The Effect of Propylene Glycol and Chromium on The Productive Capacity of Dairy Cattle

Abstract

DAIRY CATTLE management assures the integration between nutrition, biochemistry, and microbiology. Close up and post parturient stages are stressful conditions manifested by several physiological changes including feed intake, body reserves mobilization, and nutritional requirements. Chromium (Cr.) and Propylene glycol (PG) have been reported to affect energy metabolism and negative energy balance in periparturient dairy cows, respectively. Fifteen Friesian heifers were selected in the last 3 weeks of pregnancy (500 ± 5 Kg), allotted to three groups (n=5). The first group was assigned to the basal diet, the second group was fed on the basal supplemented with100 ml propylene glycol, and the third group was fed on the basal diet fortified with 10 g chromium. The highest increase milked produced was related to the addition of propylene glycol (P<0.05). The propylene glycol showed high efficacy in decreasing the problem of negative energy balance (NEB) in comparison with control group (P<0.05). After 7 weeks of the feeding trial, differential leukocyte counts showed a significant improvement referring to dietary propylene glycol and chromium supplementation. Serum glucose concentration showed the highest level within the 2nd and 8th week due to addition of propylene glycol and within the 6th week due to supplementation of Chromium. In the 8th week, serum insulin achieved a significant progression due to incorporation of Propylene glycol. During the 8th week, serum triglycerides exhibited the lowest value in the control group and the highest serum HDL value showed due to incorporation of Propylene glycol. Serum non esterified fatty acids (NEFA) displayed a significant alteration after the 7th week of the trial and chromium was more effective than propylene glycol (P<0.05). To sum up, the addition of organic chromium and propylene glycol during transition period enhanced milk yield and its components, biochemical and hematological indices and NEFA profile.