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AbstractThis manuscript aims to develop a new multivariate composite index for monitoring agricultural drought. To achieve this, the AVHRR, VIIRS, CHIRPS data series over a period of 40 years, rainfall and crop yield data as references were used. Variables include parameters for vegetative stress (SVCI, PV, SMN), water stress (PCI, RDI, NRDI), and heat stress (SMT, TCI, STCI), and a new variable related to environmental conditions was calculated through a normalized rainfall efficiency index. Then, random forest algorithm was used to determine the weights of each component of the model by considering interannual fluctuations in cereal yields as an impact variable. The multivariate composite model was compared to the VHI, NVSWI and SPI-12 indices for validation. The results show a large spatiotemporal concordance between the MDCI and the validation indices with a maximum correlation of 0.95 with the VHI and a highly significant p value (< 2.2e-16). Validation of the MDCI model by SPI-12 shows a significantly higher statistically significant relationship than that observed between SPI and VHI and NVSWI. P value range from 3.531e-05 to 6.137e-06 with correlations that vary between 0.6 and 0.64 depending on the station. It is also highly correlated with the Palmer drought severity index (PDSI) and climatic water deficit index (CWDI), with R = 0.85 and p value < 5.8e-10 and R = 0.72 and p value < 1.9e-6, respectively. Finally, the study provides a new direction for multivariate modeling of agricultural drought that should be further explored under various agroclimatic conditions.

Despite cross-breeding of Djallonke and Sahelian sheep due to the higher growth rate and final body weight of the Sahelian breeds over time, little scientific evidence exists on the ability of the crosses to withstand diseases compared to their Djallonke parents. A study involving 700 Djallonke and two crosses of the Djallonke and Sahelian breeds (50% Sahel × 50% Djallonke, 75% Sahel × 25% Djallonke) was conducted, and documented incidence of diseases, parasites and mortalities in these animals. Enteritis, Ehrlichia ruminantium and orf were more prevalent in 25% Djallonke than both 100% and 50% Djallonkes. Similarly, pneumonia was more prevalent in 50% Djallonkes, individuals of all age groups and females than all other genotypes, adults and males, respectively. Enteritis prevalence was also higher in lambs and males than animals of all age groups and females, respectively. Coccidiosis was more prevalent in individuals of all age groups and males, than lambs and females, respectively. More abscess and trauma cases were found in males than females. Higher levels of tapeworm and flea infestations were seen in lambs than weaners and adults. Conversely, more mange mite and tick infestations were seen in adults than weaners and lambs. Higher mortality rates were recorded in all other genotypes, lambs and females than in 100% Djallonke, all other age groups and males, respectively. Higher case fatality rate was recorded in haemoncosis than taeniasis cases. The Sahel x Djalloke crosses are more susceptible to infectious diseases and record higher mortality rates than the pure Djallonke genotypes. [ABSTRACT FROM AUTHOR]

Abstract Background The Djallonke sheep is well adapted to harsh environmental conditions, and is relatively resistant to Haemonchosis and resilient to animal trypanosomiasis. The larger Sahelian sheep, which cohabit the same region, is less well adapted to these disease challenges. Haemonchosis and Trypanosomiasis collectively cost the worldwide animal industry billions of dollars in production losses annually. Results Here, we separately sequenced and then pooled according to breed the genomes from five unrelated individuals from each of the Djallonke and Sahelian sheep breeds (sourced from Ghana), at greater than 22-fold combined coverage for each breed. A total of approximately 404 million (97%) and 343 million (97%) sequence reads from the Djallonke and Sahelian breeds respectively, were successfully mapped to the sheep reference genome Oar v3.1. We identified approximately 11.1 million and 10.9 million single nucleotide polymorphisms (SNPs) in the Djallonke and Sahelian breeds, with approximately 15 and 16% respectively of these not previously reported in sheep. Multiple regions of reduced heterozygosity were also found; 70 co-localised within genomic regions harbouring genes that mediate disease resistance, immune response and adaptation in sheep or cattle. Thirty- three of the regions of reduced heterozygosity co-localised with previously reported genes for resistance to haemonchosis and trypanosomiasis. Conclusions Our analyses suggest that these regions of reduced heterozygosity may be signatures of selection for these economically important diseases.

Mortality Determinants of Djallonke Kids and Crossbred between Djallonke and Sahelian Buck at Kolokope Station. Productivity of Djallonke goats is low despite their good prolificacy. This low productivity is due to the high mortality rate before weaning of the kids. Perinatal mortality is often related to the low birth weight of kids. Crosses between Djallonke goats and a Sahelian buck goat on one hand and between Djallonke goats and bucks of the same breed on the other hand were carried out during two campaigns at the National Goat Sheep Program station of Kolokopé. A mortality rate of 78.3± 14.6% was observed for pure Djallonke kids which were born with a weight less than 1 kg. During the two seasons, the mortality rate was higher but not significant for pure Djallonke (41.3 ± 7.1%) compared to the mortality of crossed ones (30.9 ± 8.1%). The factors sex, birth mode, breed and calving season did not affect the pre-weaning mortality of the kid's. Birth weight affected very significantly the kid's mortality. The crossbreeding between Djallonke goats and a Sahelian buck induced a reduction of mortality rate at weaning. This reduction was due to the improvement of the birth weight of crossbreds compared to the birth weight of the pure Djallonke. This method can therefore been considered as one of the ways to improve the survival of Djallonke kids at weaning.

Why are there no perissodactyls in sub-Saharan West Africa? There are no records of hipparions or zebras in that region and records of rhinoceroses are peripheral and sparse. Absence of records is not information of absence. More than a century of palaeontological and archaeozoological research has yielded thousands of skeletal specimens of late Tertiary or Quaternary mammals throughout most of Africa with equid and rhinocerotid specimens well represented from North, East and South Africa, but not saharan, sahelian or soudanian West Africa. This paper explores the evidence of this absence but offers no solution. [ABSTRACT FROM PUBLISHER]

Biomethanisation of an Euphorbiacea has been carried out in mesophilic condition (37°C) and in moderate thermophilic condition (48e'C) in batch digestors loaded at 5 % with dry matter. Three various preparation were studied. The fermentexibility of the plant is shown with productivites comparable to and even often higher than other biomasses. The best yield obtained in mesophilic condition with the ground plant 0.375 l/l/day) are only very slightly modified in moderate thermophilic condition (0.385 l/l/day). On the other hand with the coarse chopped plant, the yield is trebled with the temperature increase (0.238 l/l/day at 0.784 l/l/day).

A two by two factorial design including natural helminth infections (dewormed ‘D’ or not dewormed ‘ND’) and different levels of diet (basal ‘B’ or basal diet plus supplement ‘S’) was used to assess the effect of helminth infections and plane of nutrition on health and productivity of F1 (West African Dwarf (WAD) × Sahelian) crosses. The pasture composed the basal diet and supplemented animals received cottonseed and rice bran. Feed composition analysis revealed that the pasture did not provide sufficient nutrients for reproduction requirements. Feed supplementation had a significant effect on weight gain of does during pregnancy and lactation, and milk off-take was significantly higher in supplemented does compared to non-supplemented ones (31.3±2.5 l versus 17.7±2.5 l respectively, P<0.01). A peri-parturient rise in strongyle egg output was noted, and diet supplementation tended to reduce faecal egg count and to increase packed cell volume (PCV), mainly during the dry season.Deworming had a significant effect on red blood cell (RBC) count, PCV and haemoglobin (Hb) concentration, mainly during the period of peak strongyle egg output (season × deworming: P<0.001 for RBC and PCV and P<0.05 for Hb). Helminth infections combined with a basal diet seriously affected weight gain but the interaction of deworming and diet was not significant. In groups receiving the basal diet, dewormed animals had a significantly higher milk yield than those that were not dewormed (23.5±3.3 l versus 12.0±3.7 l, respectively; interaction diet × deworming: P<0.05). The higher daily weight gains of offspring born from dewormed does might be explained by the fact that, in addition to the effect of deworming on milk yield in animals receiving basal diet, the kids were less exposed to helminth eggs, whereas does that were not dewormed constituted a greater source of helminth infection for their kids. [Copyright &y& Elsevier]

Forty pure West African Dwarf (WAD) goats and 35 of its F1 crosses with the Sahelian breed were used in a multifactorial experimental design to evaluate the effects of an experimental Trypanosoma congolense infection and interactions with natural helminth infections and different levels of diet on health and productivity of these two breeds. Trypanosome infection caused a severe drop in packed cell volume (PCV), but this was not significantly affected by breed. Neither deworming nor diet had any effect on the course of anaemia after trypanosome infection. The mean score of parasitaemia tended to be higher in crossbreeds than in WAD goats although this was not significant (P>0.05). Similarly, the antibody response to trypanosome infection was not significantly different between breeds. Parasitaemia level was significantly influenced by the level of diet with the group under high supplementation having a higher mean parasitaemia score than the group under low supplementation. Weight loss due to trypanosome infection tended to be greater in crossbreeds than in WAD goats (P>0.05).During this study, there was no difference in mean helminth egg output between crossbred and WAD goats. However, between weeks 4 and 10 after trypanosome infection (corresponding to a period of heavy rainfall and highly infective pastures), the mean egg output was higher in the crossbreeds.The immunosuppressive effect of trypanosome infections was revealed by a lower antibody response to Haemonchus contortus in infected animals compared to the uninfected controls. Trypanosome infection tended to increase strongyle egg output. This study did no reveal any superior trypanotolerance of WAD goats compared to crossbreeds. [Copyright &y& Elsevier]

Four Acacia species were tested for their susceptibility to the root-knot nematode, Meloidogyne javanica, commonly found in sahelian areas. Faidherbia albida and Acacia senegal were resistant to this nematode. On the contrary, A. raddiana, A. nilotica and A. mangium were susceptible. Among these three species, the growth of A. nilotica and A.mangium was inhibited by M. javanica but A. raddiana was tolerant. The rhizobial symbiosis with F. albida and A. senegal was stimulated by the nematode. The population build-up of the root-knot nematode induced by tree species in agroforestry systems is discussed. [ABSTRACT FROM AUTHOR]