WHAT DOES IT TAKE TO BECOME INVOLVED IN NSIP?
the resulting offspring. This is called an Expected Progeny Difference or EPD. An animal with a Postweaning Weight EBV of +6 will have an EPD of +3. Since NSIP EBVS are expressed in Kilograms (KG), we can convert the EBV to pounds by multiplying by 2.2 pounds per KG. A shortcut is to just view the EBV in KG as essentially the EPD in pounds as it will be within 10% of the value. So, it would be expected that a ram with a Postweaning Weight EBV of +6 would sire lambs that would be 6 pounds heavier at post- weaning than lambs sired by the average ram. TRACKING PROGRESS Producers enrolled in NSIP have many tools at their disposal to evaluate their breeding decisions and track progress. The graph below shows the progress by one Suffolk breeder enrolled in NSIP over the past ten years. There has been a marked increase in the Weaning Weight and Postweaning Weight EBV’s. There has been a decrease in the Fat Depth EBV, which indicates progress towards leanness. There has been a slight decrease in the Eye Muscle Depth EBV. Producers can design their breeding program to focus on using the EBV’s that will help them to best achieve the goals they have set for their flock. NSIP offers a Searchable Database that includes all animals enrolled in the program. This is a helpful tool in identifying breeding stock with EBV's that may be useful in a breeding program. The database can be accessed by anyone, not just NSIP members, and can be found at http://nsip.org/searchable-database/
in individual breeding programs will depend on specifications, discounts, and premiums in current markets. There are also additional maternal traits evaluated, such as Number of Lambs Born, Number of Lambs Weaned, and Maternal Milk . A newer trait that is also gaining more interest is Fecal Egg Count , which is useful in selecting sheep for parasite resistance. EBVs begin by collecting on-farm production data that is then submitted through NSIP and the data is converted into actionable genetic information. Performance data is adjusted for variables that are not related to genetics, such as flock management techniques. EBVs are calculated on the performance of the individual animal, related animals in the same flock, and related animals in other flocks. NSIP has grouped certain EBV traits to create indexes that are useful tools for selecting breeding stock suited to a particular situation. For example, the Carcass+ Index combines Postweaning Weight, Eye Muscle Depth, and Fat . Expected Progeny Differences (EPDS) For those familiar with Expected Progeny Differences (EPDS) used in cattle, EBVS are very similar. EPDS denote the breeding value of an individual animal’s progeny, whereas EBVS denote the value of the individual animal. More simply, EBVS equal EPDs times two. While EBVS measure the total genetic merit of an individual for a trait, that animal can only transmit one-half of the genes to its resulting offspring. By dividing an animal’s EBV for a trait by ½ we can calculate the genetic contribution to
An enrollment form for the program that outlines costs can be found at http://nsip. org/wp-content/uploads/2020/12/2021- Enrollment-Form.pdf Enrolled flocks receive: • Free software for flock data management and submission • Free training and mentoring support from a like-minded sheep breeder • Advanced genetic evaluation calculations using proven technology • Comprehensive reports on both individual animals and breeds • Listing on NSIP website • Option to consign to NSIP sponsored sales • News and updates via email WHAT INFORMATION IS REQUIRED TO BE SUBMITTED? For Suffolks the information that is required for the data analysis includes: • Sire and Dam • Birthdate, type of birth, and rearing (example – triplet raised as a twin) • Weaning weight • Post weaning weight Other optional data that can be included is birth weight and ultrasound data for eye muscle depth and fat. This data is entered into Pedigree Master which is the free software program members receive. A data file is then emailed to the processing center. Data is processed twice per month and producers will receive their results within several days of the processing date. For additional information on NSIP contact: Brenda Reau, Suffolk Breed Representative, NSIP Board of Directors – reau@msu.edu or Rusty Burgett, NSIP Program Director - info@nsip.org or visit the website at www.nsip.org .
DNA tests can determine genotypes of traits controlled by a single pair of genes (Scrapie susceptibility, Spider Lamb Syndrome, presence of the Myostatin gene, etc.) HERITABILITY is the percentage of an animal’s observed or measured phenotype due to genetics. This varies by trait. Even in the more highly heritable traits, most of the observed or measured difference in individual animal performance is due to environment. NSIP SEARCHABLE DATABASE • Birth weight 15% • Weaning weight (60 days of age) 10% • Rate of gain (post-weaning) 25% • Mature body weight 40% • Fat thickness over loin eye area 30% Source: Sheep Production Handbook, American Sheep Industry Association, 2015 QUANTITATIVE GENETICS Genetic evaluations are required to estimate the genetic merit for most performance traits that are affected by multiple genes. These are usually expressed as Estimated Breeding Values (EBVs) and are measured through the National Sheep Improvement Program (NSIP). • Multiple births 10% • Milk production 10% • Loin eye area 35% ESTIMATED BREEDING VALUES (EBV’s) are used to measure the genetic merit of individual animals for those traits financially important to commercial sheep production. Estimated Breeding Values are science- based, industry-tested measurements of heritable traits that can be tracked and measured. EBVs are proven to improve on-farm productivity and enhance breeding decisions. Why Use EBVs? Many economically important traits cannot be determined by
visual appraisal alone. Using EBVs is the proven method of accurately predicting if an animal will pass on important traits such as growth rate, reproductive proficiency, carcass quality, and parasite resistance. By using EBV’s, you can get an idea of how an individual will perform, which is helpful in designing a breeding program where the environmental factor is eliminated. Producers can compare individuals based on genetic merit from flocks across the country. WHAT ARE SOME OF THE TRAITS MEASURED WITHIN NSIP THAT ARE USEFUL TO THE SUFFOLK BREED? Postweaning Weight (PWWT) EBV (kg) combines information on preweaning and postweaning growth to predict genetic merit for postweaning weight at 120 days. The Postweaning Weight EBV is expected to favor rapid growth to typical market ages. Loin Eye Muscle Depth (EMD) EBV (mm) is an indicator of genetic differences in muscling. It is derived from ultrasound measurements of loin muscle depth between the 12th and 13th ribs in live animals and adjusted to the standard postweaning weight of 110 lbs. (55 kg) for terminal breeds like Suffolks. Animals with positive Loin Eye Muscle Depth EBV are expected to produce offspring with larger loin eyes and are generally desirable. However, the emphasis placed on Loin Eye Muscle Depth EBV in individual breeding programs depends on specifications, discounts, and premiums in current markets. Fat Depth (FAT) EBV (mm) is an indicator of genetic differences in carcass fatness between the 12th and 13th ribs. It is derived from ultrasonic measurements of fat depth in live animals and adjusted to the standard postweaning weight of 110 lb. (55 kg) for Suffolks. Animals with negative Fat Depth EBV are expected to produce leaner progeny with lower, more desirable Yield Grades. However, the emphasis placed on Fat Depth EBV
USING EBV’S FOR GENETIC IMPROVEMENT THROUGH THE NATIONAL SHEEP IMPROVEMENT PROGRAM (NSIP) Quantitative genetics has been used for years across the livestock industry, and there is great potential for sheep producers to make improvements in production by using the technology. To have the best understanding of quantitative genetics, it is essential to understand phenotype and genotype. PHENOTYPE: The external appearance or some other observable or measurable characteristics of an individual. These characteristics are influenced by both the animal’s genetic makeup as well as environmental influences. Observed Phenotype = Genetics + Environmental Influence. Examples of phenotypes: • Structural correctness • Display of genetic defects • Actual weaning weight • Loin eye area • Yearling weight • Type of birth • Body condition score GENOTYPE: The genetic makeup of an animal. This is usually derived from a DNA test or a genetic evaluation. Examples of genotypes • RR at codon 171 • NN for spider lamb syndrome • EBV’s
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