Enteric methane emissions from zebu cattle are influenced by seasonal variations in rangeland fodder quality and intake.

Rangeland fodder resources used to feed ruminants in the Sahel decline considerably in both quantity and quality from the wet to dry seasons. While it is widely assumed worldwide that this seasonality of fodder supply impacts intake levels and therefore enteric methane (eCH4) emissions, there are very few references based on in vivo measurements of eCH4 in this region. The purpose of this study was to test the assumption that the seasonality of fodder supply impacts intake levels and consequently eCH4 in ruminants. Thus, eCH4 was measured in vivo in Sudanese Fulani zebu cattle during three main seasons of the year (wet season: WS, cold dry season: CDS, and hot dry season: HDS). The experiment was carried out on 10 steers aged 32 months with an average (± SD) initial BW of 138 ± 5.8 kg (i.e. 0.55 Tropical Livestock Unit - TLU) and kept in individual pens. Animals were fed with natural rangeland fodder harvested each season following herders' practices, i.e. green fodder in the WS and dry fodder hay in the CDS and HDS. Different levels of fodder were offered to the animals to reproduce the gradient of fodder availability on rangelands over the year (six trials): 3.3% BW during the CDS; 3.3, 2.3, and 1.4% BW successively during the HDS; and 2.3% in two sequential studies in the WS. Each trial lasted 3 weeks, split into 2 weeks of fodder adaptation and 1 week of data collection. The BW, quantity of voluntary DM intake, digestibility of DM digestibility and of OM digestibility, and eCH4 (GreenFeed® system) were measured for each animal. Fodder composition varied considerably between seasons (P < 0.05). The DM intake (g/kg BW per day) varied from 23.9 in CDS to 15.7 in HDS and 22.3 in WS (P < 0.001). The DM digestibility varied from 0.50 in CDS to 0.46 in HDS and 0.57 in WS. The eCH4 yields (g/kg DM intake per day) varied significantly from 25.2 in the CDS to 31.8 in the HDS and 20.5 in the WS. When extrapolated over a full year and irrespective of season, eCH4 emissions for steers amounted to 68.1 g/d (24.6 g/kg DM intake per day, 46.7 ± 3.34 kg of eCH4/TLU per year). Variations in the various parameters recorded in different areas and during the main seasons must therefore be accounted for in national inventories to refine eCH4 data for ruminants in Sub-Saharan Africa.

Dynamics of changes in the breed composition of pastoral and agro-pastoral cattle herds in Benin: implications for the sustainable use of indigenous breeds.

Data for concretely analyzing current trends regarding breed composition of cattle herds at the national scale and the logic behind it are lacking in Benin. This study aimed to investigate the factors affecting the dynamics of breed composition in traditional Beninese cattle herds. In this regard, the main reasons for acquiring new breeds by herders and management strategies for animal genetic diversity in herds were targeted. Using a semi-structured questionnaire, a total of 753 cattle herds were surveyed in six pastoral communities along a north-south transect in Benin. Data collection included original breed composition of the herds (at their installation), cattle breeds introduced in the last five years, reasons for introducing new breeds, herders' breed preferences, and perceptions concerning productive and adaptive traits of the existing breeds in the study area. Descriptive analyses of herd composition revealed breed redistribution across the country with the increasing introduction of zebu in the southern region of the country. A high percentage of nondescript crossbreeds was associated with herders' willingness to improve both milk and meat production. In this regard, the analysis of herders' perceptions using the Friedman test ranked most zebu cattle breeds as the most productive. In contrast, the taurine breeds were highly ranked by herders for their adaptive features. This study confirms that herders' breed choices fit their production objectives. In addition, strategies for effectively and efficiently managing genetic diversity within herds are expected to increase animal productivity while conserving adaptive and special traits in local breeds. The effectiveness of herders' knowledge of local cattle breeds as well as their experience may increase the success of such strategies and facilitate their adoption.

The role of cross-border transhumance in influencing resident herders' cattle husbandry practices and use of genetic resources.

For centuries, the humid West African coastal country of Benin attracts cattle herders from neighboring Sahelian countries such as Niger, Burkina Faso and Nigeria. Each year, several thousands of cattle are trekked over hundreds of kilometers to Benin following established and non-established transhumance corridors. This cross-border mobility has been shown to play an important role in ensuring the productivity of the transhumant herds through adequate late dry season access to pastoral resources. Yet, its effects on the traditional agro-pastoral production systems that are encountered along the routes in Benin have never been explicitly investigated. Therefore, we collected socio-economic household data, herd characteristics and management data from 104 resident herders and 38 transhumant herders in 2 vegetation zones of Benin. To determine whether or not the proximity to transhumance corridors affects sedentary production systems, characteristics of cattle herds and farmers' management practices were compared between villages close to (within a 25 km buffer) and far from (outside a 25 km buffer) transhumance corridors within and between vegetation zones using non-parametric statistical tests. Existing relationships between resident and transhumant herders were also identified and characterized. Subsequently, herd characteristics and management practices were compared between resident herders having relationships with transhumant herders and those without. Herd sizes of resident herders living close to transhumance corridors were larger (P < 0.01) than those of their counterparts living far away. Also, proximity to transhumance corridors had positive effects on herd management practices. The relationships between resident and transhumant herders were governed by a variety of interests including encampment/manuring contracts, exploitation of grazing lands and watering points, trading and bartering of cattle. This exchange of cattle is an important driver of change in the breed composition of local herds and represents an opportunity for resident herders to enhance their herds' productivity through crossbreeding. However, the mere replacement or indiscriminate crossbreeding of local cattle breeds with those kept by transhumant herders threatens the sustainability of the traditional resident herding systems by increasing the risk of genetic erosion and loss of valuable adaptive traits in indigenous animal genetic resources.

Smallholders' perceptions of goat farming in southern Benin and opportunities for improvement.

To be successful, initiatives to improve smallholder's goat production should directly address the needs and objectives of the keepers while promoting rational use of local genetic resources. This paper identifies the objectives, constraints and needs of goat farmers in southern Benin and discusses their relevance to the development of improvement programmes. Between November and December 2005, structured questionnaires, focus group discussions and participant observation were used to collect information from 38 goat farmers in two selected locations. Goats were kept mainly for sale whenever cash was needed. Traits related to reproduction, to behaviour, to health and to meat production were considered equally important and were ranked very highly by goat keepers. Increased net income per flock through increased number of marketable animals is the derived breeding objective from the trait analysis. Disease outbreaks resulting in high mortality, poor housing, and feed shortages were, in descending order, the most important problems. It was concluded that the development of initiatives to improve management practices is an overriding priority. It will lead to increases in productivity in the short term and foster farmers' participation in the development of long-term improvement strategies, which should include selection and controlled mating.