Genetic parameters for energy balance, fat /protein ratio, body condition score and disease traits in German Holstein cows

Abstract

Various health problems in dairy cows have been related to the magnitude and duration of the energy deficit post partum. Energy balance indicator traits like fat/protein ratio in milk and body condition score could be used in selection programmes to help predicting breeding values for health traits, but currently there is a lack of appropriate genetic parameters. Therefore, genetic correlations among energy balance, fat/protein ratio, and body condition score, and mastitis, claw and leg diseases, and metabolic disorders were estimated using linear and threshold models on data from 1693 primiparous cows recorded within the first 180 days in milk. Average daily energy balance, milk fat/protein ratio and body condition score were 8 MJ NEL, 1.13 and 2.94, respectively. Disease frequencies (% cows with at least one case) were 24.6% for mastitis, 9.7% for metabolic disorders and 28.2% for claw and leg diseases. Heritability estimates were 0.06, 0.30 and 0.34 for energy balance, fat/protein ratio and body condition score, respectively. For the disease traits, heritabilities ranged between 0.04 and 0.15. The genetic correlations were, in general, associated with large standard errors, but, although not significant, the results suggest that an improvement of overall health can be expected if energy balance traits are included into future breeding programmes. A low fat/protein ratio might serve as an indicator for metabolic stability and health of claw and legs. Between body condition and mastitis, a significant negative correlation of -0.40 was estimated. The study provides a new insight into the role energy balance traits can play as auxiliary traits for robustness of dairy cows. It was concluded that both, fat/protein ratio and body condition score, are potential variables to describe how well cows can adapt to the challenge of early lactation. However, the genetic parameters should be re-estimated on a more comprehensive data set.

Changes of fat-to-protein ratio from start to the mid-lactation and the impact on milk yield

“…Within the fact that F/P ratio can be observed at any test-day its estimation doesn't increase cost of production. Presented results are in concordance with Buttchereit et al (2012), who reported that F/P ratio and body condition score are potential variables to describe how well cows can adapt to the challenge of early lactation. Similarly, Heuer et al (1999) reported that first test-day milk yield and first test-day F/P ratio were more reliable indicators of metabolic disease, other lactation diseases, fertility, milk yield and culling than were first body condition scores (BCS) postpartum or body condition loss from the first to second scoring.…”

Analyses of genetic relationships between linear type traits, fat-to-protein ratio, milk production traits, and somatic cell count in first-parity Czech Holstein cows

“…Nevertheless attention should still be paid to F/P and the incorporation of fat-toprotein ratio into breeding programs should be considered. As noted by Buttchereit et al (2012), improvement in the overall health of dairy cattle can be expected if energy balance traits are included into breeding programs. F/P can be quite easily combined with BCS.…”

“…In their study of 1693 Holstein cows in Germany Buttchereit et al (2012) estimated a heritability of F/P of 0.30 ± 0.05. So it can be stated that F/P is a relatively highly heritable trait.…”

“…More farmers and breeders are taking an interest in F/P, since it has relatively high correlation with the occurrence of ketosis and some other health traits in dairy cattle and the phenotype is easily obtained (e.g. Buttchereit et al 2012;Koeck et al 2013).…”

“…Therefore, recent studies have shown there might be a relationship between the fat : protein ratio (F/P) in milk during early lactation and the performance during the same lactation (e.g. Buttchereit et al 2012;Koeck et al 2013). In a review by Roche et al (2009), problems associated with negative energy balance influencing production, reproduction, and health performance in dairy cattle are described in detail.…”