Progress 07/01/01 to 06/30/05
Outputs
St. Croix (hair sheep breed) and Western White-face wool-type ewes were placed in an accelerated breeding program starting August 1, 2001. Ewes were bred at 8-month intervals (August, April and December) to measure their efficacy in lambing three times in two years. The accelerated group was bred during August 2001 and 2003, December 2002 and 2004, and April 2002 and 2004. A control group of St. Croix and Western White-face ewes were bred during the normal breeding season (November at Utah State University) and lambed once per year. Control ewes were bred during November of 2001, 2002, 2003, and 2004. Birth weights and number of lambs born per ewe lambing and weaning weights were recorded. Lambs were weaned at 60 days. The data were analyzed using nested ANOVA with two factors: Breeding ways (accelerated vs. normal) and Groups (five groups, nested in the breeding way factor). There was no significant difference in birth weight and weaning weight between accelerated
breeding and normal breeding, indicating that lambs generated from accelerated breeding were similar to those from normal breeding. Whether one breeding method was better than the other was dependent on the pregnancy rate, prolificacy and the weaning rate. There was no significant difference between accelerated breeding and normal breeding with respect to prolificacy and weaning rates. However, the pregnancy rate from accelerated breeding was 69% compared to that of normal breeding of 83%. Normal breeding had a 13% higher pregnancy rate than accelerated breeding. When taking into consideration breeding times, normal breeding as once a year and accelerated breeding three times in two years, accelerated breeding resulted in 33% more breeding events than normal breeding. The St Croix hair sheep had a higher pregnancy rate than the Western White-face ewes. Seventy-nine percent of the St. Croix ewes in the accelerated breeding groups lambed, whereas 56% lambed in the Western White-face
ewes. The control St. Croix groups had a lambing rate of 90% and the Western White-face 83%. Lambs born dead, given away, or that died before weaning were not considered in the overall productivity rates because many factors were involved in lamb attrition due to the unique way the university sheep flocks are managed.
Impacts
Upon comparing pregnancy rates and breeding frequencies, accelerated breeding has a total productivity approximately 20% higher than normal breeding. If producers want to maximize productivity, then three times breeding in two years will result in greater profitability. The St Croix hair sheep out performed the Western White-faced wool sheep with 23% more of the ewes lambing, which makes them a good choice in a three times every two year breeding schedule.
Publications
- Bunch, T.D., S. Wang and K.E. Panter. 2005. St. Croix hair sheep production: A comparison between hair sheep with wool sheep in two breeding schedules. Proceeding Hair Sheep Workshop. Small Ruminant Program. Virginia State Univ., Petersburg. 17.
- Bunch, T.D., W.C. Foote, R.C. Evans, K.E. Panter and S. Wang. 2005. The St. Croix Sheep in the United States. North American Hair Sheep Symposium. San Angelo, Texas, Texas Cooperative Estension, Texas A&M University System. CD (paper and Powerpoint).
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Progress 01/01/04 to 12/31/04
Outputs
St. Croix and wool-type ewes were placed in an accelerated breeding program starting August 1, 2001. These ewes were bred at 8-month intervals (August, April and December) to measure their efficacy in lambing 3X/2 years. A control group of St. Croix and wool-type ewes were bred during the normal breeding season (November at USU) and lambed once per year. St. Croix ewes were bred to St. Croix rams. Wool-type ewes were bred to St. Croix rams and wool-type rams. Birth weights and number of lambs born per ewe lambing were recorded. Lambs were weaned at approximately 60 days and weaning weights recorded. Data analysis thus far shows that there is no significant difference in terms of birth weight and weaning weight between accelerated and normal breeding, indicating that the lambs generated from accelerated breeding were similar to those from normal breeding. The pregnancy rate of accelerated breeding was 58.1% compared to that of normal breeding of 83.2%. The normal
breeding groups had a pregnancy rate 25.1% higher than that of accelerated breeding groups. There was 33.3% more breeding in the accelerated-breeding groups than in the normal breeding groups. The accelerated breeding groups appear to have an 8% higher productivity than the normal breeding groups.
Impacts
Commercial sheep production is based upon one lambing per year. This management strategy is to use ewes that exhibit a shorter breeding season. The advantage of hair sheep is that they have a much longer breeding season and some ewes will cycle year-round as compared to the typical Western White-faced ewe. The intent of this study is to demonstrate that more pounds of lamb can be produced by hair-sheep in an accelerated breeding program. The results thus far indicate that hair sheep can out produce wool sheep with three lamb crops being produced every two years instead of the traditional once a year lambing. The use of hair sheep in an accelerated breeding program provides the producer with the option of increasing lamb production while cutting the cost in maintaining a ewe flock.
Publications
- Bunch, T.D., R. C. Evans, S. Wang, C. P. Brennand, D. R. Whittier and B. J. Taylor. 2004. Feed efficiency, growth rates, carcass evaluation, cholesterol level and sensory evaluation of lambs of various hair and wool sheep and their crosses. Small Ruminant Research. 52:239-245.
- Kaya, M.A., T.D. Bunch and M. Konuk. 2004. On Konya wild sheep, Ovis orientalis anatolica, in the Bozdag protected area. Mammalia 68:229-232.
- McNeal, L.G. and T.D. Bunch. 2004. Sheep: Reproduction Management. In Encyclopedia of Animal Science. Eds. Wilson G. Bell and Alan W. Pond. Marcel - Dekker Inc., New York.
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Progress 01/01/03 to 12/31/03
Outputs
Cholesterol levels and sensory (preference) evaluations were compared in six lambs from: 1) St. Croix hair sheep, 2) St. Croix x wool sheep, 3) Callipyge wool x St. Croix, 4) Dorper hair sheep x St. Croix, 5) Dorper x wool, Callipyge wool x wool, and 6) wool x wool. Meat cholesterol was extracted by chloroform-methanol mixture and the cholesterol levels were determined by spectrophotometric measurement of the color generated by the reaction of cholesterol with glacial acetic acid-FeSO4-H2SO4. A 9-point hedonic ballot was used for the sensory evaluation based on the following index: flavor, tenderness, juiciness and overall quality. Judges used a hedonic scale for evaluating samples ranging from 9 (like extremely) to 1 (dislike extremely). Cholesterol levels (mg/100g fresh meat) were 249.6, 170.1, 73.2, 130.7, 149.2, 50.4 and 116.5, respectively. The cholesterol level in the hair sheep (St. Croix) was significantly higher (P < 0.05) than all the other genotypes and the
lowest is in the Callipyge crosses. Significant differences (P < 0.05) existed between genotypes for every sensory characteristic measured. St. Croix had the highest overall sensory acceptance rating (6.8) and the lowest in the Callipyge wool x wool.
Impacts
The national trend for consumption of lamb has steadily declined primarily because the consumer prefers other meat choices. In general, beef, pork and poultry are preferred over the typical wool-breed lamb marketed today in retail outlets. The hair sheep lamb or hair-wool cross lamb can provide an alternative meat product with a higher sensory appeal, although the higher cholesterol may impose a negative connotation to the consumer.
Publications
- Bunch, T.D., S. Wang, C. Wu and Y. Zhang . 2003. Mitochondrial D-loop sequence variation with three extant genera of the tribe capriini. Plant and Animal Genome XI. Abstract 134, p 117.
- Bunch, T.D., R.C. Evans, S. Wang, C.P Brennand, D.R. Whittier and B.J. Taylor. 2003. Feed efficiency, growth rates and carcass evaluation of lambs of various hair x wool sheep crosses. Proc. West. Sect. J. Anim. Sci. Vol. 54: 312-314.
- Wu, C.H., Y.P. Zhang, T.D. Bunch, S. Wang and W. Wang. 2003. Mitochondrial control region sequence variation with the argali wild sheep (Ovis ammon): evolution and conservation relevance. Mammalia 67: 109-118.
- Wang, S., T.D. Bunch, R.C. Evans, C.P. Brennand, D.R. Whittier, and B.J. Taylor. 2003. Cholesterol level and sensory evaluation for lambs of Various hair x wool sheep crosses. Proc. West. Sect. J. Anim. Sci. Vol. 54: 396-399.
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Progress 01/01/02 to 12/31/02
Outputs
Feed efficiency, growth rates, carcass evaluation, cholesterol level and sensory evaluation were compared in six lambs each of the following genotypes: St. Croix hair sheep, St. Croix X wool sheep, Callipyge wool X St. Croix, Dorper hair sheep X St. Croix, Dorper X wool, Callipyge wool X wool,and wool X wool. Kilograms of feed per kg of gain varied from 2.34 to 3.09, with the highest feed efficiency in St. Croix lambs. Standardized daily gain ranged from 0.34 to 0.55 kg, with the highest rate of gain in the Callipyge wool X St. Croix lambs. Wholesale weight (kg) was the highest in the Callipyge wool X wool (19.26) and lowest in the St. Croix (15.38). Quality grade among the seven genotypes of lambs ranged from 5.5 to 7.6, with the higher grades in the St. Croix and St. Croix X wool lambs. Percent wholesale cut of body weight was the highest in the Callipyge X wool (64.1) and the lowest in the St. Croix (55.6). Percent loin eye of carcass weight was the highest in the
Callipyge wool X wool (4.5) and the lowest is the St. Croix (3.0). Cholesterol levels were the highest in the hair sheep and lowest in the Callipyge crosses. The overall sensory acceptance rating was the highest in the St. Croix (6.8) and the lowest in the Callipyge wool X wool.
Impacts
The national trend for the consumption of lamb has steadily declined primarily because the consumer prefers other meat choices. In general, beef, pork and poultry are preferred over the typical wool-breed lamb marketed today in retail outlets. The hair sheep lamb or hair-wool cross lamb provides an alternative meat product with a higher sensory appeal, and at a higher quality grade.
Publications
- Bunch, T.D., S. Wang,, N.E. Cockett, T.L. Shay, J. M. Miller, A. Maciulis, R.C. Evans, G.R. Holyoak, W.C. Foote and J.W. Call. 2002. The PRPN gene polymorphic distribution in embryo transfer flocks used for studying scrapie transmission. Plant, Animal & Microbe Genomes X. p 111
- Wang, S. N. E. Cockett, J.M. Miller, T.L. Shay, A. Maciulis, D.L. Sutton, W.C. Foote, G.R. Holyoak, R.C. Evans, T.D. Bunch. J.E. Beever, J.W. Call, W.D. Taylor and M.R. Marshall. 2002. Polymorphic distribution of the ovine prion protein (PRP) gene in scrapie-infected sheep flocks in which embryo transfer was used to circumvent the transmissions of scrapie. Theriogenology. 57:1865-1875.
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Progress 07/01/01 to 12/31/01
Outputs
Forty-two lambs were assigned to seven treatment groups according to genotype. Six lambs each of the following genotypes were used for performance evaluation: Group 1, St. Croix X St. Croix; Group 2, St Croix X normal wool sheep; Group 3, Callipyge X St. Croix; Group 4, Dorper X St. Croix; Group 5, Dorper X normal wool; Group 6, Callipyge X normal wool; and Group 7, normal wool X normal wool. St Croix rams and ewes were purebred. Dorper rams were purebred. Callipyge rams were 7/8 Suffolk and 1/8 Rambouillet Dorset. Normal rams were 7/8 Suffolk and 1/8 Rambouillet. Normal ewes were 1/2 - 1/3 Suffolk and 1/2 to 1/4 Rambouillet. No Callipyge ewes were used because the Callipyge phenotype is not expressed when passed from the dam. No Dorper ewes were available for use. Lambs were fed free choice whole barley and a commercial fattening that consisted of 16% protein, 20% fiber and 2% fat. Feed was weighed into each pen daily, with the weigh back of unused feed done weekly.
Lambs were weighed and body condition scored every two weeks. Target slaughter weights were 100-110 pounds for the smaller framed genotypes (groups 1, 2, 3 and 4) and 115-125 pounds for the larger framed genotypes (groups 5, 6 and 7). Target body condition scores were 6 - 7 for all groups. All lambs were slaughtered at the Utah State University abattoir and the data is now being analyzed.
Impacts
Hair sheep have many advantages for small farm flock production (i.e., early maturing, increased prolificacy, extended breeding season etc.); however, they are generally smaller and tend to have less retail value. This study will compare various hair-wool sheep terminal crosses under feedlot conditions and will evaluate feed efficiency, growth rate, carcass quality and sensory preference to determine whether certain hair sheep terminal crosses are more profitable and have greater consumer appeal.
Publications
- Hoefs, M and T.D. Bunch. 2001. Lumpy jaw in wild sheep and its evolutionary implications. J. Wildl. Dis. 37: 39-48.
- Wang, S., W.C. Foote, D.L. Sutton, A. Maciulis, J.M. Miller, R.C. Evans, G.R. Holyoak, J.W. Call, T.D. Bunch, W.D. Taylor and M.R. Marshall. 2001. Preventing experimental vertical transmission of scrapie by embryo transfer. Theriogenology. 56: 315-327
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