Still Birth and Weak Calf Syndrome in Suckled Calves
Over weight cows and heifers are at a higher risk of having still born calves.
In recent weeks SRUC Veterinary Services have had an increased number of still birth submissions from spring calving suckler herds. Cows and particularly heifers that have come through 2020 in good body condition and then been wintered on good quality silage are particularly susceptible just now as they will be fatter than normal.
Some thoughts on this are as follows:
A recently published study (Norquay et al 2020) undertaken by Glasgow Vet School and SRUC, looking at perinatal mortality in beef herds in Orkney showed that from 1059 calvings the incidence of stillbirth was 3.9% (range 0% to 10.1%) and this gives us some up to date reference data for the Scottish Suckler herd.
Sex of the calf, plurality and level of calving assistance were associated with significantly greater risk of perinatal loss.
Parturition‐related deaths resulting in anoxia in stage 2 labour (including bradytocia, trauma, malpresentation, twins and arthrogryposis) were the most common causes in the cases investigated.
Intrauterine infections mainly of bacterial or fungal origin (feed borne or environmental) was the next most common class.
Our experience so far this year will be similar with many of the still births seen relating to slow calvings and resultant anoxia.
We do recognise a ‘slow calving syndrome’ in suckler cows as an emerging problem.
A case definition would be still born calves or calves that die within a few hours of birth. The calf is not oversized and the cow fails to have adequate uterine contractions in second stage labour. Assisted birth is usually straightforward and the calf is born dead. No infectious or deficiency cause is identified.
Our theory is that this is related to over fat cows and subclinical hypocalcaemia. Many grass silages made in the area are of sufficient quality to ensure that cows will gain weight in the winter and many farmers are reluctant to buy in expensive straw when they have sufficient forage reserves in terms of silage. Also, silages can be high in potassium due to slurry application which may alter the DCAD of the ration pre-disposing to sub-clinical hypocalcaemia.
Monitoring cow condition and silage analysis to include minerals (especially Na, K, S, Cl, Ca and Mg) is key to making this diagnosis. Also, considering how straw and minerals are fed relative to overall feed presentation and feed trough space is an important consideration.
If you have clients experiencing such problems at the moment, do not hesitate to get in touch to consider the best way to investigate further, considering the wide range of differential diagnoses.
You can listen to our recent webinar on still births for more info.
Posted by Veterinary services on 29/04/2021
