TITLE:
Effects of a rumen protected B vitamin blend upon milk production and component yield in lactating dairy cows
AUTHORS:
Essi Evans, David T. Mair
KEYWORDS:
B Vitamin Blend; Biotin; Folic Acid; Pyridoxine; Pantothenic Acid
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.3 No.1,
January
29,
2013
ABSTRACT:
Results from 12 switchback field trials involving 1216 cows were
combined to assess the effects of a protected B vitamin blend (BVB) upon milk
yield (kg), fat percentage (%), protein %, fat yield (kg) and protein yield
(kg) in primiparous and multiparous cows.
Trials consisted of 3 test periods executed
in the order control-test-control. No diet changes other than the inclusion of 3 grams/cow/ day of the BVB
during the test period occurred. Means from the two control periods were compared
to results obtained during the test period using
a paired T test. Cows include in the analysis were between 45 and 300
days in milk (DIM) at the start of the
experiment and were continuously available for all periods. The
provision of the BVB resulted in increased (P yield. Regression
models showed that the amount of milk
produced had no effect upon the magnitude of the increase in milk
components. The increase in milk was greatest in early lactation and declined
with DIM. Protein and fat % increased with DIM in mature cows, but not in first
lactation cows. Differences in fat yields between test and control feeding periods did not change with DIM, but the improvement in protein yield in mature cows
declined with DIM. These results
indicate that the BVB provided economically important advantages
throughout lactation, but expected results would vary with cow age and stage of
lactation.