PROCEEDINGS OF THE 2010 U.S. SHEEP RESEARCH AND OUTREACH PROGRAM



Integrated Control of Parasitic Worms Using Copper Oxide Wire Particles, Sericea Lespedeza, and FAMACHA in Sheep in Arkansas
Authors: J.M. Burke1, J.E. Miller, J.A. Mosjidis, T.H. Terrill

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Background

Gastrointestinal nematodes (GIN) or stomach worms continue to plague the small ruminant industry, especially parts of the world with warm, humid climates. Haemonchus contortus or barber pole worm is a blood feeder that can cause anemia and death to small ruminants. Alternatives to chemicals are needed for GIN control because of anthelmintic resistance and a desire to reduce chemical residues in meat products.


Self-Sustainable Producer Study Groups B An Effective Model for Sheep Producers to Obtain Information and Make Production Decisions
Author: Woody Lane

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Background

Modern sheep production is a complex system of technology and business economics. Shepherds must juggle the skills of animal husbandry, practical engineering, and forage management with good business acumen, marketing, and risk management. Our American system for training livestock producers relies mainly on universities and other educational institutions. These programs usually require extended time commitments and are primarily designed for young adults who generally have little experience in farm management or financial obligations. In contrast, the adult farmers and ranchers who actually run sheep operations cannot spare months or years away from their responsibilities to attend these programs. So how can they get good information and improve their skills? Working shepherds try to keep current through a haphazard mixture of Extension workshops, neighbors, and the Internet. Sheep producers, however, would greatly benefit from a formal, organized educational framework designed to fit their schedules, which would be a constant source of science-based information and networking.


Enhancing Montana's Wool Clip Through Improved Wool Harvesting Practices
Authors: Jim Moore, Michael Schuldt and Rodney Kott

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Background

There is a worldwide shortage of professionals to work in the wool harvesting occupations including sheep shearers, wool classers and wool pressers. In Montana the shortage of sheep shearers is critical and is one of the barriers for landowners who wish to participate in the production of sheep as a profit center in their operation.

A decrease in the larger scale sheep operations has led to a decrease in the number of wool harvesting crews. In the past few years the sheep numbers have stabilized at least partially due to increases in the number of small flocks. The increase in small flocks has created a need for an increase and a more local distributed source of sheep shearers.

The strength of the sheep industry in the West is dependent on market forces, drought conditions, USDA assistance programs, and historical ranch ownership as well as the availability of expertise in management providing lambing, herding and shearing services. If any of these variables become limiting the potential growth of the industry is limited. The shortage of wool harvesting professionals has become a limiting factor for many producers in the west wishing to implement or expand their sheep enterprises. With just 17 individuals listed on the Montana Woolgrowers Association shearer page and 270,000 head of sheep in the state there is plenty of demand for qualified shearers.


Comparison of Dorper and Rambouillet Ewes for Lamb Production
Author: Dan Waldron

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Background

Many of the sheep in the Western US are of the Rambouillet breed, which is considered a dual-purpose breed, because both meat and wool have been economically important products. Dorper, a breed developed in South Africa, in a low rainfall area, is a hair/shedding breed that does not require shearing. The Dorper has been selected for carcass traits and adaptability to harsh environmental conditions typical of much of the sheep production areas of the Southwestern US. The Dorper is a potential alternative to the Rambouillet for lamb production. There are no reports available that have compared lamb production of Dorper and Rambouillet ewes in a common environment. Sheep producers need objective information on the relative production of Dorper and Rambouillet ewes in commercial conditions.

From 2003-2005, 100 Dorper ewes were acquired from 20 flocks from 10 different states and 100 Rambouillet ewes were acquired from 14 Texas flocks. Ewes were first mated to lamb at approximately 2 years of age. Performance has been recorded for the first 3 years of production on all ewes and up to 5 years of production on the ewes obtained in 2003. In August of 2004, 2005, 2006, and 2007, ewes were mated to MARC Composite or Suffolk rams in single-sire breeding pastures. In the fall of 2008, all ewes were mated to produce purebred lambs. Lambs were weighed at birth and at weaning at approximately 90 days of age. Ram lambs were fed to a target liveweight of 135 lbs. Crossbred ewe lambs were fed to a target liveweight of 125 lbs. Purebred ewe lambs were fed to al target liveweight of 100 lbs and then placed on pasture.


Mapping QTL for Breeding Out-of-Season and Milk Production in Sheep
Authors: Raluca G. Mateescu and Michael L. Thonney

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Background

In the last few years, remarkable advances in genetics have provided the research community with whole genome sequences, genetic maps, and high density SNP arrays for several species, including sheep. These genomic achievements offer new possibilities for identification of quantitative trait loci (QTL) underlying economically important traits, such as breeding and lambing out-of-season (aseasonal reproduction) and milk production. The identification of QTL is likely to lead to more efficient breeding programs, especially for traits that are difficult to improve when using traditional selection strategies.


Comparison Among Katahdin and Dorper Grades and a Composite For Commercial Lamb Production in the Southeast
Authors: W. R. Getz, B. Kouakou and S. Mobini

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Background

Results from a Southern regional study in the early 1960’s suggested there was no breed that was particularly well suited to commercial lamb or wool production in the South. By the 1990’s interest in the use of various hair sheep breeds was being expressed by land owners and extension agents in Georgia and neighboring states in the Southeast. Previous experience and more recent evidence from the literature suggested they had the potential to do well in the warm, humid environment. In 1998 a breeding program was initiated and flock established at Fort Valley State University using a foundation of 23 blackface x (Dorset x Rambouillet) and 10 white Dorper x Katahdin ewe lambs. All ewes were managed together as one flock except during a 40-day breeding season when they were organized into single-sire groups. Resulting lambs included various levels of Katahdin and Dorper grades, white Dorper x Katahdin composite, and black or mottle-face wool crossbreds. Because of the low-input, pasture-based production system ewe lambs were bred to lamb at two-years of age. Lambs were born beginning in early March of each year. Ewes lambed on pasture, checked 3x per day, and were given special attention only in the case of inclement (cold, wet, windy) weather. Male lambs were castrated and all lambs were identified with ear tags and ear notches near the time of birth. Wool-type lambs were docked. Ewe lambs were retained and returned to the flock as breeding animals. No culling was done on performance. Male lambs contributed to the carcass database. Summer pastures were based on Bahiagrass and Bermuda grass while cool-season pastures were based on ryegrass, crop residues, and in some years small grains. Cool-season and warm-season forbs were available. Grazing areas and feedstuffs were changed often as opportunities to graze idle acres were exploited. Breeding animals received free-choice mixed hay during the winter, and were fed a concentrate mix of .25 kg to .45kg per day during late pregnancy or had access or urea – molasses tubs. Free-choice trace mineral salt was available.


Residual Feed Intake of Growing Western Range Ewes
Authors: Reid Redden, Lisa Surber, Brent Roeder, and Rodney Kott

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Background

Feed costs are a major cost of sheep production and reduction of feed required could be an approach to increased profitability. Reducing feed intake or increasing feed efficiency without compromising growth rate or carcass quality could have a significant positive economic impact on the sheep feedlot industry. However, it is widely accepted to be a major cost and improvements in output per unit of feed used over the whole production system would be of significant economic benefit.


Growth Rate Alters Residual Feed Intake and Feeding Behavior in Yearling Ewes
Authors: Reid Redden, Lisa Surber, Brent Roeder and Rodney Kott

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Background

In addition, the cost of providing feed and forage to grazing animals in extensive grazing industries such as western range ewe flocks is difficult to measure. Residual feed intake (RFI) is being proposed as a tool to identify those animals that are more efficient. In most cases RFI is established on growing diets. In addition, most animal RFI experiments are conducted when the animal are gaining BW at a relatively high rate. However, repeatability of RFI on different diets and at different period of animal production has not been well documented. Furthermore, digestibility difference among RFI groups has not been evaluated.


Considerations for Increased DDGS Use in Finishing Lambs
Authors: B.W. Neville1, C.S. Schauer, K. Karges, N. Dyer and G.P. Lardy

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Background

The NDSU Hettinger Research Extension Center (HREC) and the NDSU Department of Animal Sciences have been researching the use of distiller’s dried grains with solubles as an alternative to cereal grains in finishing lambs rations. Expansion of the ethanol industry in previous years has made distiller’s dried grains with solubles a readily available feedstuff for lamb feeders in the Northern Great Plains. Inclusion of high proportions of distiller’s dried grains with solubles and other co-products in finishing rations for ruminants has been avoided; in part, due to potential problems with polioencephalomalacia (PEM) as well as concerns about optimal animal performance and carcass characteristics. The research conducted at North Dakota State University and HREC allow for some guidance to managing the use of distiller’s dried grains with solubles in lamb finishing rations.


Validation of the Equations Used in Determining Dry Matter Intake, and Metabolizable Protein Requirements for Finishing Lambs as used in the Sheep Companion Module to BRaNDS
Authors: A.S.Leaflet, Garland Dahlke, Dan Morrical and Lauren J. Secor

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Summary and Implications

The growth equations published in the 2006 NRC “Nutrient Requirements of Small Ruminants” along with the additions added to these equations when used in the Sheep Companion Module to BRaNDS appear to provide reasonable estimations of performance of feeder lambs.


Effects of Long-Term Targeted Grazing on Large-Scale Leafy Spurge Infestations
Authors: Lisa Surber, Rodney Kott, Brent Roeder, and Jim Moore

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Background

Sheep and goat grazing is being rediscovered and honed as a viable and effective tool to address contemporary vegetation management challenges such as like controlling invasive exotic weeds. Currently, there is a major targeted grazing effort in Montana to control invasive plants such as leafy spurge (Euphorbia esula). Montana State University and the Montana Sheep Institute (MSI) Project, and the research/extension team therein, have conducted a long-term research effort and demonstration trials on the use of sheep and goats to manage leafy spurge.

Leafy spurge is a perennial, invasive forb. It spreads by seeds and rhizomes and forms dense monocultures that decrease biological diversity. Mature leafy spurge plants have a 20-25-ft taproot, making mature plants resistant to herbicides. Sheep and goats prefer leafy spurge versus grasses in most situations, but sheep or goat diets rarely exceed 50% leafy spurge.

Montana researchers have developed a targeted grazing prescription for landowners and sheep producers to follow: 1) Graze an infestation until yellow bracts have been removed and monitor the residual height of the desirable species; 2) Stock infestations at approximately 1 sheep per acre per month. 3) Begin grazing period in the late spring and remove all yellow bracts by late June to mid-July and repeat later in the summer.


A Degree Day Model of Sheep Grazing Influence on Alfalfa Weevil and Crop Characteristics
Authors: Hayes Goosey, Pat Hatfield, Rodney Kott and Dennis Cash

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Background

Alfalfa, Medicago sativa (L.), is produced on approximately 1.8 million acres in Montana and is the foremost forage crop in many high, semiarid, intermountain states. Two biological stressors (insects and weeds) combined with poor field management are primarily responsible for reduced alfalfa production. In the U.S. alone, arthropods cause an estimated $260 million loss to alfalfa with the alfalfa weevil, Hypera postica Gyllenhal, being the most damaging. In colder northern states, such as Montana, temperatures restrict the weevil’s winter activity. Invertebrate animals such as alfalfa weevil require a certain amount of heat to develop from one point in their life cycles to another. Degree days units are the accumulated product of time and temperature and can be used to estimate the developmental rate of these organisms.


Effect of Sex of Co-Twin and Breed on Ewe Flock Productivity
Authors: Valerie A. Uthlaut, Brenda M. Alexander and Gary E. Moss

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Background

Even though it is not highly heritable, prolificacy is an economically important criteria for selection programs. The uterine environment for developing fetuses is influenced by the sex of the co-twin and effects differ among species. Although traits such as freemartinism are generally regarded as rare and unimportant abnormalities in prolific species such as sheep, effects of co-sibling sex on development have been reported in numerous species. The presence of male fetus influenced its female co-twin’s birth weight and emotional characteristics in humans, age of puberty and reproductive life in swine, and serving capacity in rams. Therefore, it was hypothesized that ewes co-twinned to rams may reach puberty later and have a decreased reproductive life compared to ewes co-twinned to ewes.


Comparison of Texas Rambouillet Sheep with Australian Merino F1 Crosses
Authors: C. J. Lupton, F. A. Pfeiffer, W. S. Ramsey, M. Salisbury, D. F. Waldron, J. W. Walker and T. W. Willingham

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Background

This research project was initiated in 2007 and will continue through at least August 2011. We are investigating a crossbreeding approach to increase income from Rambouillet ewes that is designed to increase wool production and value without decreasing lamb production or increasing nutrition or labor inputs. Selected Australian and U.S. Merino (M) rams were used via laparoscopic artificial insemination (LAI) and natural mating to produce crossbred lambs from locally adapted Rambouillet (R) ewes. The strategy was designed to produce offspring that are capable of growing more and finer (more valuable) wool than their dams while retaining comparable fertility, growth, and meat composition characteristics to their Rambouillet contemporaries. For acceptance by the U.S. sheep industry (especially shearers and breeders), it is also important that the crossbred sheep not have excessive skin wrinkles.


Wool Preparation and Marketing for Growers with Small Numbers of Sheep
Authors: James Moore, Lisa Surber, Michael Schuldt, Marko Manoukian and Rodney Kott

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Background

Wool is an international product with prices and quality standards set by world markets. Adapting to the requirements of a global market is particularly a problem for producers with small numbers of sheep. More and more of the responsibility for proper clip preparation are being passed to the grower. Costs associated with preparing and handling (sorting and re-packaging) these small lots of wool by buying firms is becoming increasingly more expensive. When these expenses are passed to the grower, in terms of lowered price or increased handling charges, they consume a large proportion of the wool check regardless of wool quality. Just getting wool packaged properly in bales is a difficult task. This scenario provides little incentive for these growers to improve wool quality. For many of these producers, wool is considered an expense rather than a source of income.