Tropical forage technologies can deliver multiple benefits in Sub-Saharan Africa. A meta-analysis

Abstract

Scarcity of quantity and quality feed has been a key constraint to productivity of smallholder crop-livestock systems. Tropical forages include a variety of annual and perennial grasses, herbaceous and dual-purpose legumes, and multipurpose trees and shrubs. They have been promoted in Sub-Saharan Africa (SSA) for increasing livestock productivity and household income through higher quantity and quality of herbage, while contributing to soil improvement and higher food crop yields. For the first time, we quantitatively reviewed 72 experimental studies from across SSA to take stock of geographical distribution and forage technology focus of past research; quantify magnitudes of multidimensional impacts of forage technologies; and present variability in forage agronomy data. Improved forage technologies were classified into four groups: (i) germplasm, (ii) management, (iii) cropping system integration, and (iv) feeding regime. Mean weighted response ratios were calculated from 780 pairs of observations for 13 indicators across the five impact dimensions. Improved forage germplasm had on average 2.6 times higher herbage productivity than local controls, with strongest effect in grasses. Feeding regimes with improved leguminous forages increased milk yield by on average 39%, dry matter intake by 25%, and manure production by 24%. When forage technologies were integrated with food crops, soil loss was almost halved, soil organic carbon increased on average by 10%, and grain and stover yields by 60% and 33%, respectively. This study demonstrates the central role improved forages could play in sustainable intensification of crop-livestock systems in SSA. It highlights the need for multidisciplinary and systems-level approaches and studies to quantify synergies and tradeoffs between impact dimensions. Further research is needed to explain forage agronomic yield variability, unraveling interactions between genotype, on-farm environmental conditions, and management factors. Results from this review can inform development programs, prioritizing technologies proven successful for dissemination and indicating magnitudes of expected impacts.

Genomic Selection in Tropical Forage Grasses: Current Status and Future Applications

“…In a study conducted in sub-Saharan Africa, legume, and grass cultivars released for different animal production systems increased forage production by 2.65 times when compared to that of traditional cultivars. Production was even higher when only forage grass was used (Paul et al, 2020). Until recently, germplasm introduction was the key method used for forage grass breeding, which involved the evaluation and selection of germplasm accessions as a strategy to obtain cultivars.…”

Prosopis Species—An Invasive Species and a Potential Source of Browse for Livestock in Semi-Arid Areas of South Africa

“…The shortage of sufficient and high-grade forage is a key restriction in tropical livestock production [65]. As indicated, in several parts of the tropics, the utilisation of browse species as feed for ruminants is growing, especially when the amount and value of pastures are poor for a long time [66][67][68][69].…”

Insights into the genetic architecture of complex traits in Napier grass (Cenchrus purpureus) and QTL regions governing forage biomass yield, water use efficiency and feed quality traits

“…Improving livestock feeds and forages will play a key role in global food and nutrition security and have the potential to contribute to the strategy of achieving climate-smart agriculture, restoring degraded lands and decreasing greenhouse gas emission intensities (Paul et al, 2020; Belay 2019; Bryan et al, 2013; Peters et al, 2013). The availability of adequate, high-quality feeds and forages has been a major challenge faced by the livestock sector, especially during the dry season when pasture and crop residues are scarce (Maleko et al, 2018; Mtengeti et al, 2008).…”