TY - JOUR
T1 - Relationships between milk fat and rumination time recorded by commercial rumination sensing systems
AU - Andreen, D. M.
AU - Haan, M. M.
AU - Dechow, C. D.
AU - Harvatine, K. J.
N1 - Funding Information:
The authors thank the dairy farms that participated in this research; without them this study would not have been possible. We also thank Lancaster DHIA (Manheim, PA) and Dairy One DHIA (Ithaca, NY) for their assistance with data and milk sample acquisition. The authors acknowledge I. Salfer for assistance with statistical modeling. Research was supported in part by the Agriculture and Food Research Initiative Competitive Grant no. 2016-68008-25025 from the USDA National Institute of Food and Agriculture (PI KJH) and Penn State University, including USDA National Institute of Food and Agriculture Federal Appropriations under project number PEN04539 and accession number 1000803. The authors have not stated any conflicts of interest.
Publisher Copyright:
© 2020 American Dairy Science Association
PY - 2020/9
Y1 - 2020/9
N2 - Low rumination in the dairy cow is often assumed to result in reduction of saliva flow, rumen buffering, and milk fat, which is a major contributor to milk value in many pricing systems. Rumination time (RT) of individual cows can be measured with commercial rumination sensing systems, but our understanding of how daily RT (minutes per day) is related to milk fat production is limited. Our hypothesis was that between cows within a herd, greater RT would be associated with lower milk fat concentration. Data from 1,823 cows on 2 commercial dairy farms in Pennsylvania over 8 DHIA tests were analyzed for a total of 8,587 cow test-days. Rumination was measured on farm A with CowManager SensoOr ear tags (Agis Automatisering BV, Harmelen, the Netherlands) and on farm B with SCR Hi-Tag neck collars (SCR Engineers, Netanya, Israel). Rumination data were collected for 7 consecutive days leading up to each DHIA test, summed within day, and averaged across days. Data were analyzed using linear mixed models with a repeated effect of test day. Daily RT reported by commercial rumination systems varied across and within cows and was strongly influenced by a cow effect. Greater RT tended to be associated with a small decrease in milk fat concentration in farm A, but was not related to milk fat in farm B. The reason for this difference is unclear, but may be related to a potentially greater prevalence of biohydrogenation-induced milk fat depression on farm A. The significant, but small, model coefficients for milk fat and RT indicate that the relationship between these variables may not be strong enough to permit identification of cows with biohydrogenation-induced milk fat depression based on RT from commercial systems alone. Research assessing changes in rumination before, during, and after onset of altered rumen fermentation is necessary to determine whether RT could be used to identify cows with altered rumen fermentation.
AB - Low rumination in the dairy cow is often assumed to result in reduction of saliva flow, rumen buffering, and milk fat, which is a major contributor to milk value in many pricing systems. Rumination time (RT) of individual cows can be measured with commercial rumination sensing systems, but our understanding of how daily RT (minutes per day) is related to milk fat production is limited. Our hypothesis was that between cows within a herd, greater RT would be associated with lower milk fat concentration. Data from 1,823 cows on 2 commercial dairy farms in Pennsylvania over 8 DHIA tests were analyzed for a total of 8,587 cow test-days. Rumination was measured on farm A with CowManager SensoOr ear tags (Agis Automatisering BV, Harmelen, the Netherlands) and on farm B with SCR Hi-Tag neck collars (SCR Engineers, Netanya, Israel). Rumination data were collected for 7 consecutive days leading up to each DHIA test, summed within day, and averaged across days. Data were analyzed using linear mixed models with a repeated effect of test day. Daily RT reported by commercial rumination systems varied across and within cows and was strongly influenced by a cow effect. Greater RT tended to be associated with a small decrease in milk fat concentration in farm A, but was not related to milk fat in farm B. The reason for this difference is unclear, but may be related to a potentially greater prevalence of biohydrogenation-induced milk fat depression on farm A. The significant, but small, model coefficients for milk fat and RT indicate that the relationship between these variables may not be strong enough to permit identification of cows with biohydrogenation-induced milk fat depression based on RT from commercial systems alone. Research assessing changes in rumination before, during, and after onset of altered rumen fermentation is necessary to determine whether RT could be used to identify cows with altered rumen fermentation.
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U2 - 10.3168/jds.2019-17900
DO - 10.3168/jds.2019-17900
M3 - Article
C2 - 32564959
AN - SCOPUS:85086662296
VL - 103
SP - 8094
EP - 8104
JO - Journal of Dairy Science
JF - Journal of Dairy Science
SN - 0022-0302
IS - 9
ER -