TY - JOUR
T1 - Rumen acid production from dairy feeds 2
T2 - Effects of diets based on corn silage on feed intake and milk yield
AU - Wadhwa, D.
AU - Borgida, L. P.
AU - Dhanoa, M. S.
AU - Dewhurst, Richard J.
N1 - Wadhwa, D., Borgida, L. P., Dhanoa, M. S., Dewhurst, R. J. (2001). Rumen acid production from dairy feeds. 2. Effects of diets based on corn silage on feed intake and milk yield. Journal of Dairy Science, 84, 2730-2737.
PY - 2001/12
Y1 - 2001/12
N2 - A new approach to evaluating feeds has been developed
based on in vitro estimates of rumen acid load
(acidogenicity value). The present work was conducted
to establish effects of rumen acid load on dry matter
intake and milk production of early-lactation dairy cows
fed corn silage-based diets. The effects of diet acidogenicity
were investigated independently of ingredient composition
using a series of isoenergetic and isonitrogenous
concentrates that used different raw materials to
achieve the same acidogenicity value. Six concentrates
were formulated to be fed at 7 kg/d, and two at 10
kg/d. Continuous culture equipment, which had been
modified to control and record infusions of acid and
alkali to maintain pH in the range 6.2 to 6.3, confirmed
the ranking of concentrates based on the in vitro technique.
The concentrates were offered to dairy cows in
early lactation with corn silage available ad libitum.
Forage intake declined with increasing concentrate acidogenicity,
particularly at the higher level of concentrate
feeding. However, concentrate acidogenicity had
a significant negative effect on dry matter intake even
at 7 kg/d. Feed intakes were similar for concentrates
that were formulated to be isoacidogenic, but using different
raw materials. There were only small and inconsistent
effects of concentrate acidogenicity value on
milk yield and milk fat percentage, while milk protein
percentage was higher with the high AV concentrates.
Effects on milk composition likely reflect differences in nutrient supply and there was no evidence for effects of rumen acid load per se on milk composition.
AB - A new approach to evaluating feeds has been developed
based on in vitro estimates of rumen acid load
(acidogenicity value). The present work was conducted
to establish effects of rumen acid load on dry matter
intake and milk production of early-lactation dairy cows
fed corn silage-based diets. The effects of diet acidogenicity
were investigated independently of ingredient composition
using a series of isoenergetic and isonitrogenous
concentrates that used different raw materials to
achieve the same acidogenicity value. Six concentrates
were formulated to be fed at 7 kg/d, and two at 10
kg/d. Continuous culture equipment, which had been
modified to control and record infusions of acid and
alkali to maintain pH in the range 6.2 to 6.3, confirmed
the ranking of concentrates based on the in vitro technique.
The concentrates were offered to dairy cows in
early lactation with corn silage available ad libitum.
Forage intake declined with increasing concentrate acidogenicity,
particularly at the higher level of concentrate
feeding. However, concentrate acidogenicity had
a significant negative effect on dry matter intake even
at 7 kg/d. Feed intakes were similar for concentrates
that were formulated to be isoacidogenic, but using different
raw materials. There were only small and inconsistent
effects of concentrate acidogenicity value on
milk yield and milk fat percentage, while milk protein
percentage was higher with the high AV concentrates.
Effects on milk composition likely reflect differences in nutrient supply and there was no evidence for effects of rumen acid load per se on milk composition.
KW - Concentrates
KW - Corn silage
KW - Milk production
KW - Rumen pH
UR - http://www.scopus.com/inward/record.url?scp=0035748602&partnerID=8YFLogxK
U2 - 10.3168/jds.S0022-0302(01)74727-3
DO - 10.3168/jds.S0022-0302(01)74727-3
M3 - Article
SN - 0022-0302
VL - 84
SP - 2730
EP - 2737
JO - Journal of Dairy Science
JF - Journal of Dairy Science
IS - 12
ER -