EFFECTS OF NIACIN ON MILK-YIELD, MILK-COMPOSITION, AND BLOOD COMPONENTS OF DAIRY-COWS IN HOT WEATHER

Citation
Ng. Belibasakis et D. Tsirgogianni, EFFECTS OF NIACIN ON MILK-YIELD, MILK-COMPOSITION, AND BLOOD COMPONENTS OF DAIRY-COWS IN HOT WEATHER, Animal feed science and technology, 64(1), 1996, pp. 53-59
Citations number
26
Categorie Soggetti
Agriculture Dairy & AnumalScience
ISSN journal
03778401
Volume
64
Issue
1
Year of publication
1996
Pages
53 - 59
Database
ISI
SICI code
0377-8401(1996)64:1<53:EONOMM>2.0.ZU;2-Q
Abstract
Twenty multiparous Friesian cows, 90 +/- 30 days postpartum, were allo cated to two groups of ten cows according to calving date, lactation n umber and daily milk yield, and assigned randomly to one of two diets in a cross-over experiment. The experimental diet consisted of concent rate and maize silage in the proportions 1:1 (dry matter basis) contai ning either 0 or 10 g niacin per cow per day, which was handmixed into the concentrate. The diets were offered individually as total mixed r ations in two equal proportions at 09:00 and 20:00 h in amounts suffic ient to ensure 10% refusals. Dry matter, metabolisable energy and crud e protein intakes, as well as milk yield, milk protein proportion and yield, milk lactose, total solids and solids-not-fat proportions were not affected by niacin supplementation. In contrast, niacin supplement ation increased milk fat proportion and yield. No differences were obs erved in blood serum concentrations of glucose, total protein, triglyc erides, cholesterol, Na, K, Ca, P or Mg. However, the serum concentrat ion of urea was lower when the cows were supplemented with niacin.