Comportamento, produção e qualidade do leite de vacas Holandês-Gir com climatização no curral

This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal-1day-1. A 4 × 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal-1. A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk

Efficiency of use of supplementary lighting in rearing of dairy calves during milk feeding stage

ABSTRACTThe objective of this study was to evaluate programs of supplementary lighting for calves in individual shelters with different roof materials, as a strategy to stimulate concentrate consumption and the reduction of the milk feeding period and increase financial viability. Twenty seven dairy crossed Holstein × Gir female calves were randomly distributed in individual shelters with three different roofing materials (cement fiber tile, recycled tile and thatched roofs), associated with three different light duration (12, 16 and 20 h) and with three repetitions. The experimental design was completely randomized in 3 × 3 factorial arrangement. There was no interaction between the types of roofs × supplemental light; also, there was no significant effect of the covering types on the average consumption of concentrate and occurance of diarrhea in calves. On the other hand 20 h of lighting stimulated the consumption of concentrate and allowed weaning of calves at 55 days of age and 20% reduction in the cost of rearing animals during milk feeding stage