06 July 2020
Type Media Article
Find out the reasons for calving your beef heifers at 2 years old; why farmers are reluctant to try it and get some key statistics to help make the decision.
Why do it?
- More output from the heifer over her lifetime (more calves produced)
- Reduced stocking rate compared with calving heifers at old ages
- Potential to reduce the number of stock groups
- Quicker genetic progress
- Reduces Costs – Grange work shows that for a 50 cow herd with a 20% replacement rate each additional month that calving is delayed cost of €490 or €50/heifer/month.
Why are farmers reluctant to try it?
(Only 22% of heifers calveat 22-26 months)
- Heifers aren’t sufficiently well grown at 15months to be bred
- Believe that it will stunt the heifers growth if they are bulled too early
- They are too difficult to calve
- They won’t go back in calve again to calve as 2nd calvers
- Not that saleable if things go wrong at calving.
Dispelling some of the Myths
Comparison of national statistics on the performance of 131,077 beef heifers, calved for the first time, between 23 and 40 months of age (supplied by ICBF).
| Age at 1stcalving (months) | Average subsequent calving interval(days) | % Calving for asecond time | Average calving difficulty of bulls used | Average calving difficulty of bulls used | Average calving difficulty of bulls used |
|---|
| 23-26 | 383 days | 82% | 4.7% | 50% | 3.2% |
| 27-30 | 394 days | 83% | 5.1% | 53% | 2.8% |
| 31-35 | 392 days | 87% | 5.2% | 58% | 2.6% |
| 36-40 | 386 days | 86% | 5.2% | 57% | 2.0% |
We often put up many reasons as to why not to calve heifers at 24 months such as if they calve at 2 years they will not calve again at 3 years. The table above clearly shows that this is not the case.
For example:
- Heifers that calved at 23-26 months of age had as good a subsequent calving interval and calved down again as a second calvers, just as early as their contemporaries calving down in the older age categories.
- Another reason often suggested is that they are harder to calf at a younger age. The figures do show that younger heifers do have slightly higher calf mortality. On the same token heifers irrespective of age will be more difficult to calve and as the figures show will need a higher level of assistance at calving irrespective of age.
- Correct sire selection is key if you want to consistently calve heifers at 24 months. As the table shows even younger calving heifers are being mated with sires with an average calving difficulty of 4.7% on the old scale which you could argue is high. We now have the new beef heifer calving difficulty figures available. Ideally select a high reliability bull with a beef heifer calving difficulty figure of less than 7.5%.
- Heifers that calved for the 1st time at 23-26 month had greater survivability. Heifers that undergo puberty early generally have a shorter interval between calving and onset of first heat after calving.
Key Weight Targets
| Mature Cow Weight | Weaning Wt. | Bulling Wt. | Calving Wt. |
|---|
| Target % of Mature Wt. | | 60% | 80% |
| 600kg | 260-280kg | 360kg | 480kg |
| 700kg | 300-320kg | 420kg | 560kg |
Key points
Heifers that are to calf down at two years of age will;
- Come from the best cows in the herd and be sired by bulls with strong maternal traits.
- Be born early in the calving season to allow them to be heavier at bulling
- Need to achieve a daily liveweight gain of 1.1-1.3kg/day up to weaning as research shows they will typically undergo puberty and be eligible for breeding much earlier than poorer performing contemporaries
- Have to be fed to achieve 60-80kg liveweight over the first winter so they will need good quality silage plus 1-2kg of concentrates.
- Have reached 60% of their mature weight by bulling
- Be turned out early in spring to grass to achieve good weight gain in the run up to bulling
- Be bred to a high reliability easy calving sire (Ideally < 7.5% Beef heifer calving difficulty)
- Have achieved 80% of their mature weight at calving.
Need preferential treatment if remaining indoors for a month or more after calving down. (Good silage plus 2-3kg Meal)
FAQs
The age to breed these heifers is an important decision for beef cattle producers. Historically, heifers were first bred at 2 yr of age, but as beef production systems have become more intensive over the last few decades, more and more producers have bred their heifers as yearlings to calve first at 2 yr of age.
At what age is most desirable to calve heifers? ›
The top 10% of commercial suckler herds and research herds are consistently calving heifers at 24 months of age. Work from Teagasc Grange has highlighted that a heifer calving for the first time at 36 months of age: consumes 65% more grass. 96% more silage.
What is the youngest age a heifer can get pregnant? ›
Heifers must have hit puberty and begun having estrous cycles in order to conceive. This typically happens around 1 year of age, although there are breed differences in average age at puberty, and some females may naturally undergo precocious puberty and begin cycling at or before 300 days of age.
What age should a beef heifer be bred? ›
Puberty is a function of breed, age, and weight. Most heifers will reach puberty and be bred by 12 to 14 months of age and will be between 55% and 65% of their mature weight when they first begin to exhibit estrous cycles.
How old should a beef heifer be to breed? ›
Whether you are raising or buying replacement heifers, the goal is to start breeding heifers near 12 – 14 months of age. By this time, heifers should have reached or be close to reaching puberty.
Which heifers to keep? ›
If she's big because she is older, you want to keep her. Along with that, select heifers that were born during the first 45 or better yet, the first 21 days of the calving season. “Cull the youngest heifers.” Select daughters out of the oldest cows.
Why is second breeding of heifers difficult? ›
Heifers take longer to start cycling after having their first calf than mature cows do. This means that if heifers are bred to calve at the same time as the main cow herd they are already behind coming into their second breeding season. “It's just basic biological math,” says Dr.
Is it OK for a bull to breed his daughter? ›
What are the do's and don'ts of breeding a bull to his daughter, mother, granddaughter, or sister? Mating any of the above would result in a high level of inbreeding. Generally speaking, inbreeding of this nature should be avoided.
What is the best feed ration for show heifers? ›
When heifers are young, we recommend going with a grain mix that is at least 16% protein and is fed at 1.5-2% of body weight. As ruminants, cattle are designed to digest material with a high fiber concentration.
How much do beef cattle weigh at 12 months? ›
At approximately 900 lbs,or about 12 months of age, grain finished cattle destined for beef go on feed (a balanced ration of grain and roughage). This can be either on the farm or in a feedlot.
According to the American Angus Association, the average mature cow weight is 1200 pounds. Heifers from 1,200-pound mothers will need to weigh about 780 pounds by the start of the first breeding season. If the mature size of the herd is 1,100 pounds, then the heifers can be about 715 pounds when breeding begins.
What is the best age to breed a first calf heifer? ›
Well grown British/European breed heifers can be mated at 15 months to calve at 24 months. The two main advantages of mating heifers as yearlings instead of two- year-olds are: heifers mated as yearlings produce an extra calf during their life in the herd.
What is a bulling heifer? ›
: a heifer unbred but of an age for breeding usually from 15 months to the first service.
Can you breed a bull back to his mother? ›
Each parent contributes 50% of the genetic make-up. But, if you mate a bull to its mother, 75% of the genetic make-up will be the same and the chance of the fault occurring simultaneously in both chains is very high. This is called in-breeding and must be avoided wherever and whenever possible.
How much does a 2 year old heifer weigh? ›
The approximate aver- age weight of the heifers at breeding time as yearlings was 623 pounds. At the time the calves were weaned from the heifers as two-year-olds, the heifers' average weight was 781 pounds.
Can a 2 year old bull breed? ›
“If he is 18 months of age, then he should be able to breed 15 to 18 cows. By the time the bull is two years of age, he should be able to breed 24 or 25 cows.” Lee adds it is important to remember that tremendous variability exists between bulls. Some are capable of breeding many more cows than what is typical.
What is the minimum weight to breed a heifer? ›
Most results indicate that we can develop heifers to 51%-58% of mature body weight and achieve very acceptable pregnancy rates. If your average cow weighs 1,390 lbs. (and many do), a heifer would need to weigh 904 lbs. at breeding in a traditional system, but only 709-806 lbs., according to the recent research.
What is a second year heifer? ›
The term "second-year heifers" refers to heifers that are pregnant for the second time. The terms, heifers, and cows can be used interchangeably for second-year heifers. Steers are male cattle that are castrated to prevent them from developing into bulls.
