Survey Takes a Close Look at the U.S. Sheep Industry
By AMY TRINIDAD
Sheep Industry News Editor
(Jan. 1, 2013) In a combined effort, the U.S. Department of Agriculture divisions of Animal and Plant Health Inspection Service (APHIS), Veterinary Services (VS) and National Animal Health Monitoring System (NAHMS) have compiled and released a study of the American sheep industry.
The Sheep 2011 study was conducted in 22 of the nation’s major sheep-producing states with the defined purpose of providing participants, stakeholders and the industry with valuable information representing 70.1 percent of U.S. farms with ewes and 85.5 percent of the U.S. ewe inventory.
States included in the study were California, Colorado, Iowa, Idaho, Kentucky, Kansas, Michigan, Minnesota, Missouri, Montana, New Mexico, New York, Ohio, Oregon, Pennsylvania, South Dakota, Texas, Utah, Virginia, Washington, Wisconsin and Wyoming. Similar surveys were conducted in 2001 and 1996.
Some of the findings in the study are listed below. To view all the findings visit http://www.aphis.usda.gov/animal_health/nahms/sheep/downloads/sheep11/Sheep11_dr_PartI.pdf .
Flock Management
Large operations, which own the majority of the sheep in the United States, frequently raise sheep on rangeland. Small and medium operations often graze sheep on irrigated or cultivated pasture. Many operations manage sheep on more than one type of feeding environment. The highest percentage of operations with 20 or more ewes (75.8 percent) managed at least some of their sheep on pasture.
While small operations made up 73.1 percent of sheep operations with 20 or more ewes, they represented only 22.1 percent of all sheep. Conversely, large operations only represented 5.5 percent of sheep operations but raised 53.1 percent of all sheep. The highest percentage of sheep in herded/open and fenced-range operations were on large operations (94.8 and 57.8 percent, respectively).
Inventory Expectations: The highest percentage of operations with 20 or more ewes (59 percent) expected to have about the same number of sheep in five years. A higher percentage of large operations (32.4 percent) expected to have more sheep in the next five years compared with medium and small operations (25.7 and 22.7 percent, respectively). Overall, a higher percentage of operations expected to have more sheep (23.9 percent) than operations that expected to have fewer sheep (10.6 percent).
The West region accounted for the highest percentage of operations that expected to have fewer sheep in the next five years. In the Central and East regions, the percentage of operations expecting to have more sheep was higher than the percentage expecting to have fewer sheep.
Family/personal situation was the most common reason cited for expecting to not have sheep in five years.
Sources of Information on Sheep Health: Sheep health information can be found through a wide variety of sources. The “Sheep Production Handbook,” sponsored by the American Sheep Industry Association, is a comprehensive source of information. In addition, many universities offer sheep health information through extension resources. Industry meetings, magazine, shearers and other sheep producers are also good resources. Also, a veterinarian familiar with the existing conditions on an operation can provide advice specific to illnesses, management and production. Veterinarians were considered to be a very important source of information on 40.4 percent of operations, while other sheep producers were considered a very important source on 38.3 percent of operations.
Industry meetings were considered very important sources of sheep health information on 9.6 percent of very small operations, compared with 16.9 percent of medium operations and 29.6 percent of large operations. About five of ten large operations (54.5 percent) considered other sheep producers a very important source of information, compared with about four of ten very small operations (36.1 percent).
Sheep Association and Club Membership: Overall, 22.9 percent of all operations belonged to a national sheep organization. By flock size, the percentage of operations that belonged to a national sheep organization ranged from 13.6 percent of very small operations to 57 percent of large operations. The percentage of operations that belonged to a state or local sheep organization ranged from 14.8 percent of very small operations to 76.9 percent of large operations.
Production Records: Production records can be important tools for monitoring animal performance and for tracking which lambs should be kept, which ewes should be bred and which animals should be culled. These records can be kept through handwritten notes or in computerized databases, spreadsheets or specialized farm management software.
Over half of operations (55.9 percent) kept handwritten production records and another 25.7 percent kept both handwritten and computerized production records. Nearly 15 percent of small operations kept no records, while only 3.9 percent of large operations kept no production records. For operations that kept records, the highest percentage kept records on the number of lambs born. Records of individual lamb weights—at birth and at weaning— were kept by the lowest percentage of operations.
Flock Identification (ID): Overall, 81.5 percent of operations with 20 or more ewes used at least one form of flock ID, compared with 61.4 percent of operations with one or more ewes. As flock size increased, so did the percentage of operations that used at least one form of ID. On large operations, 96.1 percent used some form of ID, compared with only 39.6 percent of very small operations. This same comparison can be made by ID type. The scrapie program ear tag was used by 77.9 percent of large operations, compared with only 31 percent of very small operations. Since smaller operations are probably less likely to move their animals, the scrapie ear tag may not be required on these operations.
Breeding Management
Age, weather, time of breeding and prebreeding practices can all affect reproductive outcome and should be considered when breeding ewes. As expected, about 98 percent of operations in all size groups bred ewes during 2010.
Reproductive Practices: Reproductive performance can be improved by intensive management practices such as flushing ewes, crutching, using teaser rams, breeding marks, ultrasound, breeding soundness exams, udder palpations, embryo transfer and estrous synchronization. Flushing provides ewes with extra nutrition prior to—and sometimes during—the breeding season. Flushing increases the number of ovulations, resulting in a higher proportion of twins and triplets.
A breeding soundness examination should be conducted prior to each breeding season to assess buck fertility. A breeding soundness exam should include a physical examination for general health, but examination of the reproductive organs (testicular palpation and size evaluation, and semen evaluation) should be the primary basis for this exam.
For operations with 20 or more ewes, 99.6 percent conducted some form of reproductive practice. The most commonly performed practice was flushing ewes prior to breeding (52.8 percent of operations). A higher percentage of small operations (22.6 percent) used breeding marks compared with large operations (8.8 percent). A higher percentage of large operations (15 percent) used ultrasound as part of their breeding strategy compared with medium and small operations (8.1 and 6.2 percent, respectively).
Breeding Seasons: Sheep normally breed during fall, although the breeding season varies depending on geography, temperature and breed. Many producers prefer fall lambing for a variety of reasons, including warmer weather for newborn lambs and for the often profitable Christmas to Easter holiday season. However, breeding in warm weather can adversely affect fertility and reduce embryo survival. Overall, 24.5 percent of operations with 20 or more ewes bred their ewes out of season (February to July). There was little difference by operation size or by region in the percentage of operations that bred ewes out of season.
Breeding Practices: Placing a ram with ewes was the most commonly used out-of-season breeding method (85.5 percent of operations). Certain breeds of sheep have a longer breeding period than other breeds and are more successful at out-of-season breeding. Genetic selection for ability to breed out of season was the second most common out-of-season breeding method used (33.8 percent of operations).
Only 1.4 percent of operations had used artificial insemination to breed at least some ewes during the most recent breeding season, while 99.8 percent of operations had bred their ewes naturally, either by their own or another operation’s rams.
Ram and Ewe Selection: Since rams account for half the flock genetics, ram selection is an important determinant of flock health and productivity. The National Sheep Improvement Program (NSIP) offers a genetic evaluation system for U.S. sheep flocks. NSIP has historically provided expected progeny differences (EPDs) to help producers determine the genetic merit of an animal for a particular trait, such as number of lambs born, wool characteristics, milking traits, etc. NSIP generates estimated breeding values (EBVs) using breed-specific genetic parameters. These values allow for genetic evaluations for carcass traits and parasite resistance across breeds, as well as other evaluations not previously available.
For operations that used rams for natural breeding during 2010, 77.4 percent reported that visual appearance was a very important characteristic while 69.8 percent indicated that meat production was very important. A total of 60.3 percent of operations identified soundness of rams’ flock of origin as very important.
Nearly six of ten large operations (59.4 percent) rated wool quality as a very important characteristic for choosing replacement ewes, while about one of five operations with 20 or more ewes (20.5 percent) rated wool quality as a very important characteristic.
Reproductive Outcomes
To estimate productivity in a flock, producers must track the number of lambs born alive and the number born dead; however, for operations in which lambs are born on the open range without close monitoring, it is not practical to track lambing rates. For these operations, lamb processing (when lambs are docked, vaccinated, castrated, etc.) may be the first time they are able to track their lambs. Without baseline information on lambing rates, it is difficult to provide answers to basic questions relative to reasons for low lambing rates. Abortions, poor mothering, lack of colostrum, pneumonia or predators can be causes of low lambing rates.
Lambs Docked: For operations that managed their sheep primarily on open range, lamb processing (when lambs are docked, vaccinated, castrated, etc.) may be the first time these operations are able to view their sheep after lambing. During docking, herded/open range operations track lambs, vaccinate, ensure that all ewes are healthy and perform other management measures. Not all operations dock any or all of their lambs, depending on whether animals are intended for replacements, show, market or other uses.
Overall, operations with one or more ewes docked 81.5 percent of lambs born alive. Large operations docked a higher percentage of lambs born alive (87.7 percent) than very small operations (64.5 percent) or small operations (75.2 percent).
Monthly Distribution of Lambs Born: Lambing in late fall through late winter provides great marketing opportunities, as lamb prices are often highest during the Easter period. Lambing in April and May synchronizes with the forage production cycle and allows for the most efficient use of forage. Lambing in April and May also coincides with the natural breeding and lambing seasons, when the ewes are likely to have larger lamb crops. For all operations, the highest percentage of lambs were born in February through May. A higher percentage of lambs born on very small operations were born in February than in any other month. April and May saw the highest percentages of lambs born on large operations (22.2 and 25.6 of lambs born, respectively). July and August were the months with the lowest percentage of lambs born for all operations. Lambing during these months requires better parasite and predator management.
Weaned Lambs Management: The operation average number of lambs weaned per ewe exposed was 1.2. This number was higher in small flocks (1.4 lambs). The operation average number of lambs weaned per exposed ewe was higher in the East region (1.5) than in the West and Central regions (1.2 and 1.1, respectively). Pasture flocks had the highest operation average number of lambs weaned per ewe exposed. The average age and average weight of lambs at weaning on all operations was (4 months and 65 lbs.). Age and weight at weaning were highest on large operations (4.8 months and 82.4 lbs., respectively).
Needs Assessment
Ewe health/management was the most important management issue for respondents, with 40 percent of respondents ranking this as their first, second or third most important issue. Infectious disease or diagnostic treatment was the second most important management issue (31 percent of respondents), followed closely by disease prevention (29.8 percent), predator control (22 percent), lamb health/management (21.3 percent) and death loss (19.6 percent of respondents). If we look only at the first priority issue, these rankings change only a little. The top four remain the same but the fifth most important issue is death loss, followed by extra-label drug use and antimicrobial use/resistance.
For producers who indicated ewe health was their No. 1 priority, their specific areas of interest include: mastitis, Q fever, OPP, Johne’s, abortion prevention, parasites, nutrition and proactive information for ewe health.
Internal parasites were the most important disease issue for respondents. Overall, 65 percent of respondents ranked internal parasites as one of their top three disease issues. This top ranking held true for producer respondents and veterinary and university extension agents. Respondents who indicated internal parasites as their highest priority disease cited the following specific areas of interest: resistance, detections, Haemonchus, new dewormers, immunity to parasites, management and treatment options. The next most important disease issues were scrapie, abortions and lameness (22.2, 19.3, and 20.2 percent of respondents, respectively).