Evaluation of hematological and biochemical parameters of bulls fed diets with different levels of free gossypol

The use of whole cottonseed feed to ruminants has attracted great interest particularly since it is an important supplemental energy and protein source for pastures. In Brazil, several studies have already evaluated the negative effects of gossypol contained in cottonseed on animal reproduction. However, the evaluation of its effects on hematological and biochemical parameters are incipient. Consequently, to evaluate the effects of the ingestion of free gossypol on the hematological and biochemical profiles of bulls animals, samples from 30 Nellore bulls, averaging 30 +/- 6 months of age and live weight of 383 kg were collected at the beginning (day 0) and end of the experiment (day 95 day). All bulls were randomly distributed into six treatments, each having five replicates: T0, 0 gram (g) of free gossypol/bull/day (cottonseed free); T1, 1 g of free gossypol/bull/day; T2, 2 g of free gossypol/bull/day; T3, 3 g of free gossypol/bull/day; T4, 4 g of free gossypol/bull/day and T5, 5 grams of free gossypol/bull/day. The results demonstrated that the hematological and biochemical values were within the physiological limits for cattle. However, some treatments revealed significant statistical differences (P<0.05) for the packed cell volume, red blood cells, gamma-glutamyl transferase (GGT), and urea during the experiment. Clinical manifestations suggestive of intoxication by gossypol were not observed.