Rearing heifer replacements from the suckler herd
Rearing heifer replacements from the suckler herd
During the past decade there has been a dramatic decline in the conformation of beef cattle mainly due to the influence of Holstein genes, through the sourcing of suckler replacements from the dairy herd. Producing replacements from beef crosses within the suckler herd will help to improve the situation. In addition fewer beef cross heifers are produced within the dairy herd increasing the pressure to produce more replacements from within the suckler herd.
Merits of rearing from within the suckler herd
- Lowers the risk of importing disease onto the farm.
- More control over breeding thereby increasing the likelihood of producing a cow, which has sufficient milk to produce a well conformed growthy calf every year.
- A criss – cross breeding programme can be developed between two beef breeds improving carcase quality while retaining hybrid vigour.
- Can assess temperament during rearing.
- Cheaper to rear the quality animal rather than purchase.
- The suckler cow premium can now be claimed on up to 20 percent of heifers within the herd thereby helping to offset rearing costs.
Considerations before retaining heifers for breeding
- Is there sufficient feed and housing for the heifers?
- Can the business withstand the short fall in cash flow as a result of not selling heifers as weanlings or stores?
In many hill herds these are likely to be major obstacles to rearing replacements. However this does not exclude the possibility of breeding suitable replacements within the hill herd and selling the heifers as weanlings or stores to a specialist heifer rearer with an option of buying back the heifers at point of bulling or calving.
Selecting suckler cows to breed replacements
Approximately 30-40 percent of the herd will be required to breed replacements. If the heifers are to calve down at two years of age then they should be selected from cows, which calve in the first half of the calving period. Suitable breeder cows must have:
- adequate milk
- an ability to breed regularly
- good temperament
- moderate maintenance requirement
- hardiness
Matching the breed to the environment
On the lowland and better quality grass covered upland farms a 75 –100 percent continental X cow ofat least R grade conformation should be the aim in order to consistently achieve well conformed growthy calves. A medium sized cow with a mature weight of 600-630 kgs, which milks well and produces a calf every year, is ideal. Breed crosses which are of similar mature size such as the Simmental x Limousin or Saler x Limousin are two examples of animals likely to meet these criteria. In general across beef breeds there is a trend that as conformation improves milk production declines and calving difficulty increases. The use of Simmental and Saler will help counteract these negative aspects.
In the harsher hill environment a smaller cow is required with a mature weight of 520 –550 kgs capable of retaining sufficient condition, when feed is scarce or of poor quality, to milk well and settle back in calf during the breeding season. Crosses between traditional breeds such as Angus x beef Shorthorn, Hereford x beef Shorthorn or Saler or Limousin crossed onto any of these three traditional breeds are examples of breed crosses likely to produce suitable replacements for the harsh hill environment.
Within the above suggested criss-cross breeding programmes it is important that bulls are selected which have a positive EBV for milk. (See Beef Technical Note number three for further detail)
As the labour situation on farms is scarce in both environments easy calved cows of good temperament are essential.
What age to calve down heifers?
To allow heifers to return into the same calving period as the main herd in which they were born they must calve down at either two or three years of age. It has been shown that the overall lifetime economic efficiency of heifers calving at three years of age is seven percent lower than heifers calving at two years of age. Alternatively if there are two herds with one calving in the autumn and the other in the spring then one can provide replacements for the other. This would allow the heifers to calve down at 28-30 months reducing the inefficiency associated with calving at three years while allowing the beef heifer more time to reach an adequate weight and maturity before calving. This is likely to be of particular benefit where heifer replacements are being reared in the hill environment.
Rearing the beef x heifer to calve down at two years of age
The beef x heifer requires more maturity and weight at service time, without being overfat, than the traditional beef x dairy heifer. In a survey of beef x heifers up to 35 percent have been found not to have cycled (reached puberty) by 15 months of age.
There are a number of factors which reduce the age of puberty:
- A moderately high plane of nutrition.
(Target less than 1 kg of liveweight gain per day through to service. Exceeding this level can reduce subsequent milk supply)
- Autumn born heifers cycle earlier than spring born heifers because of exposure to lengthening days from six months of age.
- Cross bred animals reach puberty before pure bred animals
- Heifers bred from bulls with a large scrotal circumference.
- Exposure to a bull between 12-15 months of age.
Heifer rearing targets - calving at two years
- At service aim for 65 percent of mature liveweight and Body Score of 2.5-3
- At calving aim for 85 percent of mature liveweight and Body Score of 3
Target weights at service for different breed crosses (kgs)
| 100% Continental x | 75% Continental x | Traditional x | |
|---|---|---|---|
| Liveweight | 450 | 400 | 350 |
| DLwtg (Birth-Service) | 0.9 | 0.8 | 0.7 |
| Targets weights service to Calvin (kgs) | |||
| Liveweight at calving | 600 | 540 | 450 |
| DLwtg (service - Calving) | 0.5 | 0.5 | 0.4 |
Breeding the maiden heifer
It is important heifers have at least two - three heats before being bred. Using natural service is the simplest approach to settling heifers in calf providing that a bull, well proven for ease of calving, can be obtained.
Beef x heifers do not readily show standing heat and if observing for an AI programme they can be particularly difficult to pick out in small groups of less than 20 animals. To encourage heifers to come into heat and identify them when in heat the use of a vasectomised bull fitted with a chin ball marker should be considered. Alternatively where heifers cannot be observed for heat three - four times per day a synchronisation and AI programme is the best option. Synchronisation programmes involving devices containing progesterone have given particularly good results with heifers. The benefit of using AI is that a proven easy calving bull can be selected. (See Beef Technical Note number 7 for further detail)
Breeding replacements at Greenmount College
Currently 40 April /May calving Limousin x Fr. cows at the Abbey farm are devoted to producing replacements. The herd is currently crossed with a Saler bull that is in the top 10 percent of the breed for 200-day milk EBV. The Saler x heifers’ are then crossed back to a Limousin bull with a positive milk EBV. When the Saler x Limousin cows are crossed to a terminal sire carcase breed 85 percent of the hybrid vigour of the first cross between two pure breeds is retained.
The Saler was chosen to provide ease of calving, hardiness, milk and an ability to hold flesh and breed regularly when nutrition may be limiting. The Limousin helps to retain conformation in the cow.
This herd is self-replacing with the surplus Saler X Lim. heifers joining the June calving herd at the Hill farm. This allows assessment of this particular cross in both the Lowland and the Hill. In the early years of the project sufficient cows are also AI’d to a Limousin bull with a positive milk EBV to provide ¾ Lim. x heifers for the LIMO project at the College. Full physical and financial performance information is recorded allowing the herd to be bench marked against other more traditional suckler systems.
Acknowledgements
To William McLauchlan, Greenmount college who prepared this article.