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Case Study - Breeding for Increased Fertility
The SRS® Breeding System
SRS® Merino sheep are the result of selecting for low primary fibre diameter and high density plus high length of wool fibres. The breeding system was developed by SRS® Chief Scientist and Breeding Consultant, Dr Jim Watts, a research veterinarian who specializes in skin and fleece biology. It is based on Moore’s pre-papilla cell hypothesis of follicle formation and fibre growth.
How Does it Increase Fertility?
One of the key features that stand out in SRS® Merinos is that the sheep look like clones (Figure 1). The sheep are plain bodied, open faced, have long floppy ears, bare points, and have a distinctive “triple wedge” body shape. SRS® types are bred for a calm temperament, high milk production and instinctive maternal bonding to enhance lamb survival.
Figure 1: SRS® Merinos look like ‘peas in a pod’
Commercial producers using the SRS® Breeding System have seen major improvements in survivability and reproductive fitness across a wide range of Australian environments, from the Snowy Mountains of New South Wales to the hot and vast pastoral country of Longreach, Queensland.
Case Studies from the Coal Face
Increased Returns at Deniliquin
Bill and Dianne Hooke own and operate Warwilla Station, a 38,000 acre sheep property between Deniliquin and Hay in the Riverina region of New South Wales. They join about 7,500 Merino ewes in the spring and autumn, which produce about 8 kilograms of 20-21 micron wool.
The lamb marking outcome for the May-June 2010 drop lambs was 110%. The pregnancy scanning results for the March joined stud ewes are summarized in the Table below. Rams were either joined singly to groups of approximately 70 ewes or in the case of the ewe weaners, as a syndicate of 6 rams to 218 ewes aged 7 months. A group of 35 ewe weaners were also mated to a single ram. The ewe weaners were at least 40 kilograms body weight when joined. The March joinings resulted in 149% pregnancies in the adult ewes, 99 % in the syndicate mated ewe weaners and 77% in the ewe weaners mated to a single ram.
Table 1: Pregnancy Scanning Results at East Loddon| Age of ewes at joining | Number of ewes | Pregnancy scanning | Expected lambing | Number of rams joined | ||
|---|---|---|---|---|---|---|
| Twin bearing ewes | Single bearing ewes | Dry ewes | ||||
| Adults | 449 | 257 | 155 | 37 | 149% | Single matings of 6 rams |
| 7 months | 218 | 44 | 127 | 47 | 99% | Six rams as a syndicate |
| 7 months | 35 | 5 | 17 | 13 | 77% | One ram |
“Pregnancy rates have increased by 25 to 30 % and this seems consistent with the open faced and plainbodied Merinos we have been breeding. Travelling in this breeding direction, it gives us the opportunity to join ewes at an earlier age, and the incentive to do so with the season being favourable and market prices high. We have the chance to get a better return over the lifetime of the ewe. And being able to get high pregnancy rates in the adult ewes, it puts us in a favourable position financially to other farm enterprises,” Bill Hooke commented.
Taking on Terminal Sires at Mendooran
Commercial wool producer Stuart Skinner of Mendooran said that he has seen massive improvements in his fertility this year using SRS® Genetics.
“Using SRS® short tail genetics we have been able to increase the number of lambs per ram by over 50% compared to some White Suffolk rams we were using. Not bad considering some of our SRS® Merino wether lambs also topped the Dubbo sale on the 30th of May 2011,” Mr Skinner said.
Impressive Environmental Fitness at Delegate
Commercial wool producer, Scott Dunn, who manages “Wallendibby”, Delegate, has seen massive improvements in his sheep across the board since switching to SRS® genetics, particularly fertility. “I see two important points emerging so far. Firstly, that we could simply class up the ewes according to SRS® principles and see an immediate and predicted big lift in potential lambing of about 30%. Secondly, and this seems incredible, I could go and buy 14 rams which were barely 12 months old, drive them home, a nine hour trip, give them a day off, then shear them, then vaccinate and drench them two days later, and then join them at only 1.2 % and get such high pregnancy rates,” Mr Dunn said.
Contact Us
For more information on the SRS® Breeding System or sourcing SRS® genetics please contact:
Dr Jim Watts
Chief Scientist and Breeding Consultant
The SRS Company Pty Ltd.
Tel: +61 2 48622050
E:
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