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
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.
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.
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.
Conditions for calving suckler cows this spring have been almost ideal. Some farmers have already finished calving and may be beginning to plan for next year’s crop of calves.
Your aim should be to produce one calf per cow per year and therefore have the ideal 365-day calving index. The average calf gestation is 287 days; this means there are only 78 days, or 2½ months, to get the cow back into calf.
In order to meet this target you should consider the following questions and actions.
* What does the market want? Can you produce calves to meet that demand and make a profit? Is your system suitable or do you need to change? What type and how many cows do you need to keep?
* Decide when you want your cows to calve next year and plan the service period accordingly. Consider adopting the “bull in and bull out” approach, which will tighten up your calving period. If using AI have a start and end date for inseminations.
* As cows begin to come into season, observe them closely for heats, and record dates of cycling. This will help identify problem cows.
* Mix late- and earlier-calving cows, as this has the potential to instigate and encourage the later-calving ones to start cycling earlier.
* Identify cows for culling. First up should be the problem cows. Usually the older, aggressive, lame, thin, poor-performing or those that had calving problems. Perhaps the late-calving cows should go first.
* Identify replacement heifers and the number you may need. If purchasing these, are you able to source them? If breeding your own, are they of the optimum age? If you are calving these down at 24 months, then they must be 15 months at service. Will these heifers be on target to reach their ideal bulling/service weight, which should be 60-65pc of what their mature weight will be as a first calving cow/heifer? For a 650kg mature cow/heifer the service weight should be 390-420 kg.
* Ideally calve the replacement heifers just before the main herd or your main calving period as they usually need extra time to get them back in calf again.
* Next year these heifers could replace the late-calving cows.
* If vaccinating the herd for BVD, make sure to do it on time well before the breeding season starts.
* Is the breeding herd now on a good and rising plane of nutrition, with cows coming into the optimum body condition score for service of 2-2.5?
* Are your cows deficient in any minerals?
* Do you have enough bull power to serve all your cows in the required period of time, particularly if you are trying to tighten up your calving period? Remember that one bull can cover 40 cows if given enough time to do so.
* Is your bull in a good fit condition for service and is he still working and fertile?
* Do you need to purchase a new bull, and if so are you able to source one? Perhaps you could use AI as a temporary option?
* Think about your target market — are you producing calves for the weanling/store markets? If so, your preferred choice may be a continental terminal sire. If you are taking cattle through to finish, the terminal sire could be a traditional breed where a price premium may be obtained? Or is your main aim to breed and sell potential replacements. If so, well proven maternal genetics and potentially sexed semen through AI may be the better option.
* If buying a new bull choose one with good Estimated Breeding Values (EBV), selecting one with those traits best suited to your system.
Colin McEvoy is Beef and Sheep Development Adviser at the College of Agriculture, Food and Rural Enterprise (CAFRE) in Enniskillen, Co Fermanagh