Short communication: Survival, growth to weaning, and subsequent fertility of live-born dairy heifers after a difficult birth

Abstract

The experience of a difficult birth (dystocia) is traumatic and has adverse effects on the newborn in various species. Despite affecting up to 1 in 3 births in dairy cattle, studies on calves have been mostly limited to the first day of life. The objective of this study was to investigate the effects of dystocia on the survival to calving, growth to weaning, and subsequent fertility as nulliparous animals. Historical data from live-born Holstein heifer calves born from cows with various birth difficulty scores (no assistance; moderate; high difficulty) were obtained from 2 herds (Edinburgh herd: n=1,237; Crichton Royal Farm herd: n=721). Each herd was analyzed separately for birth weights, weaning weights, growth rate to weaning, number of services to conception, and age at first calving using REML and generalized linear mixed model analyses. Survival analysis (Cox proportional hazards model) was used in the Edinburgh herd to analyze the subsequent survival of live-born heifers, whereas descriptive data are presented for the Crichton Royal Farm herd. A higher mortality risk to weaning and to first service was observed in the live-born heifers that experienced moderate difficulty at birth compared with heifers born naturally. Surviving dystocial heifers had similar growth-to-weaning and fertility performance as heifers born naturally in both herds. It could be that the performance of dystocial heifers that survived to weaning was not affected or that it was compensated for by farm management. This study highlights long-term effects of the early experience of a difficult birth and thereby stresses the importance of preventing dystocia not just from the point of view of the adult cow, but also from the perspective of the calf. This would also improve farm efficiency and calf welfare.

Evaluación genética de la facilidad de parto en la raza bovina Parda de Montaña usando los modelos lineal y umbral

“…Correlación entre el valor genético directo del modelo normal (VG_FPd_MN) y el valor genético directo del modelo normal con efectos maternos (VG_FPd_MNm) para la facilidad de parto. directos (hasta 250 € por cesárea, valores superiores a los descritos por Kluyts et al, 2007) como indirectos por la pérdida de rendimiento de la vaca, al asociarse a una menor vitalidad de los terneros (Barrier et al, 2012) y a la prolongación del periodo anéstrico de las vacas (Sanz et al, 2004).…”

“…La facilidad de parto (FP) es un carácter que se incluye en los programas de mejora genética de la mayoría de las razas de vacuno de carne, como es el caso de la raza Parda de Montaña (ARCA, 2015). La facilidad de parto es especialmente importante en los sistemas extensivos, dado que los partos difíciles pueden originar elevadas pérdidas económicas, tanto en gastos y cuidados veterinarios (Kluyts et al, 2007) como en la menor productividad de las vacas afectadas, ya que los partos difíciles incrementan la mortalidad de los terneros (Wulfhorst et al, 2010;Cervantes et al, 2010) y retrasan la recuperación de la actividad ovárica postparto (Sanz et al, 2004) pudiendo inclusive incrementar la mortalidad de las vacas (Barrier et al, 2012).…”

Systematic early obstetrical assistance at calving: II. Effects on dairy heifer calf growth, health, and survival to weaning

“…The same study concluded that overall, heifer calves born from a calving with severe dystocia had higher odds of dying before 120 d of age than calves born from unassisted calvings (Lombard et al, 2007). Barrier et al (2012) found that heifer calves born from moderate-and high-difficulty calvings had a greater hazard of dying before weaning than heifers born from unassisted calvings. The outcomes might have been worse had obstetrical assistance not been provided, but there is still a lack of evidence on which to base criteria and means of intervention.…”

“…Difficult calvings have been negatively associated with calf health, growth, and survival. Barrier et al (2012) studied the association between moderate-and high-difficulty calvings and dairy heifer calves' growth to weaning; similar to Bellows et al (1988), they found no significant difference compared to unassisted calvings. The odds of respiratory and digestive problems between birth and 120 d of age have been found to be greater in heifer calves born from calvings with mild and severe dystocia compared with unassisted calvings (Lombard et al, 2007).…”

Scientific Opinion on the assessment of dairy cow welfare in small‐scale farming systems

“…They suffer from a decreased transfer of passive immunity (Arnott et al, 2012) and are increased risk of perinatal mortality (Hoedemaker et al, 2010;Hossein-Zadeh, 2014), which is even higher for calves that have been born through caesarean section (Hossein-Zadeh, 2014). Malpresented calves require more non-routine treatments during the first 60 days (Barrier et al, 2013) and are at higher risk of mortality to weaning and to first service, but show similar growth to weaning and fertility performance to heifers born naturally (Barrier et al, 2012a).…”