SIL Flock 452 - Wairaki Romneys
Current Breeding Objectives
Our goal is to breed a low cost maternal sheep that can handle a tough environment and maximise output of quality meat and wool.
- Low costs as in no drenching, no dagging, no assistance at lambing and recently breeding for FE tolerance.
- Maximising output of quality meat and wool - Our focus is still on production and performance including quality within a low cost system and challenging environment.
We have been selecting rams and ewes to retain based on structural soundness, good constitution and genetic merit. The genetic indexes we have been using are the New Zealand Maternal Worth index (NZMW) + WormFEC (DPF) + Meat (DPM) + Dags (DPD) produced from the weekly NZ Genetic Evaluation from Sheep Improvement Limited (SIL). Since 2014 we have started using the facial eczema tolerance index (DPX) in our selection decisions. Since 2021 we have started using the methane breeding value (PACCH4) also in our selection decisions. Traits recorded are: pregnancy scan and number of lambs born (in both mixed aged ewes and hoggets), survival (derived from pregnancy scan and lambs reared), weaning weight, live weight at 6 months, meat scanning (A, B & C measurements) in the ram lambs, CT meat scanning a percentage of ram lambs, faecal egg counts in the ram lambs, dag score, fleece weight at 12 months, GGT levels (FE tolerance), mating weights, condition score of ewes and methane production.
Over the last few years there has been an increasing awareness of drench resistance and the associated problems faced by sheep farmers. These problems are only going to get worse. Many vets are seeing drench reduction tests showing resistance to all 3 major drench families. There are even farms that have resistance to the two latest drench families: Zolvix and Startec.
There could also be a trend in overseas markets in time for product where anthelmintics have not been used.
We see breeding sheep for resistance to internal parasites as the long term solution to drench resistance and a dependence on animal health products. We have been part of the WormFEC program since 1992 and have made significant progress in reducing faecal egg counts. The Adult FEC BVs have reduced by nearly a half over that period of time. We don’t drench ewes, we have reduced the number of drenches our lambs are receiving and the age at which the lambs are showing an immunity to internal parasites is getting younger. Our ram lambs are left undrenched until sampled in mid February. We can’t throw away the drench gun yet but we are heading in the right direction.
The graph opposite shows the genetic trend for the breeding value for reduced adult faecal egg count. We have achieved close to a 40% reduction in FEC over 25 years compared with an industry that hasn't changed.
Drench Reduction Test
WormFEC Gold Group
Since 2005 there has been a gene test available for the MyoMAX gene, which is a major gene in the Texel breed responsible for 60% of the lean meat. The presence of the gene is either as a double or single copy or not present. Trials have shown that an animal with two copies of the gene has approximately 10% more lean meat on its carcass than an animal that has no copies. We began crossing some of our Romneys with Texels that had two copies of the gene when the gene test was first available in order to increase the meat yield in our Romneys. With each cross we are able to identify those sheep carrying the gene while crossing each generation back to the Romney. Our objective is to breed a sheep that is 80-95% Romney with two copies of the MyoMAX gene. In other words a sheep that effectively has all the traits we have been breeding for in the Romney and looks like a Romney with the meat traits of the Texels. More than half our ewes to date have at least one or two copies of the gene. To learn more about the MyoMAX gene, download the information sheet
Whole Flock Genomics
Since 2012 we have been lambing the stud Romneys on the hill and determining the parentage of the lambs through DNA. Tissue samples are taken from lambs at tailing time and their DNA is matched to their sire and dam through the genomic parentage test. The accuracy is extremely good with each year's lambing getting a perfect match on 99.5% plus of the lambs tailed. The benefits of this is that we can lamb the ewes unassisted – reflecting what is happening on most farms in New Zealand and we get accurate parentage results which improves the accuracy of data on those animals.
Facial Eczema Tolerance
Reducing Methane Emissions in Sheep
Genetic trends show the amount of genetic gain in cents over time for a particular trait or index. The steepness of the graph indicates the rate of genetic gain - the steeper it is the faster the rate of gain. These genetic trends are based on the 2 July 2021 SIL genetic evaluation of all flocks on SIL (1335). The green line is the industry average. The dotted line is Nithdale (flock 2629).
To view Nithdale Romneys’ genetic trends click on the index or trait below:
Selection of 2th Rams Used 2016 – DPO (DPP+DPF) from NZGE (New Zealand Genetic Evaluation) - June 2019
7 Beef + Lamb NZ Genetic Awards in 4 years
2012 - ACE Dual Purpose + WormFEC Flock
2013 - SIL ACE Trait Leader for Internal Parasite Resistance & SIL ACE Trait Leader for Reproduction
2014 - SIL ACE Trait Leader for Internal Parasite Resistance & SIL ACE Trait Leader for Reproduction
(Runner up for Dual Purpose Overall)
2015 - SIL ACE Trait Leader for Internal Parasite Resistance & SIL ACE Trait Leader for Reproduction
2017 - Finalist SIL ACE Dual Purpose + WormFEC Flock
Links to ACE Reports
ACE stands for Advanced Central Evaluations – it is New Zealand’s national across flock and breed sheep evaluation to identify the best rams for economic traits. It is one of the best ways to identify top rams and top breeders across the country (across flocks and across breeds).To find out more visit the SIL website or download the latest ACE Reports in PDF format.