Milk yield and reproductive performance of dairy heifers and cows supplemented with polyunsaturated fatty acids

Abstract

-The objective of this work was to determine productive and fertility responses of Holstein-Friesian heifers and cows to supplementation with extruded linseed and soybean as sources of polyunsaturated fatty acids (PUFAs). Supplementation had a positive effect on profitability, with significant increases in milk yield in supplemented cows, but not in heifers. Treatments had no effect on milk fat content, but higher milk protein contents were observed with supplementation. A higher conception rate was found for supplemented heifers, but not for cows. Fat sources containing PUFAs are recommended for dairy cattle supplementation, since they improve fertility in heifers and milk yield in cows.

Effects of Extruded Linseed and Soybean Dietary Supplementation on Lactation Performance, First-Service Conception Rate, and Mastitis Incidence in Holstein Dairy Cows

“…The lack of effects of ELS on first-service conception rates in the present study may be attributable to the observed improvements in milk production in ELS-supplemented cows, which resulted in a negative energy balance. In addition, if, as in our study, a low number of cows were subjected to a first service, this may have contributed to the fact that there was no difference in the conception rate between the ELS-supplemented cows (44.4%) and those in the control (40.91%) [53].…”