Effect of environmental factors on changes in quantity and content of cow milk in summer | Vides faktoru ietekme uz govju piena daudzuma un sastāva izmaiņām vasaras sezonā
2004
Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Dept. of Animal Science | Paura, L., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Information Technologies. Dept. of Control Systems | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Dept. of Animal Science
Research was carried out from mid-July till mid-August with 69 Latvian brown cows in 2002. The aim of the project was to study the influence of environmental factors effects on the changes in quantity and content of milk productivity traits. The effects of factors were calculated by SPSS software. Results show that repeated use of pastures influenced the milk yield and protein content in milk (p 0.05), but didn't influence fat and lactose content in milk. The cows feed supplemented by haylage, hay and mix of concentrate affected milk yield, fat and protein content in milk (p 0.05). During our research the highest average milk yield 17.82 kg per cows was achieved feeding cows with haylage and mix of barley meal and rapeseed cake. The average fat content was increased when feeding cows with hay and barley protein content to fodder with haylage and mix of barley and pea meal. The milk yield and protein content significantly decreased with changes of temperature and humidity index from suitable climatic conditions to heat stress risk zone (p 0.05). On the second investigation day we were able to establish the changes of average milk yield, fat and protein content 10.4%, 12.4%, 5.9%, respectively. The changes of lactose content weren't significant.
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