ANGUS GROUP BREEDPLAN
Angus GROUP BREEDPLAN is an advanced genetic evaluation system that provides a genetic description of Angus cattle for a large range of traits influencing fertility, growth and carcase performance. It provides predictions of the genetic merit of individual animals called Estimated Breeding Values (EBVs).
EBVs are expressed in the units of measurement for each particular trait, and are shown as +ive or –ive values. The average EBV for different traits changes over time as the breed makes genetic progress. The averages for calves born in 2002 are displayed at the bottom of each page in the catalogue and are the easiest way to compare the merits of particular animals.
ACCURACY (%) ~ Provides an indication of the reliability of an EBV. As more performance information becomes available on an animal, it’s progeny and relatives, the accuracy of it’s EBVs for particular traits increases. The higher the accuracy, the less chance that the figure for each EBV will vary.
CALVING EASE DIRECT (%) ~ CE (dir) tells us the amount of calving ease we can expect from a particular bull, relating directly to the females he is joined to. The calving ease figures will generally only appear on the chart of a sire, but can also appear on a younger bull’s chart if there has been a lot of information gathered on his relatives. A positive value here is better.
CALVING EASE DAUGHTERS (%) ~ CE (dtrs) tells us the amount of calving ease we can expect from a particular bull’s daughters. A positive value here is beneficial.
GESTATION LENGTH (DAYS) ~ This figure gives us a value relating to the number of days from the date of conception to the calf birth date. A shorter gestation length is better as it gives more time for the cow to get back in calf and there is less chance of the calf getting too big in the uterus and increasing the chances of calving difficulties. A negative value here is better.
BIRTH WT (KG) ~ Birth weight gives us an indication of how much the calves of a particular animal will weigh at birth. This figure should be monitored, but be careful not to go too low as this can cause problems with calf mortality and calving ease down the track. We must also remember that only a small percentage of calving ease is related to birth weight.
200-DAY WT (KG), 400-DAY WT (KG) AND 600-DAY WT (KG) ~ Estimates the genetic differences between animals in liveweight at 200, 400 and 600 days of age. For example, if you have two bulls, one with a 600 day weight figure of +70 and the other with a figure of +80, you would expect the bull who is +80 to sire calves that would average 5kgs heavier at 600 days than the other (the sire provides 50% of the genes to the calf, 10kgs divided by 2). A positive value for these growth figures is better.
MATURE COW WEIGHT (KG) ~ This figure provides an estimate of the genetic differences between animals in cow weight at 5 years of age.
MILK (KG) ~ The Milk figure provides an estimate of the genetic differences between animals in milk production, expressed as a variation in the 200-day weight of their daughter's calves. Angus cattle generally don’t have a problem providing enough milk for their offspring, so we don’t really need to worry too much about pushing this figure. Too much milk can lead to udder problems and difficulty in getting back in calf, so try to keep it positive, but remember the implications of too much milk.
SCROTAL SIZE (CM) ~ This figure tells us about the scrotal circumference of an animal at 400 days of age. We measure scrotal size because there is a strong, positive correlation between scrotal size and fertility in the male and female offspring. The larger the testicles, the higher the likelihood of that bull siring more fertile daughters and getting more females in calf. A positive figure here is better.
DAYS TO CALVING ~ DC tells us about female fertility, it is expressed as the number of days from the start of the joining period until subsequent calving. A more fertile cow, i.e. one that gets in calf earlier is obviously more beneficial in a breeding program. A negative value here is better.
CARCASE WEIGHT (KG) ~ Carcase weight provides us with an estimate of the variation in carcase weight of a particular animal’s progeny at slaughter( this figure is adjusted to 650 days of age).
EYE MUSCLE AREA (CM2) ~ Results from ultrasound scanning of cattle at 15 – 18 months of age is used to calculate the expected genetic differences between animals in eye muscle area at the 12/13th rib site, in a 300kg carcase. This figure gives us a good idea of the muscling ability of the animal, the more muscling an animal possesses the better, so the higher the value here the better.
RIB AND RUMP FAT (MM) ~ Ultrasound scanning is also used to calculate these figures which estimate the genetic differences between animals in fat depth at the 12/13th rib site (Rib Fat) and P8 rump site (Rump Fat), in a 300 kg carcase. Very fat cattle may produce less yield, however cattle that are too lean, may run into fertility problems, so these figures need to be monitored. The best way to monitor yield and fertility however, is by not necessarily concentrating on fat, but by keeping an eye on yield and fertility!
RETAIL BEEF YIELD % (RBY%) ~ RBY% tells us the expected genetic differences between animals in percentage retail beef yield, in a 300kg carcase. A positive figure here is better.
INTRA-MUSCULAR FAT % (IMF%) ~ Marbling is very important for the premium markets. We can use ultrasound scanning (highly correlated to actual marble score) to provide us with an EBV that estimates the genetic differences between animals in marbling at the 12/13th rib site, in a 300 kg carcase.
$INDEX VALUES
$Index values were developed to make it easier to determine which animals are more suited to particular markets. Breedobject creates these indices, where it places relative emphasis on particular traits suited to each particular market.
RED COLOUR GENE (rc)
The red colour gene is a simple recessive gene. Red Angus animals have two copies of the red colour gene (remember that all genes come in pairs). Animals with only a single copy of the red colour gene will be black in colour, but can have red progeny if joined to other animals carrying the red gene.
If a Red Angus male and Red Angus female are mated, then 100% of the resultant progeny are expected to be red in colour. If a Black hided red gene carrier is mated to a Red Angus then 50% of the progeny are expected to be Red in colour and the remaining 50% are expected to be Black animals carrying a single copy of the Red gene (I,e. red gene carrier animals). If two Red gene carrier animals are mated, then 25% of the progeny are expected to be Red in colour, 25% will be Black non-red carrier animals and 50% will be Black carrier animals.
Sires with at least 40% accuracy for a Structural EBV are reported. |
