Effects of Organic Selenium and Probiotic Supplementation on the Performance of Indigenous and Crossbred Dairy Cows during Summer in the Tropics

The aim of the present study was to establish the influence of organic selenium and a yeast, Saccharomyces cerevisiae, in combination on animal performance, physiological status, milk production and blood metabolites in indigenous and crossbred dairy cows during hot-humid climatic conditions in tropics. A total of 18 indigenous dairy cows and 18 crossbred dairy cows were divided into two groups(control and treatment) containing 9 cows each based on parity and milk yield for a period of 45 days. The control group were fed on a basal diet comprising a concentrate mix, wheat straw, and multi-cut sorghum greens, while the treatment group were offered basal rations supplemented with organic selenium (4 g/d) along with Saccharomyces cerevisiae (1010 CFU/g; 4 g/d). There were no significant changes found in feed intake, body weight and animal physiology; however, better feed efficiency was recorded in both of the treatment groups, irrespective of breed variation. There was a non-significant increase in milk yield recorded in both treatment groups in comparison with the control. Similarly, no significant effects were observed on the haemato-biochemical profile in both animal types. Hence, it can be concluded that the supplementation of organic selenium and probiotics in combination to indigenous and crossbred dairy cattle moderately improved feed efficiency and overall performance without affecting metabolic status under heat stress conditions in the tropics.