Comparison of Sumatra sheep and three hair sheep crossbreds. I. Growth, mortality and wool cover of F1 lambs

Gatenby, R. M.; Bradford, G. E.; Doloksaribu, M.; Romjali, E.; Pitono, A.D.; Sakul, H.

doi:10.1016/s0921-4488(96)00969-8

Cited by 19 publications

(9 citation statements)

References 2 publications

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“…The results pertaining to causes leading to pre-weaning mortality as observed in the study area has been presented in Table 16. The major causes of death can be attributed to lack of proper nutrition of the dam especially during the later stages of pregnancy or post parturition (during the dry season) and during which the fast growing fetus derives nutrition from the dam and in absence of the same may lead to dystocia and retained placenta besides low birth weight of the lambs (especially if there are twins) and also mortality in the first few days of birth, the observations find similarity with the findings of Gatenby et al (1997) and Markos (2006). During the dry season the nutrition of the nursing dam is challenged and this leads to lack of milk to the neonates and hence can lead to mortality of the same.…”

Section: Sheep Health and Diseasessupporting

confidence: 65%

Traditional sheep production systems and breeding practice in Wolayita Zone of Southern Ethiopia

Lakew¹,

Melesse²,

Banerjee³

2017

Afr. J. Agric. Res.

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The study was conducted in Wolayita zone of Southern, Nations, Nationalities and People Regional State with the objectives to explain its production systems, breeding practice with major constraints of sheep productivity. Purposive sampling techniques were employed to select target farmers. Structured questionnaire, focused group discussions, secondary data sources and field observations were used to generate the required data. A total of 184 households were selected from four woredas (8 rural kebele) in both weyna-dega and dega agro-ecologies. The survey results revealed that the overall total family size and land holding were 6.4 and 1.1 ha, respectively and the overall mean sheep holding was 5.2 sheep per households. The purpose of keeping sheep was as source of income followed by manure and meat production. The key feed resources in both agro-ecologies were communal grazing and private pastures. Most important causes of sheep mortality in the study were disease and parasite, water and nutritional deficiency, drought and absence of animal clinic. The overall mean value of age at first lambing, lambing interval and twining rate are 13.5, 7.9 months and 1.5 lambs, respectively. The constraints that delay sheep production in the study area was feed and grazing land shortages disease, drought, labor shortage, water shortage and loss of sheep by predators with index value of 0.30, 0.24, 0.16, 0.15, 0.09 and 0.05, respectively. It was concluded that indigenous sheep had a potential for multipurpose role to generate income for smallholders. Therefore, genetic improvement program should aim at farmers need to cope with trait preference and existing traditional herding and breeding practice.

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Section: Sheep Health and Diseasessupporting

confidence: 65%

Traditional sheep production systems and breeding practice in Wolayita Zone of Southern Ethiopia

Lakew¹,

Melesse²,

Banerjee³

2017

Afr. J. Agric. Res.

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“…Slee (1959) used a 10-point scale relating to the percentage of body area having lost its fleece, whereas in Slee (1963), this was expanded to a 20-point scale. The 10-point scale 'was used by Gatenby et al (1997) in their study of Sumatran sheep. Pascoe et al (1976) classified 5 areas of the body into completely shed, not shed, and partially shed as the basis for their breed comparison.…”

Section: Discussionmentioning

confidence: 99%

A suggested mode of inheritance for wool shedding in sheep1

Pollott

2011

Journal of Animal Science

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The ability of a sheep to shed its own wool has an attraction in scenarios where the costs of harvesting wool outweigh its value. Certain breeds and composites have the ability to shed their wool in the spring, and these are investigated in this work in an attempt to outline the genetics of wool shedding. One flock from a breeding group in Southern England (UK) containing sheep with wool-shedding characteristics provided shedding scores (1 to 5 scale; no shedding to complete shedding) that were used in a range of genetic analyses. The particular nature of wool shedding suggested that there may be a major gene segregating in these populations that facilitates wool shedding. In addition, there was clearly variation among wool shedders in the speed and extent of shedding, so a polygenic trait was also investigated. The breeding group used a range of shedding breeds and composites in a regular program to introduce wool-shedding genes into their flocks. This allowed the testing of Mendelian ratios for shedders:nonshedders in both first-cross and first-backcross animals. Four modes of inheritance were tested: autosomal recessive, sex-linked recessive, autosomal dominant, and sex-linked dominant. The most likely mode of inheritance was autosomal dominant (P < 0.05), with a low level of incomplete penetrance. In first back-cross animals, this mode of inheritance was confirmed but with complete penetrance. Approximately 11% of shedders did not exhibit the trait as lambs. Mixed-model analyses of shedding scores allowed an investigation of factors that affected wool shedding and also the extent of any genetic and permanent animal variance. Shedding score was found to have a heritability of 0.54 ± 0.07 in lambs and 0.26 ± 0.06 in animals of all ages in one flock using Easycare, Wiltshire Horn, Katahdin, and Dorper shedding animals. Shedding score as a lamb had a genetic correlation of 0.94 ± 0.08 with shedding score as a 2 yr old, but at the phenotypic level this correlation was only 0.39 ± 0.05. No permanent animal effect was found for shedding score. Breeding for increased wool-shedding ability is possible, but improvement of the trait needs to be considered in 2 stages. First, the dominant gene needs to be introduced into the population, and then selection between animals can proceed by using EBV for the polygenic trait (speed or extent of shedding) as the basis for selection.

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“…To our knowledge, this is the only currently available information about worldwide sheep population estimates. Although sheep have adapted to live in a wide variety of environments ranging from desert to humid rain forest (Gateby et al, 1997), the central highlands of Ethiopia represent an important sheep producing area, accounting for 75% of the nation's flock and owned mostly by small holders who practice mixed crop-livestock production (Ayalew, 1995). In this area, the animals depend mostly on grazing fallow lands and crop residue with no extra supplement and minimum health intervention (Tembely et al, 1994).…”

Section: Sheep Population Distribution and Husbandry Practicesmentioning

confidence: 99%

Ovine helminthosis, a major health constraint to productivity of sheep in Ethiopia

Biffa

Jobre²,

Chakka

2006

Anim. Health. Res. Rev.

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Small ruminants represent an important component of the Ethiopian livestock production system, providing 12% of the value of livestock products consumed at the farm level and 48% of the cash income generated. Ethiopia is second in Africa and sixth in the world in terms of sheep population. The country has, however, benefited little from this enormous resource owing to a multitude of problems, disease being the most important. Disease alone accounts for mortalities of 30% in lambs and 20% in adults. Productivity losses attributable to helminth parasites are often substantial. A loss of US $ 81.8 million is reported annually due to helminth parasites. In a country confronted with challenges of an ever-rising human population and food shortage, such enormous losses caused by helminth parasites, 'the silent predators', are intolerable. Therefore, helminth control should receive special attention in poverty reduction strategies through improved productivity of livestock if the present and future challenges of food shortage are to be addressed. Productivity loss due to helminth infections can be substantially reduced through implementation of effective disease control strategies, which require an understanding of the epidemiology and ecology of parasites and parasitic infections under local conditions. This paper reviews extensive evidence demonstrating that helminthosis is a major constraint to productivity of sheep in Ethiopia. It also discusses epidemiology and ecology of major helminth parasites in the country and suggests strategies for improved control in various agro-ecological zones and production systems.

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Comparison of Sumatra sheep and three hair sheep crossbreds. I. Growth, mortality and wool cover of F1 lambs

Cited by 19 publications

References 2 publications

Traditional sheep production systems and breeding practice in Wolayita Zone of Southern Ethiopia

Traditional sheep production systems and breeding practice in Wolayita Zone of Southern Ethiopia

A suggested mode of inheritance for wool shedding in sheep1

Ovine helminthosis, a major health constraint to productivity of sheep in Ethiopia

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