No abstract

In this century, climate change is one of the major problems affecting livestock productivity. This study aimed at evaluating the effect of body coat color pattern and sex on heat regulation and heat stress tolerance in indigenous goat breeds exposed to solar radiation. In the experiment, 4 bucks and 4 does (8 to 9 months age) with black, white, grey and brown coat color were selected and exposed to solar radiation during 12 days during the summer period. Water and feed were served add libitum. The consumption were measured daily at 17:00 for each animal. Rectal temperature (RT) and rate pulse (PR) were measured three-time (7:00, 12:00, and 17:00) every day on each animal during the experimental period. At the end of the experiment, blood samples were collected from the jugular vein and immediately delivered to the lab to determine biochemical (serum protein: albumin and globulin), and hematological parameters. Exposing goats to temperature variation affected the physiological, hematological as well as biochemical parameters in all subjects. The female with a black body coat color was mostly affected. The heat stress induced an increase of RT and PR, an increase in water consumption while depression in food intake was observed. Blood platelets, hematocrits, red cell distribution, white blood cell and albumin were damaged in goats with black coat color compared to goats with white coat color. These variations in physiological, hematological and biochemical parameters in female black goat could affect its productive and reproductive performances in high-temperature environments.

Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers' socio-economy status in various production systems. This review aimed at giving a summary overview on the goat's production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat's distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa.

The study was carried out from August to September 2016 in the Western Highlands of Cameroon. The main objective was to contribute to a better understanding of biodiversity of honeybees for their preservation and genetic improvement. To attain this, samples of 420 workers bees belonging to Apis mellifera subspecies were obtained from 14 localities in the study zone. Body measurements in mm gave the following values: honey bee length (10.98 ± 0.06), abdomen length (6.71 ± 0.03), width of the yellow band on the second (2nd) abdominal tergite (1.48 ± 0.01), width of fourth (4th) abdominal tergite (1.32 ± 0.01), length of cover hair on the fifth (5th) abdominal tergite (0.29 ± 0.00), antenna length (4.27 ± 0.02), proboscis length (4.39 ± 0.11), length of nervure A (0.60 ± 0.00), length of nervure B (0.25 ± 0.00), discoidal shift (-0.13 ± 0.01), anterior right wing length (9.31 ± 0.03), anterior right wing width (3.14 ± 0.01), posterior right wing length (6.38 ± 0.03) and posterior right wing width (1.69 ± 0.01). A correlation coefficient significantly (p<0.01) higher (0.72) was obtained between the length of posterior right wing and the length of the anterior right wing. The cubital index is 2.36 ± 0.04. Populations of honeybees studied consist of three genetic types; genetic types 2 and 3 are closer together. The observed biodiversity suggests that honeybees constitute a natural resource with genetic variability needed for preservation and genetic improvement.