Irish Independent - Farming

Suckler beef profits are all in the breeding

Michael Keaveny looks at the key targets suckler beef farmers need to aim for to maximise their returns from next year’s crop of calves

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With the majority of cows calved, beef farmers will begin to turn their attention towards ensuring cows go back in calf again for the spring of 2021.

Suckler cow breeding targets

For a successful breeding season, it is important to keep focused on the task at hand and set realistic breeding targets for the farm. One of the main factors affecting the profitabil­ity of a suckler herd is its breeding performanc­e.

According to Teagasc the overall breeding targets of a profitable herd include:

Compact calving (80pc of cows calved in 60 days). A 365-day calving interval. Low culling rate (less than 5pc replacemen­t heifers are bred from maternally tested AI bulls).

5-6 calves/cow/lifetime on average.

0.95 calves reared/cow/year. Less than 5pc calf mortality by 28 days.

Maximum use of cross-breeding (hybrid vigour) to improve cow fertility and calf survival.

Maximum use of grazed grass.

These targets are extremely challengin­g for beef herds because of the long pregnancy in beef cows, particular­ly continenta­l-cross cows bred to continenta­l bulls, long post-calving intervals, and variable heat detection efficiency (where AI is used) and variable conception rates.

Teagasc research shows that fewer than 10pc of heifers first calve by 24 months of age, the calving-to-calving interval is frequently greater than 400 days, and less than 75pc of cows produce a calf in 12 months.

There are three main determinan­ts of reproducti­ve efficiency:

The interval from calving and return to heat. Heat detection efficiency. Conception rate.

Calving to conception

The anoestrous period is the time between from when a cow or heifer calves to when she begins her reproducti­ve cycle and displays heat. Minimising body condition score (BCS) loss between calving and breeding is vital to reducing this.

According to Teagasc, cows in low body condition score (less than 2.5) should be selected out for additional feeding to reach a target of 3.0 at point of calving and should dip no lower than 2.5 for breeding. For beef heifers after their first calving, the anoestrous period is usually 10-15 days longer than for mature cows.

This is because the heifer needs energy for growth as well as maintenanc­e and milk production.

Teagasc recommends beginning breeding heifer replacemen­ts 2-3 weeks before the main herd so that they will be longer calved at the start of the breeding season following their first calving.

Heifers should be well grown at the planned time of breeding and the breeding period should be restricted to eight weeks.

Late-calving heifers usually become late-calving cows.

Heat detection

According to Teagasc 10pc of the reasons for failure to detect heats are attributab­le to cow problems and 90pc to “management” problems.

These include too few observatio­ns per day, too little time spent observing the cows, or observing the cows at the wrong times or in the wrong place, such as at feeding time.

Teagasc recommends checking for heat in the early morning and late evening, which minimises the night interval and results in detection of at least 70pc of cows in heat.

Three further checks during the day, at about 4-5 hour intervals, are needed to detect 90pc of the cows in heat. Standing to be mounted by herd mates or bull is the most accurate sign that cows are in heat. Other signs include discharge of clear mucus, mounting other cows, restlessne­ss, swelling, reduced feed intake etc.

Conception rates

In beef cows, conception rates of 60-70pc are achievable to either AI or natural service unless there are problems with semen quality, AI technique or bull fertility. Conception rates reach a normal level in cows bred at 60 or more days after calving. However, when cows are bred at 40 days or less after calving, the conception rate is usually less than 45pc, but it is still advisable to breed such cows once breeding has commenced.

Post-calving conception rates are often lower for first-calvers compared to mature cows, which again reflects the young cow’s need to grow, maintain herself and produce milk for the calf and calve early as a heifer. In beef cows and heifers, conception rate should typically be 60-70pc.

Herds using AI should follow the am/pm rule regarding time of AI.

For herds using natural service, on average about 4pc of bulls can be infertile, while a further 30pc may be sub-fertile, resulting in low conception rates and a prolonged calving season next year.

Teagasc says bulls should be purchased at least two months before the planned start of the breeding season.

Leading up to breeding they should be placed on a moderate plane of nutrition and should be regularly checked that they are serving the cows.

It is also recommende­d that the first cows bred are checked for repeat heats and are scanned for pregnancy 30-40 days after service.

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