SIL Flock 2629

In the early 1980s a number of twin bearing ewes were screened from the commercial flock at Nithdale and rams primarily from the North Island, from breeders who were part of the New Zealand Romney Development Group, were put across these ewes. Breeding an easy care sheep that could lamb unassisted was the initial focus.
Nithdale 664/10 – Winner of the 2015 NZ Beef + Lamb Sheep Industry Awards: Dual Purpose + Worm Resistance

Nithdale Purchases Wairaki Romney Stud

We purchased the Wairaki Romney Stud from Richard and Trudy Slee in 2014. It has given us the opportunity to increase the size of our stud Romney flock to just under 2000 ewes. We will maintain this stud as straight Romneys allowing us to offer both pure Romneys and Romney/Texels we have been breeding since 2005.

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 - Focus is still on production and performance including quality within a low cost, challenging environment.

We have been selecting rams and ewes to retain based on structural soundness, good constitution and records. The records we have been using are the dual purpose production (DPP) index + WormFEC (DPF) produced by Sheep Improvement Limited (National Sheep Database). Since 2014 we have started using the facial eczema tolerance index (DPX) in our selection decisions. All reports now are generated from the National Genomic Evaluation (NGE) which combines data from over 150 flocks that have been DNA testing. Traits recorded are: pregnancy scan, number of lambs born, 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 and condition score of ewes.

Worm Resistance

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. 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. In the SIL-ACE Dual Purpose + WormFEC list (April 2016) we have a total of 12 rams in the top 100.

MyoMAX Gene

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 the 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

Total Meat Yield of Nithdale lambs through the Alliance viascan 2005-2016 compared with the Southland Average 2007-2016

Sheep 50 & 5K

ince 2011 Sheep 50K has been commercially available for the Romneys. From the DNA taken from a tissue sample the genetic potential of an animal can be determined for currently 22 traits including fertility, worm resistance, lamb growth, carcass weight, meat yield, wool weight and facial eczema resistance. A molecular breeding value is produced for each particular trait and this is blended with the current estimated breeding value (determined by the animal’s individual performance and performance of relatives) to come up with a genomic breeding value. The smaller version sheep 5K has been commercially available since 2014 and being cheaper is able to be used over more animals. To learn more about Sheep50 & 5K, click here.

DNA Parentage

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 Shepherd Plus gene test. The accuracy is extremely good with last years lambing getting a perfect match on 99.5% 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.

Genetic Trends

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 new SIL genetic evaluation of all flocks on SIL (1135). 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:

  • DPO (Dual Purpose Overall)
  • Worm Resistance (Note drop in 2014 is the addition of the Wairaki Flock - not as good for worm resistance. Also industry average is getting worse as little active selection for it - however Nithdale gets better!)
  • Reproduction
  • Lamb Growth
  • Wool

Selection of 2th Rams Used 2016 – DPO (DPP+DPF) from NZGE (New Zealand Genetic Evaluation) - 26 Aug 2016

Nithdale 1063/14 - Used by Nithdale and Waihora (Taupo) this year. DPO 2532
Nithdale 1237/14 - Used by Nithdale, Paki-iti (Fielding) and Mount LInton Station this year. Double MyoMAX. DPO 1620
Nithdale 2155/14 - Used by Nithdale and ARDG (Waikato). Sporodesmin dosed at 0.5mg/kg bodyweight with nil liver damage. DPO 2129, DPX 1591
Nithdale 182/14 - Single MyoMAX. DPO 2045

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

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.