Performance of Borana and crossbred cows fed a basal diet of native grass hay supplemented with different protein source concentrate feeds

No Abstract. Animal Production Research Avancees Vol. 3 (3) 2007: pp. 174-18

Present status and future direction in feed resources and nutrition research targeted for wheat based crop-livestock production system in Ethiopia

Mixed crop-lvestock production system is the major agricultural production system in Ethiopia with a wide array of Development challenges and opportunities. One of the key challenge in improving the agricultural productivity of the system is feed scarcity and undernutrition. The major basal feed resources in wheat based farming systems are native pasture, crop residue and aftermath grazing. The contribution of each feed resource to the total feed varies from area to area based on cropping intensity. In the most intensively cultivated areas, crop residues and aftermath grazing account for about 60-70% of the basal diet suggesting wheat straw to be the dominant feed in wheat based farming system. The current scenario in feed availability in wheat based crop-livestock production systems suggest basal feed of less than 1.6 ton/TLU per annum. Local research efforts on nutritive value of wheat straw were limited to characterization work and few animal response studies. Potential to upgrade nutritive value of wheat straw either through treatments and or supplementation is elaborated using data generated in similar environments. The role of forage legumes in improving the feed resource base and farming system are highlighted and research findings in integration strategies reviewed. Future research directions focus on upgrading the nutritive value of wheat straw and the use of forage legumes in the farming system

Nutritional characteristics and strategies to enhance utilization of tropical feeds for low resource livestock producers

Livestock under holdings of low-resource producers in the tropics are faced with a variety of feeds that are qualitatively and quantitatively deficient in available nutrients. Emerging practices of hay-making and inter-cropping of cereal with legumes have improved feed quality, but the lack of appropriate post-harvest technologies have introduced further variation in quality. This review contends and shows that roughages can be put into groups within which members are more like one another than they are like members of other groups with respect to animal responses when these are fed with or without supplementation with forage legumes (FL). The review also acknowledges the deficiency of chemical properties alone in the identification and selection of potential forage supplements and suggests an integrated approach incorporating agronomic characteristics and biological indices of feed quality. Results from various Reports were integrated to identify indices that could be used to delineate forage legumes are good sources of rumen degradable N, but only a few (e.g., Desmodium intortum, Chamaecytisus palmensis and Leucaena leucocephala) are potential sources of escape protein. Because there is no clear reconciliation between Reports on important attributes of forage legumes, it was only possible in a few instances to synthesise Reports in the context of FL factors that influence responses. Despite the paucity of relevant data, the level of supplementation with FL that maximizes roughage intake is quite different from that which optimizes digestibility or productivity. The picture is made more complex by the possibility of interaction between supplementation and roughage quality on animal responses. This review attempts to identify hiatus in nutrition research which according to the authors would yield the most benefit

Interrelationships of chemical properties, in vitro digestibility and ruminal degradability characteristics of protein sources

Associations among chemical properties, in vitro digestibility and ruminal degradability characteristics of herbaceous legumes, browse species and oilseed cakes were studied using correlation analysis based on a total of 50 feedstuff samples. Chemical properties were poorly related to in vitro organic matter digestibility (IVOMD). In browse species only crude protein (CP) was strongly associated with IVOMD while in oilseed cakes, CP and fiber components were strongly related to IVOMD. Fractional rates of ruminal degradability of N were strongly related to NDF content of herbaceous legumes, hemicellulose to cellulose ratio in browse species and lignin content in oilseed cakes. Potential degradability of N was poorly related to chemical properties of herbaceous legumes and browse species but strongly related to CP and fiber components in oilseed cakes. Potential degradability of OM was poorly related to IVOMD of herbaceous legumes and browse species but strongly related in oilseed cakes. Fractional rate of organic matter disappearances accounted for more than 85 percent of the variation in IVOMD of browse but only up to 10 percent in herbaceous legumes and oilseed cakes. Hourly OM disappearances and IVOMD were poorly related to IVOMD in hrbaceous legumes but strongly related in the ranges of 24-48 hr in browse and 36-48 h in oilseed cakes. Chemical properties of protein sources were poorly related to biodegradability suggesting need for basic research to determine the fundamental properties of cell walls that constrain their intrinsic digestion rates and potential degradability

Evaluation of various mathematical models in describing ruminal degradability of protein sources

Five mathematical models were evaluated for their ability to describe ruminal degradability profiles of protein sources composed of herbaceous legumes, browse species and oilseed cakes. Degradability constants of dry matter, organic matter, nitrogen and neutral detergent fiber of the feeds were taken into account. Tests of regression coefficients, analysis of residual behavior and ocnsistencies in parameter estimates were adopted for model comparison and validation. The conventional exponential model was the best for all feed classes in describing DM, OM and N disappearance while the exponential decay model was the best in describing degradation profile of NDF for all feed classes