Author : Danielle Andreen
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (111 download)
Book Synopsis INVESTIGATING APPLICATIONS OF RUMINATION DATA FOR IMPROVING MILK FAT PRODUCTION ON COMMERCIAL DAIRY FARMS. by : Danielle Andreen
Download or read book INVESTIGATING APPLICATIONS OF RUMINATION DATA FOR IMPROVING MILK FAT PRODUCTION ON COMMERCIAL DAIRY FARMS. written by Danielle Andreen and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Milk fat is the most variable component of milk and is closely related to rumen fermentation. Specific subclinical diseases that reduce milk fat production, like biohydrogenation-induced milk fat depression (BH-induced MFD) or subacute ruminal acidosis (SARA), are responsible for some of this variability. Both conditions arise from altered rumen fermentation, which is difficult to monitor in commercial herds, but are financially detrimental to farms as butterfat is currently the most valuable component of milk. Rumination is a well-studied behavior in dairy cows that is an intrinsic part of rumen fermentation, and thus may serve as an indicator of conditions like SARA and BH-induced MFD. Commercially-available rumination sensing systems are becoming more widely implemented on dairy farms, which has made rumination data for individual cows easily accessible. This presents the opportunity to investigate these data could be used to identify cows with altered fermentation and improve milk fat production and profitability of dairy farms.The relationship between average daily rumination time (RT; min/d) and milk fat concentration and fatty acid (FA) profile was first investigated on commercial farms with the CowManager SensoOr ear tag system (CM; Agis Automatisering BV, Harmelen, the Netherlands) or the SCR neck-collar system (SCR; SCR Engineers; Netanya, Israel). In these experiments milk FA profile was used as a non-invasive indicator of rumen fermentation, as FA profile is responsive to changes in nutrition and development of BH-induced MFD or SARA. In our dataset of 1733 cows from five commercial farms in Pennsylvania and New York, we found no association between numerical RT and milk fat concentration. However, associations between RT and milk FA indicators of SARA and BH-induced MFD were observed. Surprisingly, greater daily rumination time, rather than less rumination time as hypothesized, was associated with a FA profile indicative of these conditions. This may be due to cows increasing rumination in response to altered rumen fermentation. A follow-up experiment with two of the original five farms was conducted, one farm with each observation system, to investigate how RT was associated with milk fat production over a year-long period. After accounting for individual cow effects and other variables, RT was associated with small reductions in milk fat concentration only in the CM farm, and had no relationship to milk fat in the SCR farm. It is unclear whether the difference between farms was due to rumination measurement method, a potentially greater prevalence of BH-induced MFD in the CM farm, or other reasons. Regardless, it appears the relationship between RT and milk fat may not be strong or consistent enough to enable use of rumination data to identify cows with altered rumen fermentation. In conclusion, numerical baseline rumination time, as reported by commercial rumination systems, is not strongly related to milk fat concentration or prevalence of BH-induced MFD. Rumination time is highly influenced by individual cow effects, and even after accounting for the effect of cow and other variables, RT is associated with only small reductions in milk fat concentration. Further research examining changes in rumination time specifically during onset of MFD or SARA is required to fully assess the usability of commercial rumination data for detection of these conditions.
