Influence of dietary gossypol of commercial and transgenic cottonseed on β-carotene and vitamin E status of dairy cows

Crossbred multiparous cows (20), divided in 2 groups of 10 each were fed on concentrate mixtures containing either commercial (group 1) or transgenic. (group 2) cottonseed as protein supplement in which gossypol level was 1.23 and 1.52% (on hull free and DM basis). Concentrate mixtures were fed for 4 weeks along with berseem ad lib. and wheat straw (1 kg). Thereafter. both the groups were switched over to the concentrate mixture containing ground nut-cake as the only protein supplement and the quantity of concentrate mixture and fodder was maintained. Dietary inlake of gossypol was 1215 and 1468 ppm in groups 1 and 2. respectively. Total DM intake in groups 1 and 2 was 13.05 and 13.35 kg/day on feeding cotton seed based diets and yalues on feeding normal farm concentrate mixture in respective groups were similar There was no difference between the groups for DM intake on feeding cottonseed or ground nut-cake based diets. Berseem was the major source ofB-carotene during both the trials; however β-carotene content was reduced during the second trial due to the maturity of crop. β- carotene content of concentrate mixture 2 was higher than that in concentrate mixture 1 and the variation rilay be attributed tei the type of cottonseed. Total B-carotene intake in both the groups was similar and higher In first trial than that in second one. Vitamin E content of both the concentrate mixtures was similar and total vitamin E Intake was also similar in both the groups, however, intake 'of B-carotene and vitamin E intake in second trial was reduced (P<0.05) in comparison to the firt trial. Plasma β-carotene was higher (9.37 µg/ml) in group 2 than that in group 1 (3,76 µg/ml). Plasma vitamin E concentration was similar in both the groups and on shifting cows on couonsee-d free diet i.e. gossypol free diet. the plasma β-carotene,and vitamin E were similar. however, plasma B-carotene concentration was lower than that recorded on feedint cottonseed basted diet due to the less intake of B-carotene. It can. therefore, be concluded that dietary gossypol to the level of 1500 ppm of diet did not affect β-carotene and vitlmin E status of lactaing cows.