Estimation of genetic parameters for preweaning and postweaning growth traits in the Gudali beef cattle using multiple trait derivative free restricted maximum likelihood

Records on pedigree information and growth traits of Gudali beef calves were obtained from the Institute of Agricultural Research for Development, Cameroon. Data were edited to have complete information on calf, sire and dam identity, sex, dates and season of birth, herd and weights at birth (BWT), 6 months (6 MWT), weaning (WWT), 12 months (12 MWT), yearling (YWT), 18 months (18 MWT), 24 months (24 MWT) and 36 months (36 MWT). Genetic parameters were estimated using multiple trait derivative free restricted maximum likelihood (MTDFRML) program. The estimated direct (h2a) and maternal (h2m) heritabilities for BWT, 6 MWT, WWT, YWT, 18 MWT, 24 MWT and 36 MWT obtained were 0.39, 0.10, 0.25, 0.21, 0.18, 0.25, 0.18 and 0.05, 0.07, 0.11, 0.10, 0.05, 0.09, 0.07, respectively. Estimates of maternal genetic variance and corresponding heritabilities (h2m) were lower than estimates for direct additive variance and heritability (h2a). The genetic correlation between direct and maternal influence were negative. The across-trait direct and maternal genetic correlation estimates were medium to high with the exception of BWT and 18 MWT; BWT and 36 MWT, had negative values. The positive values reported for the additive and maternal correlations between the growth parameters indicate that selection for one trait resulted in genetic improvement in the other. The moderate values of heritabilities indicate that selection for growth traits was effective.Key words: Covariance, heritability, genetic correlation, growth traits

Mise en évidence d'un agent coagulant utilisable en fromagerie dans les fruits de Balanites aegyptiaca

Study of a Suitable Cheese Making Milk-clotting Agent from Balanites aegyptiaca Fruits. As slaughtering of zebu (Bos indicus) calves in Cameroon is forbidden, calf abomasa are rare on markets so it is diffi cult to prepare rennet. The aim of this study was to look for other sources of milk clotting extracts, especially from Balanites aegyptiaca fruits. B. aegyptiaca is a widespread tree in northern Cameroon. Its fruit is pulpy with a thin and hard epicarp, a dark brown mesocarp and a hard endocarp enclosing an oil seed. The fruits of B. aegyptiaca were harvested at Pitoa (9°23' N, 13°32 E). Milk clotting, determined by the Berridge method, was only obtained with mesocarp extracts. The experimental design of the extraction was a split-plot (5 4 4) with 5 mesocarp concentrations, 4 temperatures and 4 maceration times. Optimum extraction was performed when macerating 50 g mesocarp in 100 ml water at 4 °C during 9 h. Protein content (91 14 mg. ml-1) was determined by bicinchoninic acid assay. Five proteins of respective molecular masses 27, 30, 42, 44 and 90 kg.mole-1 were observed by SDS-PAGE under reducing conditions. The force of the extract was determined by comparing its milk clotting time to that obtained with rennet. Proteolytic activity of the extract was measured by hydrolysis of bovine haemoglobin and titration of free NH2 using l'ophthaldialdehyde reagent. Counting of coliforms was carried out on DCL gelose, that of the total aerobic mesophil fl ora on PCA and that of the sulfi to-reducing fl ora on TSN. The extract only contained coliforms and aerobic mesophil fl ora. Fresh cheese was made with zebu milk using rennet or B. aegyptiaca mesocarp extract. Indemnes of Specifi que Pathogen Organism mice were fed with these cheeses then with crude B. aegyptiaca mesocarp extract. No abnormality, nor toxicity were observed on mice. A panel was allowed to appreciate these cheeses. Statistical analysis was conducted using SASsoftware. It was concluded that B. aegyptiaca mesocarp extract is suitable for cheese manufacture

Dry Season Effect on Live Weight and some Body Dimensions of Working Donkeys in the Sudano-sahel Region of Cameroon

Live weight (LW), heart girth (HG), trunk length (TL), body length (BL) and height-at-withers (HW) of 135 working donkeys, aged between two and 15 years, were monitored during the dry season of 1996 and 1997. This was to determine period(s) of the dry season when feed supplementation and/or health care should be reinforced in preparation of high work demands during the rainy season. Variations in LW, HG, TL, BL, HW, HG:HW and TL:HW from start of the dry season to the start of the rainy season were highly significant (P< 0.001). Correlations between live weight and the other measures were positive and highly significant (P< 0.0001). Males showed weight gains between start of the cold-dry-season (CDS) and start of the hot-dryseason (HDS). Weight gains in castrates were between start of the CDS and end of the HDS (April). Female donkeys maintained weight gains through out the dry season. Consequently, supplementation of castrates and males at the beginning (January) and end (April) of the HDS as to reinforce and maintain significant weight gains for maximize draught energy potential for rainy season work demands, is necessary. Where the female donkey express weight gain but poor bodied there will be need for supplementation in order to booster and enhance endurance. Also, estimates of HG, TL, BL, HW, HG:HW and TL:HW may be useful indicators for the selection of working donkeys as to optimize draft capacity and endurance for rainy season work demands

Effets de la saison sur les qualités microbiologiques de Kilishi, une viande sèche traditionnelle du Cameroun

Effects of Season on the Microbiological Quality of Kilishi, a Traditional Cameroonian Dried Beef Product. The microbiological quality of Kilishi, a traditional Cameroonian dried meat, produced in the Northern part of the country, was studied over one-year period. 79 Kilishi samples collected at various selling points were used for microbiological evaluation. The results on the microbiological analyses were then subjected to a statistical analysis using the General Linear Model (GLM) approach to assess environmental factors that affect quality. Final results indicated that the quality of Kilishi was greatly affected (P< 0.001) by the season and location of production though the total bacterial, mould and yeast counts (cfu/g) were lower than the recommended acceptability limit for the total viable bacterial counts of micro-organisms in meat at the point of consumption

Non-genetic Factors Affecting Gestation Lenght and Postpartum Intervals in Gudali Zebu Cattle of the Adamawa Highlands of Cameroon

The effects of non-genetic factors (sex of calf, calf birth weight, age of cow, season of calving) affecting gestation length (GL) and open days period (OP) in the Ngaoundere Gudali cattle of the Adamawa (Cameroon) was investigated. Mean GL was 293.4 ± 0.4 d. Sex of the calf significantly (P< 0.05) affected GL, with male calves being carried in utero approximately 3 days longer than the females (294.1 ± 1.2 vs 291.1 ± 1.2 d). Calf birth weight tended to increase as gestation lengthened. Parity and age of the cow had no significant (P> 0.05) effect on GL. The mean duration of the OP (from calving to conception) was 267.7 ± 7.4 d. Approximately 23.2% of the cows conceived within 90 days of calving and a total of 55.6% had conceived by 360 days. The distribution of the OP was bimodal, and could have been influenced by seasonal availability of feed, or long (6 months) mating season allowing cows to calve during the following mating season. Calving to conception interval was significantly (P< 0.001) affected by month of calving and parity. Sex of the calf did not affect significantly the duration of the postpartum period, although this period was 5 days longer following the birth of a male calf

Structure des troupeaux et conduite de l'Elevage bovin periurbain de Ngaoundere au Cameroun Structure of herds and peri-urban cattle management in Ngaoundere, Cameroon

Une enquête a été menée entre mars 2002 et février 2003 dans la zone péri-urbaine de Ngaoundéré. L'objectif de l'étude était de caractériser les troupeaux bovins et d'analyser la conduite de l'élevage. Les données ont été collectées sur 83 troupeaux de zébus de race Goudali, répartis dans 3 localités. Les résultats obtenus ont montré que la taille moyenne du troupeau est de 64 têtes, lequel est composé de 46 et 54 % de femelles et de mâles respectivement. Les vêlages surviennent généralement en saison pluvieuse (68%) et les avortements en saison sèche (61%). Les mortalités sont élevées en saison sèche (65 %), chez les jeunes de 0 à 1 an (52%), surtout dans les élevages situés prés du centre urbain. Ces mortalités sont liées aux principales causes suivantes: maladies (40 %), causes indéterminées (33 %), accidents (22%), morsures de serpents (5%). La Fièvre aphteuse (25%), la Trypanosomose (14%), le Charbon symptomatique (12%), la Tétanie d'herbage (8%) et la Fasciolose (8%) sont considérés comme les principales contraintes. Les éleveurs ont recours à la médecine traditionnelle et moderne pour le traitement des maladies de manière non systématique. L'alimentation est basée sur l'exploitation des pâturages relativement pauvres, notamment en saison sèche. Les produits de complémentation distribués sont le sel et le natron (49%), le tourteau de coton (35%) et les résidus des récoltes (16%). La production laitière de la race locale est faible (2 à 3 l / j) et la quantité moyenne traite est estimée à 1,5 l / vache/ j. Le lait trait est plus destiné à la consommation domestique (65%) qu'à la vente (35%). D'autres produits tels que le travail, la peau et les déjections sont aussi utilisés.Mots-clés: élevage, bovins, périurbain, Ngaoundéré, Cameroun Bulletin of Animal Health and Production in Africa Vol. 54(1) 2006: 53-6

Reproductive status of cows slaughtered at the Ngaoundere Municipal Slaughter House and factors responsible for potential losses in herd productivity

The reproductive status (RS) of 2,103 cows slaughtered at the Ngaoundere Municipal Slaughter House (NMSH) in view of highlighting potential losses resulting from the slaughtering of pregnant cows (PC) were assessed. Concurrently, 390 of the cows evaluated for RS were randomly selected for a detailed identification of the possible causes of infertility from the gross reproductive pathologies (GRP) observed in the reproductive tract. Data were collected between July and December, 2004 and analyzed using SAS program (1991). Of a sample of 2,426 animals slaughtered, 2,103 (86.6%) were cows. The prevalence of PC slaughtered was 37.3%. Majority (83%) of the cows slaughtered were below 9 years of age. The PC slaughtered (7.5 years) were significantly (