Sheep industry focuses on genetic improvement
The sheep industry’s National Sheep Improvement Program (NSIP) continues to work on improving America’s sheep flock’s genetic viability.
“The motto of the NSIP is, ‘A profit driven selection tool,’” commented Reid Redden, chairman of the NSIP Board of Directors. “We have selected this because there was a lot of misinformation about the program. NSIP does not change sheep. It is a genetic selection tool to help improve the decisions that producers make.”
Though NSIP can provide tools to make genetic selection, Redden said the tool does not replace producer’s ability to select for good structure and a phenotype that is compatible with the production environment.
Redden, also the North Dakota State University Extension sheep specialist, addressed producers during a webinar sponsored by the American Sheep Industry Association and Rebuild the Sheep Inventory Committee, broadcast on Dec. 17.
NSIP works to provide quantitative data producers can utilize to support the qualitative data they are proficient at analyzing.
“We are looking at things we can measure and use to improve our flock and market animals to other breeders,” said Redden.
Redden continued that the program allows producers to compare apples to apples, rather than apples to oranges, to make decisions.
“The initiative also allows us to make profitability measurements,” he said. “There is a large part of the industry that doesn’t take time to connect these measurements to profitability.”
“This program is essential for the sheep industry,” Redden emphasized.
NSIP was formed by the sheep industry in the 1980s by ASI, individual producers and scientists within the land-grant university system.
“The program developed EPDs, or expected progeny differences, for sheep, but in the late 2000s and early 2010s, we began a transition to Sheep Genetics, which is an entity form Australia,” Redden explained.
Within the Sheep Genetics program, a component called LambPlan figures the estimated breeding value, or EBV, which is a calculation that is essentially two times the EPD.
“When we transitioned to LambPlan, we were able to use software that we haven’t had before, which improved the ability of producers to submit data,” Redden said. “Another good aspect of LambPlan is that it send reports twice a month.”
At the same time that the industry was beginning to explore use of EBVs, Redden noted that U.S. production of lamb began to decline, but consumption remained steady because imports were able to keep up with demand.
“We need to produce more lamb with fewer ewes,” he said. “NSIP can help the industry accomplish this goal.”
An additional focus of NSIP is to involve producers from a wide array of breeds.
“We have a board of directors and each breed is represented,” said Redden.
Breeds represented include PolyPay, Suffolk and Dorset, Katahdin, Hampshire, Targhee and Rambouillet. An at-large member of the board is also elected.
“We have about 20 breeds, and less than half of those are quite active,” Redden remarked. “We have about 150 flocks participating in the program and submitting data, for around 10,000 sheep that are active.”
Redden explained that a variety of EBVs have been determined for the program, and the accuracy of each EBV is also reported.
The EBVs are separated into growth, production, carcass and wool traits.
“The growth traits include a birth weight for lambs,” said Redden. “This is not one of the bigger traits we use, and it needs to be collected within 24 hours after the lamb is born.”
Weaning weight is an additional EBV, collected between 45 and 90 days. Post weaning weight is also collected between 91 and 305 days of age.
“In most farm flocks, this is our target end-point for lambs,” said Redden of post-weaning weight.
Yearling weight is collected from 290 to 430 days of age.
“We also have production traits,” Redden commented. “We look at the number of lambs born and the number of lambs weaned.”
The two traits are analyzed independently because separate genes determine them.
Carcass and wool
Under carcass weight, loin eye muscle depth and fat depth are measured.
“We are looking for a deeper loin eye,” said Redden.
An additional interesting trait collected is parasite resistance, which is analyzed by using fecal egg counts for lambs.
“Those with lower than average fecal egg counts are superior genetically if we select for parasite resistance,” he explained.
“Some of the wool traits we collect include fleece weight, micron diameter and staple length,” Redden continued.
Other EBVs are also available, he added.
To simplify the EBVs, Redden notes that indexes have been developed.
Carcass Plus selects for positive post-weaning weight, positive eye muscle depth and negative fat depth.
A U.S. Hair Index has been developed for the Katahdin breed and U.S. Maternal Index for PolyPay sheep, both of which seek a positive weaning weight, maternal weaning weight, or milk, and a slight negative for number of lambs born.
The U.S. Range Index is among the more complicated indexes. It looks at positive post-weaning weight, positive milk values, negative yearling weight, negative fiber diameter and positive number of lambs born.
Currently, Redden added that the program isn’t doing what it could to support the industry as a result of the small participation.
“The lack of acceptance of the technology has put our industry at a disadvantage to foreign competition, and it does give them benefit,” he explained. “In the future, I’d like to see 50 percent or greater of our seedstock sheep breeders get into this program.”
While Redden marked the goal as ambitious, he noted that Australia and New Zealand set similar goals and have accomplished them.
“I also think we need at least 50 percent or more of our commercial buyers using EBVs when they make breeding decisions,” he continued. “It is possible for our industry to meet these goals, but we need to have a strong focus.”
Enrolling in the program requires an annual fee based on flock size, with averages from $2.50 to $3.50 per ewe. To bolster the program, NSIP will waive the fee for the first year and for the first three years for producers under age 22.
“There are still some animal data fees involved, but enrollment is free for the first year,” said Redden.
Additionally, Redden noted that the meat goat industry is not currently involved in the program and NSIP is seeking an active group of breeders to get the ball rolling.
“This is the greatest opportunity for our industry to make improvements,” he said.
“The U.S. lamb crop is about 110 percent,” Redden continued. “To put the U.S. at an advantage, that number needs to be closer to 150 percent.”
Wyoming produces a 112 percent lamb crop on average.
“We need a higher level to maintain viability in the global sheep industry,” he emphasized.
Since rolling out the use of LambPlan in 2004, Redden noted that producers using EBVs for selections have made improvements.
“We have seen significant improvements,” he said.
For example, in PolyPay sheep, ewes were weaning nine kilograms more lamb than in 2005.
Suffolks weaned almost two kilograms more as a breed and increased post-weaning weight, or 120-day weight, by nearly three kilograms.
“As a group, they are improving traits that relate directly to profitability,” said Redden. “Suffolks are also improving the product at the same time.”
From 2004 to 2013, loin muscle depth remained stagnant while fat depth dropped enabling producers to raise heavier lambs that still hit yield grade two and three levels.
“Those traits are both going in the directions they should be,” he commented.
Katahdin sheep increased the number of lambs born and the number of lambs weaned, as well.
Redden noted that these examples are just a subset of the successes seen in the program.