Four-star and five-star female breakdown

It has been suggested in some quarters that the Replacement Index is promoting first cross beef heifers from the dairy herd and that all of these beef x dairy females are 4 or 5 stars automatically. This is not the case.

Analysis

Analysis of the national suckler cow herd after the August evaluation run shows that there are 437,299 suckler cows that are 4 or 5 stars on the Replacement Index. Of this, 315,457 (72%) are suckler bred cows (beef sire and beef dam), while 121,842 (28%) are first crosses from the dairy herd (beef sire and dairy dam). Analysis of un-calved females shows that there is a slightly higher percentage of beef x dairy heifers in the 4 or 5 star categories. 503,136 heifers are 4 or 5 star on the Replacement Index. Of this, 324,533 (65%) are suckler bred animals (beef sire and beef dam), while 178,603 (35%) are first crosses from the dairy herd (beef sire and dairy dam). Table 1 gives a breakdown of the analysis.

Replacement Index makeup

The Replacement Index gives an overall summary of an animal’s strengths and weaknesses across all of the traits of importance for a suckler cow. Maternal traits, such as milk and fertility make up a large proportion of the Index. The importance of a suckler cow’s ability to pass on good growth genes to her progeny is also acknowledged through the emphasis on traits such as carcass weight and conformation.

Emphasis on Milk

The ability of a suckler cow to produce milk is a key determinant of the weight gain of her calf from birth to weaning. The milk figure in the €uro-Star Index is expressed as maternal weaning weight. The higher this figure is in an animal’s index, the higher their genetic merit is for milk production which leads to heavier calves at weaning time. Each kg unit of maternal weaning weight is worth €5.58 to the overall Replacement Index. The fact that beef x dairy females tend to have high maternal weaning weight figures (>10 kg) as a result of the dairy influence, means that in many cases their overall Replacement Indexes are made up primarily of milk. While they benefit greatly from their dairy background on milk, they tend to have very low, even negative carcass figures.

Breeding a balanced animal

As already stated, the Replacement Index takes into account both maternal and terminal traits. Adoption and the correct implementation of the Replacement Index as a tool to help select breeding stock will lead to a more “balanced” efficient suckler cow in the future with adequate milk, fertility and carcass traits. It is for this reason that the BDGP encourages participating farmers to introduce more high Replacement Index breeding stock into their herds.

Completion of Requirements

1. Survey Data: Survey data should be recorded online (www.icbf.com, www.agfood.ie or via farm software) or on paper survey forms posted to participants. Remember additional data (docility, quality, scour and pneumonia) must be recorded for calves when they reach 5 months of age.

2. DNA Samples: Participants must return DNA samples (tissue tag or hair card) for 60% of their reference number. For replacement of DNA samples for animals sold or dead please contact 1850 625 626.

3. Carbon Navigator: Participants must ensure that they have completed a Carbon Navigator with an approved adviser (list available at www.agriculture.gov.ie/beefschemes). The new extended deadline for completion of the carbon navigator is 30 November 2016.

Table 1: Analysis of breed type makeup of 4 and 5 star females

	Total 4 or 5 Star	Beef x beef	Beef x dairy
Suckler cows	437,299	315,457 (72%)	121,842 (28%)
Beef heifers	503,136	324,533 (65%)	178,603 (35%)

Q&A

Q. Are all beef x dairy females automatically 4 or 5 stars on the Replacement Index?

A. No they are not. While these females have the benefit of a high genetic merit for milk production due to their dairy background, they also tend to have very low carcass traits. The beef bulls that these heifers are sired by also have a big influence as they represent 50% of the animal’s genetics.

Q. Milk is a big problem for my herd. What can I do to help improve it?

A. While high Replacement Index stock will generally have positive milk figures, this may not always be the case. If you specifically need to improve milk in your herd then you will need to look at the milk figure in the €uro-Star Index of males and females. A positive milk figure is desired and the higher this figure is the better.

Replacement changes already made

Name: Tom O’Reilly, Cunareen, Aughnacliffe, Co. Longford

Farming System: Suckler to weanling.

4 and 5 star females: Cows: 22; Heifers: 16.

Stock bull or AI: AI and stock bull mopping up.

Replacement strategy: Breed my own.

Tom O’Reilly farms a 26-cow suckler herd on a fragmented farm in Aughnacliffe, Co Longford. Tom is also a weighing technician for ICBF.

What is your farming system?

We calve our cows in the springtime, between January and April. Bull calves are sold in the mart as weanlings. Heifer calves are kept until the start of the breeding season. At this point, I keep the most suitable heifers as replacements and sell the remaining. Heifers are calved at two to two and a half years old.

What changes have you made to your replacement strategy?

I made a change to by breeding strategy about eight years ago, I realised I needed more milk in my cows. I was using very terminal type bulls, the weanlings were excellent grades but had low weights and my replacement heifers were not grown enough to calve down at 24-30 months. I have been using more milky bulls since then, the weights of my calves have increased and heifers are making target weights to calve at 24-30 months. When selecting AI bulls I am looking for bulls with good maternal traits, especially milk and temperament.

Have you taken time to look through your latest BDGP report?

I found it interesting to see the animals that have had a change to their index as a result of genotyping. I had a very nice-looking heifer with excellent back pedigree; she has had two calvings now and the progeny were average. She doesn’t seem to have the genetic make-up of her parents. I wasn’t surprised to see in the latest report that her index has dropped.