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

Abstract

Good calving management should not only ease the transition of cows into lactation, but also contribute to providing healthy replacement animals for the herd. Difficulty during parturition has been found to be detrimental to the offspring. Because of the association of obstetrical intervention with undesirable outcomes, the general management recommendation for calving is to let cows give birth unassisted whenever possible. Unfortunately, very few studies have investigated the effects of planned early assistance during calving, regardless of whether or not another problem exists. To investigate the effects of early assistance during apparently normal calvings, a clinical trial was conducted on 257 Holstein cows. They were observed through the second stage of calving, and before calving they were divided randomly between 2 assigned interventions: not assisted or early assistance during the second stage of parturition. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted, not assisted, early assistance, and late assistance (for cows in the not assisted group that did not calve unassisted within the 1 h maximum time allowed). Early assistance was given 15 min after first sight of both front hooves of the calf and done using human force only. Heifer calves (n=129) born from enrolled dams were followed until weaning to assess the effect of assigned and actual calving interventions on their growth, health, and survival. Heifer calves' weight at birth was positively associated with weight at 7 wk, but the effect varied by assigned and actual intervention. As a routine management practice, giving early assistance during calving to dairy cows did not influence average daily gain, health, or survival in dairy heifer calves up to weaning at 7 wk of age.

Birth conditions affect the longevity of Holstein offspring

“…Even though results from this study indicated that calving assistance has negative effects on offspring longevity, delivery assistance alone is not likely to be a problem. Systematically assisting the delivery of calves that do not present clear signs of dystocia improves the calf vigor and does not influence the likelihood of stillbirth (Villettaz Robichaud et al, 2017a) as well as the occurrence of pneumonia, diarrhea, and the survival of the offspring up to weaning at 7 wk old (Villettaz Robichaud et al, 2017b). Even though further studies are needed to evaluate the long-term effects of systematically assisting the delivery on offspring longevity, this would indicate that calving assistance as a consequence of dystocia would have a negative effect on offspring Terminal node identified by the survival tree algorithm for the length of productive life.…”