The effects on ruminal pH and serum haptoglobin after feeding a grain-based supplement to grazing dairy cows as a partial mixed ration or during milking.
Ruminal pH and serum concentrations of haptoglobin (Hp) were measured in order to assess the risk of subacute ruminal acidosis (SARA) in grazing cows offered rolled wheat grain twice daily in the dairy at milking (Control group; n= 64), or as a partial mixed ration (PMR group; n= 64) on a feedpad. Cows were allocated various levels of the supplement (8, 10, 12 or 14 kg dry matter/day). Ruminal pH was measured in 16 rumen-fistulated cows (eight PMR and eight Control group cows), using indwelling pH meters, recording every 10 min for 14 days. Serum Hp was analysed in samples collected from 125 cows. No differences in ruminal pH or serum Hp concentration were found between treatment groups, or levels of feeding. It was concluded that, using ruminal pH patterns and Hp as markers of SARA at the feeding levels used in this study, there were no differences between grazing cows fed the supplement either as grain in the dairy or as a PMR fed on a feedpad.
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia. Electronic address: coombejoanne@gmail.com.
J E
JE
Coombe
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia.
M F
MF
Pyman
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia.
P D
PD
Mansell
Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Vic. 3821, Australia.
M J
MJ
Auldist
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia.
G A
GA
Anderson
Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Vic. 3821, Australia.
W J
WJ
Wales
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia; Animal Welfare Science Centre, University of Melbourne, Parkville, Vic. 3010, Australia.
M J
MJ
Conley
Information Technology Services, University of Melbourne, Parkville, Vic. 3010, Australia.
S
S
Manos
Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Vic. 3821, Australia.
M
M
Hannah
Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia; Animal Welfare Science Centre, University of Melbourne, Parkville, Vic. 3010, Australia.
A D
AD
Fisher
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D015415:Biomarkers; D002417:Cattle / Q000097:blood / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D002523:Edible Grain; D005260:Female; D006242:Haptoglobins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007774:Lactation; D012417:Rumen / Q000737:chemistry / Q000502:physiology*
D015415:Biomarkers; D006242:Haptoglobins
Haptoglobin; Partial mixed ration; Ruminal pH; Subacute ruminal acidosis