Suckler Herd Fertility

Suckler Cow Fertility

Fertility is a main driver of profitability in a Suckler herd, with profitability directly linked to the number of calves reared and sold per cow served per year. The cost of production per cow per year is in the range of £350-800, which is a hefty sum taken out of profits from selling a calf. Therefore any barren cows that get a free ride through the year are costing and pulling down that margin of profitability further. Therefore I fully encourage culling of barren cows post early PD (pregnancy diagnosis).

PD’ing should be carried out once the bull has been out from the cows for a month - the vets can give more accurate dates the younger the calf is. PD’ing the cows once they are over 5 months in calf increases inaccuracy and would be more of a YES or No answer. All of our vets would rather PD when they’re 40 - 90 days following service - this may mean doing 2 PD sessions but will give a lot better accuracy. Ideally we would PD once the bull has been in for 3 cycles and then again a month after he’s been taken out. Knowing when your cows are going to calve is very useful for targeting resources and labour and we would encourage all of our farmers to PD their cows, thus picking up on any fertility problems early and giving as accurate dates as possible.

With healthy fertile bulls and fertile cows we can expect a conception rate of 60% for each 21 day ovarian cycle. However a sub fertile bull or cows of poor fertility due to being thin (below a Body Condition Score (BCS) of 2.5-3) may give half the conception rate, or even less.

Therefore, at the end of 3 months with bulls running with the cows we’d expect 3% barren. Whereas if we half that conception rate, a quarter of the herd may not be in calf.

If actual on farm figures are over 5% barren at the end of the service period, we should be investigating what may be affecting this – bull fertility, nutrition, trace elements, infectious disease etc.

Bull Fertility

A fit and healthy bull is essential to good fertility on farm, and should be achieving 60% of cows in calf per cycle, assuming you’ve got a ratio of 1 bull/30 cows. Full health checks should be performed 2 months before service is needed as it takes 60 days to produce healthy sperm. Therefore he should be sound, with any foot problems being sorted 2 months before mating is required and he should be in BCS 3 – 3.5. Again, heavy or thin bull’s fertility is decreased and they tend to have more health problems. A bull fertility exam could be performed on farm to check the quality of his sperm. True infertile bulls are quite rare but do happen, however sub fertile bulls are much more common, so conception rates may drop by half or more, thus leaving a much higher proportion of cows barren at the end of the service period.

For any advice on Suckler fertility please contact the Farm Office on 01491 651479.

In 2018 we will be launching a Suckler Health Club - more information coming soon!