Effect of protected fat on productive and reproductive performance of Friesian lactating cows during postpartum period

Abstract EN

The objective of this study was to evaluate the effects of adding protected fat (PF) in the ration of lactating cows on feed intake, digestibility coefficients and rumen activity as well as reproductive performance during the period from calving to six months of lactation.

A total of 12 Friesian lactating cows between the 1st and 2nd parity and live body weight (LBW) of 532.7±23.5 kg were used.

Cows in the 1st group were fed concentrate feed mixture (CFM) as control (G1), while cows in the 2nd group were fed CFM supplemented with 5% protected fat (G2).

Average daily DM intake was nearly similar in G1 and G2.

Average daily TDN intakes were higher in G2 by about 4.7 % than G1.

Higher digestibility coefficient was observed in G2 than G1.

pH of rumen liquor were higher (P<0.001) in G2 than in G1 (6.06 vs.

5.83), while concentration of VFA,s was not significant by treatment (13.63 and 14.15 mEq/100 ml).

Concentration of NH3-N was higher (P<0.0) in G1 than G2.

Concentration of acetic acid in rumen liquor of cows of G2 was higher (P<0.001) in G2 than G1, while propunic acid showed a reverse trend (P<0.05).

No significant difference was observed between the two studied groups concerning concentration of butiric and isobutiric acids.

Changes of LBW was higher (P<0.05) in G2 than G1 (7.73 vs.

14.5 kg, respectively).

Daily milk yield and fat corrected milk increased (P<0.05) by about 10.34 and 21.99% in G2 than G1.

Percentage of fat and protein in milk cows were higher (P<0.05) in G2 than G1 and somatic cell count decreased (P<0.05) by about 19.52% in G2 than G1.

Number of ovulatory cycles / cow during the experimental period decreased (P<0.05) in G2 than G1 Postpartum first estrous interval was not affected by treatment, while postpartum first service interval and service period length were shorter (P<0.001) in G2 than in G1.

Cows in G2 showed shorter days open period (108.8 d) than G1 (150.5d).

In conclusion feeding Friesian cows during the 1st and 2nd parities on CFM supplemented with 5% protected fat improved milk yield and post partum reproductive traits.