Genetic and Environmental Effects on Age at First Estrus and on Wool and Lamb Production of Crossbred Ewe Lambs

Cedillo, Rose Mary; Hohenboken, W. D.; Drummond, J.

doi:10.2527/jas1977.446948x

Cited by 19 publications

(15 citation statements)

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“…If gestation lengths were fixed at 150 d, then ewe Iambs were mated as early as 367 d of age in the Morlam system and as early as 340 d of age in the Dorset Carnal system. Feasibility of producing changes in the level of age at first breeding to as early as 240 d, or even earlier, was reported by Fahmy et al (1980) and Cedillo et al (1977).…”

Section: Resultsmentioning

confidence: 90%

Lambing Performance of Morlam and Dorset Ewes under Accelerated Lambing Systems

Iñíguez

Quaas

Vleck

1986

Journal of Animal Science

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Two accelerated lambing systems, Morlam using Morlam sheep (USDA, Beltsville 1966to 1975 and Carnal using Dorset ewes (Cornell 1978(Cornell to 1981, were evaluated for first lambing ages, interlambing intervals and conception probabilities. Morlam ewes were continuously exposed to rams over the year, while Carnal Dorset ewes were exposed every other month. Morlam lambs were mated as early as 367 d of age and Carnal Dorset lambs as early as 340 d. Early lambing was associated with higher rates of perinatal mortality (P>.05) and smaller litter size (P<.O1). Lambing years among Morlam ewes and season of birth of Carnal Dorset ewes influenced (P<.01) their first lambing ages. Lambing intervals averaged 293 and 303 d among Morlam and Carnal Dorset ewes, respectively. Age at first lambing and season in which the previous lambing occurred with influential factors (P<.01) on lambing intervals of Morlam ewes; longer intervals resulted when ewe lambs were mated at early ages (<12 too), and when the previous lambing occurred in winter. Estimates of conditional probabilities of conception by month given the occurrence of estrus, reflected seasonal changes in both systems. The overall probability of conception for the Morlain system (P=.16) was relatively higher than that for the Carnal Dorset system (P=.14); numbers of lambings per ewe per yr were 1.28 and 1.21, respectively. Estimates of heritability for age at first lambing, lambing interval and conception probability were. 31, .06 and .30, respectively.

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Section: Resultsmentioning

confidence: 90%

Lambing Performance of Morlam and Dorset Ewes under Accelerated Lambing Systems

Iñíguez

Quaas

Vleck

1986

Journal of Animal Science

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“…With a measured staple length of nearly 11 cm, fleeces from F 1 ewes sired by Finnsheep rams had a Cedillo et al (1977) reported that 1/2 Finnsheep (and 1/2 Columbia or 1/2 Suffolk) ewes produced fleeces with longer staple length than other crossbred types in the study (1/2 Romney, 1/2 North Country Cheviot, or 1/2 Dorset and 1/2 Columbia or 1/2 Suffolk). Fahmy (1987) reported that fleeces from Finnsheep-sired ewes had a staple length of 13.7 cm, which was longer than that of purebred DLS ewes.…”

Section: Age Of Ewe-year Of Shearingmentioning

confidence: 84%

“…These sire breeds represented the full range of fleece quantity and quality, from the fine-wooled Booroola Merino to the coarse, medullated hair sheep of the St. Croix and Barbados breeds. Wool is an additional source of income in most sheep operations and can represent 15 to 25% of gross income (Hohenboken 1976;Cedillo et al, 1977). Therefore, breed effects for traits that influence fleece value should be a consideration when selecting breeds for a crossbreeding system.…”

Section: Introductionmentioning

confidence: 99%

Performance of hair breeds and prolific wool breeds of sheep in southern Illinois: wool production and fleece quality.

Bunge

Thomas

Nash

et al. 1996

Journal of Animal Science

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The objective of this study was to compare weight and quality of fleeces of different F1 ewe types produced from breeds with a broad range of fleece types. Weights of 629 fleeces produced during 1988 through 1991 from F1 ewes that were daughters of Suffolk and Targhee dams and Finnsheep, Combo-6, Booroola Merino, St. Croix, and Barbados sires were recorded. Staple length was measured on the mid-side of each ewe present in 1991. Fleeces shorn in 1991 were sent to a wool marketing organization, and staple length, wool grade, and clean fleece yield were subjectively estimated (n = 220). Mid-side fleece samples were collected from no more than two randomly selected ewes from each subclass (breed of dam-breed of sire-age of ewe) in 1991 (n = 78) and sent to a wool laboratory where fiber diameter, yield, and percentage of colored, med, and kemp fibers were objectively determined. Ewes from Targhee dams produced fleeces with greater weight, greater fiber length, smaller fiber diameter, lower yield, and fewer colored fibers than ewes from Suffolk dams (all differences significant, P < .01). Booroola Merino-sired ewes produced heavier (P < .01) fleeces than did Finnsheep- and Combo-6-sired ewes (4.13 and 3.09 kg, respectively), and in turn, Finnsheep- and Combo-6-sired ewes produced heavier (P < .01) fleeces than did ewes sired by hair breed rams (3.09 and 1.70 kg, respectively). Among hair breed-sired ewes, St. Croixsired ewes produced heavier (P < .01) fleeces than did Barbados-sired ewes (1.88 and 1.52 kg, respectively). Fleeces produced by Booroola Merino-sired ewes had smaller (P < .01) fiber diameter than all sire breed groups except Combo-6-sired ewes, and fleeces produced by St. Croix-sired ewes had greater (P < .01) fiber diameter than all other sire breed groups. Lab scoured yield was greater (P < .01) for fleeces from ewes from hair breed than for fleeces from ewes from wool breed sires (74.2 vs 66.1%). Proportions of undesirable fibers (med, kemp, and colored) were 20 to 600 times greater (P < .01) in fleeces of ewes from hair breed sires than in fleeces of ewes from wool breed sires. In general, F1 ewes from Booroola Merino sires produced the heaviest, highest quality fleeces, and ewes from the hair breed sires of St. Croix and Barbados produced the lightest, lowest quality fleeces. Ewes from Finnsheep and Combo-6 sires produced fleeces that were more similar to the fleeces of ewes from Booroola Merino sires than to the fleeces of ewes from the hair breed sires.

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“…Nevertheless, comprehensive evaluation requires that other factors, such as wool production and quality, must also be considered. Wool is an additional source of income in most sheep operations and can represent 15-25% of gross income (Cedillo et al 1977). Therefore, breed effects for trait that influence fleece value should be considered when selecting breeds for a crossbreeding system.…”

Section: Introductionmentioning

confidence: 99%

Wool characteristics in the third generation of Arkharmerino × Ghezel and Arkharmerino × Moghani crossbreed sheep

Esfandyari

Aslaminejad

Rafat

2011

Trop Anim Health Prod

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This investigation was conducted to evaluate the comparative productive performances and effect of some environmental factors on wool characteristics of Arkharmerino × Ghezel (Ar × Gh) and Arkharmerino × Moghani (Ar × Mo) crossbreed sheep. The mid-side fleece samples taken from animals during 2 years (2007-2008) were analyzed. Each sample was measured for average fiber diameter, fiber diameter variability, staple length, proportion of medullated fiber, proportion of kemp, and comfort factor. The comparative values for these fleece characteristics in F(3) generation Ar × Gh were 28.78 ± 0.48 μm, 36.84 ± 1.16%, 11.94 ± 0.35 cm, 7.07 ± 0.93%, 1.02 ± 0.23%, and 68.93%, respectively; while those traits were 29.79 ± 0.43 μm, 41.86 ± 1.16%, 11.96 ± 0.37 cm, 8.13 ± 1.06%, 2.71 ± 0.45%, and 63.33 ± 3.66% for Ar × Mo, respectively. The effects of genotype, sex, birth type, and year of birth were analyzed. Genotype had a significant (P < 0.01) effect on average fiber diameter and proportion of kemp, and Ar × Gh crossbreeds had lower diameter with less proportion of kemp. The two differences in fiber characteristics that were attributable to sex were fiber diameter variability and proportion of medullated fiber, and females had higher measure than males for both traits. Statistical analysis showed that crossbreeding with Arkharmerino generally had positive effects on the fleece favored to be used in the hand woven authentic carpet production.

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Genetic and Environmental Effects on Age at First Estrus and on Wool and Lamb Production of Crossbred Ewe Lambs

Cited by 19 publications

References 0 publications

Lambing Performance of Morlam and Dorset Ewes under Accelerated Lambing Systems

Lambing Performance of Morlam and Dorset Ewes under Accelerated Lambing Systems

Performance of hair breeds and prolific wool breeds of sheep in southern Illinois: wool production and fleece quality.

Wool characteristics in the third generation of Arkharmerino × Ghezel and Arkharmerino × Moghani crossbreed sheep

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