Feasibility of using automatic milking system data from commercial herds for genetic analysis of milkability

Abstract

The objective of this study was to investigate how useful data from automatic milking systems used in commercial herds are for genetic analysis of milkability traits. Data were available from 4,968 Swedish Holstein and Swedish Red cows over a span of 5 yr (2004-2009) from 19 herds. The analyzed milkability traits were average flow rate, box time, milking interval, and number of milkings per day. Variance components were estimated for genetic, permanent environmental, and residual effects in first and later (second and third) lactations, and were used for estimation of heritabilities and repeatablilites. The experiences of the data quality and editing procedures showed that almost half of the data and about a quarter of the cows had to be excluded from the analyses due to incomplete or inconsistent information. However, much more data are available than is needed for accurate genetic parameter estimations. For the genetic analysis, a repeatability animal model was used that included the fixed effects of herd, year and season, lactation month, and milk yield. The repeatability coefficients were at a high level: highest for average flow rate, with estimates between 0.8 and 0.9. The estimated heritability coefficients were in the range of 0.37 to 0.48, 0.21 to 0.44, 0.09 to 0.26, and 0.02 to 0.07 for average flow rate, box time, milking interval, and number of milkings, respectively. The results from the present study unraveled large genetic variation in milkability traits. The genetic parameter estimates were well in agreement with previous studies of milkability, which proves the feasibility of using data from automatic milking systems for genetic analysis.

Changes in milking parameters with robotic milking

“…The present study found more MCD in summer and winter months and in the group of older cows (multiparous). In investigating mean MCD, Carlström et al (2013) and Castro et al (2012) obtained results similar to those of the present study, whereas Gygax et al (2007) obtained a slightly lower result, at 2.5 (range: 0.8 to 3.9 per cow). A higher MCD value in relation to the one obtained in this study was reported by Deming et al (2013; 2.8 ± 0.4 times a day), and Madsen et al (2010) reported on average as many as three milkings per day.…”

“…Lower mean MCD values, i.e. from 2.1 to 2.5, were observed by WagnerStorch and Palmer (2013), Hogeveen et al (2001), Mačuhová et al (2003), Carlström et al (2013) and Bach et al (2009).…”

“…High variability in the frequency of cow visits to the robot are observed depending on the lactation stage, some changes may be also attributed to the preferences of individual animals. As emphasised by various authors (Friggens and Rasmussen, 2001;Wagner-Storch and Palmer, 2003;Carlström et al, 2013), MCD can be increased, which should drive up MY. At the same time, cows with more MCD were observed to yield about 20 % more milk as compared to cows with the least MCD (Løvendahl and Chagunda, 2011).…”

“…As emphasised by numerous authors (Hogeveen et al, 2001;Pirlo et al, 2005;Edwards et al, 2014;Lee and Choudhary, 2006), it is important that animals have a positive experience at milking time and do not mind using the AMS. The milking robots currently used allow cows to freely chose the time of milking and to dynamically adjust the intermilking interval throughout lactation as well as throughout the day (Carlström et al, 2013). Cows introduced to AMS barns quickly adapt to the new way of milking, and farmers with milking robots can precisely track many parameters related to the milking performance of their cows.…”

Factors associated with intramammary infection in dairy cows caused by coagulase-negative staphylococci, Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, or Escherichia coli

“…As the interaction term between breed and annual milk yield was nonsignificant, reasons other than just higher milk production must explain the difference between HOL and NR. One possible explanation could be the generally better milkability of the HOL breed (i.e., quicker milk release and larger minute flow; Carlström et al, 2013). These characteristics may be associated with milk leaking tendency and a looser teat canal, which predispose the udder to bacterial invasion via the teat opening.…”