Page 28 - Hauroko Valley Sale Catalogue eBook.pdf

RUMP - Rump Fat EBV (mm) estimates the genetic differences in fat depth at the P8 site on
a 300kg dressed carcase. More positive EBVs indicate more subcutaneous fat and earlier maturity.
Two fat EBVs are listed as there is variation between animals regarding fat depth at the two sites.
INTRAMUSCULAR FAT - Intramusclar Fat (IMF) EBVs are estimates of generic
difference between animals in intramuscular fat (marbling) at the 12/13 rib site in a 300kg carcase.
Larger, more positive, IMF EBVs are generally more favourable.

ACCURACY: An accuracy is presented with each EBV and gives an indication of the amount of
information that has been used in the calculation of that EBV. The higher the accuracy, the less
the animals EBV is likely to change as more information is analysed for that animal or its relatives.
Accuracy below 75% should be considered low.

INDEXES: The Indexes are derived by acknowledging the relative importance (weightings) of
EBV’s across the 16 EBV’s produced by A.B.R.I. They are derived in relation to Market returns, less
the cost of production, with all indexes expressed in dollar terms.

Selection Indexes rank animals for a single production goal – PROFIT. They take the hard work out of
determining how much emphasis to give each of the available growth, maternal, carcase and fertility
EBVs, when selecting parent animals. An Index is a composite EBV (EBV for Profit) for traits best
suited to a particular production system and/or target market.

There are three breed-specific Indexes for Hereford cattle:

1. Hereford Prime/Maternal Index: Estimates the genetic differences between
animals in net profitability per mixed age cow joined for a typical self-replacing commercial herd
where Hereford bulls are joined to either Hereford or other British breed females and targeting
the production of grass finished steers for the Hereford Prime program. Selected heifers are
retained for breeding and so maternal traits are of importance. Steers target 550 kg live weight
(300 kg carcase weight & 7 mm P8 fat) at 20 months of age, and heifers 475 kg (260 kg carcase
weight & 8 mm fat depth), at 22 months of age.
2. Beef Heifer Index: Estimates the genetic differences between animals in net profitability
per yearling heifer joined for a typical self-replacing commercial herd where Hereford bulls
are joined to either Hereford or other British breed heifers. Selected heifers are retained for
breeding and so maternal traits are of importance. Steers target 510 kg live weight (280 kg
HSCW and 7 mm P8 fat depth) and heifers 450 kg ( 250 kg HSCW and 8 mm P8 fat depth) at
20 months of age.
3. Dairy Beef Index: Estimates the genetic differences between animals in net profitability
per mixed age dairy cow joined with all progeny destined for slaughter. Steers and heifer progeny
target 550 kg live weight (300 kg carcase weight and 6 mm fat depth) at 24 months of age and
at 475 kg live weight (260 kg carcase weight and 7 mm fat depth) at 22 months, respectively.

2021 HEREFORD BREED AVERAGES FOR ALL RECORDED 2019 DROP CALVES
EBV DIR DTRS GL BWT 200 WT 400 WT 600 WT MCW MILK SS DTC
+2.1 +1.8 -0.6 +4.1 +33 +55 +78 +67 +17 +2.0 -2.9
EBV CWT EMA RIB RUMP RBY IMF INDEX HP $ B/H $ D/B $
+52 +3.5 +0.7 +0.8 +0.8 +0.5 +110 +112 +105

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