Evaluation morphométrique des chevaux pur-sang Arabe en Algérie: mensurations corporelles et proposition d’équations barymétriques

Cette étude vise à la caractérisation morphobiométrique des chevaux de course pur-sang arabe et à l’estimation d’équations barymétriques adaptées à cette race. La caractérisation a concerné 98 chevaux, dont 44 femelles et 54 mâles, tous âgés de trois ans et plus, auprès de 77 propriétaires-éleveurs dans 3 hippodromes d’Algérie (Zemmouri, Tiaret et Caroubier). Dix-neuf mensurations étaient relevées ainsi que le poids vif (PV). Le poids moyen est de 456,2 +/- 43,0 kg, variant de 335 kg à 545 kg. La sélection des variables à inclure dans les équations barymétriques a été réalisée à l’aide de la procédure stepwise du SAS. Quatre mensurations parmi les 19 réalisées ont été retenues pour la proposition d’équations d’estimation du poids vif des chevaux : le périmètre thoracique (PT), la hauteur à la croupe (HC), la longueur de l’encolure (LE) et le tour de l’encolure (TE). Ainsi, les équations proposées pour les mâles et pour les femelles sont respectivement de : PV= 7,024*PT - 787,119 (R²=0,99); PV=6,207*PT + 0,633*HC + 0,668*TE - 0,878*LE - 746,370 (R²=0,96). Les résultats de cette étude devraient permettre aux propriétaires-éleveurs et entraineurs de suivre aisément le poids de leurs chevaux. Ce suivi est nécessaire pour adapter l’activité et l’alimentation des chevaux et favoriser leur performance en course

Echocardiographic Evaluation of Cardiac Morphologic and Functional Variables in Double-Muscled Calves

We studied, by means of echocardiography in vivo, the cardiac consequences of the double-muscled character selection in beef cattle. Morphologic and functional echocardiographic variables were regularly estimated in 17 Friesian and 8 Belgian White and Blue calves during their growth. A total of 50 and 44 sets of data were collected in each group, respectively. Recordings were obtained, using 2-dimensional and M-mode echocardiography, and included measurements in long- and short-axis views of the heart. Most of the diastolic measurements of the left ventricle were not significantly different between breeds when normalized for body weight. To the contrary, systolic measurements of left ventricular wall thickness and dimensions were significantly (P less than or equal to 0.001) lower and greater, respectively, in Belgian White and Blue calves than in Friesian calves. This was interpreted as a result of significantly (P less than or equal to 0.001) lower left ventricular systolic functional indices in Belgian White and Blue than in Friesian calves. Echocardiographic evidence that the double-muscled selection in cattle induces alteration in morphologic variables of left ventricle was not found. However, results indicate that indices of left ventricular systolic function are lower in double-muscled calves than in calves with standard conformation

A basic characterization of small-holders’ goat production systems in Laghouat area, Algeria

Abstract In order to investigate the practices of goat breeding and establish a classification of goat herds, a survey was conducted with 106 goat breeders in the semi-arid region of Laghouat. Two indigenous breeds were encountered in this survey: the Arabia and the Mekatia; the Arabia being found as the dominant. The results show that breeders choose the breeding goats with a goal of generating more income in cash from the sale of products. The goat milk marketing chain appears to be weak. The milk produced is primary used for home consumption. A multivariate analysis categorized the goat farming of Laghouat region into three groups corresponding to three different farming systems: cluster 1 (pastoral system), cluster 2 (mixed crop-livestock system) and cluster 3 (small herds in zero grazing system). The in-depth study of the goals and contexts of goat farming in Laghouat will allow policy makers to design strategies for sustainable development of goat breeding in the region

Estimation of genetic parameters of racing traits of Arabian horses in Algeria

The results of the flat races organized in Algeria from 1995 to 2007 by the Algerian Horse Racing Society, were used to estimate genetic parameters of racing performances of Arabian horses. The data consist of 36 492 race records, obtained from 913 horses. The pedigree file of the horses includes 1812 animals from 166 stallions and 392 mares. The analysis was performed on two traits: the logarithm of average annual virtual earnings per start (LAEV/S) and a normalized ranking (PERF). To identify the fixed effects to be included in the genetic model, a preliminary analysis was conducted using the General Linear Models (GLM) procedure from SAS software. The effects of age (3 to 8 years and older), sex (male or female), year (1995 to 2007) and the interaction between year of the race and age and between sex and age were included in the model for both traits. In addition, two random effects, a direct genetic effect of the animal and a permanent environmental effect were included in the mixed model. The variance components and genetic parameters were estimated by the restricted maximum likelihood (REML), procedure using the MTDFREML program. The analysis, using a repeatable animal model, led to the following estimation of genetic parameters: for LAEV/S, heritability was 0.23 (±0.04), while estimate of repeatability was 0.34 (±0.04). The heritability for the normalized ranking was higher, 0.37 (±0.05), indicating that this trait might be more appropriate for breeding programs of Arabian horses in Algeria. The repeatability estimate for the normalized ranking was 0.59 (±0.04) and the genetic correlation between this trait and LAEV/S was 0.79

Genetic parameters of racing performance traits of Arabian horses in Algeria

The data used in the present study were recorded at the Algerian Horse Racing Society for 36492 racing performance of 913 Arabian horses from 1995 to 2007. The aim of the study was to identify the genetic parameters underlying three traits: two earnings traits, namely the logarithm of average annual virtual earnings (LAEV) and the logarithm of average annual virtual earnings per start (LAEV/S), and a ranking trait, the normalized ranking (PERF). To identify the fixed effects to be included in the genetic mixed model, a preliminary analysis was conducted using the General Linear Models (GLM) procedure from SAS software. The effects of age, sex, year and the interaction between year of the race and age and between sex and age were included in the model for the three traits. Afterwards, two random effects, a direct genetic effect of the animal and a permanent environmental effect were included in the mixed model. The variance components and genetic parameters were estimated using the restricted maximum likelihood (REML) procedure with the MTDFREML program. The analyses with this repeatable animal model led to the following estimation of the genetic parameters: for LAEV, heritability was 0.225 (±0.041), while estimate of repeatability was 0.330 (±0.040). For LAEV/S, heritability was 0.164 (±0.027), while estimate of repeatability was 0.215 (±0.022). The heritability for the normalized ranking was higher, 0.369 (±0.054), indicating that this trait might provide faster progress for breeding programs of Arabian horses in Algeria. The repeatability estimate for the normalized ranking was 0.587 (±0.045). The genetic correlation between LAEV and LAEV/S was 0.99, revealing a almost complete genetic dependence between these two traits, 0.69 between PERF and LAEV and 0.79 between PERF and LAEV/S

Pedigree analysis in the Arabian horse in Algeria: estimation of inbreeding coefficient

The studbook of the Arabian horse used in this study is recognized by international authorities such as the WAHO (World Arabian Horse Organization). The pedigree file of the horses includes 1812 animals from 166 stallions (with an average of 10.11 ± 17.33 offspring) and 392 mares (with an average of 4.30 ± 3.76 offspring). The maximal pedigree depth was 18 generations. Inbreeding coefficients of horses present in our data were estimated using the software "Pedigree Viewer" and MTDFREML software on the basis of the provided pedigree. The estimation of the inbreeding coefficient for the 1812 horses showed that 1177 animals from all those present in the pedigree were consanguineous, with an inbreeding coefficients varying from 0,00002 to 0,265, with an overall mean of 0,0275 ± 0,001. The average value of the inbreeding coefficient in the population of Arabian horses in Algeria is thus relatively high. It is to be noticed that this average coefficient of inbreeding is less than the threshold established as problematic in the inbreeding literature (6%); however, 13.5% of the total population shows inbreeding coefficients above this threshold. It is therefore important to educate owners-breeders to the problems that consanguinity can generate, and to avoid as much as possible practices that increase inbreeding, such as a too intensive use of a major ancestor, the use of a too small number of breeding animals and the use of crosses between related individuals. All these measures are necessary to prevent rapid inbreeding increase, which would result in a significant loss of genetic diversity, with a medium-term potentially negative effect on racing performances and reproduction

Selection criteria as used by owners-breeders of racehorses in Algeria

Due to positive externalities and the need to work on a large scale, animal breeding is usually carried out by breeders associations or states. In Algeria, racehorse breeding is in the hands of unorganized breeders-owners. Through a survey conducted with 461 owners-breeders between 2009 and 2011, this study investigates their perceptions, objectives and practices regarding selective breeding. Racehorse breeding is a full-time professional activity for a third of interviewees. The holdings are small-sized with 77% owning one or two mares. The regular practice of insemination could categorize breeders according to their professionalization (38.4% professional vs. 61.6% occasional breeders). Seniority in the sector was also used to classify breeders, considering as “young” the breeders under 10 years experience (38.8%) and as “senior” those above 10 years (61.2%). More than professionalization, seniority shows a significant impact on practices and objectives. Thus, seniority influences breed choice (young breeders tend to specialize while senior own both Arabian and Thoroughbreds; p<0.001), age at first foaling (sooner among senior breeders; p<0.01), information sources considered for selecting stallions (senior use more diversified sources; p<0.01), the importance granted to the price of insemination (greater for the young breeders; p<0.001), the importance granted to the ranking compared to earnings (the ranking being more important to young breeders, p<0.001), and the priority given to breeding (young breeders give rather priority to a buy-race-resell activity; p<0.001). Finally, racehorse breeding in Algeria is poorly professionalized, the only financial goal being cost coverage. Despite inappropriate practices, an interest for selection is noticed

Environment factors affecting racing performances of Thoroughbred horses in Algeria

The results of the flat races organized in Algeria from 1995 to 2007 by the Algerian Horse Racing Society were used to estimate non-genetic parameters of racing performances of Thoroughbred horses. Performances were assessed through two earnings traits (the logarithm of annual virtual earnings: LAEV and the logarithm of average annual virtual earnings per start: LAEV/S) and a normalized ranking (PERF). The phenotypic correlations between these traits were calculated, in order to deduce what is common and what is specific to each measure. The environment factors that were investigated are age (3 to 8 years and older), sex (male or female), year of race (1995 to 2007) and the interactions between these factors. The General Linear Model (GLM) procedure from SAS software was used to identify and quantify the non-genetic factors affecting racing performances. The results showed significantly high positive correlations (p<0.001) between the three traits, hence considered as accounting for similar aptitudes. The effects of age (with a plateau between 4 and 5 years) and year (with an increasing trend for more recent years) turned out to be significant (p<0.001) for the three traits, the sex effect was only significant for the PERF trait (with better performances for males than females) and an interaction between the age and year of the performance was the only significant interaction (p<0.05) for the LAEV trait. The significant effects of these non-genetic factors indicate the need to adjust the earnings and ranks in the context of a program for genetic improvement of Thoroughbred horses in Algeria