From farmers to livestock keepers: a typology of cattle production systems in south-western Burkina Faso.

Cattle production is an essential livelihood strategy in south-western Burkina Faso. Although having a distinct cultural role and known to be resistant against African animal trypanosomosis, the Lobi taurine cattle breed is endangered due to its low market value. As the first step in preservation efforts, our study aimed to develop a typology of production systems at the farm level. We used a structured questionnaire and focus group discussions for collecting data on household characteristics, socioeconomic activities, livestock, and access to services. The sample comprised 169 households in three communities. The analytical strategy included factor analysis of mixed data and hierarchical clustering. We identified four distinct types of cattle production systems: (1) sedentary Lobi farms, (2) sedentary crossbreed farms, (3) semi-transhumant Fulani zebu farms, and (4) transhumant Fulani zebu farms. Significant factors in developing this typology were the farmers' ethnic group, crop diversity, cattle herd size, cattle herd composition, number of small ruminants, and livestock management strategies. Across all production systems, men were considered being primary decision-makers in cattle production, with women, herders, and children being responsible for specific tasks. All identified production systems are increasingly confronting disease pressure and scarcity of water and land. Future efforts in preservation and breeding will need to respond to these trends in the agroecosystem, integrate risk management measures, and resonate with the specific needs of the different household members involved in cattle rearing.

Differences in genetic structure assessed using Y-chromosome and mitochondrial DNA markers do not shape the contributions to diversity in African sires.

Up to 173 African sires belonging to 11 different subpopulations representative of four cattle groups were analysed for six Y-specific microsatellite loci and a mitochondrial DNA fragment. Differences in Y-chromosome and mtDNA haplotype structuring were assessed. In addition, the effect of such structuring on contributions to total genetic diversity was assessed. Thirty-five Y-chromosome and 71 mtDNA haplotypes were identified. Most Y-chromosomes analysed (73.4%) were of zebu origin (11 haplotypes). Twenty-two Y-haplotypes (44 samples) belonged to the African taurine subfamily Y2a. All mtDNA haplotypes belonged to the "African" taurine T1 haplogroup with 16 samples and nine haplotypes belonging to a recently identified subhaplogroup (T1e). Median-joining networks showed that Y-chromosome phylogenies were highly reticulated with clear separation between zebu and taurine clusters. Mitochondrial haplotypes showed a clear star-like shape with small number of mutations separating haplotypes. Mitochondrial-based FST -statistics computed between cattle groups tended to be statistically non-significant (p > .05). Most FST values computed among groups and subpopulations using Y-chromosome markers were statistically significant. AMOVA confirmed that divergence between cattle groups was only significant for Y-chromosome markers (ΦCT  = 0.209). At the mitochondrial level, African sires resembled an undifferentiated population with individuals explaining 94.3% of the total variance. Whatever the markers considered, the highest contributions to total Nei's gene diversity and allelic richness were found in West African cattle. Genetic structuring had no effect on patterns of contributions to diversity.

Resistance to gastrointestinal parasite infection in Djallonké sheep.

Gastrointestinal parasitism places serious constraints on small ruminant production. The situation has been exacerbated by development of drug resistance in many parasite populations, leading to interest in identification of animals with genetically mediated resistance or tolerance to nematode infections. This study assessed the response to natural infection with gastrointestinal nematodes (GIN) in Djallonké sheep during the rainy season in the Sudan-Guinea Savannah region of Burkina Faso. Haemonchus contortus is the most prevalent GIN at this site and time. Djallonké lambs (n=434) were sampled from 40 households and evaluated at a common location in southern Burkina Faso. Lambs were dewormed with levamisole at 2 to 6 months of age and returned to infected pastures. Fecal egg counts (FEC), packed cell volumes (PCV), and FAffa Malan CHArt (FAMACHA©) scores were determined 28 and 35 days after deworming. Lamb mortality was monitored throughout the experiment. Least-squares means for BW increased from 13.8±0.2 kg at 28 days to 14.0±0.2 kg at 35 days (P<0.01). Simple means and medians for FEC were 615 and 100, respectively, at 28 days and 850 and 175, respectively, at 35 days. The FEC exhibited strong right skewness. Following logarithmic transformation and back-transformation of resulting least-squares means to the original scale, FEC were higher (P<0.01) for males (208±27) than females (122±10). Least-squares means for PCV decreased (P<0.001) from 28 (36.3±0.5%) to 35 days (33.7±0.5%), and were higher (P<0.01) for females (36.0±0.4%) than males (33.9±0.7%). Correlations (r) between repeated measurements of BW, FEC, PCV and FAMACHA scores at 28 and 35 days were all positive (P<0.001). The correlation between FAMACHA scores and PCV was negative at 28 (r=-0.14) and 35 days (r=-0.18) (P<0.001). This study revealed that BW was an easily measured predictor of the ability of the lamb to resist infection with GIN and maintain PCV, and confirmed that FAMACHA scores are useful indicators of differences in FEC. Approximately 40% of female and 30% of male lambs did not show detectable levels of infection (i.e. FEC=0) under field conditions. The great variability that was observed in FEC and PCV suggests potential to use Djallonké sheep in breeding programs to enhance resistance to GIN.

Assessing introgression of Sahelian zebu genes into native Bos taurus breeds in Burkina Faso.

A total of 350 samples were analyzed to estimate zebu gene proportions into two different taurine cattle breeds of Burkina Faso (Lobi and N'Dama) using 38 microsatellites and various statistical methodologies. West African and East African zebu samples were sequentially used as reference parental populations. Furthermore, N'Dama cattle from Congo, the composite South African Bonsmara cattle breed and a pool of European cattle were used successively as second parental populations. Independently of the methodology applied: (a) the use of West African zebu samples gave higher admixture coefficients than the East African zebu; (b) the higher zebu proportions were estimated when the European cattle was used as parental population 2; and (c) the use of the N'Dama population from Congo as parental population 2 gave the more consistent zebu proportion estimates for both the Lobi and the N'Dama breeds. In any case, the zebu admixture proportions estimated were not negligible and were always higher in the N'Dama cattle than in the Lobi cattle of Burkina Faso. This suggested that the introgression of Sahelian zebu genes into the taurine cattle of Southern West Africa can follow a complex pattern that can depend on local agro-ecological features. The current research pointed out that the estimation of admixture coefficients is highly dependent on both the assumptions underlying the methodologies applied and the selection of parental populations. Our analyses suggest that either too high or nil genetic identity between the parental and the expectedly derived populations must be avoided.