Beef farming - breeding

Calves - profit at calving time

Profit from better beef breeding - at calving time

Difficult calvings, dead calves, all of which increase stress and the number of sleepless nights at calving time. But you can now do something about it. Information is now available which allows you to base your bull selection on facts.

During the last 30 years the industry progressed by simple breed substitution, imported continental breeds. Now, the next generation of beef producers must look at what they have inherited and select those animals capable of delivering a profitable future. Fortunately, modern technology and breeding tools are available and if used correctly, can help make the difference. It is important when purchasing any pedigree sire to base the final decision on both visual assessment and genetic information.

Base the future on Estimated Breeding Values (EBV’s).

These are given for a number of recorded traits. AI Services collect the information from pedigree breeders in Northern Ireland and it is then processed by Signet, through the Beefbreeder service. This is possible due to a powerful computer program, known as Best Linear Unbiased Prediction ‘BLUP’. It is able to separate out the genetic factors influencing an animal’s performance from the environmental factors, ie. feeding level and feed type. It is determined by the animal’s own performance and also the performance of it’s relatives. Therefore, using EBV’s to aid stock selection means you are basing decisions on an animals estimated genetic ability and not only on the stockman’s ability to turnout stock.

The EBV’s associated with calving are shown in Table 1. To maximise financial gain it would be best to select bulls with the relevant correct balance of positive and negative trait values, as highlighted.

Each EBV has an associated accuracy value expressed as a percentage point ranging from 0 to 100. The greater the value the more accurate the EBV.

To simplify selection decisions these values have been combined into a multi-trait selection index, known as the Calving Value Index.

The Calving Value Index

This is an overall assessment of the economic value of an animal’s effect on calving, designed to help producers select easy-calving bulls. It is calculated by combining the gestation length and calving ease EBV’s, which also takes into account the birthweight EBV. The calving value is presented as a cash value per head, representative of the bull’s genetic ability. As a bull passes on half his genes to the next generation the value must be halved. For example a bull with a Calving Value of +4 is expected to produce calves which save an average of £2 each in costs associated with calving, compared with a bull with a Calving Value of 0. Positive values mean increased profits, negative values mean a reduction in profits.

Selecting for profit

Compare two bulls. Bull A carries superior genetics for both calving value and beef value when compared with bull B.

Bull A generates an extra £750 income as compared to bull B and with increased selection by pedigree breeders the financial rewards will increase. At Greenmount College the average calving value of the stock bulls is 1. Bulls with high negative values are avoided to ensure physical and financial losses at calving time are kept to a minimum.
So the simple message is:

££ Increase returns by selecting good looking bulls with the right figures ££

Profit from better beef breeding

This article is the first in a series examining how modern breeding technology allows beef producers to select and breed, efficient and profitable animals. It is an introduction to the figures, which are used to describe the performance of beef animals. This information is available from pedigree breeders and is generally shown on cards placed above the bulls at the premier bull sales. Similar information is also available on the heifers and cows in a recorded herd. Other articles will examine how best to use of this information to:

• minimising costs associated with calving
• improve carcase weight and quality
• produce heifer replacements from suckler cows

History

Since the domestication of animals by man, selection has occurred. This has been a mixture of both natural selection ‘survival of the fittest’ and deliberate animal breeding. The deliberate methods of improvement have included:

Breed substitution

The replacement of native breeds with continental breeds such as the Charolais.

Crossbreeding

Combining two breeds such as the Hereford and British Friesian to produce a suckler cow exhibiting hybrid vigour for improved performance.

Within breed selection

Breeding from the better performing animals within a purebred population.
In the late 1960’s pedigree recording schemes based animal selection on raw weights collected from farms. This information was useful in ranking animals according to their mothering ability and growth rates within the recorded farm, but did not allow across farm comparisons of stock.
Therefore, central performance test stations were set up. These got around the problems of small herd size and the inability to compare animals across herds by rearing bulls together post weaning under standard management conditions. However the test stations were extremely costly to maintain and run. It was also difficult to ensure sufficient bull numbers of the correct type and genetic potential entered the station.

Today

In 1991, Best Linear Unbiased prediction ‘BLUP’, a statistical procedure, became available for processing performance data. BLUP separates out the genetic factors influencing an animal’s performance from the non-genetic ‘or environmental’ factors, such as the way it is managed or fed. This is achieved by creating genetic links between groups of animals. For example at least one individual in a group must be the offspring of a sire who also has offspring in another group. This has been possible through the use of AI, which has spread the genetics of certain desirable bulls throughout many herds. BLUP makes use of this linkage to take out differences in management and environment, which occur between farms. This BLUP technology has replaced the need to bring animals together to a central test station. It produces a series of Estimated Breeding Values (EBV’s).

What are EBV’s?

Consider two bulls at a local sale. Both bulls have 400 day weights; bull A was 687kg and bull B 626kg. Automatically we would consider bull A to carry the better genes for growth. However, this may not be the case as bull B may have been lighter at 400 days because he had been ill, received less meal, was not given individual attention and the list goes on. Therefore, actual data can be very confusing and somewhat misleading when comparing bulls at a sale on the basis of weight only.

EBV’s estimate the worth of the animal’s genes for the recorded traits. It is determined by the animal’s own performance and also the performance of it’s relatives. Traits are those indicators of animal performance, which are measured. EBV’s have the same units as the traits (for example kg for liveweight) and are expressed relative to a common baseline. For example, a bull with an EBV of +40kg for 400 day growth is genetically 40kg superior at 400 days compared with the average of the bulls born in the base year, normally 1980. As half of the bull’s genes are passed onto his progeny the calves sired by this bull would be expected to be 20kg heavier on average at 400 days compared with calves sired by an average bull born in the base year.

EBV’s of all beef animals in the same breed can be directly compared. Bulls of the same breed can be compared across herds and also between years. In successive articles the individual recorded traits will be discussed.

Accuracy

With each EBV there is also an accuracy value which is expressed as percentage points ranging from 0 to 100. This provides a guide to the likelihood of an EBV changing ‘up or down’ as more information on the animal and its relatives becomes available. The greater the value the more accurate the EBV. The main factors, which affect the accuracy of EBV’s are:

• whether the animal has been measured itself for the particular trait
• the amount of information on the trait from relatives of the animal
• the heritability of the trait, how easy or difficult it is to pass superior genes from one generation to the next
• the amount of information available on other traits which are related to the trait of interest, for example the birthweight and 200 day weight will influence the 400 day weight of an animal
• the number of animals within a recorded group, the more the better

Multi trait indexes

EBV’s can be combined into a multi-trait selection index for a specific breeding objective in order to maximise improvements. Economic weightings relevant to current market conditions are used to ensure each trait is given the appropriate amount of emphasis in the index. The two indexes available at present are:

Beef Value

To improve the financial value of the carcase by genetically improving carcase weight, fat and conformation scores in line with current commercial carcase pricing structures.

Calving Value

To improve profitability by reducing the costs associated with difficult calvings and extended gestation lengths.

These values are presented as cash values for each animal. Positive values means increased profits, negative values mean a reduction in profits.

At Greenmount College the present stock bulls have average calving and beef values of 1 and 24, respectively. This equates to an extra £12.50 profit per beef calf sired by these bulls over and above a bull with calving and beef values of 0.

Gold Star Bulls

In Northern Ireland there is a gold star scheme which identifies genetically superior bulls in terms of growth and carcase quality. To qualify for a gold star bulls must be recorded through AI services/ Signet Beefbreeder and have been weighed at least three times. The bull must have a current Beef Value equal to or greater than the current breed average beef value and the beef value must have an accuracy of 30% or above. At breed society sales, bulls meeting this criterion will also be subject to an additional inspection by nominated members of the particular breed. Bulls sold directly off farm will also be required to pass an inspection by nominated members of the particular society. Therefore Gold Star bulls should be both visually pleasing and financially rewarding.

££ Increase returns by selecting good looking bulls with the right figures££

Profit from better beef breeding - when finishing cattle

Producing what the market requires as efficiently as possible is commercial reality for all beef producers. The quality of the bull used on the farm is one of the major factors, which will determine the economic viability of a beef producers business, especially at today’s prices. Tools are now available which can aid in bull selection. These are based on actual measurements as discussed in previous articles.

The Estimated Breeding Values (EBV’s) in relation to growth and carcase quality are given in Table 1. These are determined by the animal’s own performance and also the performance of it’s relatives. To maximise financial gain it would be best to select bulls with a mixture of positive and negative trait values, as highlighted.

Each EBV has an associated accuracy value expressed as a percentage point ranging from 1 to 100. The greater the value the more accurate the EBV.

To simplify selection decisions these values have been combined into a multi-trait selection index, known as the Beef Value Index.

The Beef Value Index

This is an overall assessment of the economic value of an animal’s ability to produce a carcase demanded by the market in terms of weight, conformation and fat class. It is influenced most by 200 day growth, 400 day growth, muscle score, fat depth and muscle depth. The beef value index is also presented as a cash value per head, representative of the bull’s genetic ability and must be halved, as the bull passes on half his genes to the next generation. For example a bull with a Beef value of +24 is expected to produce calves, which will produce an extra £12 income/head, compared to a bull with a Beef Value of 0. Again positive values mean increased profits.

Selecting for profit

Compare two bulls. Bull A carries superior genetics for both calving value and beef value when compared with bull B.

Bull A generates an extra £2750 income as compared to bull B and with increased selection by pedigree breeders the financial rewards will increase. At Greenmount College the average Beef Value for the stock bulls is 24. Therefore in terms of the financial value of the carcase each calf sired by these bulls will on average generate an extra £12.00 profit compared with calves from a bull with a beef value of 0.
So the simple message is:

££ Increase returns by selecting good looking bulls with the right figures ££

Rearing heifer replacements

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

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.

Synchronisation

The use of synchronisation and artificial insemination in beef cows

About two thirds of the suckler herds in Northern Ireland have less than 20 cows. Many of these farms cannot afford to purchase a top quality recorded stock bull. Use of artificial insemination (AI) is difficult as many farmers keep cows in remote locations or have off farm employment.

Synchronisation enables groups of cows to be prepared for breeding at a time selected in advance. It gets around the problems of accurate heat detection, which can limit the use of AI in suckler herds. AI allows beef producers to gain access to superior genetics, through the use of bulls with high Estimated Breeding Values. Several bulls may be selected for use in the herd, allowing flexibility. The mating policy includes bulling heifers to easy calving bulls and the selection of milkier cows mated to beef bulls with good 200 day milk EBVs for the production of heifer replacements.

Guidelines to synchronisation

The following are general guidelines. For detailed instruction on the different methods of synchronisation contact your local vet.

Do:

• select cows carefully
• at least seven weeks calved before synchronisation device/implant is put in
• body condition score at least 2.5 - avoid thin cows, body score less than 2 -avoid fat cows body score greater than 4
• have no signs of discharge - problem cases should be checked by the vet
• avoid cows with a - history of breeding problems - which have produced more than seven calves
• cows should be settled at grass or in the house for at least three weeks
• feed cows well in the month after service
• plan the breeding program carefully in conjunction with your vet and AI personnel
• follow the recommended time program - accurate timing of AI following removal of implants is very important
• provide a good working environment - a good crush is essential for restraining cows during insertion and removal of implants, and to facilitate AI

Don't:

• don't stress the cows during synchronisation or the weeks following service- stress factors include changes in nutrition and housing, dosing, injecting, foot trimming
• don't assume that cows are long enough calved - check that they are
• don't use cows which might have been served already - it may cause them to abort
• don't use on cows that tend to be nervous
• don't expect miracles! - normal conception rates are about 60 percent

AI following synchronisation

In cows single fixed time AI can be carried out 56 hours after the implants have been removed, with heifers the AI should be carried out 48 hours after implant removal. Double fixed time Ai can be carried out at 48 and 72 hours after the implant has been removed. All animals should be AI’d whether or not they are seen in heat.

Improving conception rates

PMSG may be given by intramuscular injection at the time of implant removal. It should be used in beef cows where their condition (body score <3) and plane of nutrition are poor and in adult cattle, which have calved less than 60 days previously. Approximate cost £2/cow.

Many trials have found positive benefits from injecting cows with GnRH or GnRH agonist (for example fertirelin acetate). Cows can be treated at the time of insemination or between days 11 to13 after insemination. When treated at insemination conception rates have been shown to improve by about four - six percent. But it was found to be more successful when cows were treated between days 11 to 13 after insemination, with conception rates improving by about 11 percent (54 to 65 percent conception to first service). Approximate cost £5/cow.

Unlike heifers, cows have a much greater range in their length of oestrus. When a more precise synchronisation is required e.g. for embryo transfer or large-scale synchronisation, the additional treatment with a prostaglandin injection a minimum of 24 hours before the implant is removed, will give a tighter oestrus period. In this case one insemination 54-56 hours after implant removal is required.

In recent years work has been carried out by SAC scientists to develop a Triple Synchronisation programme. It has been shown using CIDR implants, GNRH and prostaglandin injections that conception rates of 90 percent can be achieved. This programme costs around £50/pregnancy.
Before considering any of the above seek advice from your local Veterinary Surgeon.

Planning Chart for Synchronisation and AI

Although the program can be started on any day of the week the following option avoids weekend operations.

Timing is crucial

Using the preferred regime aim to insert and remove implants in the morning and AI cows 56 hours after removal.

For example, if you want to inseminate on a Friday, implant/inject on the Monday morning of the previous week (day 0). Remove the implant and inject with PMSG on Wednesday morning of the following week (day 9). Heifers can then be inseminated on Friday morning [48 hours after implant removal] (day 11) and cows on Friday afternoon [56 hours after implant removal] (day 11).

What to do if cows are still standing following AI

Occasionally cows will show standing heat after they have been inseminated. If an individual cow is still showing standing heat on the day following AI it is worth having her served again.

What to do with repeat breeders

Synchronisation may have a beneficial effect on repeat breeders. If the problem with these cows is a short or silent heat, their continual repeating may be due to wrong time AI. In such cases synchronisation may eliminate this problem.

Proven benefit of synchronisation and AI

In a series of projects, Beef Technologists at Greenmount College examined the use of crestar implants and CIDR devices as methods of synchronisation. In the first project a total of 12 spring calving suckled calf producers used the crestar implant during a two year period. In the first year, 91 cows were synchronised and double AI’d at 48 and 72 hours after withdrawal of the implant. In the second year, 43 cows were single AI’d at 56 hours after the implants were removed.

In the first year of the 91 cows exposed to synchronisation and double insemination, 55 AI calves were produced. This resulted in a conception rate to Ai of 60.4 percent. In Year 2, of 43 cows exposed to synchronisation and single AI, 20 produced calves. A conception rate to Ai of 46.5 percent.

Table 1. The 200 day weight, conformation* and growth potential^ scores of calves born to cows synchronised and Ai’d or natural service.

* Based on a conformation score where E=1, U=2, R=3, O=4, P=5
^ Based on a growth potential score where 1= excellent, 2 = very good, 3=good, 4= fair and 5 = poor

Table 1 shows the performance of the calves born to Ai sires and those born to natural service. The male and female calves produced by AI bulls were 36 and 51 kg heavier at 200 days of age than the calves bred by natural service. This extra weight was reflected in the higher growth potential scores for AI calves. Also the calves born to Ai sires were better shaped as indicated by higher conformation scores.

Economics

Assuming the following costs/cow, crestar and insertion by vet £8.13, crestar removal by vet £1.20 and single AI costing £8.95, the cost of the synchronisation and double AI is £46.73/calf born (60 percent conception rate and £28/cow synchronised and double AI’d). The cost of the synchronisation and single AI is £41.50/calf born (46 percent conception rate and £19.10/cow synchronised and single AI’d). Assuming natural service costs of £18/calf for a bull producing 40 calves per annum, though the cost on the average sized N.Ireland farm is likely to be double this at £36/calf, where a bull can be substituted by synchronisation and Ai the increased weight and calf quality must cover the additional cost. In the project outlined above the additional weight at 200 days averaged 43kg/calf.

This in itself should cover the synchronisation and Ai costs even before considering possible premiums for improvements in the quality of the calves as denoted by improved conformation and growth potential scores. It is much more difficult to justify synchronisation and AI where it is not substituting for a bull. From the project it is calculated that the extra weight gain would have to be worth £109/100kg to cover the costs of synchronisation and double Ai or £97/100kg to cover the costs of synchronisation and single AI

Using Crestar or CIDR synchronisation techniques

In a subsequent three year project based on 12 farms, cows were selected for synchronisation using the crestar technique or the CIDR technique. Initially in year one the cows were randomly selected but in years two and three cows were physically assessed as to their suitability for using the CIDR. Only cows assessed to firmly retain the CIDR implant were synchronised using this technique. In total 195 cows were synchronised using the crestar technique and 58.5 percent held in calf to first service. A similar conception rate was observed when using the CIDR technique. Of 134 cows synchronised, 55.2 percent held in calf to first service.

Summary of Synchronisation and AI

Advantages

• the use of proven superior bulls
• a more compact calving
• reducing the amount of heat detection
• shortening the calving to conception interval

Disadvantages

• considerable handling of cows, a minimum of three times
• a cost of about £19/cow for synchronisation and single AI and £28/cow for synchronisation and double AI.
• will not improve cow fertility and may prove disastrous with poor breeding management

Conclusions

Don’t keep a bull to mate less than 15 cows/year, it is more economical to use synchronisation and AI.

At store and finished beef prices above 75p/kg liveweight it is more economical to use synchronisation and AI rather than mate cows to a poor quality bull.