Breed and environmental effects on components of ewe productivity in terms of multiple births, artificial rearing and 8-month breeding cycles

Demirören, Erdinç; Shrestha, J. N. B.; Boylan, W. J.

doi:10.1016/0921-4488(95)00626-v

Cited by 32 publications

(15 citation statements)

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“…Environmental influences resulting from variations in year and age of dam were significant for all the traits studied, indicative of close agreement with those reported in the literature (Vesely and Peters 1979;Demiro¨ren et al 1995). These effects were important, and not being the primary objective of the study will not be discussed further.…”

Section: Resultssupporting

confidence: 76%

Evaluation of sheep genetic resources in North America: Ewe productivity of purebred, crossbred and synthetic populations

Shrestha¹,

Boylan²,

Rempel³

2008

Can. J. Anim. Sci.

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Evaluation of sheep genetic resources in North America: Ewe productivity of purebred, crossbred and synthetic populations. Can. J. Anim. Sci. 88: 399Á408. Ewe productivity from divergent genetic types of established purebreds e.g., Dorset (D), Lincoln (L), Rambouillet (Ra), Suffolk (Su) and Targhee (T); fecund-type breeds e.g., Finnsheep (F) and Romanov (Ro) breeds, and their reciprocal crosses; the Outaouais (O) and Rideau (R) Arcott breeds and their reciprocal crosses; and Synthetic I (½ F, ½ L), Synthetic II (½ D, ½ Ra) and Synthetic III (¼ F, ¼ L, ¼ D, ¼ Ra) populations were evaluated. Prolificacy, fecundity, ewe weight, grease fleece weight, wool grade, lamb survival and total lamb weights at birth, 30 d and 140 d per ewe lambing were considered jointly as a measure of ewe productivity. In general, fecund-type breed cross and Arcott breed cross were highest in productivity, the fecund-type breed, Arcott breed and synthetic populations were intermediate, in contrast the established breeds was lowest. Regardless of significantly heavier ewe and grease fleece weights, and superior wool grade of the established breeds, their poor performance can be attributed to lower prolificacy, fecundity and total lamb weights (P B0.05). Within established breeds, the D, L, Ra and T breeds were comparable in productivity to the Su breed, but lower than the F breed (PB0.05). The Ro breed surpassed the F breed because of significantly higher prolificacy and fecundity, and heavier ewe weight and total lamb weights, while grease fleece weight and wool grade were inconsistent. The F and Ro breeds were comparable to the Su breed despite significantly higher prolificacy and fecundity, in contrast to lighter ewe and grease fleece weights, lower wool grade, lamb survival, similar total lamb weights. Although the R breed produced significantly heavier grease fleece weight and total lamb weights than the O breed, both breeds were similar to the Su breed despite their significantly higher prolificacy and fecundity, in contrast to similar ewe weight, wool grade, lamb survival and total lamb weights, and lighter grease fleece weight. The O and R breeds were more productive than the F breed as a result of significantly heavier ewe weight, superior wool grade, higher lamb survival and heavier total lamb weights, despite their similar prolificacy, fecundity and grease fleece weight. Synthetic I and Synthetic III with Finnsheep lineage surpassed Synthetic II in productivity as a result of significantly higher prolificacy and fecundity, and heavier total lamb weights, despite similar ewe and grease fleece weights and inconsistent wool grade and lamb survival. At the same time, Synthetic I and Synthetic III were not only similar to the Su breed, but surpassed the F breed, whereas Synthetic II was similar to the Su breed and lower than the F breed. Finally, systematic crossbreeding and composite population of complementary fecund-type and established breeds achieved increased productivity from additive genetic variation and heterosis. . Pour mes...

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Section: Resultssupporting

confidence: 76%

Evaluation of sheep genetic resources in North America: Ewe productivity of purebred, crossbred and synthetic populations

Shrestha¹,

Boylan²,

Rempel³

2008

Can. J. Anim. Sci.

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“…Environmental influences resulting from variations in year, sex, type of birth (or type of birth and rearing, where applicable) and age of dam had significant influences on lamb weights and daily gains, signifying close agreement with the literature (Sidwell and Miller 1971;Vesely and Peters 1979;Demiro¨ren et al 1995). Environmental influences for lamb weights and daily gains have been extensively reported in the literature and, since they are not the primary objective of the study, their effects will not be discussed further.…”

Section: Resultssupporting

confidence: 66%

Evaluation of sheep genetic resources in North America: Lamb productivity of purebred, crossbred and synthetic populations

Shrestha¹,

Boylan²,

Rempel³

2008

Can. J. Anim. Sci.

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Evaluation of sheep genetic resources in North America: Lamb productivity of purebred, crossbred and synthetic populations. Can. J. Anim. Sci. 88: 391Á398. Lamb weights and daily gains from divergent genetic types of established purebreds, e.g., Dorset (D), Lincoln (L), Rambouillet (Ra), Suffolk (Su) and Targhee (T), and fecund-type breeds, e.g., Finnsheep (F) and Romanov (Ro), their reciprocal crosses and Suffolk sired specific cross Su(F )Ro) were evaluated. Also evaluated were lambs of the Outaouais (O) and Rideau (R) Arcott breeds and their reciprocal crosses, in addition to SyntheticThe established purebreds produced heavier lambs at birth and weaning, Arcott breed crosses gained weight more rapidly resulting in heavier lambs at 140 d, and fecund-type breeds produced lighter lambs (P B 0.05). In general, daily gains and lamb weights of all genetic types were similar, except that fecund-type breeds produced significantly lighter lambs. Lamb weights of T were most at birth, and Su at weaning and 140 d, while Les races pures e´tablies donnent des agneaux plus lourds a`la naissance et au sevrage; les hybrides Arcott grossissent plus rapidement, ce qui donne des agneaux plus lourds a`140 jours, tandis que les races fe´condes engendrent des agneaux plus le´gers (PB0,05). Dans l'ensemble, tous les types ge´ne´tiques produisent des agneaux de gain quotidien et de poids similaires sauf les races fe´condes, dont la proge´niture est sensiblement plus le´ge`res. Les agneaux T sont ceux qui enregistrent le meilleur poids a`la naissance, alors que les agneaux Su le font au sevrage et a1 40 jours, les agneaux F se caracte´risant par le poids le plus faible (P B0,05). Chez les races e´tablies, les agneaux SU e´taient les plus lourds et les agneaux L les plus le´gers, ceux des races L, Ra et T se situant entre les deux. Le gain quotidien, y compris le poids au sevrage et a`140 jours, des hybrides F et R profite d'une he´te´rosis de 7 a`9 %, alors que les hybrides Arcott be´ne´ficient non seulement d'une he´te´rosis de 5 a`8 % mais e´taient comparables aux agneaux SU. Paralle`lement, les agneaux Su(F)Ro) enregistrent une performance semblable a`la moyenne de leurs parents. Les agneaux des populations synthe´tiques pesaient en moyenne 8 a`24 % de plus que la moyenne de leurs races parentales a`140 jours, ce qui laisse croire une meilleure re´tention de l'he´te´rosis.

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“…A razão deste resultado não é clara; provavelmente envolvia outros fatores não identificados ligados ao metabolismo nutricional. Molle et al (1995) Demirören et al (1995) observaram influência significativa do ano sobre os parâmetros reprodutivos das ovelhas e atribuíram este fato às influências ambientais.…”

Section: Resultsunclassified

Desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante a estação de monta

et al. 2006

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RESUMO -Objetivou-se com este estudo analisar o desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante o período de acasalamento. Utilizaram-se 112 ovelhas (63 no primeiro ano e 49 no segundo) dos grupos raciais Hampshire Down, Ile de France, Suffolk e Corriedale. Os animais foram separados em três grupos: T1 (sem suplementação), T2 (suplementação com 600 g/dia de milho triturado) e T3 (suplementação com 600 g/dia de concentrado constituído de 75% de milho triturado e 25% de farelo de soja). As ovelhas sob suplementação (T2 e T3) apresentaram maiores pesos e ganhos de peso até o final da estação de monta. Os escores da condição corporal também foram maiores ao final da estação de acasalamento nas ovelhas sob suplementação, implicando maior deposição de tecidos (músculo e gordura) no corpo do animal. O flushing não resultou em maior taxa de parição nem em aumento de partos gemelares, porém, Reproductive performance of ewes submitted to different feeding managements before and during the breeding period ABSTRACT -The objective of this study was to investigate the reproductive performance of ewes submitted to different feeding management before and during the breeding period. A total of 112 ewes, 63 in year one and 49 in year two of the study, from the genetic groups Hampshire Down, Ile de France, Suffolk and Corriedale, were used. The ewes were separated in three groups: T1 (without supplementation), T2 (supplemented with 600 g/day of ground corn) and T3 (supplemented with 600 g/day of a concentrate containing 75% of ground corn and 25% of soybean meal). Supplemented ewes (T2 and T3) had higher body weight and more weight gain until the end of the breeding period than those not supplemented. Body condition scores were also greater at the end of the breeding period for supplemented ewes, indicating a greater fat and muscle deposition.Supplementation did not improve fertility rate and twins birth rate, but increased birth rate in ewes supplemented with corn. Age and genetic group both affected birth rate. It was concluded that feeding corn to ewes improved the number of lambs per ewe.

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Breed and environmental effects on components of ewe productivity in terms of multiple births, artificial rearing and 8-month breeding cycles

Cited by 32 publications

References 15 publications

Evaluation of sheep genetic resources in North America: Ewe productivity of purebred, crossbred and synthetic populations

Evaluation of sheep genetic resources in North America: Ewe productivity of purebred, crossbred and synthetic populations

Evaluation of sheep genetic resources in North America: Lamb productivity of purebred, crossbred and synthetic populations

Desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante a estação de monta

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