Blood Polymorphism in West African Breeds of Sheep

This paper reports the blood groups and blood protein distribution in West African sheep breeds. About 100 animals of the Djallonke, Fulani and Touabire breeds were sampled for blood polymorphism analysis. Their blood groups were typed by haemolytic and agglutination reactions, and their blood proteins by starch gel electrophoresis. Almost all the loci analysed showed variability in the three breeds, with the Touabire and Fulani being closer to each other than to the Djallonke.     

Effect of Dwarf (dw) and Frizzle (F) Genes on the Performance of Layers under Senegalese Conditions

The influence of sex-linked dwarf (dw) and incompletely dominant frizzle (F) genes on growth, egg production and quality were investigated. The experimental stock comprised 100 chicks of four genotypes: normal feathered, normal size (ffDw); normal feathered, dwarf (ffdw); frizzle, normal size (FfDw); and frizzle, dwarf (Ffdw). The dwarf gene reduced the body weight, shank length, feed intake, egg production and egg weight. The frizzle gene also reduced most of these traits, except for egg production, the interaction between the two genes being positive only for growth traits and egg number. Neither of the two genes significantly influenced egg quality. It was concluded that the dwarf gene may have some practical interest in tropical environments, while more needs to be known about the frizzle gene. This revised version was published online in July 2006 with corrections to the Cover Date.     

Performance, plasma hormones, histochemical and biochemical muscle traits, and meat quality of pigs administered exogenous somatotropin between 30 or 60 kilograms and 100 kilograms body weight.

Forty-five Large White barrows were injected daily i.m. with either excipient from 30 to 100 kg BW (CTRL), excipient from 30 to 60 and porcine somatotropin (pST; 100 micrograms/kg BW) from 60 to 100 kg BW (pST-60), or pST (100 micrograms/kg BW) from 30 to 100 kg BW (pST-30). Somatotropin accelerated overall growth rate (+4 and +9% for pST-60 and pST-30, respectively), increased longissimus (+10.3 and +14.7%) and semitendinosus (+17 and +13%) muscle weights, and decreased backfat (-49 and -58%) and leaf fat (-49 and -53%) weights. The administration of pST resulted in a similar increase in muscle fiber size for all fiber types in both longissimus (LM) and semispinalis (SS) muscles (+21%). Somatotropin had otherwise little effect on muscle fiber types and biochemical traits of LM, whereas dramatic changes were observed in SS. The relative area occupied by Type IIB fibers was increased (+22 and +29%) and that of Type I fibers was decreased (-10 and -15%). In pST-30 animals, myosin ATPase activity (+15%) and native myosin fast isoform proportion (+10%) were augmented, and energy metabolism was more glycolytic (lactate dehydrogenase: +25%) and less oxidative (citrate synthase: -13%; beta-hydroxyacyl-CoA dehydrogenase: -21%). Compared to CTRL animals, administration of pST increased muscle water concentration (LM: +.8 and +1.1%: SS: +3.3 and +3.3%) and decreased intramuscular fat (LM: -29 and -27%; SS: -39 and -50%). The pH measured 45 min and 24 h postmortem, glycogen content, reflectance, and index of light diffusion were mostly not affected by pST treatment. In conclusion, pST had a very favorable effect on growth performance without any important effect on meat quality traits except for the reduction in intramuscular lipid content. The results indicated that the effects of pST on muscular histochemical and biochemical characteristics were different in LM and SS muscles.     

Analysis of microbiological and chemical quality of poultry meat in the vicinity of the Mbeubeuss landfill in Malika (Senegal)

A total of 100 samples of poultry meat were collected in poultry farms in the vicinity of the Mbeubeuss landfill in the Niayes (Senegal) for microbiological and chemical analysis. Fifty-four (54) samples were collected in farms located less than 1 km from the landfill and 46 samples were collected in farms located a bit further (more than 1 km from the landfill). Microbiological quality was determined using techniques recommended by Association Française de Normalisation (AFNOR). Lead and cadmium concentration in poultry meat was measured by flame spectrometry while total mercury was determined by atomic absorption spectrometry. Three percent (3%) of the samples’ quality were unsatisfactory for E. coli, 1% for Staphylococci and 7% for Salmonella spp. Poor meat quality was found either in farms located less than 1 km of the landfill or in farms located at more than 1 km of the landfill. Except for Salmonella, only meat samples from poultry receiving drinking water from well showed unsatisfactory microbiological quality. The samples were free of cadmium and lead but were contaminated by mercury. Sixty-eight percent (68%) of the samples contained mercury with a high contamination level (>0.011 mg/kg) in 20% of the samples. No significant difference was found between the farms that were nearest to and further away from the landfill while the source of drinking water seemed to be the main cause of contamination of poultry meat by mercury.