Factors Associated with Mortality of Lambs Born to Ewe Hoggets

Ridler, Anne; Flay, Kate J.; Kenyon, P. R.; Blair, Hugh T.; Corner-Thomas, René A.; Pettigrew, Emma J.

doi:10.3390/ani12030319

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…It is possible to observe that for each additional kilo of lambs born per litter, there was an increase of 1.32 in the total amount of kilos of lambs weaned per litter. This result is related to a higher pre-weaning survival rate provided by the birth weight of the offspring, since lambs with higher birth weights have lower mortality rates (Ridler et al, 2022), which contributes to an increase in the number of animals that arrive alive at weaning and, consequently, a greater number of kilos of weaned lambs.…”

Section: Attribution Of Economic Values To Zootechnical Indicatorsmentioning

confidence: 99%

“…With a higher average gain, the animals are able to reach the selling weight faster and stay in the system for less time, which reduces production costs and increases profit. are dependent on the ewe's prolificacy rate, maternal nutrition and lambing order (Ridler et al, 2022). Wolfová et al (2011) found that birth weight had an absolute economic value of US$ 3.81 kg -1 ewe -1 and a relative economic value of 1.17% for Merinolandschaf sheep.…”

Section: Seminamentioning

confidence: 99%

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Valoração econômica para indicadores técnicos na produção de ovinos

et al. 2023

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Os objetivos deste trabalho foram de identificar e modelar as inter-relações entre indicadores zootécnicos utilizados na produção de ovinos, em um sistema intensivo no Brasil, e verificar o impacto desses indicadores nos resultados econômicos e produtivos da propriedade. Para tanto, foram desenvolvidos dois modelos de regressão múltipla para determinar quais indicadores influenciaram, e em que proporção, a quantidade de quilogramas de cordeiros vendidos no sistema. A fim de determinar os efeitos dos graus FAMACHA© das ovelhas durante a monta e parto, em relação à quantidade de produção em quilogramas de cordeiros desmamados, foram realizadas duas análises de variância de um fator, nas quais valores econômicos absoluto (VEA) e relativo (VER) foram atribuídos aos indicadores zootécnicos. Essa abordagem foi feita com o objetivo de verificar quais índices têm maiores efeitos no lucro e, consequentemente, devem ser priorizados nos critérios de seleção. Os principais indicadores foram a prolificidade, peso da ovelha ao parto, idade da ovelha ao parto, ganho médio diário, sobrevivência da prole e grau FAMACHA© da ovelha ao nascimento e ao parto; sua significância (P<0,05) determinou o número de quilogramas de cordeiros produzidos no sistema. O indicador com maior VEA e VER foi a idade da ovelha ao parto, com US$ 3,78 ano-1 ovelha-1 e 54,09%, respectivamente. O grau FAMACHA© 1 proporcionou o maior retorno ao sistema, com valor econômico absoluto de US$ 1,09 ovelha-1 na monta e US$ 1,71 ovelha-1 no parto. Os graus 4 e 5 causaram prejuízos tanto à monta quanto ao parto, com -US$ 1,15 ovelha-1 e -US$ 1,44 ovelha-1 para o grau 4, e -US$ 1,24 ovelha-1 e -US$ 1,76 ovelha-1 para o grau 5 na monta e no parto, respectivamente. Os resultados indicaram que o produtor pode manipular a taxa de descarte do rebanho para aumentar a idade das matrizes a fim de garantir uma maior produtividade das ovelhas. Outra indicação seria a aplicação de critérios de seleção para garantir o aumento do número de animais superiores presentes no sistema, principalmente animais resistentes a helmintoses. Essa estratégia pode facilitar o aumento dos lucros sem a necessidade de aumentar significativamente os gastos com insumos.

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Section: Attribution Of Economic Values To Zootechnical Indicatorsmentioning

confidence: 99%

Section: Seminamentioning

confidence: 99%

Valoração econômica para indicadores técnicos na produção de ovinos

et al. 2023

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“…Ridler and others [ 143 ] reported that the greatest cause of death for lambs born to ewe lambs was stillbirth (~40%), followed by starvation exposure (26%) and dystocia (17%). They identified that low lamb birth weight, multiple litters, and increasing ewe lamb weight gain from breeding to late pregnancy were risk factors for both lamb mortality and stillbirth.…”

Section: Factors Affecting Performance During Lambing and Lactationmentioning

confidence: 99%

“…Ridler and others [ 143 ] noted that, over the lambing period, death of the ewe lamb accounted for 11% of lamb deaths. Their results also indicated the importance of monitoring ewe lambs over the lambing period to assist not only newborn lambs to ensure adequate survival rates, but also the young dam.…”

Section: Factors Affecting Performance During Lambing and Lactationmentioning

confidence: 99%

Breeding Ewe Lambs: An Australasian Perspective

Kenyon

Corner-Thomas

2022

Animals

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A number of potential advantages have been identified for breeding ewe lambs at 7 to 9 months of age, including increased lifetime productivity and profitability. However, breeding at this young age in extensive pastoral systems, such as in Australasia, can be associated with a number of disadvantages resulting in uptake of this management procedure being relatively low. This review highlights the known differences between ewe lamb and mature ewe reproductive performance, thus differing in their management. The review then summaries the scientific literature of factors that affect ewe lamb reproductive success, with a focus on recent studies conducted under extensive pasture-based conditions in Australasia. In particular, this review outlines the importance of ewe lamb live weight and body condition score on their productivity. The potential long-term consequences of breeding a ewe lamb at a young age in terms of her future success and that of her offspring to weaning are briefly outlined. In addition, the potential impacts of selecting progeny born to ewe lambs as future replacement ewes are discussed. Throughout this review, optimal management guidelines from prior to breeding the ewe lambs until rebreeding at 2 years of age are provided. Lastly, areas requiring future research are identified and discussed.

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Identification of risk factors for ewe mortality during the pregnancy and lambing period in extensively managed flocks

Flay,

Chen,

Yang

et al. 2023

BMC Vet Res

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Background Ewe mortality during pregnancy and lambing is an issue for sheep producers globally, resulting in reduced productivity and profitability, compromised ewe welfare, and poor consumer perception. Despite these negative consequences, there was little investigation into factors associated with ewe death during this time. Therefore, this study aimed to assess associations between ewe body condition score (BCS), weight, reproductive parameters, and risk of mortality during pregnancy and lambing. Methods Four cohorts from three commercial New Zealand farms participated, with 13,142 ewe lambs enrolled and followed over time. Data were collected for five consecutive lambings. Visits aligned with key on-farm management times, specifically: prior to breeding, at pregnancy diagnosis (PD), prior to lambing (set-stocking), and, at weaning of their lambs. At each visit, ewes were weighed, BCS assessed and reproductive status was recorded when relevant (litter size at PD and lactation status after lambing). Ewes that died or were culled were recorded, and any ewes that were absent from consecutive visits were presumed dead. Logistic regressions were developed to assess the relationship between weight and BCS at each visit, PD result (single or multiple-bearing) and lactation status (wet or dry) in each year, and, risk of mortality during the pregnancy and lambing period in each year. Results In the PD to weaning period, mortality incidence ranged from 6.3 to 6.9% for two-tooth (18-months-old at breeding) to mixed-age (54-months-old at breeding) ewes. For ewe lambs (7 to 8-months-old at breeding), mortality was 7.3% from set-stocking to weaning. Heavier ewe lambs at PD were less likely to die during lambing (OR: 0.978, p = 0.013), as were those with greater set-stocking BCS. In subsequent years, BCS was a predictor of ewe death, with odds of mortality greatest for ewes < BCS 2.5. Additionally, for poorer BCS ewes, increasing weight reduced risk of mortality, but there was no impact of increasing weight in greater BCS ewes. Conclusions This study identified risk factors associated with ewe mortality during the pregnancy and lambing period. Flock owners can use these to either cull at-risk ewes or proactively intervene to reduce likelihood of mortality, thereby improving flock productivity, profitability and welfare.

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Factors Associated with Mortality of Lambs Born to Ewe Hoggets

Cited by 5 publications

References 24 publications

Valoração econômica para indicadores técnicos na produção de ovinos

Valoração econômica para indicadores técnicos na produção de ovinos

Breeding Ewe Lambs: An Australasian Perspective

Identification of risk factors for ewe mortality during the pregnancy and lambing period in extensively managed flocks

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