Reproduction and adaptation characteristics in D’man sheep

D’man breed (D) is found in the oasis of the subsaharian regions of Morocco and reared usually in sedentary type of management with small flocks (< 10 ewes). Preliminary field surveys showed that D is early maturing, prolific and aseasonal. Hence, a multidisciplinary research programme on D was started in 1974. This paper reports the findings of these studies and describes the approach used to (1) characterize and evaluate the performances of D in field and station, (2) study the physiological mechanism involved in its peculiar reproduction and production, (3) study the genetic basis of reproduction parameters, and (4) evaluate use of D in crossbreeding schemes to improve the productivity of other Moroccoan breeds. Results show that D is one of the rare breeds that is simultaneously early maturing, highly prolific and completely aseasonal. However, studies on water turnover and nitrogen recycling show that D is not well adapted to hot climate and poor nutrition. Its reproduction parameters are relatively independent of photoperiod and related to a low sensitivity to negative oestrogen feedback. D male is characterized by high libido and can be used for synchronizing oestruses through the »ram effect». Crossbreeding experiments with non-prolific sheep confirm the heritability of reproductive parameters. However, the genetic basis for these is not yet well known

Rumen ecology research planning. Proceedings of a workshop

This workshop was conducted to identify and prioritise areas of rumen ecology which are promising for their potential impact on improving nutrition status of tropical ruminants, to develop a rumen ecology research programme for ILRI based on relevance to developing countries and ILRI's comparative advantage vis-a-vis other institutions, to identify potential collaborators in advanced research institutes, and to define model(s) of collaboration. Major topics of discussion include - potential application of rumen ecology manipulation to animal nutrition in developing countries, state of art in manipulation of the rumen microbial ecosystem, and state of art in bioengineering of rumen microorganisms

Effet de la race de l'hémicastration et de la FSH sur la population folliculaire ovarienne chez les agnelles

Utilisant la méthode histologique quantitative de l'ovaire, on a comparé l'effet race, hémicastration et traitement avec FSH après hémicastration chez l'agnelle âgée de 15 jours de deux races différant par leur taux d'ovulation: D'man (haute prolificité), Timahdite (basse prolificité). Le nombre et la distribution des follicules ovariens ne difIèrent pas significativement entre les deux races à l'âge de 15 jours et l'hémicastration n'a pas d'effet à courtterme sur la population des follicIes ovariens et sur la concentration de FSH. La concentration de FSH augmente après hémicastration et injection de FSH. Le nombre des follicules primordiaux (avec une couche de cellules cubiques) augmente après traitement avec FSH, Le nombre de follicules à antrum est doublé et l'atrésie est réduite de moitié chez les deux races. La race prolifique (D'man) montre une sensibilité à la stimulation par FSH plus marquée que chez la race non-prolifique (Timahdite)

International Livestock Research Institute: Mandate, programme and potential contribution to rangeland improvement in the WANA region

This paper reviews the work of the International Livestock Research Institute (ILRI) and traces the origin of the centre. The relevance of its programme to the West Asia and North Africa (WANA) region is outlined

Reproductive performance and productivity of Menz sheep in the Ethiopian highlands

Ewe lambs attain puberty at 10 months and 16.9 + 0.01 kg (56 percent of mature weight) and first lamb at 15 months. Postpartum anoestrus in 76 days, lambing interval is 8.4 months and 65 percent of ewes lamb three times in 2 years with a gestation period of 149 days. Ewes cycle year-round but oestrus activity declines from June to September due to increased silent ovulations. Fertilisation rates are high (greater or equal to 90 percent) but lambing rate is 72 percent, suggesting moderate embryonic mortality. Conception rates to first, second and third oestrus postpartum are 78 percent, 18 percent and 4 percent, respectively. Litter size (prolificacy) is 1.12 but can be increased by 10-40 percent through premating ewe nutrition management or treatment with gonadotropins. Ewe oestrus activity can be synchronised by ram introduction after a period of isolation and with progesterone sponges or prostaglandin F2 alpha therapy. Lambs average 2.0 + 0.1 kg at birth but preweaning mortality (15 percent) and slow growth, resulting in 8.6 kg weaning weight, still limit overall productivity index to 11.0 + 0.87 kg per ewe per year, and the annual reproductive rate to 1.4 lambs per ewe. In the traditional management system, where most animals are raised, further studies are required into better nutrition and control of diseases (endoparasitism) in young animals to increase reproductive efficiency, flock productivity and number of animals for finishing and slaughter. This could serve as a model for interventions in other ruminants in the agroecological zone

Development of the population of ovarian follicles during the prepubertal period in D'man and Timahdite sheep

International audienc

Development of the population of ovarian follicles during the prepubertal period in D'man and Timahdite sheep

International audienc

Un modele de recherche sur les systemes laitiers periurbains en Afrique subsaharienne

La definition d'un systeme laitier periurbain, en reliant les caracteristiques de la production a celles de la consommation tout en considerant les acteurs intermediaires et leurs logiques a permis d'organiser un ensemble d'activites de recherche en fonction de leurs objectifs a differentes echelles d'observation ou d'action. Des methodologies specifiques sont progressivement mises au point sur une base modulaire. Deux exemples sont presentes. Le modele de recherche permet de selectionner des sites de recherche dans un cadre regional et d'y identifier des priorites de recherche tout en assurant un equilibre entre disciplines

Effect of experimental fascioliasis on feed intake, nitrogen retention and body weight changes in open and pregnant Menz sheep

The effect of a sub-clinical fascioliasis infection on feed intake, OM digestibility (OMD), N retention (NRET), rate of BW changes and lamb birth weight was studied in 23 open and 17 pregnant Menz ewes. The infection was imposed by oral dosing with Fasciola hepatica in pregnant and open ewes. All ewes were assigned to four treatment groups: pregnant infected (PI), pregnant non-infected (PC), open infected (OI) and open non-infected (OC). The infected ewes became anaemic from Week 8 post-infection (p.i.) and F. hepatica eggs were first observed in the faeces from Week 11 p.i. During two NRET trials (at ewes voided higher urinary N, resulting in lower NRET at 8 weeks p.i. Infected ewes also had lower weight gains than control ewes. Lambs from infected dams weighed less at birth than lambs from control dams. It was concluded that under the conditions of the present experiment, although subclinical fascioliasis did not affect feed intake or digestibility coefficients, it did reduce the rates of live weight changes, NRET, and lamb birth weight. Consequently, it reduced the overall productivity of infected ewes