Is cow fertility crucially important?

While the majority of cows calve in February and March in the South, up North a large majority of cows calve from September to January, so getting these cows back in-calf is high on the agenda at the moment. Improving fertility will also be a significant factor to surviving 2015 and the low output prices.

Poor conception rates, extended calving intervals and reduced days to first service are all common problems for dairy farmers.

Many of the Dairylink Ireland project farms are no different, with problems ranging from spread calving patterns to poor heat detection. All these problems together are called infertility and it has a very real cost.

If a farmer was to receive a bill for infertility in the post, then drastic changes would occur. Ask yourself what would your farm bill be?

This article looks at the specific losses incurred as a result of poor fertility performance, outlines specific problem areas and suggests ideas for improvement.

The cost issue

The main area affected by infertility is loss in milk yield, with more late-lactation cows in the herd and subsequently less peak-yielding cows in early lactation at high feed rates.

This, coupled with increased culling of infertile cows, an increase in vet and AI costs, and less calves sold contributes to a significant overall cost to the farm business, which can be difficult to identify and quantify.

The example in Table 2 highlights the fertility situation on a Dairylink Ireland project farm using a sample herd size of 100 for illustration purposes.

Using the cost assumptions from Table 1, the cost of infertility to the project farm is £22,546/€28,905 per 100 cows, as illustrated in Table 2.

This total cost can be divided into two distinct parts. Firstly, from costs associated with an extended calving interval, including loss in milk yield, loss in calf sales and extra veterinary treatments, which equates to £12,694/€16,274 for 100 cows (£2.82/€3.62 per cow per day).

Secondly, the additional cost of extra culling and subsequent replacement of cows due to not being in-calf, which amounts to £9,852/€12,630. I have used the CAFRE cost of infertility in the dairy herd calculator to generate these figures.

Record keeping

In order to make any improvement in fertility, breeding records are key. Having good records with accurate information will allow you to identify and deal with problem cows before they become too costly.

Ultimately, the recording system should be able to produce action lists – showing individual cow due dates, drying-off dates, breeding dates and other important information.

Various computer packages exist to help collect and report on this information and while these packages are useful, simple conventional paper records like 21-day pocket dairies, wall charts and boards can be as effective when it comes to improving fertility. The best approach to record keeping is to use what you are comfortable with, provided it can deliver reliable and useful information. Ask yourself if the inspector came in to look at your fertility records, would they pass the test?

I know on many Northern farms the answer is no. In the South, farmers are lucky to have ICBF, which is the central database or hub for all this information.

Heat detection

Northern and Southern dairy farms with autumn-calving cows are very busy at the moment with calving, feeding, cleaning and milking.

Research from AFBI Hillsborough, Moorepark and Holland has highlighted that spending an extra 30 minutes per day on heat detection can increase rates by 10%, reduce the calving index by five days and reduce the culling rate of cows not in-calf by 2.5%.

This would add up to a £2,500/€3,205 cost saving on a 100-cow herd with a six-month breeding period. To get the best detection results, cows should be observed when night falls and the yard is quiet.

Research has also shown that observing for longer time periods, for example 20 to 30 minutes, can improve heat detection by up to 40%.

Tail paint and tail crayons are two of the most effective and cost-effective products to help heat detection. Write down what you see to determine when the paint mark is being removed or triggered.

Two of the Dairylink Ireland project farms use the self-adhesive scratch cards attached at the top of the tail head. Both farmers are reporting good results with the cards.

However, because all cows are now housed, some cards are being scratched on cubicles or walls, so be careful.

Cow condition

Any stress on the cow can shorten the display of heat, consequently making it more difficult to detect. Specifically, loss of body condition after calving is normal, but in some cases, excessive loss will have a knock-on effect on fertility. This is particularly relevant this winter, with low-energy silage being fed to many cows at the critical breeding stage.

Making sure the diet is balanced and formulated to the cow’s need is important to reduce the dietary stress on the herd. This has been one of the major challenges for the Dairylink project farmers this winter.

If individual cows are in particularly poor condition or have had a very hard calving, milking them once a day for a period of time can help the cow to recover.

Performance indicators

In order to make any significant improvement in herd fertility, each individual farmer needs to look at the correct performance indicators for their herd and set realistic targets for these indicators.

Calving interval and conception rates have a role to play in herd fertility performance, but key figures such as in-calf rate may be more beneficial to farmers attempting to get more cows pregnant.

The six-week in-calf rate for compact calving herds and a 100-day in-calf rate for herds with spread calving periods are more relevant.

These figures would measure the proportion of cows intended for rebreeding that are in-calf within six weeks or 100 days of calving.

Table 3 highlights other important fertility indicators and targets that can be used to assess herd fertility performance.

The focus needs to be on improving the areas of fertility performance most out of line with the relevant targets highlighted.

Summary

As illustrated in this article, the cost associated with infertility stems from many areas of herd management. Small improvements in these areas, such as heat detection and improving fertility recording, can make a significant impact on fertility and the associated cost of not getting cows in-calf.