Genetic Evaluation of some Carcass Characteristics Assessed by in vivo Real Time Ultrasonography in Baluchi Sheep

Subject Areas : Camel

ع.  محمدی ¹ (Department of Animal and Poultry Breeding and Genetics, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran)
س.  حسنی ² (دانشگاه علوم کشاورزی و منابع طبیعی گرگان)
س.  زره داران ³ (Department of Animal Science, Ferdowsi University of Mashhad, Mashhad, Iran)
م.  باقری ⁴ (Veterinary Clinic, Near Laleh Residential Complex, Asian Highway, Mashhad, Iran)
ع.  میرشاهی ⁵ (Department of Clinical Science, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran)

Received: 2018-01-24 Accepted : 2018-03-15 Published : 2018-09-01

Keywords: genetic parameters, backfat thickness, Baluchi sheep, longissimus muscle area, ultrasound measurements,

Abstract :

In order to evaluate carcass characteristics of a nucleus flock of Baluchi sheep, in vivo ultrasound technique was used to measure backfat thickness (UBFT) and longissimus dorsi muscle area (ULMA) and also to estimate genetic parameters for these ultrasonic traits and live weights in different ages. The data were collected from 576 animals during 2011. (Co)variance components were estimated by univariate and bivariate animal models using restricted maximum likelihood and Asreml software. Females had higher UBFT and ULMA than males. Estimates of direct heritabilities were 0.32, 0.23, 0.27, 0.02, 0.12, 0.22 and 0.18 for UBFT, ULMA, birth weight (BW0), weaning weight (BW3), 6 month weight (BW6), 9 month weight (BW9) and yearling weight (BW12), respectively. There were positive and high genetic (0.68±0.15) and phenotypic (0.62±0.03) correlations between UBFT and ULMA. The genetic correlations among ultrasonic and pre 6 month weights were positive and low except for BW0 and ULMA (0.39±0.28). Contrarily, moderate to high positive genetic correlations between ultrasonic traits and weaning and post-weaning weights were found (0.33 to 0.61). Phenotypic correlations between ultrasonic and growth traits were positive and ranged from 0.09 to 0.37. High positive genetic correlation between UBFT and ULMA suggests that selection for larger muscle mass result in higher fat carcasses.

References:

Abbasi M.A., Abdollahi-Arpanahi R., Maghsoudi A., Vaez Torshizi R. and Nejati-Javaremi A. (2012). Evaluation of models for estimation of genetic parameters and maternal effects for early growth traits of Iranian Baluchi sheep. Small Rumin. Res. 104, 62-69.

Abdel-Mageed I.I. and Abo El-Maaty A.M. (2012). The effect of backfat thickness at mating on the reproductive and productive performances of ewes. Small Rumin. Res. 105, 148-153.

Adams N.R., Briegel J.R., Greeff J.C. and Bermingham E.N. (2006). Feed intake, body composition and plasma metabolic hormones in Merino sheep that differ genetically in fleece weight or fiber diameter. Australian J. Agric. Res. 57, 27-32.

Agamy R., Abdel-Moneim A.Y., Abd-Alla M.S., Abdel-Mageed I.I. and Ashmawi G.M. (2015). Use of ultrasound measurements to predict carcass characteristics of Egyptian ram-lambs. Asian J. Anim. Vet. Adv. 10(5), 203-214.

Aguilar-Hernandez E., Chay-Canul A.J., Gomez-Vazquez A., Magaña-Monforte J.G., Ríos-Rincón F.G. and Cruz-Hernandez A. (2016). Relationship of ultrasound measurements and carcass traits in Plibuey ewes. J. Anim. Plant Sci. 26(2), 325-330.

Alliston J.C. (1980). Evaluation of carcass quality in the live animal. Pp. 75-96 in Sheep Production. W. Haresign, Ed. Butterworths, London, United Kingdom.

Ap Dewi I., Saatci M. and Ulutas Z. (2002). Genetic parameters of weights, ultrasonic muscle and fat depths, maternal effects and reproductive traits in Welsh Mountain sheep. J. Anim. Sci. 74, 399-408.

Atkins K.D. (1986). A genetic analysis of the components of lifetime productivity in Scottish Blackface sheep. Anim. Prod. 43, 405-419.

Atkins K.D., Murray J.I., Gilmour A.R. and Luff A.L. (1991). Genetic variation in live weight and ultrasonic fat depth in Australian Poll Dorset sheep. Australian J. Agric. Res. 42, 629-640.

Atti N. and Mahouachi M. (2011). The effects of diet, slaughter weight and docking on growth, carcass composition and meat quality of fat-tailed Barbarine lambs. Rev. Trop. Anim. Health Prod. 43(7), 1371-1378.

Banks R.G. (2002). Enhancing the value of meat from wool sheep: Is there a need for specialisation? Wool Technol. Sheep Breed. 50, 584-595.

Bewley J.M. and Schutz M.M. (2008). Review: an interdisciplinary review of body condition scoring of dairy cattle. Prof. Anim. Sci. 24, 507-529.

Bibe B., Brunel J.C., Bourdillon Y., Loradoux D., Gordy M.H., Weisbecker J.L. and Bouix J. (2002). Genetic parameters of growth and carcass quality of lambs at the French progeny-test station Berrytest. Pp. 11-06 in Proc. 7^th World Congr. Genet. Appl. Livest. Prod., Montpellier, France.

Bicer O., Pekel E. and Guney O. (1984). Effects of docking on growth performance and carcass characteristics of fat-tailed Awassi ram lambs. Small Rumin. Res. 8, 353-357.

Bishop S.C. (1993). Selection for predicted carcass lean content in Scottish Blackface sheep. Anim. Prod. 56, 379-386.

Bishop S.C., Conington J., Waterhouse A. and Simm G. (1996). Genotype × environment interactions for early growth and ultrasonic measurements in hill sheep. Anim. Sci. 62, 271-277.

Boujenane I. and Kansari J. (2002). Estimates of (co)variances due to direct and maternal effects for body weights in Timahdite sheep. J. Anim. Sci. 74, 409-414.

Brash L.D., Fogarty N.M., Gilmour A.R. and Luff A.F. (1992). Genetic parameters for live weight and ultrasonic fat depth in Australian meat and dual-purpose sheep breeds. Australian J. Agric. Res. 43, 831-841.

Brewer M.S. (1994). Consumer attitudes toward food safety issues. J. Food Saf. 14, 63-76.

Brown D.J., Ball A.J., Huisman A.E., Swan A.A., Atkins K.D., Graser H.U., Banks R.G., Swan P. and Woolaston R.R. (2006). Sheep genetics Australia. Pp. 3-5 in Proc. 8^th World Congr. Genet. Appl. Livest. Prod., Belo Horizonte, Brazil.

Butterfield R.M. (1988). New Concepts of Sheep Growth. University of Sydney Press, Sydney, Australia.

Cameron N.D. and Bracken J. (1992). Selection for carcass lean content in terminal sire breeds of sheep. Anim. Prod. 54, 367-377.

Conington J., Bishop S.C., Waterhouse A. and Simm G. (1995). A genetic analysis of early growth and ultrasonic measurements in hill sheep. Anim. Sci. 61, 85-93.

Delfa R., Teixeira A., Gonzalez C. and Blasco I. (1995). Ultrasonic estimates of fat thickness and longissimus dorsi muscle depth for predicting carcass composition of live Aragon lambs. Small Rumin. Res. 16, 159-164.

Department of Health. (1994). Nutritional Aspects of Cardiovascular Disease. Report of Health and Social Subjects. London, United Kingdom.

Donovan P.B.O., Ghadaki M.B., Beheshti R.D. and Salehi B.A. (1973). Performance and carcass composition of docked and control fattailed Kellakui lambs. Anim. Prod. 16, 67-76.

El Fadili M., Michaux C., Detilleux J. and Leroy P.L. (2000). Genetic parameters for growth traits of the Moroccan Timahdit breed of sheep. Small Rumin. Res. 37, 203-208.

Farid A., Izadifard J., Edris M.A. and Makarechian M. (1983). Meat from culled old ewes of two fat-tailed Iranian breeds. 2. Meat, subcutaneous fat, and bone in the wholesale cuts. Iranian Agric. Res. 2, 93-114.

Fernandez C., Gallego L. and Quintanilla A. (1997). Lamb fat thickness and longissimus muscle area measured by a computerized ultrasounic system. Small Rumin. Res. 26, 277-282.

Fisher A.V., Enser M., Richardson R.I., Wood J.D., Nute G.R. and Kurt E. (2000). Fatty acid composition and eating quality of lamb types derived from four diverse breed × production systems. Meat Sci. 55(2), 141-147.

Fogarty N.M., Brash L.D. and Gilmour A.R. (1994). Genetic parameters for reproduction and lamb production and their components and liveweight, fat depth and wool production in Hyfer sheep. Australian J. Agric. Res. 45, 443-457.

Fogarty N.M., Safari E., Taylor P.J. and Murray W. (2003). Genetic parameters for meat quality and carcass traits and their correlation with wool traits in Australian Merino sheep. Australian J. Agric. Res. 54, 715-722.

Gilmour A.R., Cullis B.R., Welham S.J. and Thompon R. (2004). ASREML: Program User Manual. NSW, Agriculture, Orange, Australia.

Gilmour A.R., Luff A.F., Fogarty N.M. and Banks R. (1994). Genetic parameters for ultrasound fat depth and eye muscle measurements in live Poll Dorset sheep. Australian J. Agric. Res. 45, 1281-1292.

Gizaw S., Lemma S., Komen H. and Van Arendonk J.A.M. (2007). Estimates of genetic parameters and genetic trends for liveweight and fleece traits in Menz sheep. Small Rumin. Res. 70, 145-153.

Gowane G.R., Chopra A., Prakash V. and Arora A.L. (2010). Estimates of (co)variance components and genetic parameters for body weights and first greasy fleece weight in Malpura sheep. Livest. Sci. 131, 94-101.

Greeff J., Davidson R. and Skerritt J. (2003). Genetic relationships between carcass quality and wool production traits in Australian Merino rams. Proc. Assoc. Adv. Anim. Breed. Genet. 15, 330-333.

Grundy S.M. (1987). Monounsaturated fatty acids, plasma cholesterol, and coronary heart disease. Am. J. Clin. Nutr. 45(5), 1168-1175.

Hall D.G., Fogarty N.M. and Gilmour A.R. (1995). Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 1. Lamb birth weight, survival and growth. Australian J. Exp. Agric. 35, 1069-1074.

Henderson D.C. (1990). The Veterinary Book for Sheep Farmers. Farming Press Books, Ipswich, United Kingdom.

Hopkins D., Hegarty R., Walker P. and Pethick D. (2006). Relationship between animal age, intramuscular fat, cooking loss, pH, shear force and eating quality of aged meat from sheep. Australian J. Exp. Agric. 46(7), 879-884.

Hopkins D.L., Stanley D.F. and Ponnampalam E.N. (2007). Relationship between real-time ultrasound and carcass measures and composition in heavy sheep. Australian J. Exp. Agric. 47, 1304-1308.

Hosseini Vardanjani S.M., Miraei Ashtiani S.R., Pakdel A. and Moradi Shahrebabak H. (2014). Accuracy of real-time ultrasonography in assessing carcass traits in Torki-Ghashghaii sheep. J. Agric. Sci. Technol. 16, 791-800.

Husain S.S., Wolf B.T. and Haresign W. (2007). Genetic parameters of lamb weights and ultrasonic muscle and fat depths in Beulah Specklefaced sheep. Small Rumin. Res. 70, 116-123.

Jafaroghli M., Rashidi A., Mokhtaric M.S., Shadparvar A.A. (2010). (Co)variance components and genetic parameter estimates for growth traits in Moghani sheep. Small Rumin. Res. 91, 170-177.

Jones H.E., Lewis R.M., Young M.J. and Simm G. (2004). Genetic parameters for carcass composition and muscularity in sheep measured by X-ray computer tomography, ultrasound and dissection. Livest. Prod. Sci. 90, 167-179.

Junkuszew A. and Ringdorfer F. (2005). Computer tomography and ultrasound measurement as methods for the prediction of the body composition of lambs. Small Rumin. Res. 56(1), 121-125.

Karim S.A. (2004). Nutrition and feeding management of sheep for mutton production. Pp. 88-99 in Proc. Natl. Semin. Opportun.Challen. Nutr. Feeding Manag. Sheep Goat. Rabbits for Sustain. Production. Central Sheep and Wool Research Institute, Avikanagar, Malpura, India.

Kashan N.E.J., Manafi Azar G.H., Afzalzadeh A. and Salehi A. (2005). Growth performance and carcass quality of fattening lambs from fat-tailed and tailed sheep breeds. Small Rumin. Res. 60, 267-271.

Khaldari M., Kashan N., Afzalzadeh A. and Salehi A. (2008). Growth and carcass characteristics of crossbred progeny from lean-tailed and fat-tailed sheep breeds. South African J. Anim. Sci. 37(1), 51-56.

Khaldari M. and Tajic P. (2006). Study of growth and carcass characteristics of F1 and R1 cross lambs from Zandi and Zel breeds. J. Vet. Res. 61(3), 277-284.

Kashan N.E.J., Manafi Azar G.H., Afzalzadeh A. and Salehi A. (2005). Growth performance and carcass quality of fattening lambs from fat-tailed and tailed sheep breeds. Small Rumin. Res. 60, 267-271.

Kempster A.J. (1983). Carcass quality and its measurement in sheep. Pp. 59-74 in Sheep Production. W. Haresign, Ed. Butterworths, London, United Kingdom.

Kenyon P.R., Morris S.T. and West, D.M. (2010). Proportion of rams and the condition of ewe lambs at joining influences their breeding performance. Anim. Prod. Sci. 50(6), 454-459.

Kiyanzad M.R. (2004). Predicting carcass physical and chemical composition of Moghani and Makui sheep in breeding flocks. (body measurements and carcass characteristics). Anim. Sci. J. (Pajouhesh and Sazandegi). 64, 2-11.

Kiyanzad M.R. (2005). Comparison of carcass composition of Iranian fat-tailed sheep. Asian-Australian J. Anim. Sci. 18(9), 1348-1352.

Koots K.R., Gibson J.P., Smith C. and Wilton J.W. (1994). Analyses of published genetic parameter estimates for beef production traits. 1. Heritability. Anim. Breed. Abstr. 62(5), 309-338.

Lake S.L., Scholljegerdes E.J., Nayigihugu V., Murrieta C.M., Atkinson R.L., Rule D.C., Robinson T.J. and Hess B.W. (2006). Effect of body condition score at parturition and postpartum supplemental fat on adipose tissue lipogenic activity of lactating beef cows. J. Anim. Sci. 84, 397-404.

Larsgard A. and Kolstad K. (2003). Selection for ultrasonic muscle depth; direct and correlated response in a Norwegian experimental sheep flock. Small Rumin. Res. 48(1), 23-29.

Larsgard A.G. and Olesen I. (1998). Genetic parameters for direct and maternal effects on weights and ultrasonic muscle and fat depth of lambs. Livest. Prod. Sci. 55, 273-278.

Leeds T.D., Mousel M.R., Notter D.R., Zerby H.N., Moffet C.A. and Lewis G.S. (2008). B-mode, real-time ultrasound for estimating carcass measures in live sheep: Accuracy of ultrasound measures and their relationships with carcass yield and value. J. Anim. Sci. 86, 3203-3214.

Macit M. (2002). Growth and carcass characteristics of male lambs of the Morkaraman breed. Small Rumin. Res. 43, 191-194.

Maniatis N. and Pollott G.E. (2002). Maternal effects on weight and ultrasonically measured traits of lambs in a small closed Suffolk flock. Small Rumin. Res. 45, 235-246.

Matika O., van Wyk J.B., Erasmus G.J. and Baker R.L. (2003). Genetic parameter estimates in Sabi sheep. Livest. Prod. Sci. 79, 17-28.

Maxa J., Norberg E., Berg P. and Milerski M. (2007a). Genetic parameters for body weight, longissimus muscle depth and fat depth for Suffolk sheep in the Czech Republic. Small Rumin. Res. 72, 87-91.

Maxa J., Norberg E., Berg P. and Pedersen J. (2007b). Genetic parameters for carcass traits and in vivo measured muscle and fat depth in Danish Texel and Shropshire. Acta Agric. Scandinavica. Sect. A. Anim. Sci. 57(2), 49-54.

McClelland T.H., Bonaiti B. and Taylor St. C.S. (1976). Breed differences in body composition of equally mature sheep. Anim. Prod. 23, 281-293.

Miraei-Ashtiani S.R., Seyedalian S.A.R. and Moradi Shahrbabak M. (2007). Variance components and heritabilities for body weight traits in Sangsari sheep, using univariate and multivariate animal models. Small Rumin. Res. 73, 109-114.

Mohammadi K., Rashidi A., Mokhtari M.S. and Beigi Nassiria M.T. (2011). The estimation of (co)variance components for growth traits and Kleiber ratios in Zandi sheep. Small Rumin. Res. 99, 116-121.

Mohammadi Y., Rashidi A., Mokhtari M.S. and Esmailizadeh A.K. (2010). Quantitative genetic analysis of growth traits and Kleiber ratios in Sanjabi sheep. Small Rumin. Res. 93, 88-93.

Mokhtari M.S., Rashidi A. and Mohammadi Y. (2008). Estimation of genetic parameters for post-weaning traits of Kermani sheep. Small Rumin. Res. 80, 22-27.

Moreno C., Bouix J., Brunel J.C., Weisbecker J.L., Francois D., Lantier F. and Elsen J.M. (2001). Genetic parameter estimates for carcass traits in the inra401 composite sheep strain. Livest. Prod. Sci. 69, 227-232.

Nejati-Javaremi A., Izadi F., Rahimi G. and Moradi M. (2007). Selection in fat-tailed sheep based on two traits of fat-tail and body weight versus single-trait total body weight. Int. J. Agric. Biol. l9, 645-648.

Nik-Khah A. (1984). The growth and carcass quality of Afshari, Turkey and Mehraban lambs on different diets. Proc. Aust. Soc. Anim. Prod. 15, 489-499.

Notter D.R. and Hough J.D. (1997). Genetic parameter estimates for growth and fleece characteristics in Targhee sheep. J. Anim. Sci. 75, 1729-1737.

Nsoso S.J., Young M.J. and Beatson P.R. (2004). Genetic and phenotypic parameters and responses in index component traits for breeds of sheep selected for lean tissue growth. Small Rumin. Res. 51, 201-208.

Olesen I. and Husabø J.O. (1994). Effect of using ultrasonic muscle depth and fat depth on the accuracy of predicted phenotypic and genetic values of carcass traits on live ram lambs. Acta Agric. Scand., Sect. A, Anim. Sci. 44, 65-72.

Orman A., Caliskan G.U. and Dikmen S. (2010). The assessment of carcass traits of Awassi lambs by real-time ultrasound at different live weights and different sex. J. Anim. Sci. 88, 3428-3438.

Rao S. and Notter D.R. (2000). Genetic analysis of litter size in Targhee, Suffolk, and Polypay sheep. J. Anim. Sci. 78, 2113-2120.

Rhind S.M., Wetherill G.Z. and Gunn R.G. (1990). Diurnal profiles of LH, prolactin and progesterone and their inter-relationships in ewes in high or moderate levels of body condition. Anim. Reprod. Sci. 24, 119-126.

Ripoll G., Joy M., Alvarez-Rodriguez J., Sanz A. and Teixeira A. (2009). Estimation of light lamb carcass composition by in vivo realtime ultrasonography at four anatomical locations. J. Anim. Sci. 87, 1455-1463.

Roden J.A., Merrell B.G., Murray W.A. and Haresign W. (2003). Genetic analysis of live weight and ultrasonic fat and muscle traits in a hill sheep flock undergoing breed improvement utilizing an embryo transfer programme. Anim. Sci. 76, 367-373.

Rodríguez A.B., Landa R., Bodas R., Prieto N., Mantecon A.R. and Giraldez F.J. (2008). Carcass and meat quality of Assaf milk fed lambs: Effect of rearing system and sex. Meat Sci. 80, 225-230.

Rondon Z., Forcada F., Zarazaga L., Abecia J.A. and Lozano J.M. (1996). Oestrous activity, ovulation rate and plasma melatonin concentration in Rasa Aragonesa ewes maintained at two different and constant body condition score levels and implanted or reimplanted with melatonin. Anim. Reprod. Sci. 41(3), 225-236.

Russo G.L. (2009). Dietary n-6 and n-3 polyunsaturated fatty acids: From biochemistry to clinical implications in cardiovascular prevention. Biochem. Pharmacol. 77(6), 937-946.

Saatci M., Dewi I.A. and Ulutas Z. (1999). Variance components due to direct and maternal effects and estimation of breeding values for 12-week weight of Welsh Mountain lambs. Anim. Sci. 69, 345-352.

Sahin E., Yardimci M., Cetingul I., Bayram I. and Sengor E. (2008). The use of ultrasound to predict the carcass composition of live Akkaraman lambs. Meat Sci. 79, 716-721.

Sanudo C., Alfonso M., Sanchez A., Delfa R. and Teixeira A. (2000). Carcass and meat quality in light lambs from different fat classes in the EU carcass classification system. Meat Sci. 56, 89-94.

SAS Institute. (2003). SAS^®/STAT Software, Release 8. SAS Institute, Inc., Cary, NC. USA.

Shelton M. (1990). Influence of docking fat tail (Karakul) sheep on lamb production. Small Rumin. Res. 3, 73-76.

Shelton M., Willingham T., Thompson P. and Roberts E.M. (1991). Influence of docking and castration on growth and carcass traits of fat-tailed Karakul, Rambouillet and crossbred lambs. Small Rumin. Res. 4, 235-243.

Shoridea A.R. (2001). Winter nutrition of breeding ewes with bagasse pith. MS Thesis. Ferdowsi University of Mashhad, Mashhad, Iran.

Silva S.R., Afonso J.J., Santos V.A., Monterio A., Guedes C.M., Azevedo J.M. and Dias-da-Silva A. (2006). In vivo estimation of sheep carcass composition using real-time ultrasound with two propes of 5 and 7.5 MHz and image analysis. J. Anim. Sci. 84(12), 3433-3439.

Silva S.R., Gomes M.J., Dias-da-Silva A., Gil L.F. and Azevedo J.M.T. (2005). Estimation in vivo of the body and carcass chemical composition of growing lambs by real-time ultrasonography. J. Anim. Sci. 83, 350-357.

Simm G., Avalos E., Dingwall W.S., King J.W.B., Parratt A.C., Owen M.G. and Cuthbertson A. (1985). Selection for improved lean meat production in Suffolk sheep – performance-test regime and use of ultrasonics and X-ray computed tomography. Anim. Prod. 40, 528-529.

Simm G. and Dingwall W.S. (1989). Selection indices for lean meat production in sheep. Livest. Prod. Sci. 21, 223-233.

Sink J.D. (1979). Factors influencing the flavor of muscle foods. J. Food Sci. 441, 1-11.

Snyman M.A., Erasmus G.J., Van Wyk J.B. and Olivier J.J. (1995). Direct and maternal (co)variance components and heritability estimates for body weight at different ages and fleece traits in Afrino sheep. Livest. Prod. Sci. 44, 229-235.

Stanford K., Bailey D.R.C., Jones S.D.M., Price M.A. and Kemp R.A. (2001). Ultrasound managements of longissimus dimensions and backfat in growing lambs: Effect of age, weight and sex. Small Rumin. Res. 42, 191-197.

Stanford K., Jones S. and Price M. (1998). Methods of predicting lamb carcass composition: A review. Small Rumin. Res. 29, 241-254.

Swatland H., Ananthanarayanan S. and Goldenberg A. (1994). A review of probes and robots: Implementing new technologies in meat evaluation. J. Anim. Sci. 72, 1475-1486.

Tait R.G.J. (2016). Ultrasound use for body composition and carcass quality assessment in cattle and lambs. Vet. Clin. North America. Food Anim. Pract. 32(1), 207-218.

Thatcher L.P. and Couchman R.C. (1983). Determining consumer requirements for lamb loin chops - a preliminary study. Rev. Market. Agric. Econ. 51, 167-177.

Theriault M., Pomar C. and Castonguay F.W. (2009). Accuracy of real time ultrasound measurements of total tissue, fat, and muscle depths at different measuring sites in lamb. J. Anim. Sci. 87, 1801-1813.

Thorsteinsson S. and Eythorsdottir E. (1998). Genetic parameters of ultrasonic and carcass cross-sectional measurements and muscle and fat weight of Icelandic lambs. Pp. 149-152 in Proc. 6^th World Congr. Genet. Appl. Livest. Prod., Armidale, Australia.

Van Vleck L.D., Snowder G.D. and Hanford K.J. (2003). Models with cytoplasmic effects for birth, weaning, and fleece weights, and litter size, at birth for a population of Targhee sheep. J. Anim. Sci. 81, 61-67.

Vatankhah M., Moradi-Shahrbabak M., Nejati-Javaremi A. Miraei-Ashtiani S.R. and Vaez-Torshizi R. (2004). A review of sheep breeding in Iran. Pp. 590-596 in Proc. 1^st Congr. Anim. Aquat. Sci., Tehran, Iran.

Ward C.E., Trent A. and Hildebrand J.L. (1995). Consumer perception of lamb compared with other meats. J. Sheep Goat Res. 11, 64-70.

Warner R.D., Greenwood P.L., Pethick D.W. and Ferguson D.M. (2010). Genetic and environmental effects on meat quality. Meat Sci. 86(1), 171-183.

Webb E.C. and O'Neill H.A. (2008). The animal fat paradox and meat quality. Meat Sci. 80(1), 28-36.

West K.S., Meyer H.H. and Sasser R.G. (1989). Ewe body condition and nutrition effects on embryonic loss. J. Anim. Sci. 67, 424-431.

Wood J.D., Enser M., Fisher A.V., Nute G.R., Sheard P.R., Richardson R.I., Hughes S.I. and Whittington F.M. (2007). Fat deposition, fatty acid composition and meat quality: A review. Meat Sci. 78, 343-358.

Yazdi M.H., Engstrom G., Nasholm A., Johansson K., Jorjani H. and Liljedahl L.E. (1997). Genetic parameters for lamb weight at different ages and wool production in Baluchi sheep. Anim. Sci. 65, 247-255.

Yousefi A.R., Kohram H., Zare Shahneh A., Nik-khah A. and Campbell A.W. (2012). Comparison of the meat quality and fatty acid composition of traditional fat-tailed (Chall) and modern tailed (Zel) Iranian sheep breeds. Meat Sci. 80, 225-230.