10 steps toa successfulbreeding season

With the breeding season getting into full swing in spring calving suckler herds, Livestock Editor Justin McCarthy looks at what steps farmers can take to make sure they hit their fertility targets.

High fertility rates are one of the key drivers of profitability in a suckler herd.

Steps taken during the calving season to avoid difficult calvings, uterine infections and to get herd health right will pay dividends over the next 12-14 weeks.

The overall objective of a successful breeding season is to achieve:

High conception rates

A maximum calving spread of 12 weeks.

Table 1 details the key performance indicators (KPIs) with regard to suckler herd fertility. I have left space for you to record actual on-farm performance alongside.

Your Herd Plus data will allow you to quickly establish the performance of your herd in relation to the targets.

Unless you establish your current position, you will not be able to chart your progress. Failing to hit the targets outlined in Table 1 will have a significant impact on herd output and ultimately profitability.

For example, only achieving a conception rate of 40% in each oestrus period will result in just 86% of the herd being in-calf after a 12 week breeding season.

Where a conception rate of 60% is achieved, 97% of the herd will be in-calf after 12 weeks. The following ten steps are by no means definitive but if put into practice will help you to work your way towards hitting your fertility targets and driving herd output.

STEP 1Don't try to build Rome in one season

It is important to emphasise at the outset that Rome wasn't built in a day.

Depending on the starting position, it will take two to three years for many farmers to achieve the targets set down in Table 1.

For example, where the calving spread is currently running at 18-20 weeks, trying to pull this back to 12 weeks over the period of one breeding season is simply not possible without collapsing farm output and driving up the need for capital investment. Therefore, a planned approach is required.

Figure 1 details how a farm currently operating an 18 week breeding period can gradually pull back to 12 weeks by reducing the duration of the breeding period by two weeks over a period of three years.

The rate of progress can be fast-tracked by culling later calving cows or cows with poor fertility and replacing them with heifers calving down at the start of the calving season.

Obviously the level of culling will be dependent on the level capital available for investing in replacement stock.

STEP 2Separating the cow and the calf

One option available to farmers looking to tighten the calving spread while avoiding significant levels of culling is to restrict the cow access to the calf from three weeks after birth.

Teagasc research found that separating the cow from the calf promoted a faster return to heat. The trial work showed that cows left with ad-lib access to their calves returned to heat 62 days post calving compared to 42 days where calves only suckled once per day.

The once per day suckling did not lead to any scour or nutritional problems.

While there is additional work associated with this method there is the potential to reduce the calving spread by almost three weeks.

It will also help reduce the level of culling required and therefore reduce the need to invest capital in purchasing replacement stock.

Farmers who have gone down this route find that both the cows and calves quickly get trained in on the system.

In most cases, the cows are turned out to grass during the day and are returned to the shed to be suckled at night.

STEP 3Body Condition Score

The body condition score (BCS) of the cow has been shown to directly impact on fertility.

Having cows either too thin or too fat at calving or mating will significantly reduce the fertility of your herd and increase your calving interval.

In the case of a spring calving herd, the average condition score at calving should be 2.5 increasing to 3 during the mating season.

With grazing conditions having been excellent this spring, there should be no excuses for cows being too thin at the start of the breeding season.

STEP 4Trace elements

Trace elements are the spark plugs to fertility. It is always worthwhile to get your vet to screen the herd in order to identify any deficiencies.

Copper, Selenium, Iodine and Cobalt are the four trace elements where deficiencies are likely to arise and all can have a significant impact on herd fertility. Table 2 details the background, symptoms, and control methods for these four key trace elements:

STEP 5Keep a breeding diary

When the breeding season commences it is essential that a diary is kept each day. The first entry should be the date the stock bull was entered into the herd or when AI commenced.

It is at this point that you should also establish when the bull is going to be taken out or when AI will cease. This date should also be recorded in the diary at the start of the breeding season. Some farmers will enter a reminder into their mobile phone.

Keeping accurate records is also key to monitoring the fertility of your herd and quickly identifying whether you have a problem.

Undoubtedly, a fertility problem is going to cause economic losses. However, the extent of these losses will depend on how long it goes undetected.

In many cases, poor fertility is not detected until the end of the breeding season. It is much easier to keep accurate records when using AI.

However, when using a stock bull you can still record the tag number of any cows that you see the bull mounting. A high level of cows repeating should trigger an immediate investigation.

In larger herds where a number of stock bulls are being used they should be rotated across the herd. However, where breeding your own replacements be careful of in-breeding.

STEP 6Calve heifers at start of breeding season

First calving heifers will take up to 30 days longer to resume cycling after calving than a mature cow.

Therefore, to ensure these animals do not quickly slip to the end of the calving season, in the second year they should be mated to calf down three to five weeks before the main herd -- therefore giving them more time to go back in calf in year two.

With calving difficulty also having a negative impact on conception rates, maiden heifers should only be inseminated to easy calving bulls.

Where replacement heifers are being calved down at 24 months, they should have reached 65% of mature weight at first service.

The breeding season for heifers should be limited to a maximum of nine weeks -- some farmers will reduce this back to six weeks to ensure that only the most fertile heifers are entering the herd.

STEP 7Plenty of bull power

Getting the bull to cow ratio right will have a major bearing on conception rates.

There is no definitive figure as to the number of cows a stock bull can serve over the course of the breeding season as factors such as age, muscularity and even terrain will all have a major bearing.

As a general rule of thumb, a mature stock bull operating on a typical Irish farm will be able to serve 40 cows over a 12 week period.

However, it is essential that he is in good condition at the start of the breeding season eg has had no health issues in the six weeks prior to the start of the breeding season and is good on his feet.

Where the stock bull is exceptionally muscular, this can impede his mobility and therefore the number of cows he is expected to serve should be adjusted accordingly.

Where the herd is grazed in a rotational system, the bull will be required to cover less ground and therefore even muscular bulls will be able to cover 35-38 cows over the course of the breeding season.

However, where the herd is set stocked or where the terrain is rough, the number of cows in the group should be reduced back to 30. Where terrain is rough, bull functionality is critical to achieving high conception rates.

STEP 8Don't overwork the young lad

A YOUNG bull is a fragile animal and should not be expected to serve any more than six to 10 cows during his first breeding season.

Expecting a young bull to cover 30-40 cows in year one will impact negatively on conception rates and the development of the bull.

It is good practice to allow the young bull to run with the herd for the last three weeks of the breeding season when the level of activity will be low.

STEP 9Vasectomised bull

Sub-Oestrus or silent heats can be a major problem in herds using AI. Although the cow is ovulating, she shows little or no signs of visible heat. Investing in a vasectomised bull to detect these cows is money well spent.

STEP 10Scanning

Scanning is not only an excellent management tool, it also allows you to quickly identify any fertility issues. Ultrasound scanning can be carried out six weeks after conception.

This is extremely useful where using AI as you can scan throughout the breeding season.

Cows scanned in calf can be removed from the group, allowing you to concentrate on the cows that have yet to go back in calf.