جستجوی مقالات مرتبط با کلیدواژه « مدت زمان هوادهی » در نشریات گروه « علوم دام »

Milk samples are monthly collected from each registered cow by Dairy Herd Improvement (DHI) center to analyze milk components. Adequate air bubbling through the milk in an on-farm weigh jar requires ensuring homogeneity before taking representative samples. This experiment was conducted to determine the effect of air bubbling time on milk fat percentage. The milk samples (n=960) were taken from 120 lactating Holstein cows at second meal of milking during 2 sequential days. After each cow milking، the sampler valve was opened to allow air to enter and mix the milk. Four samples serially were taken from the same weigh jar at 0، 10، 20 and 30 seconds air bubbling. Milk components were determined at DHI laboratory. The results showed، least square means of milk fat percentage was lower (p<0. 01) for control group (2. 58±0. 076) compare to the others. There were not significant differences between 10، 20، 30 seconds air bubbling (3. 5±0. 074، 3. 57±0. 074 and 3. 66±0. 074، respectively). There were no differences between air bubbling times when a weigh jar contains lower than 6 kg milk. In conclusion، 10 seconds air bubbling through the milk in a weigh jar could be enough before milk sampling.