Supplementary Practices Improving Holstein Cattle Performance During Hot Seasons

Abstract

Heat stress is a major problem facing dairy producers and negatively influences production, performance, and welfare. The study aims to improve milk production and quality during the hot season, which supports milk safety and dairy chain sustainability. Forty-two Holstein cows in the middle of the first lactation were used and divided into a control group (22 cows) that received control diet and a treatment group (20 cows) that received a control diet supplemented with 200 g of potassium carbonate through 30 days. Milk yield for all cows were recorded, while a total number of 84 milk samples were collected on the tenth day of the trial and at the last day of the trail. In addition, 16 blood samples were collected for both groups. Milk composition, somatic cell count (SCC), and bacterial profile were evaluated. The results indicated that the average milk yield was higher in the treatment group, which increased by 10.3%, while the fat % was decreased by 21-25% compared with the control group. The physiological parameters gave no significant differences between groups, except urea which recorded higher levels in the treatment group (34.6 vs. 30.6 mg/dl). SCC was significantly decreased by 52.5-56.3% compared with the control. Also, a significant enhancement of milk stability against overheating was recorded in the treatment group. The study proved that using potassium carbonate at the farm level during hot season could improve milk production and quality, subsequently, it might extend shelf life, safety, and stability of raw milk supplied through the dairy chain.