Browsing by Author "Umberger, Steven H."
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- 4-H Animal Science Non-Ownership Livestock Project, Unit IIFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension, 2004)4-H project for youth aged 12-15 interested in livestock but do not or cannot have animals of their own.
- Addressing the consequences of predator damage to livestock and poultryUmberger, Steven H.; Geyer, L. Leon; Parkhurst, James A. (Virginia Cooperative Extension, 2005-09-01)To prevent uninformed decisions that could further exacerbate livestock and poultry losses from predators, it is important to understand the regulations and procedures affecting compensation for damages and the deterrent strategies for offending animals.
- Agronomy HandbookBrann, Daniel Edward; Abaye, Azenegashe Ozzie; Peterson, Paul R.; Chalmers, David R.; Whitt, David L.; Chappell, Glenn F.; Herbert, D. Ames Jr.; McNeill, Sam; Baker, James C.; Donohue, Stephen J.; Alley, Marcus M.; Evanylo, Gregory K.; Mullins, Gregory L.; Hagood, Edward Scott; Stallings, Charles C.; Umberger, Steven H.; Swann, Charles W.; Reed, David T.; Holshouser, David L. (Virginia Cooperative Extension, 2009-05-01)Provides readers with a source of agronomic information such as field crops, turfgrasses, variety selection, seed science, soil management, nutrient management and soil suitability for urban purposes that does not change frequently - pesticide and varietal information changes frequently and is therefor not included.
- Animal Science Non-Ownership Livestock Project, Unit IFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension Service, 1980-10)The Animal Science Project Units I, II and III are designed for individual 4-H'ers and 4-H clubs that are interested in livestock but do not or cannot have animals of their own. These are short-term projects and may be followed up by other livestock and meats projects or by the Junior Stockmans Project. These projects may be used in school clubs, community clubs, special project clubs or on an individual basis. Meats judging, livestock judging or participation in the Junior Stockmans contest may all result from these Animal Science Projects plus many other activities related to the livestock industry.
- Animal Science Non-Ownership Livestock Project, Unit IIFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension Service, 1980-10)The Animal Science Project Units I, II and III are designed for individual 4-H'ers and 4-H clubs that are interested in livestock but do not or cannot have animals of their own. These are short-term projects and may be followed up by other livestock and meats projects or by the Junior Stockmans Project. These projects may be used in school clubs, coITTTiunity clubs, special project clubs or on an individual basis. Meats judging, livestock judging or participation in the Junior Stockmans Contest may all result from these Animal Science Projects plus many other activities related to the livestock industry.
- Animal Science Non-Ownership Livestock Project, Unit IIIFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension Service, 1980-10)The Animal Science Projects Unit I, II and III are designed for individual 4-H'ers and 4-H clubs that are interested in livestock but do not or cannot have animals of their own. These are short term projects and may be followed up by other livestock and meats projects or by the Junior Stockmans Project. These projects may be used in school clubs, conmunity clubs, special project clubs or on an individual basis. Meats judging, livestock judging or participation in the Junior Stockmans contest may all result from these Animal Science Projects plus many other activities related to the livestock industry.
- Animal science non-ownership livestock project. Unit IFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension, 1990)A 4-H project record book designed for individuals or clubs that are interested in livestock but do not or cannot have animals of their own.
- Animal science non-ownership livestock project. Unit IIIFord, Jesse Ray; Umberger, Steven H. (Virginia Cooperative Extension, 1990)A 4-H project record book designed for individuals or clubs that are interested in livestock but do not or cannot have animals of their own.
- Budget Analysis of Spring, Fall with Winter Clean-up, and High-Fertility Fall Lambing Systems in a Simulated Fixed Forage ResourceAndrew, Shelley Lewis Jr. (Virginia Tech, 1998-08-03)A successful business needs to generate enough cash to cover expenses, current debt, and family living expenses, pay interest on owned and borrowed capital, maintain productivity, and earn a reasonable return for the operator. Income from sheep production is generally only part of a total farm and nonfarm income. Thus options, opportunity costs, and decisions regarding the sheep production enterprise are not isolated; they affect other agricultural enterprises. Sheep production consistently returns profits to producers, which makes it an enticing agricultural enterprise. There are advantages in raising sheep in Virginia, such as abundant, high-quality forage, moderate climate, pasture improvement, and good access to markets with high demand for lamb. The disadvantages to sheep production are unavailable and inexperienced labor and operators, predators, and inconsistent market demand and supply. Sheep producers have the opportunity to choose which lambing system fits their existing operations and lifestyle. The use of economic analysis enables operator to make sound business management decisions. To compare different lambing systems (spring, fall with winter clean-up, and high-fertility fall) in a systematic way, a simulation model was constructed with a fixed forage resource of 50 acres of pasture including typical Virginia mountain pasture plus various amounts of fescue for stockpiling. The simulation included a production calendar; nutritional requirements for ewes, lambs, and artificially reared triplets; growth rates for lambs; lambing distributions; forage growth; and enterprise budgets including income, costs, and returns. A economic analysis was performed for each lambing system with average prices or with plus or minus one standard deviation for prices of corn, SBOM, and market lambs, and price differentials for market lambs across lambing seasons. Comparisons of each lambing systems produced various results. In spring lambing, only 78 ewes could be maintained on the fixed forage resource, while the fall with winter clean-up and high-fertility fall lambing system each had 115 ewes. This result occurred because of limited forage in July and August and higher nutrient requirements for spring lambing in those months. The overall nutrient requirements were higher in the fall with winter clean-up and high-fertility fall lambing than in spring lambing as a result of the increased ewe and lamb numbers. Concentrate consumption by lambs was also greater for fall with winter clean-up and high-fertility fall lambing than for spring lambing because of the increased numbers of lambs. Because of the low number of ewes and lambs, spring system produced the most hay. Labor costs were highest in fall with winter clean-up lambing because of the two lambing seasons. In the economic analysis system, each lambing was compared. With 10-year average prices for market lambs, corn, and SBOM, high-fertility fall lambing had the greatest income ($17,467), followed by fall with winter clean-up lambing ($14,695), and spring lambing ($10,358). This result occurred because high-fertility fall and fall with winter clean-up lambing had more lambs sold at higher market lambs prices than spring lambing. With 10-year average prices for market lambs, corn, and SBOM, high-fertility fall lambing had the highest cost ($7,935), followed by fall with winter clean-up lambing ($7,360), and spring lambing ($6,084). This was the result of increased ewe and lamb numbers in high-fertility fall and fall with winter clean-up lambing than spring lambing. High-fertility fall lambing had the greatest returns ($6,210), followed by fall with winter clean-up lambing ($4,025), and spring lambing ($2,028). On a fixed forage resource, increasing fertility in fall lambing clearly results in increased returns. In this model, forage availability controlled the number of ewes that a lambing system can have because of limited summer growth and had a major impact on profits. Conclusions of Tolman (1993) differed from those found within this thesis. On a per ewe basis, she found that spring lambing to yielded the highest returns whereas this thesis found that high-fertility fall lambing yielded the highest returns. A key difference between this study and that of Tolman (1993) was after weaning this thesis feed fall lambs stockpiled fescue and she feed fall lambs feed in dry lot.
- Control of Internal Parasites in SheepWhittier, W. Dee; Zajac, Anne M.; Umberger, Steven H. (Virginia Cooperative Extension, 2009)Internal parasites are a threat to sheep health and productivity. Increased understanding of the role and actions of internal parasites provides the basis for more effective control programs.
- Control, Treatment, and Elimination of Foot Rot from SheepWhittier, W. Dee; Umberger, Steven H. (Virginia Cooperative Extension, 2009)Ovine foot root is an infectious, contagious disease of sheep that causes severe lameness. Control and elimination of the disease should be the goal of all sheep producers.
- Effects of breed and ram exposure on Spring estrous behavior and Summer fertility in domestic ewesNugent, Russell A., III (Virginia Tech, 1987-04-25)The present studies were conducted to check the effects of acute ram introduction into a flock of anestrus ewes in Virginia. Ewes were bled via jugular venipuncture twice weekly and serum samples were radioimmunoassayed for progesterone (P4) content as an indicator of estrous activity. All rams were fitted with crayon equipped marking harnesses for use as an indicator of mating behavior in ewes. The first study tested the effects of introduction of vasectomized rams into a flock: of' 50 Dorset (D) and 50 Hampshire (H) purebred ewes in either May or June. More D ewes ovulated (96% vs 72% for H ewes) and mated (80% vs 20% for H ewes) in May. Of ewes which mated in May 65% D but no H ewes continued to cycle in June after removal of rams. Of ewes exposed to rams in June no difference among breeds was observed in percentage of ewes ovulating but more D ewes (72%) mated than H ewes (44%). Twenty-four percent of D but no H ewes cycled continuously throughout the 68 d or the study. Lambing date significantly affected mating behavior in H but not D ewes. The second study tested the effects of ram breed on incidence of mating and subsequent lambing in Rambouillet x Q Suffolk ewes In June and July of 1984 and 1985. Ewes were Q pre-exposed to either confined Suffolk (S) or Dorset (D) Q yearling rams or no (N) ram for 2 wk prior to breeding by Q either S or D rams. Lambing date was significantly affected by breeding treatment in 1984 and by pre-exposure treatment in 1985. Sixty-three percent of the ewes lambed in 1984 while 65% lambed in 1985.
- Feeding SheepUmberger, Steven H. (Virginia Cooperative Extension, 2009)Discusses feeding of ewes, lambs and rams, various feeds for sheep, and nutrient values and limitations of those feeds.
- Melengestrol acetate and norgestomet for the induction of synchronized estrus in seasonally anovular ewesJabbar, Ghulam (Virginia Tech, 1993-12-14)Two commercially available progestogen products for cattle, melengestrol acetate (MGA) and norgestomet (SMB) , were evaluated for their ability to induce synchronized estrus in anovulatory ewes. Seasonally anestrous ewes (n=232; determined by blood serum progesterone concentration) of mixed breeding were randomly assigned within broad age groups to one of seven treatments: 1) control (C); 2) MGA only (OMGA); 3) MGA + zeranol (RMGA); 4) MGA + PG-600 (PMGA; 400 IU pregnant mare's serum gonadotropin + 200 IU human chorionic gonadotropin in a 5 mL dose); 5) 5MB only (OSMB); 6) 5MB + zeranol (RSMB); and 7) 5MB + PG-600 (PSMB). Beginning 10 d before breeding, OMGA, RMGA, and PMGA ewes were fed .3 mg MGA/d provided through a mixture of shelled com and a commercially prepared pelleted supplement containing MGA. Concomitantly, OSMB, RSMB, and PSMB ewes were given a 3 mg norgestomet implant inserted subcutaneously on the back of the ear. Immediately preceding initiation of the MGA and 5MB treatments, RMGA and RSMB ewes were given a single i.m. injection of 2.5 mg zeranol. At the end of the 10-d treatment period, MGA feeding was discontinued and the norgestomet implants were removed. Concomitantly, PMGA and PSMB ewes were given a single i.m. injection of PG-600 (5 mL). All treatment groups were combined into one breeding group on May 4, 1992, with a ram to ewe ratio of 1: 17 for a 30-d breeding period. Mating to synchronized estrus was greater (P < .0001) for progestogentreated ewes. Within progestogen treatments, more (P < .000 1) 5MB ewes were marked within the first 5 d of breeding than MGA ewes. Overall, there were no treatment differences in estrus response for the 30-d breeding period. Blood serum samples collected during the first 14 d of breeding were analyzed for progesterone as an indicator of corpora lutea formation. Even though a large proportion of C ewes displayed luteal activity, only 12 % exhibited behavioral estrus within the first 17 d of breeding. Progestogen treated ewes exhibited a shorter mean interval (P < .0001) from ram introduction to lambing. Fertility and prolificacy were not different for C, MGA, or 5MB ewes. Of the two progestogen treatments used alone, lambing rate was 85 and 59 % (P < .03) for OMGA and OSMB ewes, respectively. Ewes plimed with zeranol before MGA or 5MB treatment exhibited similar levels of fertility and intervals from ram introduction to lambing compared with ewes receiving an injection of PG-600 after progestogen treatment. These data indicate that progestogen products commercially available for cattle may be useful in enhancing out-of-season breeding performance in sheep.
- Oxytocin-induced cervical dilation in sheep: mechanism of action and potential use for nonsurgical artificial inseminationSayre, Brian L. (Virginia Tech, 1995)Exogenous oxytocin aids in the transcervical passage of an AI pipette into the uterus of ewes, and it may be an effective adjunct to sheep AI procedures. Experiments were conducted to evaluate the effects of oxytocin on variables that may affect fertility. The results of this study indicate clearly that oxytocin dilates the cervix in ewes (Exp. 1) without affecting the movement of sperm to the oviducts (Exp. 3) or fertilization rate (Exp. 9). Oxytocin probably binds to uterine and cervical receptors (Exp. 6) and stimulates uterine tetany (Exp. 2) and prostaglandin release (Exp. 5). Because of the irregular arrangement of smooth muscle in the sheep cervix (Exp. 4), uterine tetany may physically dilate the cervix. Also, prostaglandin synthesis, primarily PGF2, may be involved in a chemical softening of the cervix. Most likely, a combination of uterine contractions and cervical softening allow dilation and transcervical passage of an AI pipette. Although oxytocin does not affect sperm transport (Exp. 3) or fertilization (Exp. 9), fertility after transcervical AI is decreased (Exp. 8). Cervical manipulation seems to decrease fertility, but the mechanism is unclear. Therefore, a greater understanding of the physiology of the sheep cervix is necessary before oxytocin-induced cervical dilation can be implemented with nonsurgical AI procedures in sheep.
- Profitable Artificial Rearing of LambsUmberger, Steven H. (Virginia Cooperative Extension, 2009)Describes the management and economics of raising lambs artificially. Using the techniques described, lambs can be successfully reared on milk replacer at a similar cost to rearing on the ewe.
- Reproductive performance of dorset ewes in the star accelerated lambing systemLewis, Ronald M. (Virginia Tech, 1990-05-05)Reproductive performance of Dorset ewes in the Cornell University STAR accelerated lambing program was evaluated. This program consists of five 30-d concurrent breeding and lambing periods per year beginning on January 1 (Sl), March 15 (S2), May 27 (S3), August 8 (S4) and October 20 (S5). Optimally, a ewe could lamb every 7.2 mo beginning at 1 yr of age, Records on 1,084 ewes over 7 yr beginning S1, 1982 Reproductive traits considered were ewe fertility, prolificacy, days to first lambing (DFL) and days between lambing (DBL). Fertility and prolificacy differed (P < .001) by exposure seasons. Exposure during favorable seasons (S1, S4, S5) increased fertility (P < .001) and prolificacy (P < .01) over that observed in unfavorable seasons (S2, S3). On average, first lambing occurred at 476 ± 5 d with ewe lambs first exposed during S1, S4 and S5 lambing at younger ages (P < .001). Ewes had more DBL (P < .001) if initial exposure following lambing occurred during an unfavorable season. A curvilinear relationship of ewe age with fertility (P < .001) , prolificacy (P < .01) and DBL (P < .05) was observed in ewes less than 4 yr old. At first exposure following lambing, fertility was lower (P < .001) than at subsequent exposures and ewes that had nursed lambs were less prolific (P < .01) than those that had not. Prolificacy and nursing status had little effect on fertility or DBL (P > .10). Fertility was transformed to an underlying liability scale based on the expected fertility of ewes of a given age and reproductive history. Variance components were estimated by least-squares (LS) and restricted maximum likelihood (REML) procedures. First-exposure fertility was not heritable. heritabilities for fertility at first post-lambing exposure, first-lambing prolificacy, and second-lambing prolificacy were .191 ± .088 (LS) and .200 ± .132 (REML), .914 ± .091 (LS) and .158 ± .144 (REML), and .168 ± .082 (LS) and .210 ± .137 (REML), respectively. Genetic variation in DFL (P < .01) and DBL (P < .001) was found. Although intrasire ewe variation was detected for prolificacy (P < .001) and DBL (P < .01), repeatability estimates were low and smaller than heritability.
- Selection to improve spring fertility in a crossbred sheep populationAl-Shorepy, Salih Abdu (Virginia Tech, 1995-03-13)Reproductive and productive performance of a composite sheep population, containing 50% Dorset, 25% Rambouillet and 25% Finn sheep breeding and under selection for ability to lamb in the fall, was evaluated. Traits considered were spring fertility, faIl litter size, live weights at birth, weaning, and at about 90 and 120 d of age, and scrotal circumference at weaning and at about 90 and 120 d of age. Fertility was defined as 1 or 0 depending upon whether a ewe lambed or failed to lamb, respectively, in fall. Litter size was defined as the number of lambs born per ewe lambing. A total of 1,102 exposures were used. Fertility averaged .59 for adult ewes (3 years and older), .45 for second-lambing ewes and .11 for yearling ewes (12 months old). Mean litter size averaged 1.89 across seasons and ages. Scrotal circumferences (SC) and body weights (WT) were measured at means of65, 96 and 128 d. Data were collected on 1878 lambs over 5 years; 63 sires and 420 dams were represented. Genetic parameters were estimated by restricted maximum likelihood (REML) using various animal models. Heritability estimates for spring fertility ranged from .07 to .11. Litter size heritability was .05 for fall lambing and .10 for all lambings. Heritability estimates for weights from birth to 120 d ranged from .04 to . 19. Heritabilities for SC ranged from .02 to .25. Estimated genetic correlations among weights were large, and ranged from. 77 to unity. The genetic correlations of litter size with birth weight (BWT), 90-d weight (90WT) and 90-d scrotal circumference (90SC) were .17, .33 and .36, respectively. Genetic correlations of spring fertility with BWT, 90WT and 90SC were .22, -.31 and .29, respectively. Mixed model methodology was applied to estimate genetic trends for fertility, litter size, BWT, weaning weight (WWT), 90WT and 90SC resulting from selection for fall lambing. Positive genetic gains in both spring fertility and fall litter size were observed. Rate of increase was higher for fertility than litter size, which was due to direct selection for fertility. Selection for spring fertility did not cause significant correlated changes in BWT, WWT, 90WT or 90SC. Thus, no genetic antagonisms resulted from the selection for fall lambing.
- Sheep Grazing ManagementUmberger, Steven H. (Virginia Cooperative Extension, 2009)Describes successful grazing of sheep, including nutrient requirements, stocking rates, fencing, and various forages
- Virginia 4-H : Market Lamb Project GuideUmberger, Steven H.; Wahlberg, Mark L. (Virginia Cooperative Extension, 1995)Virginia is the largest sheep producing state in the eastern United States. There are approximately 125,000 breeding-age ewes in Virginia, and Virginia producers raise 140,000 market lambs a year. Sheep play a key role in utilizing the vast amount of pasture forage available throughout Virginia. Sheep are the most efficient converters of grass to a choice meat product of all the livestock species. Over ninety percent of a ewe's yearly energy requirement comes from forage.