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In Lebanon, small ruminants hold a key role in the economy of marginal regions and contribute to the income of the population involved in pastoral activities. The production does not meet the national growing demand for milk and meat, thus Lebanon depends on importation to satisfy the needs of the population. The aim of the thesis is to identify the principle rearing systems available in Lebanon and to optimize the small ruminant’s production and reproduction according to those systems. The welfare notion will be studied in order to evaluate its impact on animal productivity and to aware farmers of welfare importance in their management strategy. The experimental work started by the elaboration of a detailed questionnaire to be filled at the 517 farms representing the seven Lebanese districts. This survey was structured to collect informations related to the farm and the farmers, the production parameters, the reproduction parameters, the hygiene and the animal welfare. Results showed three different clusters representing the small ruminants systems in Lebanon and indicated on this thesis as “intensive system” 5 farms with a herd size of 740 ± 707 head, “semi-intensive system” 246 farms with a herd size of 145 ± 109 head and “extensive system” 266 farms with a herd size of 200 ± 152 head. Results concerning the effect of rearing systems on the reproduction of sheep and goats in Lebanon showed a weight at birth of kids and lambs varying from 3.9 Kg to 5.4kg between the different rearing systems. Prolificacy was 1.11 and 1.27 in the extensive system, 1.28 and 1.40 in the semi-intensive system and 1.79 and 1.77 in the intensive system for sheep and goats respectively. Fertility recorded 88%, 85 and 80% in the intensive, semi-intensive and extensive systems respectively. First lambing occurred at 12 months in the intensive system, 20 months in the semi-intensive and 21 months in the extensive for both sheep and goats. The average milk yield of ewes in intensive flock was 336.7 l/year, ewe in semi-intensive and extensive system produced 163.5l/year and 129.9l/year respectively (p Animal welfare was studied in six semi-intensive and extensive farms to evaluate the effect of different stressors on the animals: environmental, physical, nutritional, management, pathological and psychogenic stressors. Cardinal physiological parameters were within the normal range for the small ruminants raised in semi–intensive systems during both winter and summer periods. The extensive system results, showed a high values of the pulse rate and the breathing score (107.55 ± 3.67 and 1.38 ± 0.49 respectively) during the summer period at noon when goats and sheep were exposed to high temperatures in direct sunlight. Sheep and goat houses were often inadequate in terms of design, materials and size. During May, small ruminants raised in both extensive and semi-intensive system, showed the higher body score condition (3.45 and 3.3 respectively). In extensive system, BCS declined during the summer period to reach a 2.4 score in September. While in semi-intensive system BCS maintained the same score during July and decreased to a score of 2.8 in September. BCS increased in November (around 3.15) for both systems and decreased again during January and March with a more expressive trend in the extensive system. Dehorning is practiced in a limited way in both semi-intensive and extensive system (7% and 10% respectively when needed). The third experiment focused on the Bio molecular Study of the Melatonin receptors. 338 blood samples from 9 farms of local multiparous sheep (n=164) and goats (n=174) with a regular cycle, similar body condition score and similar average productivity, were collected using 2.5ml EDTA tubes in duplicate and directly refrigerated. Samples were frozen and transmitted with dry ice to the veterinary department in Sassari for DNA extraction and PCR analysis. Data concerning production and reproduction of the sampled animals were recorded. In all the analyzed sheep samples amplification products resulted in a single fragment of 824-bp in length that correspond to the entire MTNR1A exon II. Also in goat samples PCR evidenced a single band of 824-bp in length, corresponding to the MTNR1A exon II, according to the newest goat reference sequence ARS1 - Capra hircus melatonin receptor type 1A gene – GenBank assembly accession number: GCA_001704415.1. The allelic and genotypic frequency at the position g.17355458C>T found in the Awassi sheep showed a high frequency of the C allele and of the genotype C/C. The two most representative SNPs of the MTNR1A gene in the Awassi breed did not show any association with reproductive seasonality. The very limited variability found between the two breeds of goats analyzed in this research, does not make it possible to investigate the relationship between melatonin receptor polymorphism and reproductive seasonality. To work in a sustainable perspective, it is highly suggested to keep the entity of each system with improving the zootechnical and welfare operations to valorize the natural rangelands and benefit from the native breeds characteristics and potentials. |
