Milk Composition and Productivity of Holstein Cows in Ryegrass Grazing and Crude Glycerin in The Diet

Abstract

Objective: The aim of this project was to evaluate the effect of crude glycerin addition in the diet, milk composition and milk yield in dairy milking cows on different stages of lactation.   Theoretical  framework: It is necessary to balance the supply of protein and energy in the diet of  lactating cows. Within this context, a by-product of the Biodiesel industry, called crude glycerin, is low cost and has a high energy value for ruminants, since its main component is glycerol, which ruminants have the capacity to use as a precursor gluconeogenic (Chung et al., 2007).   Methods: The experiment was performed with Holstein cows (n=18), divided in two groups of treatment: 1) Basal diet without crude glycerin addition, 2) Diet with 10% of crude glycerin addition in the dry matter. Individual milk samples were collected for the analysis of the percentage of Fat, Protein, Lactose, Total Solids and Somatic Cell Count (Cs mL-1), as well as milk production (liters -1 and corrected for 4% fat).   Results and conclusion:  It was concluded that the addition of crude glycerin in the diet had no significant effect on the milk production and composition of cows of the Dutch breed.   Originality/value: The study results have crucial implications for cow nutrition strategies. Implication of the research: The study results have crucial implications for strategies in the Nutrition of the cows.