Induction of lactation in heifers: Production, chemical, and cellular composition of milk

Abstract

The lactation induction protocol is a new possibility to reduce the non productive time of cows that are not pregnant and not being milked due to different factors. Therefore, this study aims to evaluate the effectiveness of a lactation induction protocol on the production of milk and its chemical and cellular composition. For this purpose, we compared primiparous Holstein heifers with lactation-induced heifers. Fourteen females with an average age of 25 months were divided into two groups. The first was the induced group (n = 7), composed of nonpregnant heifers in puberty, and the second was the control group (n = 7), composed of pregnant primiparous heifers. The induced group received estradiol benzoate, progesterone, cloprostenol sodium, dexamethasone, and recombinant bovine somatotropin. Milk production and chemical and cellular composition were evaluated for 210 days of lactation. In the induced group, all females responded to the lactation induction protocol with a production of 17.9 ± 5.8 liters/cow/day, equivalent to 67.54% of the production of the control group. The induced group had a higher percentage of solids, fat, protein, and somatic cells than the control group (P<0.05). Both the induced and the control groups showed negative correlations between milk and fat percentage and between lactose and somatic cells. The lactation induction protocol used in our study was effective at inducing lactation in heifers being economically viable.