Fertility traits of Holstein, Brown Swiss, Simmental, and Alpine Grey cows are differently affected by herd productivity and milk yield of individual cows

Abstract

Milk yield has a strong effect on fertility, but it may vary across different herds and individual cows. Therefore, the aim of this study was to assess the effects of breed and its interaction with level of milk production at the herd level (Herd-L) and at a cow-within-herd level (Cow-L) on fertility traits in dairy cattle. Data were gathered from Holstein (n = 17,688), Brown Swiss (n = 32,697), Simmental (n = 27,791), and Alpine Grey (n = 13,689) cows in northeastern Italy. The analysis was based on records from the first 3 lactations in the years 2011 to 2014. A mixed model was fitted to establish milk production levels of the various herds (Herd-L) and individual cows (Cow-L) using milk as a response variable. The interval fertility traits were interval from calving to first service, interval from first service to conception, and number of days open. The success traits were nonreturn rate at 56 d after first service, pregnancy rate at first service, and the number of inseminations. The interval from calving to first service, interval from first service to conception, and number of days open were analyzed using a Cox's proportional hazards model. The nonreturn rate at 56 d after first service, pregnancy rate at first service, and the number of inseminations were analyzed using logistic regression. There was a strong interaction between breed and productivity class at both Herd-L and Cow-L on all traits. The effects of herd and cow productivity differed from each other and differed among breeds. The dual-purpose Simmental and Alpine Grey breeds had better fertility than the specialized Holstein and Brown Swiss dairy cows; this difference is only partly attributable to different milk yields. Greater herd productivity can result in higher fertility in cows, whereas higher milk yield of individual cows within a herd results in lower fertility. These effects at both Herd-L and Cow-L are curvilinear and are stronger in dual-purpose breeds, which was more evident from low to intermediate milk yield levels than from central to high productivity classes. Disentangling the effects of milk productivity on fertility at Herd-L and Cow-L and taking the nonlinearity of response into account could lead to better modeling of populations within breed. It could also help with management-for example, in precision dairy farming of dairy and dual-purpose cattle. Moreover, assessing the fertility of various breeds and their different responses to herd and individual productivity levels could be useful in devising more profitable crossbreeding programs in different dairy systems.

Pure-breeding with sexed semen and crossbreeding with semen of double-muscled sires to improve beef production from dairy herds: Factors affecting heifer and cow fertility and the sex ratio

“…Our results showed that, after correcting the data for all the other confounding factors, cows reared on farms characterized by a higher mean level of milk production had on average a better conception rate than cows reared on farms with lower productivity (Figure 1). In a similar study carried out in a different environment (mountainous areas with lower milk production levels), we found a tendency for a curvilinear response, with a reduction of average conception rate increasing the mean herd milk yield up to 20 to 25 kg/d and an improvement of conception rate increasing further mean herd milk yield level to 30 to 35 kg/d (Toledo-Alvarado et al, 2017). These tendencies were more pronounced in dual-purpose breeds, such as Simmental, and less evident in specialized dairy breeds, such as Holstein-Friesian and Brown Swiss.…”

A research on longevity, culling reasons and milk yield traits in between Holstein and Simmental cows

“…There are many studies showing the negative correlation between high milk yield and reproduction performance (Lucy 2001;Dobson et al 2008;Walsh et al 2011). These results are in parallel with international studies in which milk yields of two breeds are compared (Micinski et al 2014;Janzekovic et al 2009;Budimir et al 2011;Toledo-Alvarado et al 2017). At national literature, on the other hand, there is no reference study where these two breeds are compared for milk yields.…”

Reproductive Performance in a Selected Sample of Dairy Farms in Una-Sana Canton, Bosnia and Herzegovina

“…is points to reproductive shortfalls compared with other studies [29,30]. Farms with low pregnancy rates (first service and cumulative) at individual animal level had the highest NSP.…”