Alain Xandé

Sources of variation in nutritive values of tropical forages from the Caribbean

The chemical composition, in vitro digestibility with rumen liquor and agricultural factors (age of regrowth, season, level of fertilization) of 1313 tropical forages from various islands of the Caribbean and of La Re´union were recorded in a database. The nutritive values were expressed in the French unit system, i.e. digestible energy, metabolizable energy, net energy for lactation, net energy for maintenance and growth, protein digestible in the small intestine supplied by rumen-undegraded dietary protein (PDIA), protein digestible in the small intestine supplied by microbial protein from rumen-fermented organic matter (PDIME), protein digestible in the small intestine supplied by microbial protein from rumen-degraded dietary protein (PDIMN), and voluntary dry matter (DM) intake by sheep (VDMIs), dairy cows or growing cattle. Digestibility of DM and OM and voluntary DM intake were determined with regression equations fitted to tropical data previously reported. The age of regrowth and the type of forage were the main sources of variation, whereas the country, season and level of nitrogen fertilization had no important effect on energy or protein values. Mean nutritive values are given for each type of forage and age of regrowth after correction for the level of nitrogen fertilization, season and country.

The ability of faecal nitrogen to predict digestibility for goats and sheep fed with tropical herbage

Faecal indices were evaluated to assess organic matter digestibility (OMD) for small ruminants fed with Digitaria decumbens. A continuous digestibility trial was conducted with five Creole bucks and five Black-belly rams, fed with fresh cut Digitaria decumbens from 15 to 70 days of re-growth. The amount of herbage offered, the refusals and the faeces were weighed daily for each animal during 55 days. Herbage and faeces samples were kept to determine dry and organic matter (DM and OM), crude protein (CP), neutral and acid detergent fibre (NDF and ADF) and lignin contents (ADL). OMD was calculated per week and per animal. Predictive regressions of OMD were calculated for each species, from all the faecal components measured (CPf, NDFf, ADFf and ADLf), using linear or curvilinear models. Regressions from CPf had the lowest residual standard error (<0.028) when calculated for each species, compared with regressions from the other faecal components. Among the regressions from CPf, the lowest standard error of the predictive parameters was obtained with a model in the form of a-b/CPf, for each species. The latter allows prediction of OMD at pasture, consistent with theoretical energy requirement for both goats and ewes grazing a Digitaria decumbens based sward.

Comparison of fresh and dried Digitaria decumbens grass intake and digestion by Black-belly rams

The intake and digestion of fresh and dried Digitaria decumbens grass by rams was compared using a 2 x 2 factorial design. The experiment took place in Guadeloupe (French West Indies) in 1996. Eight rams (mean liveweight: 45.7 ± 3.1 kg) were maintained in metabolism cages. Digitaria decumbens grass was cut daily and distributed to four of them, the other four were fed the following day with the equivalent forage which had meanwhile been dried for 20 h at 60 °C. Chemical composition (g/kg of dry matter (DM)) of the two diets based on neutral detergent fibre (NDF, 713, S.E. 18), acid detergent fibre (ADF, 361, S.E. 13) and crude protein (CP, 90, S.E. 4) was similar. The DM intake (61.0 and 53.2 g/W 0.75 , S.E. 2.0, P < 0.05), the NDF (0.753 and 0.727, S.E. 0.004, P < 0.011) and CP (0.588 and 0.544, S.E. 0.014, P < 0.09) total tract digestibility of fresh and dried herbage were different. Nylon bag estimates of effective DM degradability and fractional degradation rates (per h) in the rumen were 0.436, 0.414 (S.E. 0.005, P < 0.004) and 0.048, 0.038 (S.E. 0.002, P < 0.02) for fresh and dried grass, respectively. Rumen digestibility of organic matter and NDF were 0.516, 0.541 (S.E. 0.021) and 0.763, 0.692 (S.E. 0.019), respectively. The rumen turnover rates of particles (per h) were 0.024 and 0.015 (S.E. 0.001, P < 0.05) for fresh and dried forage respectively. The efficiency of microbial protein synthesis (g microbial nitrogen/kg organic matter apparently degraded in the rumen) was similar with the two diets: 33.5 and 33.0 (S.E. 3.3, P < 0.9) for fresh and dried forage respectively. In conclusion, fresh Digitaria decumbens was nutritionally superior to dried. This is probably due to a faster degradation rate and a lower rumen retention time of the fresh forage.

Preweaning Productivity of Suckling Goats and Sheep in Guadeloupe (FWI) under Intensive Reproductive Rate and Grazing Management

In Guadeloupe, small ruminants are reared for meat production under pasture conditions. Intensive rotative grazing systems (irrigated, fertilized and high-stocked tropical pastures) allow satisfactory levels of production but generate high post-grazing residues. Experiments were designed to control these. A system in which residuals were mown (RM) was tested in comparison to the control system (residuals remained, RR). The same design was carried out over two years with Creole goats and Martinik sheep. An accelerated reproductive rate (3 parturitions over 2 years) was carried out. Systems were compared at three parturition seasons per year (dry, intermediate and rainy seasons). Each group was composed of 20 goats (36.0±2.5 kg) or 20 ewes (46.8±2.4 kg). The systems exhibited high levels of productivity in both species compared to other results in the tropics: more than 50 and 30 offspring born alive per hectare and per reproductive season for the goat and ewe flocks, respectively. The annual production at birth was 110 kg kids/ha per year and 133 kg lambs/ha per year (i.e. 21% more). Corresponding values at weaning were 630 kg kids/ha per year and 785 kg lambs/ha per year (i.e. 25% more). The RM system produced 10% more than the RR system in Creole goats, while it produced 35% more in Martinik sheep. Seasonal effects and other factors of variation are discussed.

Animal and quality of life in traditional society in the Caribbean islands

Abstract The present topic is an analysis of the traditional society of Guadeloupe, French West Indies. The author deals with the birth of that society and its current trends; he recounts the circumstances under which the domestic animal was to be a real contribution to the daily life of the farmer. The horse is the symbol of conquest, nobility, power, and swiftness which positive qualities were also believed to be found in the overseer and master. Important as the horse’s role may have been, it was played along with other animals, in particular the cattle, the donkey, the mule, the goat, the sheep and several poultry species. As a whole, that kind of farming practice was labour-saving, made transport easier for the farmer, provided more food and filled a gap in finances; moreover, domestic animals were used to take part in entertainment. On the larger sugar cane farms, where cattle became strategically less important as a consequence of motor transport, the big farmers moved to the production of milk and meat. The growing local demand in food came to be supplied by this change. As for the average citizen who had recently had access to land ownership, he kept on dealing with that kind of domestic animal farming as a sustainable means of work. Cattle became integrated into his daily life. They were used in all the major events of his family life. Consequently, their market value increased, leading to a type of capitalisation. As a result of the farming of the Creole cattle, pig, goat and sheep, tradition was maintained alive, and the farmer’s life level was improved. Recently, some farmers developed official pastoral tourist events based on the skills and gifts of those animals. This recent attempt implies that there is an urgent need to set up a new research programme, in order to better identify, define and improve that heritage.