Effect of tomato dregs supplementation on the quality of bovine milk production in the Holstein breed

This work focused on the one hand on the characterization of tomato by-products (Solanum lycopersicum L. 1753) and on the other; on the supplementation of tomato spent grain in the diet of Holstein breed cows and its effect on the volume and quality of milk. A comparative study between two lots; one contains dairy cows fed through a diet without tomato spent grain, the second batch fed with tomato spent grain. The physicochemical analyzes of tomato spent grain focused on the water content, dry matter, mineral matter, total proteins, fat, defatted matter, Phosphorus, Calcium and vitamins A and Vitamin E. We note that tomato spent grain is very rich in vitamin A and E as well as in calcium and phosphorus and that it also has a low fat and protein content. According to the results obtained, we notice an improvement in the following physicochemical parameters of milk: a significant increase (p < 0.001) in density which goes from 1026 ± 1.97 to 1028 ± 2.14, a significant increase (p < 0.01) in fat which goes from 40.74 ± 7.07 to 43.94 ± 8.45, and a significant increase (p < 0.001) of the dry extract which goes from 124.56 ± 11.31 to 148.7 ± 29.88. A significant increase (p < 0.001) in the average daily volume of milk is observed in the batch supplemented with tomato spent grain (13.73 ± 3.47 l/d) compared to the batch not supplemented with tomato grain (11.12 ± 3.00 l/d). The statistical study reveals that there is a relationship between the duration of supplementation and the continuous improvement of parameters: density (p < 0.001); dry extract (p < 0.001); degreased material (p < 0.001).