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Performance Recording

[sire & dam summary]

 

Performance Recording – Annual Report 2007

In 2005 this report identified that bull sales from Perth and Carlisle grossed over £1.75 million, highlighting the strength and scale of the Limousin breeding industry. In 2007, this figure has risen to over £3 million, demonstrating buyers’ increasing commitment and a new demand for the breed in times that are considerably more difficult for suckler herds than even just three years ago.

This should therefore give some comfort that the product is good. Despite the difficult operating conditions, buyers are returning, new buyers are coming on board and sales are increasing. Sale evidence continues to identify too, that recorded bulls are keenly sought after, with a continuing strong relationship between price and Beef Value (Table 1).

Table 1: Carlisle Autumn Bull Sale Results

Beef Value No Sold Average Price (gns)
Top 1% 18 8567
Top 10% 35 3831
Top 25% 21 3743
Average 6 3600
Below Average 6 2333
Non-Recorded 23 2900


The average price increases as Beef Value increases with a significant premium paid for bulls in the Top 1%

Non-recorded bulls sold at an average price less than those with just average Beef Values.

It would be easy for all to sit on these laurels, but there is a proverb that says ‘if we don’t change, we don’t grow’ and 2007 has seen a year of significant change brought about by Signet and the Society working together to enhance future performance recording for breeders and their buyers.

NEW DATABASE
The Society’s new pedigree database allows all Signet performance data to be entered alongside the pedigree records of each individual animal. This means that pedigree and performance records are now held on one file (rather than two) leading to a much more accurate BLUP analysis than previously with many more animal records successfully linking in to it.

New Pen Card

NEW PEN CARDS
At some of the breed sales this year we trialled a new design of pen card illustrating the Estimated Breeding Values (EBVs) in the form of a bar chart (diagram 1). Support from breeders and buyers has been strong and, as a result, this will now become the standard form of presentation at all breed sales.

NEW MATERNAL EBVS AND INDEXES
These new EBVs and Indexes have been developed from trial data collected from commercial and pedigree herds in the UK over a period of several years and are unique in this respect. They specifically target producers wishing to select bulls to breed suckler replacements:

New EBVs
Calving Interval (days)
Age at First Calving (%)
Longevity (years)
Maternal Calving Ease (%)

Data is also being collated from breeders to produce EBVs for other ‘functional’ traits such as Udder and Teat Shape, Cow Weight and Scrotal Circumference. Once sufficient data banks have been built up, these EBVs can be developed.

New Indexes
With these new maternal EBVs has come a new Maternal Value Index. Incorporating the four new EBVs above as well as the existing 200-Day Milk EBV, this index identifies the overall economic value of an animal’s ability to produce breeding females.

Two further Indexes have also been developed and will be released when the new Cow Weight EBV referred to above can be published. They are a) Maintenance Value (the economic cost of cow size) and b) Maternal Production Value (incorporating the Maternal Value Index, the Maintenance Value Index and the existing Calving Value and Beef Value Indexes to predict the overall economic value of an animal in terms of its genetic merit to produce female replacements for breeding AND males for finishing).

NEW DOCILITY EBV
There is evidence that buyers of all breeds would like to place much more emphasis on selecting for animal temperament than they can at the moment and this is almost a direct result of less time and labour available on farms to handle stock. Forms have recently been released asking breeders to start collecting temperament scores on animals aged between 350-500 days using a scale based on their behaviour in the crush. This will start collection of a bank of data that will be analysed to produce the eventual EBV. How quickly this happens will depend on breeder support and the quantity of data received to carry out its development.

NEW COMMERCIAL DATA
An independent study completed this year by Harper Adams University College (on behalf of EBLEX and Genus) identified that dairy-bred calves sired by a Limousin bull with a Beef Value in the Top 1% of the breed were worth over £45/head more than calves sired by a bull with a Beef Value in the Bottom 1%. In addition, calving performance was as predicted from the sire’s calving EBVs.

Performance recording works and 327 herds are currently involved in the scheme. Breeders that do not record their herds should have the confidence to do so. Simply because an animal is currently non-recorded does not mean it will have ‘poor figures’ and there is a risk that some high performers will fail to be identified and their true value realised just because the information is not available.

AND FINALLY…
The Limousin breed dominates the market in terms of its prevalence in commercial herds (source: BCMS). The breed will undoubtedly change as commercial producers’ objectives change and performance recording has an important role to play within that. Indeed, for the 327 herds that currently record, the process has started already; whilst some of the new EBVs above may be regarded by some as folly, their advent has been driven by the decoupling of subsidy and producers’ shift in demand for ‘functionality traits’ as well as the more traditional ‘production traits’. If we don’t change, we don’t grow.

download Genetic Trends (.xls file)

Understanding Estimated Breeding Values (EBVs)

Estimated Breeding Values (EBVs) estimate the genetic worth of animals. They are produced for each animal for each recorded trait from Beefbreeder and Society records using BLUP technology. EBVs use the same units as the recorded traits (eg kg for liveweight) and are expressed relative to a common baseline for all animals in all contemporary groups. In the UK, the baseline is set so that the average of the breeding values for all animals born in 1980 is zero.

Because BLUP takes environmental influences into account and all EBVs are expressed relative to a common base, direct comparisons can be made across herds (as long as they are linked genetically). Across-herd BLUP increases the size of the genetic pool from which replacements can be accurately chosen, thus increasing selection intensity and reducing the risk of inbreeding.

Comparisons can also be made between animals across time allowing measurement of genetic progress. Genetic progress in a breed can be charted year by year, both nationally and on an individual herd basis. This provides a valuable check for breeders and can be an important marketing tool for convincing commercial customers that the breed is improving.

DIRECT TRAIT EBVs

Because sires and dams only pass on half of their genes each to the next generation, their direct trait EBVs must be halved in order to establish how much of their genetic superiority (or inferiority) will be passed on.

BIRTH WEIGHT (KG)
High birthweights are more likely to be associated with difficult calvings. A bull with an EBV of –1 is expected to produce calves 0.5kg lighter at birth than calves sired by a bull with an EBV of 0.

GESTATION LENGTH (DAYS)
Gestation length affects birth weight and consequently calving ease (ie a shorter gestation length results in easier calvings because birth weights are lower). A shorter gestation length is also important because it increases the interval between calving and the start of mating, which gives the cow more time to recover.

The more negative a bull’s EBV, the shorter the expected gestation length when his offspring are born. A bull with a gestation length EBV of –2 is expected to produce calves that are born one day earlier than calves sired by a bull with an EBV of 0. To maximise accuracy, Beefbreeder currently only uses gestation length records that refer to an AI mating, although the use of data from some natural matings is being considered.

CALVING EASE

This EBV predicts the effect of using a particular bull on the percentage of unassisted calvings when his calves are born. It is recorded subjectively using 5 categories: category 1 indicates no assistance is required; category 5 refers to surgery section other than elective caesarean. Approximately 3% more of the calves sired by a bull with an EBV of +6 for calving ease are expected to be born easily compared to calves sired by a bull with an EBV of 0.

200-DAY GROWTH (KG)
The EBV is a measure of an animal’s genetic potential for growth from birth to weaning at about 200 days. A bull with an EBV of +20 for 200 day growth is expected to produce calves 10kg heavier at weaning compared to calves sired by a bull with an EBV of 0.

400-DAY GROWTH (KG)
The 400 day growth EBV is a measure of the animal’s genetic potential for growth to 400 days of age. A bull with an EBV of +40 for this trait is expected to produce calves 20kg heavier at 400 days than calves sired by a bull with an EBV of 0. Selection for faster growth (ie high 400 day EBVs) results in animals which will have heavier carcases at a constant fat class or leaner carcases at a constant age. Selection for high growth rates also results in an overall increase in mature size for that breed (and therefore higher birth weight).

MUSCLING SCORE (POINTS 1-15)
This EBV is a visual assessment of an animal’s conformation at around 400 days of age. Animals are assessed on a 1 to 15 point scale based on the EU carcase classification system. A score of 1 indicates very poor conformation (equivalent to P) whereas the muscles of animals with a score of 15 will be extremely well formed (equivalent of E). The scale is adjusted for fat.

A bull with a muscling score of 1.0 is expected to produce calves 0.5 points better on the conformation scale than calves sired by a bull with an EBV of 0.

MUSCLE DEPTH (MM)
This is based on the ultrasonic measurement of eye muscle depth at around 400 days and provides a direct measure of carcase worth in live animals. A bull with an EBV for muscle depth of +0.2 is expected to produce calves with 0.1mm greater eye muscle depth compared to calves sired by a bull with an EBV of 0.

FAT DEPTH (MM)
Fat depth is based on an ultrasonic measure of backfat depth at around 400 days of age. Negative EBV’s for fat depth indicate leanness. A bull with an EBV of –0.2 for fat depth is expected to produce calves 0.1mm leaner at 400 days than calves sired by a bull with an EBV of 0.

A negative fat depth EBV suggests that if the animal was slaughtered at the same weight as an animal with a positive EBV for this trait it would produce a leaner carcase or, if required, it could be taken to a heavier weight to achieve a similar carcase fat cover.

MATERNAL TRAIT EBVs
Maternal traits are only expressed by females so a bull’s EBV for 200-day milk, when halved, gives an indication of how well a bull’s heifer calves will perform as mothers when they themselves are mated.

200-DAY MILK (KG)
The maternal component of the 200 day weight record estimates how much of the performance of the calf up to 200 days (weaning) is due to the dam’s maternal performance. For example milkiness, uterine capacity and general mothering ability. A bull with an EBV of +4 for 200 day milk is expected to produce heifer calves which will have above average maternal characteristics leading to their calves being 2kg heavier at 200 days than calves from heifers sired by a bull with an EBV of 0.

Information to derive 200 day milk EBVs comes from two main sources – the most valuable one being the 200 day weights of offspring (of cows) or grand offspring (of bull or cows). Other things being equal, families with high genetic merit for 200 day milk will leave calves with higher weaning weights than families with lower EBVs.

However, it takes a long time to get many records on offspring or grand offspring and, in the meantime, records of 200 day weight (and correlated traits) from the animal and its relatives can help. In this case 200 day milk EBVs are based on the fact that, in general, families with high genetic merit for weight gain are slightly poorer than average for milk yield, ie there is a negative correlation between milk production and growth. (This is similar to the situation across breeds where faster growing breeds tend to be poorer milk producers.)

SELECTION INDEXES
EBVs can be combined into a multi-trait selection index for a specific breeding objective, or set of objectives, (eg an index for growth and carcase traits) and selection can be based on this. It is widely agreed that this is the most efficient method of improving several traits at once. Economic weightings relevant to current
market conditions may be used to ensure each trait is given the appropriate amount of emphasis in the index.

BEEF VALUE
The Beef Value ranks animals on the expected carcase financial merit of their offspring. The objective of the Beef Value is to improve financial returns by improving carcase weight, fat and conformation scores in line with current commercial carcase pricing structures.

For example, a Beef Value for a bull of 20 means his carcase is estimated to be £20 more valuable than the carcase from a bull with a Beef Value of 0. As with the EBVs a bull’s Beef Value must be halved to estimate the value of his calves. If the cow’s Beef Value is also known (eg in a pedigree herd) the best estimate of the value of the calf is half the cow’s Beef Value plus half the bull’s Beef Value. For example, if a cow with a Beef Value of 10 is mated to a bull with a Beef Value of 20 the expected Beef Value of their calve is 5 + 10 = 15.

All Beef Values are expressed relative to a common base year which is defined so that an average animal born in 1980 had a Beef Value of £8. Beef Values cannot be compared across breeds and to avoid confusion they are prefixed with two letters which indicate which breed they refer to. This is LM for Limousin, eg LM15.

CALVING VALUE
The objective of the Calving Value is to improve financial returns by reducing the costs associated with difficult calvings (eg veterinary costs, loss of production) and longer gestation lengths (eg feeding/housing the pregnant cows, extended calving intervals). It is designed to help producers select terminal sires that will produce calves that do not have extended gestation lengths and which are born easily.

The Calving Value is presented as a cash value per head and must be halved in the same way as the Beef Value. For example, a bull with a Calving Value of 4 is expected to produce calves which save an average of £2 in calving and gestation length costs compared to calves sired by a bull with a Calving Value of 0.

All Calving Values are expressed to a common year which is defined such that an average animal born in 1980 had a Calving Value of £2. The values cannot be compared across breeds and to avoid confusion with the Beef Value they are suffixed with the letter C, eg LM4C indicates a Calving Value of +4.

Having two indexes provides users of the Beefbreeder genetic evaluation scheme with flexibility. The economic importance of the various traits differs substantially across breeds and production systems and two indexes allow trade-offs to be made between the emphasis put on calving traits and on growth and carcase traits.

EBV ACCURACY
There are several factors that affect EBV accuracy:
-       the amount of information available on the trait from the animal itself;
-       the amount of information on the trait from relatives of the animal;
-       the heritability of the trait concerned;
-       the amount of information from the animals and its relatives on traits correlated with the trait of interest and the strength of the correlation’s;
-       the number of contemporaries recorded.
Accuracy values are presented along with the EBVs and they indicate how close the EBVs are to the true breeding values of the animal. In the UK they are expressed as percentage points ranging from 0 to 100.

Accuracy’s provide a guide to the likelihood of an EBV changing (up or down) as more information on the animal becomes available, for example a low accuracy value indicates that there is a high chance the EBV will change. However, it is important to note that the BLUP evaluations will have already compensated for a lack of information on an animal by adjusting its EBVs towards the average.