show lower semen quality in G-A compared to G-B (P<0.05). Semen-ejaculate volume and sperm concentration in the first ejaculates were significantly (P<0.05) higher than second and third ejaculates. On the contrary, the advanced sperm motility was higher (P<0.05) in second and third ejaculates than the first. Concerning ETE designing, G-A was recorded significantly (P<0.05) higher sperm morphological abnormalities than G-B. The fertility rate was defined significant (P<0.05) higher percentage of nanny goat kided in G-B than G-A. These results suggest that replacing 30% of concentrate with hay could maintain semen quality and fertility of Zaraibi goat bucks after intensity of semen collection by ETE.