YIELD RESPONSE OF LACTATING HOLSTEIN DAIRY-COWS TO DIETARY FISH-MEAL OR MEAT AND BONE MEAL

Citation
Jm. Akayezu et al., YIELD RESPONSE OF LACTATING HOLSTEIN DAIRY-COWS TO DIETARY FISH-MEAL OR MEAT AND BONE MEAL, Journal of dairy science, 80(11), 1997, pp. 2950-2963
Citations number
39
Journal title
ISSN journal
00220302
Volume
80
Issue
11
Year of publication
1997
Pages
2950 - 2963
Database
ISI
SICI code
0022-0302(1997)80:11<2950:YROLHD>2.0.ZU;2-9
Abstract
Experiments were conducted to examine the effects of the source and am ount of dietary protein on yield and composition of milk from Holstein dairy cows. Study 1 used 36 multiparous cows at 125 +/- 59 d in milk in a replicated 2 x 2 Latin square design. Treatments were diets formu lated to contain 16% crude protein (CP) in which 11% was fish meal or meat and bone meal supplied 11% of dietary CP. Intakes of dry matter, CP, and net energy for lactation; yields of milk; and percentage of mi lk fat were not affected by treatment. Fish meal increased contents of milk total N, casein N, and noncasein N but did not increase contents of NPN; fish meal also tended to increase milk CP yields. Study 2 use d 78 cows (31 primiparous) at 31 +/- 2 d in milk in a randomized block design. Two treatment diets were formulated to contain 16 or 18.5% CP , and soybean meal was the sole source of supplemental protein in thos e diets. The two other treatment diets were formulated to contain 16% CP; in these diets, fish meal or meat and bone meal partially replaced soybean meal. Treatments did not influence yield or composition of mi lk from multiparous cows. Compared with a soybean meal diet containing 16% CP, a soybean meal diet containing 18.5% CP or diets containing 1 6% CP and containing meat and bone meal or fish meal increased the mil k yield of primiparous cows similarly. Fish meal or meat and bone meal increased the efficiency of protein utilization for milk yield.