Opportunities and limitations of food - feed crops for livestock feeding and implications for livestock - water productivity

Abstract

The paper discusses the contribution of crop residues (CR) to feed resources in the context of the water productivity of CR in livestock feeding, using India as an example. It is argued that crop residues are already the single most important feed resource in many livestock production systems in developing countries and that increasing their contribution to livestock feeding needs to be linked to improving their fodder quality. Using examples from multi-dimensional crop improvement, it is shown that CR fodder quality of key crops such as sorghum, rice and groundnut can be improved by genetic enhancement without detriment to grain and pod yields. Improving crop residue quality through genetic enhancement, agronomic and management interventions and strategic supplementation could improve water productivity of farms and systems considerably. The draw-backs of CR based feeding regimes are also pointed out, namely that they result in only moderate levels of livestock productivity and produce higher greenhouse gas emissions than are observed under feeding regimes that are based on high quality forages and concentrates. It is argued that feed metabolisable energy (ME) content should be used as an important determinant of livestock productivity; water requirement for feed and fodder production should be related to a unit of feed ME rather than feed bulk. The paper also revisits data from the International Water Management Institute (IWMI) work on livestock–water productivity in the Indian state of Gujarat, showing that water input per unit ME can vary several-fold in the same feed depending on where the feed is produced. Thus, the production of one mega joule of ME from alfalfa required 12.9 L of irrigation-derived water in south Gujarat but 50.7 L of irrigation-derived water in north Gujarat. Wheat straw in south Gujarat required 20.9 L of irrigation-derived water for 1 MJ ME and was in this instance less water use efficient than alfalfa. We conclude that water use efficiency across feed and fodder classes (for example crop residue v. planted forages) and within a feed is highly variable. Feeding recommendations should be made according to specific water use requirement per unit ME in a defined production system.

Vegetation Changes in the Miombo Woodlands in Northwestern Zimbabwe: A Case Study of Nkayi District 1990 to 2017

“…They are also home to a diverse range of wildlife that includes antelopes, giraffes, rhinos, lions, and some of the largest populations of elephants in Africa [5]. However, over the years, these ecosystems have experienced vast changes in their physical nature, which affect the roles they play as a result of land degradation caused by humans who clear land for cultivation [3]. Land degradation manifests itself in many forms, and the common way is through the transformation of the land from its natural state into man-made land use forms, e.g.…”

“…Land use change is often the first consequence of population and economic growth, and it can be argued that low soil fertility, lack of infrastructure, and the presence of diseases have been the main factors preserving miombo [3,7,19]. However, due to increased demand for land for cultivation, a new dimension was created leading to massive land cover changes and degradation.…”

Extractable soil nutrient effects on feed quality traits of crop residues in the semiarid rainfed mixed crop–livestock farming systems of Southern India

“…soil nutrient and associated crop yield) on livestock are manifold: (1) low feed availability because of low biomass productivity; (2) low feed quality associated with multi-nutrient deficiencies (Gowda et al 2004). Blümmel et al (2009b) also suggested that as a compensation for low feed quality, livestock's total dry matter demand can be higher, and this puts additional pressure on the already feed-deficit farming systems and thus hampers efforts made by the international and local communities to take advantage of the development opportunity offered by the global 'livestock revolution' [e.g. increasing demand for livestock products (Steinfeld et al 2006)].…”

Identifying Investment Opportunities for Ruminant Livestock Feeding in Developing Countries

“…The screening of a wide range of cultivars of rice, wheat, maize, sorghum, pearl millet, cowpea, groundnut, pigeon pea and chickpea has shown that differences of 3-5% units in digestibility can be exploited without detriment to grain yield (Blümmel et al, 2009c). Conventional and molecular breeding techniques for improving the food and feed traits simultaneously are more expensive but have higher impact potential because full genetic crop variability can be explored and utilized .…”