Category: Volume 1
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Main variability factors of Inter-farms dairy cows productivities in Tunisia

Etude des Principaux Facteurs de Variabilité Inter-Fermes de la Productivité Laitière Bovine en Tunisie

M. HAMMAMI ^*

B. JEMMALI

Laboratory of Improvement and Integrated Development of Animal Productivity and Food Resources, Higher School of Agriculture of Mateur, University of Carthage, Tunisia

Abstract - This work aims the identification and assessment of the main factors of milk production variability in Tunisian cattle herds. Twenty-three (23) farms located in different regions and in different sectors (OTD, UCPA, SMVDA, private) with 6708 controlled cows. The principal components analysis showed that food-related factors explain 22.81% total variance of milk production. Indeed, the latter can be predicted by three factors with R2 = 0.76. The results showed that the farms that produce more milk per cow are those where the amount of dry matter ingested per cow and day is the highest. Similarly, the majority of the farms that give the most of concentrate produce more milk. 23 studied farms milk production varies from 3606.7 to 7106.6 liters per cow per year.

Keywords: cows productivities, factors, variability, farms, Tunisia

Résumé - Ce travail vise l’identification et l’évaluation des principaux facteurs de variabilité de la production laitière dans les élevages bovins tunisiens. Vingt trois (23) élevages répartis dans différentes régions et relevant de différents secteurs (OTD, UCPA, SMVDA, privés) avec un effectif de 6708 vaches contrôlées ont fait l’objet de cette étude. L’analyse en composantes principales à montré que les facteurs liés à l’alimentation expliquent 22,81% la variance totale de la production laitière. En effet, cette dernière peut être prédite par trois facteurs avec R²= 0,76. Les résultats ont montré que les fermes qui produisent plus de lait par vache sont celles où la quantité de matière sèche ingérée par vache et par jour est la plus élevée. De même, la majorité des fermes qui donnent le plus de concentré produisent plus de lait. La production laitière des 23 fermes étudiées varie de 7106,6 litres/vache/an à 3606,7 litres/vache/an.

Mots clés : productivité, variabilité, inter-ferme, Tunisie

Category: Volume 1
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Identification of polymorphism at the STAT5 locus in dairy cows in Tunisia

S. Ouerghi

B. Jemmali

I. Trab

A. Ben Gara

B. Rekik

Laboratory of Improvement and Integrated Development of Animal Productivity and Food Resources, Higher School of Agriculture of Mateur, University of Carthage, Tunisia

Abstract - The aim of this work is to identify the genetic polymorphism at the level of the STAT5 locus affecting the fertility traits in dairy cows. A total of 120 blood samples taken from dairy cows were used. The extraction of the genomic DNA was done and the target regions were amplified by specific primers. The polymerization chain reaction generated 820 bp amps. The PCR products were digested with a restriction enzyme BstEII to determine the presence / absence of substitution of the C allele by G at the STAT5 locus. CC genotypes; CG and GG respectively have the sizes 820 // 820; 820 // 676 and 676 // 676 bp. Identification of the substitution of C by G at the STAT5 locus may be a promising alternative for improving fertility performance in dairy cows in Tunisia.

Keywords: STAT5, polymorphism, fertility, dairy cows, Tunisia

Category: Volume 1
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Study of the genetic polymorphism of leptin in holstein dairy cows in Tunisia

B. Jemmali¹

R. Baccouche²

M. Kamoun¹

A. Ben Gara¹

B. Rekik¹

¹Laboratory of Improvement and Integrated Development of Animal Productivity and Food Resources, Higher School of Agriculture of Mateur, University of Carthage, Tunisia

²National Agronomique Institute of Tunisia,University of Carthage,Tunisia

Abstract - Leptin is a glycoprotein which is involved in the defense mechanisms of the mammary gland of dairy cows. The level of this protein secretion rises significantly in response to viral or bacterial infections. This study aims to analyze the polymorphism of the gene responsible for the biosynthesis of leptin by PCR-RFLP technique. A total of 160 blood samples were collected from dairy Holstein breed cows situated in four Tunisian governorates: Bizerte, Nabeul, Kairouan, Kasserine. The genomic DNA extraction was realized by the salt extraction method. The regulatory region of the gene was amplified by a PCR reaction with the extension of specific primers. The amplification products were cleaved using a restriction enzyme Sau3AI. The results showed the presence of two alleles A and B and three genotypes AA, AB, BB with a dominance of the allele A. Results indicate that animals carrying the BB gene could contribute to a reduction of somatic cells in cattle. Based on this observation, they are more resistant to mastitis; this peptide can be considered as a candidate gene for udder health.

Keywords: dairy cattle, genetic polymorphism, leptin, PCR-RFLP.

Category: Volume 1
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Characterization and evaluation of Tunisian rabbit farm sustainabilities: IDEA method indicators

Caractérisation et évaluation de la durabilité des exploitations cunicoles Tunisiennes : Les indicateurs de la méthode IDEA

M. Ben Larbi^1*

I. Daboussi²

N. Mhamdi³

B. Jemmali¹

¹Higher School of Agriculture of Mateur, University of carthage, Tunisia.

²Tunisian Poultry and Rabbit Association, Tunisia.

³Laboratory of the animal and food resources, National Agronomique Institute of Tunisia, Tunisia.

Abstract - Sustainability of five rabbit farms was assessed by IDEA method, "Sustainability Indicators of Agricultural Farms" to know the sustainability of this sector in Tunisia. The three sustainability scales (agro-ecological, socio-economic and territorial) were characterized. Farms investigated are characterized by limited economic scale (44.6 / 100) sustainability within this lever action is to improve sustainability with a score of 4.2 / 30 efficiency (6.6 / 25) and transmissibility (8.8 / 20), while their agro-ecological sustainability is characterized by good agricultural practices (30.6 / 34). Only socio-territorial scale is not based on the concept of production system, but rather depends on the lifestyle of the breeder. By cons, assessing the overall sustainability of operations, such as production standards in terms of sustainability require the analysis of interactions between the three sustainability scales.

Keywords: Sustainability, IDEA method, rabbit breeding, Tunisia.

Résumé - La durabilité de cinq élevages cunicoles a été évaluée par la méthode IDEA, « Indicateurs de Durabilité des Exploitations Agricoles ». Les trois échelles de durabilité (agro-écologique, socio-territoriale et économique) ont été caractérisées. Les élevages enquêtés se caractérisent par une durabilité limitée par l’échelle économique (44,6/100), à l’intérieur de celle-ci le levier d’action réside dans l’amélioration de la viabilité avec une note de 4,2/30, l’efficience (6,6/25) et la transmissibilité (8,8/20), alors que leur durabilité agro-écologique est caractérisée par de bonnes pratiques agricoles (30,6/34). Seule l’échelle socio-territoriale ne repose pas sur la notion de système de production, mais dépend davantage du mode de vie de l’éleveur. Par contre, l’évaluation de la durabilité globale d’une exploitation, comme la production de références en matière de durabilité, exigent l’analyse des interactions entre les trois échelles de durabilité.

Mots clés : Durabilité, méthode IDEA, élevage cunicole, Tunisie.

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