Caractéristiques Phénotypiques Des Races Caprines Élevées En Régions Sahariennes. Cas Des Régions D’ouargla Et Biskra

Résumé: The identification or determination of the breed or population standards to be kept is the essential step of the valorization and conservation program. In this sense, investigations have been carried out into the morphological characters of local goat breeds raised in the southeastern region of Algeria. The methodology followed for measurements of morphological traits is that described by FAO (2013). The characterization of the average daily gain was carried out by a monthly control of the goats’ kids during 6months. For milk production; the study was based on the weighing of kids before and after feeding every week during 6 months. Phenotypically three populations have been identified (Arbia in Biskra and Ouargla regions and Mekatia in Ouargla region). The uni and multi-variate analysis of body measurement data showed a variety of characteristics of the goats studied. Two animal classes for both sexes have been distinguished. The most discriminating factors that make it possible to better characterize females goats are HW, HB, EL, ICL, ED, WH, CF, EW and HL. Factors that characterize the male’s goat are: the height at the back, the circumference of thigh and the circumference of forearm and of interior cannon bone length and the hair length. The evaluation of growth performance, milk production and milk quality under the extensive breeding conditions of Arbia goats led to the following results: the daily milk production was 0.89±0.91 kg per day and the total production for a lactation of 170 days was 160 ±43 kg of milk. The milk was characterized by an average composition of 3.5% of fat, 3.0% of total protein, 4.6% of lactose, 89.5 g / l total dry extract, 0.6% of salts, an acidity of 18.2 ˚D and a density of 1032. Regarding the growth performances: the male kids birth weight was 2.58±0.43 kg, the body weight was 6.0±1.15 kg at 30 days, 8.6±1.25 kg at 60 days, 11.5±1.4 kg at 90 days, 14.3±1.7 kg at 120 days, 17.4±2.5 kg at 150 days and 19.9±2.6 kg at 180 days. While the female kids weight was at birth 2.37±0.34 kg, at one month 5.54±0.73 kg, at 3 months 10.7±1.6 kg, and 15.7±2.3 kg at 6 months. The average daily weight gain was for the males and the females respectively of 114±39 and 105±24 g between birth and 30 days, 97±46 and 90±3 g between 60 and 90 days, and 81±34 and 54±24 g for the period from 150 to 180 days. For the reproductive performance of this goat, the fecondity, prolificacy, fertility, abortion and mortality rates were respectively: 112.38%, 136.09%, 92.20%, 11.29% and 18.69%. The Saharan regions have a goat biodiversity with specific adaptations to the conditions of the natural environment. These animals deserve specific attention by decision makers and breeders for their preservation and promotion, but also by scientists to establish more information and knowledge. A significant risk to emphasize is the existence of anarchic crossbreeding between breeds which complicates the task of one who seeks to identify and characterize pure breeds.

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