Performance of Lactating Crossbred Cows under Different Housing Systems During Summer in Konkan Agro-ecological Conditions”
An investigation was carried out on nine lactating crossbred cows (J×L) cows which were allotted randomly into three comparable shelters in switch over design. Three different type of shelters were, 1- Asbestos roofing; 2- Paddy straw thatched roof house; 3 - White painted asbestos roof. Temperature humidity index was higher in macro -environment followed by thatched roof shed, white painted asbestos roof and asbestos roofing. Thatched roof shed had significant (P<0.05) incremental effect on the milk production and milk composition of cows than the cows in white painted roof shed and asbestos roof shed during summer. Overall paddy straw thatched roof shed effectively ameliorates environmental temperature, humidity and THI during summer season in the Konkan region.
Modifications in Freestall Housing for Dairy Cows During the Summer
Abstract Modifications in freestall housing were tested over three summers in three-treatment switchback trials with 10 lactating dairy cows per treatment group. Modifications were 1) overhead insulation, 2) overhead insulation plus roof sprinkling, 3) roof sprinkling, 4) inspired-air-cooling, and 5) no cross ventilation. Freestall areas were cross ventilated except 5). Compared with unmodified control, roof sprinkling plus insulation and inspired-air-cooling reduced body temperature and respiration rate while roof sprinkling lowered body temperature. No cross ventilation elevated body temperature and respiration rate. Roof sprinkling resulted in higher milk production. The inconsistent response of milk production to modification apparently was related to nutritional management. In blood samples drawn at 1500 h, urea nitrogen was higher in the controls during the second summer. In plasma of samples taken at 0800 h during the third summer, cows under roof sprinkling had higher concentrations of calcium, cholesterol, and protein than controls. No cross ventilation lowered protein in plasma. As indicated by reductions in body temperature and respiration rate, roof sprinkling, roof sprinkling plus insulation, and inspired-air-cooling improved the comfort of lactating cows during the summer and provided potential for higher milk production while no cross ventilation reduced animal comfort.
Studies on milk secretion. The influence of inanition.
In this paper data are presented on cows receiving no food but having access to all of the water which they wished. The yield and composition of the milk were determined at various times during the periods of starvation. The composition of the milk showed changes which were progressive in the sense that they followed a definite course. They were characterized by a marked lowering in the amount of milk produced, by an increase in the total solids (chiefly an increase in the percentage of fat and ash, with a slight increase in proteins), and by a pronounced decrease in the lactose. The decrease in lactose corresponded with a decrease in the dextrose content of the blood, thereby supporting the conclusion that the lactose of milk has as its precursor dextrose of the blood. All the changes in milk composition during starvation can be directly related to the simultaneous changes in the blood. The following companion paper on insulin and phloridzin as they affect milk secretion further develops these hypotheses.