Influence of iodine on reproductive performance of bucks fed subabul (Leucaena /eucocephala) leaf-meal

Abstract

The effect of supplementation of iodine on male reproduction of goats, when their diet contained subabul (Leucaena leucocephala) leaf-meal. was assessed using 6 adult bucks (2.5-3 years; 24.4±0.94 kg). The bucks were randomly divided into 2 groups of 3 animals each. viz., control (I₀) and iodine supplemented (I₁₀₀). The animals were fed on a concentrae supplement along with leucaena leaf-meal (LLM). The latter to meet 50% of their CP requirements. Wheat straw was given ad lib. In addition, animals under group I₁₀₀ received 100 ug of supplemental iodine/head /day. Semen was collected and analyed at monthly intervals during the 3 months of experimental feeding. Plasma samples were analyed for testosterone at the begining and end of the experiment. The results revealed that animals under I₁₀₀ group maintained their libido throughout the experimental period in contrast to a progressive declie observed in the I₀ group. The concentration of spermatozoa (3.25±0.39 vs 2.74±0.24 billion ml^-1) and percent live spermatozoa (76.67±1.82 vs 66.17±2.00) were significantly (P<0.01) higher in iodine supplemented (I₁₀₀) than the non-supplemented bucks (I₀). Other semen characteristics, viz. semen volume, pH, number of spermatozoa per ejaculate and mass activity although similar (P>0.05), tended to be higher in I₁₀₀ group. The initial fructose content, similarly, tended to be higher in I₁₀₀ than I₀ animals. Mean plasma testosterone level was significantly (P<0.04) higher in 1₁₀₀ than I₀ (1.78±0.21 vs 1.14±0.46ng ml^-1), The study indicated that supplementation of iodine to leucaena based diet can improve the male reproductive performance of goats.