Factors related to milk fat to protein ratio | Dejavniki povezani z razmerjem med mascobami in beljakovinami v mleku
2009
Babnik, D., Agricultural Inst. of Slovenia, Ljubljana (Slovenia) | Jenko, J. | Verbic, J.
On the basis of data from 6.247.383 milk samples with known fat and protein content collected from milk recording scheme from 1.1.2000 to 31.12.2008, factors related to milk fat content to protein content ratio (FPR) were examined. Similarity in average FPR between different breeds (Brown (BB): 1.23; Simmental (SB): 1.25; Holstein (HB): 1.25), and small variations between years (from 1.22 to 1.27) and months (from 1.20 to 1.28) were detected. On the other hand, large variations between herds (coefficient of variation (CV)= 7.5 to 8.4%) and between individual milk samples within breeds and years or months (CV= 15.5 to 19.5%) were found out. Some variations between herds were associated with the type and amount of forage and concentrate in the daily ration. According to the literature the recommended values for optimal FPR within 1.1 to 1.5 were assumed. Percentages of all milk samples collected from 10th to 65th day of lactation with FPR over 1.5 were 23%, 17%, and 20%, and those of milk samples with FPR below 1.1 were 17%, 20%, and 18% for HB, BB, and SB, respectively. During lactation, high percentage of milk samples with low FPR (1.1) could indicate a suspect on the frequent presence of subclinical rumen acidosis in herds. The results from this study, such as great variation in FPR and/or likely low milk protein content, indicate that a great deal of high producing cows are managed inappropriately, especially HB cows in the early phase of lactation.
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