Not all countries in the world have an ample supply of corn available to include in their poultry diets. The quest for alternatives is often driven by crops that are locally available. That led to research into sorghum and now into teff grain.
Teff grain is a grass-like crop with very small size of grain, 150 kernels make up the weight of a single wheat kernel. The University of Missouri as a host to a USDA Cochran Fellowship Program, trained six participants from Ghana involving poultry feeds and feed formulation, looking into the possibilities of including teff. The training discussions revealed situations where Ghanaian corn shortages existed and, therefore, options for partial substitution of corn with other cereal feed grains and feed fat energy sources were considered.
While there are some data available regarding teff as a human food source, there is little information available for teff as an animal feedstuff, particularly for monogastric animals such as chickens. Therefore, commercially available teff grain was purchased for use in the trial and it underwent proximate composition and amino acid analyses. The details of the study, results of the analyses and the performance of male broiler chicks fed experimental diets for 21 days are described below.
To test the effect of teff in the diet of broiler chicks in comparison to the traditional corn soy feed, the broiler chicks were divided into either the basal corn-soy diet or diets containing at least 10% teff. The four diet groups included:
At week 1, there were no significant treatment differences for body weight or feed consumption values. Only feed conversions differed significantly with the 10% whole teff and teff as ingredient treatment chicks having feed conversions significantly higher than those of control corn soy. Both treatments had numerically higher feed consumption numbers. However, reasons for these results were unclear at week 1.
At week 2, chicks receiving the teff as ingredient diet had significantly heavier body weights than all other treatments. Additionally, chicks receiving the 10% whole teff and the teff as ingredient diets both had significantly higher feed consumptions than either the control corn soy or the 10% ground teff chicks. Feed conversion results were similar to those observed at week 1 in that the 10% whole teff and the teff as ingredient fed chicks had significantly poorer conversions than control corn soy fed chicks. It was observed that some chicks receiving the 10% ground teff treatment had incidences of fine, flour-like feed adhering to their beaks.
At week 3, results revealed significant treatment differences for body weight, feed consumption and feed conversion. Body weights were significantly heavier for chicks fed the teff as ingredient diet than those in all other treatments. As compared to the 10% ground teff treatment, chicks receiving the 10% whole teff diet were also significantly heavier. Relative to feed consumption, both the 10% whole teff and teff as ingredient chicks consumed significantly more feed than either the control corn soy chicks or those receiving the 10% ground teff treatment. The teff as ingredient chicks also consumed significantly more feed than those fed the 10% whole teff diet. Feed conversion data at week 3 consistently showed that, under these conditions, heavier chicks consumed more feed and were significantly less efficient than those on the control corn soy and 10% ground teff diets. Feed conversion data suggest an over-consumption of feed by all chicks at week 3, perhaps because all diets were low in metabolisable energy.
Feed palatability may have influenced these results. The reduced body weight of chicks receiving the 10% ground teff diet compared to other teff-fed chicks suggests a feed palatability problem. This may have been caused by the partial grinding of teff grain and the flour-like adherence of feed on the beaks of chicks on that treatment. On the other hand, the higher feed consumption and heavier body weights of chicks fed the teff as ingredient diet, with added fat, suggests superior palatability of that feed and an improved energy utilisation of this diet.
The digestibility of whole teff may have also influenced these results. At the termination of the study it was observed that an amount of whole teff grain was found in the faeces of chicks in teff-fed treatments. This suggested some undigested teff grain could be passing through the chicks. While this was not measured, it reinforced a concern that young chicks may not be able to digest all of the whole teff and could be another cause of increased feed consumption of chicks on whole teff treatments. Nonetheless, partial grinding of the teff in the 10% ground teff treatment did not apparently improve teff digestibility or utilisation under these conditions. Any improvement in digestibility of partially ground teff in this study may have been offset by reduced palatability.
Overall, the 3 week data show that all diets containing teff were at least comparable, in bird performance, to the control corn soy diet, under these conditions (at the 10% substitution level). All 3-week feed conversion data were considered high for this battery study. This observation and the fact that heavier chicks were significantly less efficient than lighter weight control corn soy chicks suggest that all diets were low in energy. On the other hand, these low energy diets might be typical of corn-soy diets found in Ghana where economical feed fat sources may not always be present. These overall results do suggest that when corn supply is inadequate, at least a short-term substitution of a small amount (10%) of corn with another cereal grain could be considered for broilers up to 3 weeks of age. Additional study to test the repeatability of these results is warranted.