Uso de citrato trissódico protegido na dieta de vacas leiteiras: produção e qualidade do leite

Abstract

This study aimed to evaluate the effect of including protected trisodium citrate (0, 25 g or 50 g) in the diet of cows in different phases of pre-peak lactation (1 to 60 days of lactation), phase I (61 to 100 days of lactation), phase II (101 to 200 days of lactation) and phase III (over 201 days of lactation). Twenty-seven Holstein cows were used, blocking the animals according to calving date, calving order, milk production, live weight and body condition score. The experiment lasted 98 days. Milk production, milk quality assessments, dry matter intake and milk efficiency were carried out in seven experimental periods, namely: 10 to 14 days, 24 to 28 days, 38 to 42 days, 52 to 56 days, 66 to 70 days, 80 to 84 days and 94 to 98 days. The diet consisted of 50% roughage (corn silage) and 50% concentrate (ground corn, soybean meal, mineral supplement, buffer and limestone). Citrate doses were offered individually at the time of morning feeding, in the form of top-dressing. The inclusion of 25 g of trisodium citrate had increased milk production in kg/cow/day, as well as higher milk production corrected for fat, energy and protein in cows up to 60 days of lactation (p<0.05 ) when compared to the inclusion of 50 g of trisodium citrate. For cows up to 200 days of lactation, trisodium citrate (50g) decreases (P<0.05) the concentrations of milk fat and protein, as well as the concentrations of total solids and defatted dry extract in cows until the end of lactation. On the other hand, it maintains high milk production and low concentration of somatic cells and the presence of subclinical mastitis by the CMT test. Thus, the use of protected trisodium citrate proved to be effective in reducing somatic cells in milk, as well as influencing composition and production, thus improving animal performance during lactation. However, the dose to be recommended must consider the lactation phase of the animal, given the results during the phases.