Production a double objectif d’Andropogon gayanus Kunth, en culture pluviale dans le plateau central du Burkina Faso

L’influence du rythme d’exploitation sur la production à double finalité a été étudiée chez la graminée pérenne locale Andropogon gayanus, dans le plateau central du Burkina Faso. La culture de l’espèce a consisté en la mise en place, par repiquage, d’éclats de souches, suivie de l’exploitation, durant deux années. Les résultats montrent que la coupe de la plante à 40 jours de repousse permet d’obtenir la production fourragère la plus importante, soit 3434 kg de MS/ha, en première année, et 3500 kg de MS/ha, en deuxième année d’exploitation, avec un rendement en pailles, en fin de cycle, respectivement, de 1337 et 1351 kg de MS/ha. La production de fourrage la plus faible est observée avec la coupe de la plante à 30 jours de repousse, suivie de la récolte de la paille en fin de cycle (1107 kg de MS/ha en première année, et 1095 kg de MS/ha en deuxième année. Quant à la production de pailles, l’exploitation en fin de cycle de la plante est le rythme le mieux indiqué pour une production maximale de paille. La coupe de la plante à 40 jours de repousse (pour la production de fourrage), suivie d’une deuxième en fin de cycle (pour la fourniture de paille) se révèle donc être le meilleur rythme d’exploitation, permettant d’obtenir la production optimale, à double finalité, de l’espèce Andropogon gayanus, dans les conditions climatiques nord-soudaniennes. La conservation du fourrage produit et son utilisation, surtout pendant la période de soudure, de même que la confection des seccos à partir des pailles, contribuent à améliorer les revenus des agrospasteurs de la zone.Mots-clés : Andropogon gayanus Kunth, agropasteur, rythme de coupe, fourrage, pailles Burkina Faso.DUAL PROPOSE PRODUCTION OF Andropogon gayanus KUNTH UNDER PLUVIAL CULTIVATION IN THE CENTRAL PLATEAU OF BURKINA FASOThe influence of the rhythm of exploitation on the production of fodder and stem of a local perennial grass Andropogon gayanus Kunth was studied in the Central Plateau of Burkina Faso. The setting up of the species has consisted of planting out of split stumps the first year, followed by exploitation during two years. The results show that cutting the plant at 40 days after regrowth give higher fodder, 3434 kg/ha DM the first year and 3500 kg/ha DM the second year. The corresponding value for stem at the end of growing cycle were respectively 1337 and 1351 kg/ha of DM. The lowest fodder production is obtained with cutting the plants 30 days after planting (1107 and 1095 kg/ha DM the first and second year respectively). For the maximum production of straw, the plants should be exploited only at the end of the development cycle. The cutting of the plants at 40 days after planting is them the best rhythm of exploitation allowing optimal production of the species in terms of fodder and stem in the climatic condition of north Sudan. The conservation of fodder produced and its utilization during harsh period, as well as the making of straw mat «secco» contributed to improve the incomes of agropastoral farmers in the area.Keywords : Andropogon gayanus Kunth, agropastoral people, rhythm of exploitation, forage, stems, Burkina Faso

Chèvre Sahélienne burkinabée; Avortement; Complément alimentaire; Reproduction; Variation saisonnière; Burkina Faso

The aim of this study was to assess over two periods (dry season and wet season) the effect of a mineral supplementation covering the needs in phosphorus, iodine, copper, zinc and manganese, in association with nitrogen supplementation, on the abortion rate and other reproduction parameters of 66 Burkinabe Sahelian does. The four diet treatments applied were: natural grazing (nG) only; nG + mineral supplementation; nG + nitrogen supplementation; and nG + mineral and nitrogen supplementation. The dry season results showed a significant effect of the mineral and/or nitrogen supplementation on the reduction of abortion incidence. The treatment which combined both mineral and nitrogen supplementation was the most efficient because no abortion was observed in the animals that benefited from it. Among the does that aborted during the dry season, primiparous does were the most affected (50% of abortion cases). No abortion was observed during the rainy season, thus indicating the uselessness to give pregnant does mineral and nitrogen supplementation during that season, when grazing resources are plentiful and of quality. During that season goat fecundity increased by over 12.3 points (in percentages), compared to that recorded during the dry season. Whatever the season, supplementation also improved other reproduction parameters such as the fertility rate, parturition rate, fecundity rate, and kids’ weight at birth

Dairy and Weight Performances of Burkinabe Sahelian Goats Fed a Diet Supplemented with Local Feed Resources

In dairy production, in addition to the indispensable contribution of nitrogenous and energetic nutrients, it is essential that animal needs in some minerals be covered. To investigate this proposition, 32 Burkinabe Sahelian does in third lactation, aged 4 to 4 and half years, were divided into four groups in order to evaluate the effect of four isonitrogenous supplementation diets, formulated by using local millet bran and cowpea hay, and differing from one another by the values of the ratios (i) digestible crude proteins/feed unit (122, 122, 133 and 153 for groups 1, 2, 3 and 4, respectively) and (ii) concentrate/fodder (1.27, 1.27, 0.5 and 0 for groups 1, 2, 3 and 4, respectively). Group 1, compared to group 2, received in addition to an isonitrogenous supplementation, ad libitum mineral supplementation. Milk yields, and weight performances of does and their kids were monitored for 13 to 14 weeks. The larger addition of concentrate (local bran) did not significantly affect goat milk production. However, it was noted that the concentrate globally helped increase by 11% total daily production (milk collected + milk consumed by the kids). It increased by over 40% when the quantity of milk collected was considered. The milk yields of goats that received mineral supplements (group 1) were significantly (p < 0.05) higher, with on average 358 ± 62 g vs 267 ± 70, 215 ± 32 and 197 ± 76 g per animal and per day of collected milk for groups 2, 3 and 4, respectively. The milk composition in dry matter, fat, proteins and minerals was not significantly affected in the supplemented diets. However, the milk collected from groups 2, 3 and 4 had relatively higher fat and protein contents. The milk from group 1 was significantly more concentrated in lactose: 4.35% vs 3.9, 3.8 and 3.6% for groups 2, 3 and 4, respectively. Does’ daily weight gains (DWGs) were + 7.6 ± 15.9, – 18.3 ± 3.3, – 26.3 ± 31.1 and – 23.7 ± 16.2 g for groups 1, 2, 3 and 4, respectively. Kids’ DWGs were 50.7 ± 17.3, 46.5 ± 22.5, 39.1 ± 16.6 and 36.8 ± 14.2 g for those belonging to groups 1, 2, 3 and 4, respectively. The estimated consumption index values were 11.1 ± 3.9, 11.6 ± 1.7, 13.2 ± 2.0 and 13.9 ± 2.2 for kids in groups 1, 2, 3 and 4, respectively. This study showed that with the correct combination of local feed resources, it is possible to improve markedly the milk production of Sahelian goats, and to improve it significantly when it is associated with mineral supplementation