Changes of daily milk content in different lactation phases
2002
Paura, L. | Kairisa, D. | Jonkus, D. (Latvia Univ. of Agriculture, Jelgava (Latvia))
The milk content of 77 cows was tested for milk yield, fat, protein, lactose content and somatic cell count (SCC) every day during one month from the 12th of July till the 11th of August, 2001. The final data included 2203 test day samples. Repeatability of milk yield, protein and somatic cell count was high, ranging from 0.71 to 0.84, and for fat and lactose the percent was moderate - 0.49 and 0.30, respectively. Repeatability of productivity traits was found higher in the second lactation phase than in the first lactation phase excluding trait lactose content. Moderate phenotypic correlation existed between the protein and fat contents. Negative phenotypic correlation was found between milk yield and fat content, between milk yield and protein content and between lactose content and somatic cell count.
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