Comparison of the longevity and lifetime performance of Scottish Blackface ewes and their crosses within hill sheep flocks

Annett, R. W.; Carson, A. F.; Dawson, L. E. R.; Irwin, D.; Gordon, Alan; Kilpatrick, D. J.

doi:10.1017/s1751731110002107

Cited by 22 publications

(27 citation statements)

References 19 publications

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“…Therefore the carry-over effects of a high litter size at one lambing on subsequent litter outputs (Amer et al, 2007) may also affect ewe survival. A possible mediation of this effect through ewe lifetime might be the excessive loss of body reserves, as in this study and elsewhere (Annett et al, 2011) a low body condition score at weaning is associated with a low stayability. Alternatively the adverse effects of a high level of early prolificacy on the subsequent ewes' survival may primarily reflect a mismatch between the ewes' genetic potential for growth and reproduction and their nutritional environment.…”

Section: Discussionsupporting

confidence: 62%

Effects of the level of early productivity on the lifespan of ewes in contrasting flock environments

Douhard

Jopson²,

Friggens

et al. 2016

animal

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Selection for high levels of prolificacy has allowed substantial improvements in the production efficiency of New Zealand (NZ) sheep farms, but the consequences on ewe lifetime performance are mostly unknown. In this study, the relationship between the level of prolificacy early in ewes' productive lives and their probability to survive later (i.e. stayability) was evaluated in two contrasting NZ flock environments. Records were obtained from 6605 ewes from four ram breeder flocks representing either a moderate ( n = 2) or a highly variable ( n = 2) nutritional environment. All ewes lambed for the first time at 2 years of age and were mated the following year. The number of lambs born during the first 2 years of productive life (NLB 2-3 ) was used as a measure of early prolificacy. Effects of NLB 2-3 on stayability to 4, 5, 6, 7 and 8 years old were analysed using logistic regression. Curvilinear effects (logit-transformed) were detected ( P < 0.05) until stayability to 6 years and to 8 years old in the highly variable and the moderate environment, respectively. The NLB 2-3 that resulted in maximum expected stayability to various ages was 3.9 to 4.2, and 4.5 to 4.7 lambs in the highly variable and in the moderate flock environments, respectively. In addition, ewe stayability was reduced when the proportion of the litter that survived from birth to weaning (i.e. ewe rearing ability) was submaximal during the early productive life. High prolific ewes had a low rearing ability whatever the environment whereas the rearing ability of lowly prolific ewes was apparently more sensitive to the nutritional environment. The poor maternal performance of ewes with low levels of NLB 2-3 led to a premature culling by breeders whereas the high early reproductive effort associated with high levels of NLB 2-3 seemed to be at the cost of ewes' survival, even in the moderate flock environment. In conclusion, the flock environment influenced the level of early prolificacy beyond which ewe longevity was reduced. It is suggested that further selection for high and early prolificacy in NZ flocks is likely to impair ewes' lifetime productivity.

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Section: Discussionsupporting

confidence: 62%

Effects of the level of early productivity on the lifespan of ewes in contrasting flock environments

Douhard

Jopson²,

Friggens

et al. 2016

animal

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“…Stayability rates across the breeds in the current study (61% at 3 years, 24% at 5 years) were similar to rates reported for sheep. Ewe stayability rates through 3 and 5 years were consistent across studies at 63 and 32% [21], 63 and 34% [1], and 62 and 22% [17]. In crossbred ewes, stayability rates were somewhat higher over 5 years at 68% with wide variation across 8 genotypes [25].…”

Section: Resultsmentioning

confidence: 75%

“…With-in breed exit proportions were similar (P > 0.30) for each cause among breeds (Table 2). In sheep evaluations where culling for poor performance, conformation faults, and (or) age was practiced, half of ewe exits were attributed to health-related culls or deaths [17,21]. Norman and Hohenboken [22] reported 42% of ewe attritions over 4 years were illness-based with another 37% classified as unknown.…”

Section: Resultsmentioning

confidence: 99%

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Comparison of Boer, Kiko, and Spanish meat goat does for stayability and cumulative reproductive output in the humid subtropical southeastern United States

Pellerin

Browning

2012

BMC Vet Res

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BackgroundLongevity is the amount of time breeding females stay active in a herd by avoiding death or culling because of illness or reproductive failure. This is a trait of economic relevance in commercial small ruminant breeding herds as it affects lifetime reproductive output. The purpose of this study was to determine if breed of meat goat influences breeding doe survival rates and cumulative reproductive performance under semi-intensive management.ResultsBoer (n = 132), Kiko (n = 92) and Spanish (n = 79) does were evaluated for longevity trends and cumulative kid production. The herd was managed on humid subtropical pasture. Does had the chance to complete 2 to 6 production years. Survival curves were analyzed for 2 culling methods. The actual culling practice removed does after two failures to wean a kid. An alternative culling protocol removed doe records after the first failure to wean a kid. Kid production traits analyzed across herd life were the total number of kids weaned and cumulative kid weight weaned to the 2-, 3-, and 5-year stayability endpoints. Most (82%) doe exits were illness-related under the actual culling method. Reproductive failure represented 51% of doe exits under the alternative culling protocol. Boer does had greater survival declines (P < 0.01) from 2 to 6 years of herd life compared with Kiko and Spanish under both culling protocols. Boer does had lower stayability rates (P < 0.01) at each year endpoint for both culling protocols. Under the alternative protocol, over 50% of Boer does failed to complete 2 years, whereas over 50% of Kiko and Spanish does successfully completed 4 years. Boer does had lower (P < 0.01) total number of kids weaned and cumulative weight weaned through each stayability endpoint compared with Kiko and Spanish.ConclusionBoer does had low stayability and cumulative kid production rates compared with Kiko and Spanish does. Poor health was the primary driver of does exiting the herd. Kiko and Spanish does did not differ for longevity and lifetime performance indicators.

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“…The results of Caldeira et al (2007) propose that metabolic imbalance can occur with a BCS below 2.0 or above 4.0, which may be suggestive of reduced health outcomes for ewes in these ranges. The survival of Scottish Blackface ewes within the flock has been shown to increase up to BCS 2.5, but above this level no further gain is apparent (Morgan-Davies et al 2008;Annett et al 2011). On one of three farms, periodontal disease was associated with lower BCS (Orr & Chalmers 1988) indicating poor teeth can have implications for a ewe's ability to maintain body condition.…”

Section: Animal Welfare and Bcsmentioning

confidence: 99%

Review of sheep body condition score in relation to production characteristics

Kenyon

Maloney

Blache

2014

New Zealand Journal of Agricultural Research

253

210

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Body condition scoring of sheep was first developed as a technique in the 1960s. Unlike live weight, it circumvents the issues of skeletal size, breed and physiological state and is not influenced by gut fill or the length and wetness of the fleece. This review outlines the use of the technique and the relationships between body condition score and other physical measures. In addition, it summarises the literature, across a range of breeds and environments, on the effects of body condition score on reproductive and lactational performance, and the growth and survival of the offspring to weaning. We have proposed that while the relationship between body condition and production traits is positive, it is unlikely to be linear. Where appropriate, the review outlines areas that would benefit from further research. Finally, it outlines what a suitable body condition score profile might be for a ewe over the entire breeding cycle.

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Comparison of the longevity and lifetime performance of Scottish Blackface ewes and their crosses within hill sheep flocks

Cited by 22 publications

References 19 publications

Effects of the level of early productivity on the lifespan of ewes in contrasting flock environments

Effects of the level of early productivity on the lifespan of ewes in contrasting flock environments

Comparison of Boer, Kiko, and Spanish meat goat does for stayability and cumulative reproductive output in the humid subtropical southeastern United States

Review of sheep body condition score in relation to production characteristics

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