Ease of Calving
Introduction: This is the sixth of a series of 12 articles on Simon Frost’s suckler herd at Youlgreave in the Peak District. Simon achieves top 1% performance with his upland herd of 125 Limousin x Holstein-Friesian cows put to Charolais bulls which is the basis of the Farmers Weekly/Harper Adams Beef Focus Farm concept. The Charolais bulls have top 1-5% Terminal Indexes with focus on calving ease, growth and muscle EBV’s. The calves are sold at weaning to Alan and John Dore at Chesterfield and intensively finished. Last year the bull calves recorded a carcase weight of 438kg at 447 days old, which is exceptional performance.
This article discusses factors affecting calving ease and presents the birth weight and calving ease scores from the 2011 Hopping Farm calf crop.
Ease of calving Ease of calving together with high daily carcase gains are key factors in determining profitability with suckled calf production.
Simon Frost uses high index Charolais bulls across his herd of Limousin x Holstein-Friesian suckler cows. Charolais bulls are also used on the bulling heifers which is a strategy few suckler producers would contemplate. This decision is taken based on the confidence in the bulls Calving Ease Direct EBV which have a high accuracy percentage. This avoids keeping a bull of a different breed which is likely to have a lower daily carcase gain.
The Charolais has the highest carcase weight for age figure of all the beef breeds but this is associated with the highest incidence of difficult calvings since high growth rates are correlated to increased calf birth weights which creates issues with calving difficulties. It should be stated however that there is more variation within a breed than between all of the major beef breeds and that there are easy calving Charolais bulls as well as very hard calving Charolais bulls. Simon Frost spends a considerable amount of time studying the bull sale catalogues to search for ‘curve benders’ – easy calving bulls identified by EBVs but with very high growth rates and muscle area. The Breedplan performance recording system provides breeders with practical help in identifying bulls with excellent growth and muscling that the breed is renowned for. Meanwhile an improvement in Calving Ease of the national Charolais herd has been achieved in the last year and the Charolais is the only beef breed to have achieved this.
The beef industry needs to take a ‘leaf out of the book’ of the poultry industry. This is a sector that doesn’t receive subsidy and producers have had to focus on genetic improvement for growth and FCR. In the 1950s it took a bird 77-84 days to get to table weight. About 15 years ago it took 42- 43 days to get to 2.25 kg with an FCR of about 1.8- 1.9. Now it takes 35 days with an FCR of 1.7. What must be remembered that despite this tremendous improvement in growth rate is that ‘the egg has never got any bigger’!
Pedigree breeders must give greater priority to calving ease and I see no place for hard calving bulls in the beef industry. Bulls that are easy calving can be identified by the Calving Ease Direct EBV which should have a positive score with a high accuracy of at least 45% but ideally over 50%. Using these bulls on cows that are in lean condition (score 2) at calving will significantly minimise calving problems and deaths.
The calving data from the 2011 calf crop from Simon Frost is presented in table 1. It compares the calving results from two sires, Littlebovey Altra and Balthayock Clifford. When comparing the two bulls Altra has the best Calving Ease Direct EBV (+2.4 versus -3.1) and lower Birth Weight EBV (+2.2 versus +3.6kg) however Clifford has the highest 400 day weight EBV (+62 versus +44kg) and Terminal Index (45 versus 35). The results clearly show how faith can be put in EBVs with Altra’s calves being born lighter with an easier calving score. Calving difficulty score is based on a scale from 1 (unassisted) to 5 (caesarian).
Table 1. Hopping Farm 2011 Calf Crop Results.
|Sire||Altra (Terminal Index +35 Top 5%)||Clifford (TI +45 Top 1%)|
|Calving Ease Direct EBV (%)||+2.4 (Breed Average -0.1)||-3.1|
|Birth Wt EBV (kg)||+2.2 (Breed Average +2.5)||+3.6|
|Birth Wt (kg)||37.0||41.9||43.4||48.3||40.1||49.0|
|Birth Wt Range (kg)||35-41||39-45||40-47||43-51||38-48||33-57|
|Calving Ease Score (1-5)||1.0||1.4||1.4||2.0||1.4||2.2|
|Calf Mortality (%)||0||0||0||0||0|
Altra was used on the replacement heifers which go to the bull 3 weeks before the main herd and he was then put to a group of cows. It is interesting to note that the calf birth weights from the cows were on average 6.2kg heavier compared to the first calving heifers. Simon Frost attributes much of this to the condition of the heifers. The heifers started the winter in mid pregnancy in fit condition (score 3-3.5) and were outside living off ‘snow and straw’ (they also got 3.5kg of 45%DM silage plus free access to mineral buckets). They were housed in early January four-six weeks from calving and fed a low energy ration based on 6kg of silage and ad lib straw supplying only 62 MJ of ME. The heifers calved down at condition score 2.25 and as can be noted from table 1 calving problems were virtually nonexistent.
Simon Frosts approach to managing calving and hence minimises losses is to try and be present at the birth which does mean some late nights or early starts in the morning. This is only practically possible with a compact calving period. This supervision ensures that the calf receives its first vital colostrum intake within 30 minutes of being born. Over the years Simon has developed his expertise to supervise calvings and believes too many stockmen are too quick to get on the calving ropes and pull the calf especially when the head and shoulders are out. Patience is often required!
The calf that died from Clifford was 1 out of 29 bull calves that were born and according to Simon Frost it was a thick heavy shouldered and well fleshed calf that weighed 47kg and would have easily graded an E if he had survived. Despite this loss a mortality rate of 1.2% from 84 calves sired from the 2 bulls is exceptional performance. Overall calf mortality for the herd was 0.8% which compares favourably to calf mortality rates in ‘average’ and top 1/3rd EBLEX recorded LFA sucker herds of 2.2% and 1.7% respectively.
The mother of the calf that died also had a very difficult calving last year so she has been marked for culling. This aspect of culling dams which have birthing difficulties (not attributed to the sire) is a strategy which the easicare sheep producers have adopted.
This year the vet was only called out once to deal with a difficult calving. It was a big calf presented backwards so the decision was taken to carry out a caesarian in order to get a live calf.
The third bull used by Simon Frost last year was Swalesmoor Duke. His Calving Ease Direct EBV is +4.5 with a Birth Weight of +2.0kg yet an impressive 400 day weight EBV of +48kg and Terminal Index of +40 making him a Top 1% bull. His calving data is shown in table 2 and clearly identifies him as having the easiest calving figures of the three bulls and again confirms the reliability of EBVs.
Table 2. Calving Data for Duke.
|Duke (TI +40 Top 1%)|
|Calving Ease Direct EBV (%)||+4.5 (Breed Average -0.1)|
|Birth Wt EBV (kg)||+2.0 (Breed Average +2.5)|
|Dam||Limousin x Cows|
|Birth Wt (kg)||40.2||47.8|
|Birth Wt Range (kg)||37-43||35-54|
|Calving Ease Score (1-5)||1.0||1.8|
|Calf Mortality (%)||0||0|
Simon Frost regularly hosts visit by Harper Adams students. The ideal time is just after calving when the students see the new born calves. Many students comment that the calves don’t look very big or impressive, but the answer to that is that if you choose easy calving bulls then you are going to get modest sized calves that are born alive and not dead! When the students then see the bulls that are intensively finished that are from last year’s calf crop weighing 700kg at 13 months old there is ‘sheer and utter silence and a dropping of jaws’ as they cannot believe how much the bulls have grown!
The results from the 2011 calf crop clearly illustrate that EBVs work and the take home message is ‘have faith in EBVs to improve performance and profit’.
The beef industry must embrace EBVs. In North America and Australia breeding bulls are often purchased ‘blind’ by the buyer and selected purely on EBVs. They are also starting to embrace genomic enhanced EBVs using DNA technology to identify factors such as tenderness, marbling but also recently to identify dry matter intake and residual feed intake. Some pedigree breeders in the UK are now starting to use this technology to aid breed selection and improvement. This gives a lot more data to support bull buying decisions. There is a classic phrase ‘Information is Power’ which definitely applies to EBVs.
The UK beef producer would never buy a bull without seeing him in the flesh since he will want to see the bull walk and assess his style. My plea to the industry is that if he has an ugly head or his ears are in the wrong position do not reject him if he has fantastic EBVs! What commercial value has a head – NONE.
Ease of Calving summary:
• Select bulls with positive Calving Ease Direct EBVs and high 400 day and eye muscle area EBVs i.e. curve benders’
•Aim for accuracy figures of 45% or higher with the Calving Ease Direct EBV
• Target Birth Weight EBV ideally at breed average or lower
• Calve cows at Condition Score 2
• Have faith in EBVs