Identification of cow-level risk factors and associations of selected blood macro-minerals at parturition with dystocia and stillbirth in Holstein dairy cows

Abstract

A deeper understanding of the risk factors for dystocia and stillbirth could help farmers make decisions about dairy cow management. The objectives of this study were to investigate cow-level risk factors associated with dystocia and stillbirth in a relatively large sample of dairy cows using multivariable linear regression models. The data consisted of 51,405 calving records of 14,546 Holstein cows from 3 dairy herds in Isfahan Province, Iran, collected between April 2011 and September 2017. To investigate the association between selected blood macro-minerals and the incidence of dystocia and stillbirth, blood samples were collected at the time of parturition from a random subset of these cows, which included 1311 animals. The incidence of dystocia and stillbirths averaged 14.7% and 4.3%, respectively. Results showed that calving year, calving season, dry period length, BCS, parity, calf sex, calf birth weight, twin status, and stillbirth were significantly associated with the incidence of dystocia. According to the Random Forest (RF) classifier, we found that dry period length, calf birth weight, and parity were the most important cow-level risk factors for the incidence of dystocia. Calving year, calving season, parity, twin status, dry period length, calf birth weight, calf sex, and dystocia were significantly associated with the incidence of stillbirths. The most important risk factors identified by the RF classifier for stillbirths were twin status, parity, dry period length, and calf birth weight. Also, interactions between the cow-level risk factors associated with dystocia and stillbirth were identified. The incidence of dystocia was associated with the interactions of twin status × calf birth weight and twin status × stillbirth. According to our analysis, the incidence of stillbirth is caused by interactions among several factors, such as twin status × length of dry period, twin status × calving season, and twin status × parity. The highest incidence of dystocia (21.3%) and stillbirths (5.4%) was observed in hypo-calcemic cows. In conclusion, twin status seems to be a determining factor for the incidence of stillbirths but not for dystocia. Finally, the results of this study may help the dairy industry make management decisions aimed at reducing dystocia and stillbirth rates.

Reproductive Disorders of Cattle in the Tole District of Southwest Ethiopia and Their Prevalence and Associated Risk Factors

“…Tis result is in agreement with the results of Hiew [65] and Benti and Zewdie [21], who stated that dystocia is more prevalent in monoparous cattle than pluriparous cattle. Momoparous cattle had a higher risk of developing dystocia than pluriparous cattle, according to previous fndings [66][67][68]. However, herd size, herd type, breed, age group, body condition, type of breeding, management system, calving season, previous history of dystocia, and cattle interaction with a dog did not signifcantly afect the prevalence of dystocia in cows (Table 5).…”

Stayability in Simmental cattle as affected by muscularity and body condition score between calvings

“…In addition, fat or over-conditioned dairy cows are at higher risk of developing a combination of metabolic, digestive, infectious and reproductive conditions known as the “fat cow syndrome” ( 71 , 72 ). Bahrami-Yekdangi et al ( 73 ) reported that in over-conditioned cows (BCS > 3.75; odds ratio = 1.27) the incidence of dystocia was larger than in other cows. An excessive accumulation of body fat predisposes to more insulin resistance, especially during the prepartum, a metabolic disorder with characteristics similar to human type 2 diabetes ( 74 , 75 ).…”

Impact of age at first calving on performance traits in Irish beef herds

“…This suggests that heifers genetically predisposed to younger AFC are genetically predisposed to produce smaller and more easily born calves but are more likely to have calving difficulties associated due to maternal effects (i.e., smaller body size, narrow pelvic area). In addition, heifers with an older AFC are likely to have a greater levels of fat deposition and greater body conditions scores which are associated to dystocia ( Bahrami-Yekdangi et al, 2022 ). Younger AFC will cause higher cost on beef herds due to the increased calving assistance required ( Phocas et al, 1998 ; Amer et al, 2001 ), due to the increased labor and veterinary costs, as well as the impact on subsequent lactations and higher risk of mortality ( Ring et al, 2018 ).…”