Quelle race bovine pour la Tunisie ?

M. DJEMALI

A. HAMROUNI

A. NAJJAR

Laboratoire des Ressources Génétiques Animales et Alimentaires-INAT, Univesité de Carthage, 43 Av. Charles Nicole 1080 Mahrajène Tunis

Abstract – Several qualities can distinguish a dairy cattle breed: its physical appearance / conformation, milk production and qualities, good health, feed efficiency and genetic merit to name a few. Productivity is often cited as a criterion of choice. The Holstein breed was chosen as an example in this article to answer the question "which breed of cattle for Tunisia?". This is an example that shows that the cow you need to have is a cow you create by selection and not an ideal breed you want to have. Over 20 traits are currently included in the US Holstein breed’s selection goal equation with different weights covering milk quality traits, health, reproduction, feed efficiency, longevity, conformation and negative weighting for milk. A Holstein cow produces over 10,000 kg of milk / year with a record reached in 2017 of 35,000 kg / year. On a total protein production improvement, made in a progressive and cumulative manner, of 175 kg between 1970 and 2017 compared to the basis of comparison (yield in kg of protein from a 1970 cow), the contribution of genetics has been more than double that achieved by herd management. To achieve these performances, the Holstein breed benefits from a reliable program of genetic improvement supported by a breed association and an intelligent marketing global system. It now dominates the world and serves its breeders, semen production centers and sellers of its genetics. In short, it has become an industry. The answer to the question which breed of cattle does Tunisia need becomes, therefore, a question what do we want to do with our breed that we love so that it becomes the best?!

Keywords: genetics, breed, milk, Holstein

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Etat des lieux des ressources génétiques bovines en Tunisie

A. HAMROUNI¹, M. DJEMALI¹, R. LAHSOUMI², A. DRIDI¹, A. NAJJAR¹, Y. BEN SASSI-ZAIDY¹

¹Animal Genetic and Feed Resources Lab. INAT, University of Carthage, 43 Charles Nicole 1082 Mahrajène, Tunis, Tunisia

²Offifice de l’Elevage et des Pâturages. 30 Avenue Alain Savary 100, Tunis, Belvédère

Abstract - The objective of this study was to inventory bovine genetic resources and analyze breeding practices and their relationship with performances. A survey of 105 cattle breeders in the region of Béjà, Bizerte and Mahdia was carried out. The farms investigated were mainly composed of pure breeds, in particular the Holstein, Brown Swiss and Charolaise. The change in the national bovine genetic makeup is very remarkable. Currently, the total number of cattle is 593,000 female units of which 380,000 are pure breeds and 213,000 cross breeds. Cattle farming is largely based on smallholders (61%) who have a certain level of technicality. The first criteria by breeders for choosing cattle were productive performance and phenotype. The breeders identified another secondary criterion such as the adaptation of the breed. Indeed, knowledge of the selection criteria can contribute to the implementation of projects oriented towards improving the productive potential of animals. In general, animal performance was poor. The latter is a result, not only from poor feeding behavior, but also from a great weakness in the knowledge and skills of breeders in genetics. Unfortunately, the lack of consistency of national genetic evaluation and the absence of strategies to select the best adaptive animals in different environments can accentuate low productivity and consequently lead to unsustainable breeding programs in Tunisia.

Key words : Bovine, genetics, inventories, breeds, crosses

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Caractérisation moléculaire des ressources génétiques ovines en Tunisie : Apport à la gestion et à l’adaptation au changement climatique

Y. BEN SASSI-ZAIDY^1,2

A. HAMROUNI¹

F. CHARFI-CHEIKHROUHA² 

M. DJEMALI¹

¹ Animal Genetic and Feed Resources Research Lab, INAT, Carthage University, Tunis, Tunisia

² Laboratory of Diversity, Management and Conservation of Biological Systems, LR18ES06, Université de Tunis El Manar, Faculty of Sciences of Tunis, 2092 Tunis, Tunisia.

Abstract – Animal genetic resources for food and agriculture play a crucial role in tackling climate change. Animal genetic diversity, especially of locally well-adapted breeds, provides the basis for climate change adaptation. Thus, there is a general need to improve the inventory and the genetic diversity characterization of these “targeted” breeds in order to support the planning of climate change adaptation measures and conservation strategies for animal genetic resources. The objectives of this paper were to: 1) characterize the Tunisian sheep genetic resource at the molecular level using 17 microsatellites markers, 2) Identify the “targeted” Tunisian sheep breeds to be conserved and considered in a reviewed breeding goals adapted to account for the effects of climate change. The molecular investigation of the genetic variability within and among the five Tunisian sheep breeds; Barbarine (BAR), Queue Fine de l’Ouest (QFO), Noire de Thibar (NTH), Sicilo-Sarde (SS), D’man (DM) and the crossbred (CRO: BAR x QFO), reveals a high genetic diversity reservoir especially for BAR and NTH breeds. The well-adapted and rustic BAR sheep breed reared in harsh and fluctuating climate ranges, is the most variable breed. The crossbred population CRO appeared the least genetically variable with the largest inbreeding value. This crossbreeding trend is a real threat to the sheep genetic variability and to the BAR’s integrity leading to a genetic erosion of the BAR gene pool. Improvement and conservation strategies for the sustainable use and development of BAR breed coping with climate change are urgently needed.

Keywords: Sheep genetic resources; Genetic diversity; microsatellites markers; climate change; conservation strategies.

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L'importance de la variation génétique et de la modélisation pour faire face aux effets du changement climatique sur les ressources génétiques pour l'alimentation et l'agriculture

Revue bibliographique

DJEMALI, M.

A. HAMROUNI

I. BEN ABDALLAH

N. ALBAKRI

I. DHOUADI

Laboratoire des Ressources Génétiques Animales et Alimentaires-INATn Université de Carthage, 43 Av. Charles Nicole 1080 Mahrajène Tunis

Abstract – Climate extremes are disastrous circumstances to animal and plant genetic resources. Traditional knowledge and scientific breakthroughs enabled the world to cope with nature between these climate extremes using a variety of genetic resources under different production systems to provide food for a growing population of more than 7 billion. Soil and water management and conservation are essential in sustainable agriculture but the secret of coping with climate change resides in the genes and mainly in their variation. The overall objective of this paper was to describe how genetic variation and modelling could be potential key elements in dealing with climate changes in agriculture. “Climate action” is the 13^th of the 17 SDGs of the United Nations 2030-Agenda. The first Earth Summit (1992) showed that human actions were dismantling the Earth’s ecosystems, eliminating genes at an alarming rate. Global warming was in 2017, plus 1 degree Celsius above the level of the preindustrial era and it is expected to grow. This reality should encourage breeders to include adaptation traits in future selection programs. The dominant genetic resources for food and agriculture in the world, however, are those produced by developed countries under optimum production systems mainly for high yields. Low yields of genetic resources native to the majority of developing countries were a major constraint for not selecting them. This was enhanced by the lack of skills and funding. Since 1898 the actual INAT and since 1932 the actual INRAT were pioneers in exploring and valuing the genetic diversity of cereals in Tunisia through breeding. More than 100 cereal varieties coping with Tunisia varying environments have been selected. When I left the National Gene Bank in 2012, it was the richest reservoir of autochthonous genetic diversity with 38000 plant accessions including 5000 repatriated from foreign gene banks. The Black Thibar sheep Breed was a wise matching of the genotype with its environment. Specific adaptation traits like heat tolerance and disease resistance are found in native unselected genetic resources. Some of them are lost forever and the remaining are being threatened by genetic erosion and anarchic crossings. National authorities and the world community should be aware that one of future tools to cope with climate changes reside in the genomes of these low input genetic resources. They already have genes allowing them to stand high temperatures, survive under the scarcity of water and feed resources. Modelling and breeding schemes are needed to enhance their productivities and better respond to climate change while reducing gas emissions. This paper shows the importance of animal genetic resources as a biological tool to cope with climate change and examines whether national priorities to mitigate the negative effects of climate change have considered this option.

Keywords: Climate, Genes, Production system, Gas emission, SDGs

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