The nutritional profile of pigeon pea is interesting for poultry, with values close to field pea. Antinutritional factors are present but in a lesser quantity than for other legume seeds, leading to higher nutritive value (Nwokolo et al., 1985; Ologhobo, 1992). For example, the toxicity assessed by the effect of pigeon pea on organ weights or blood parameters is generally low (Ologhobo, 1992). However a high variability in nutritional value is reported in literature, with sometimes low digestibility values (Chrysostome et al., 1998; Nwokolo, 1987; Yamazaki et al., 1988). This can be due to:
Variation in composition and antinutritional factors. For example, white-seeded varieties are sometimes claimed to have a higher nutritional value than dark ones (Odeny, 2007) even if experiments have sometimes failed to confirm this (Nwokolo et al., 1985).
Diet formulation. In some cases the level of amino acids (particularly methionine) is deficient in experimental diets, which can lead to mis-interpretation of results (Babiker et al., 2006)
Technological treatments. Thermal treatments seem to have a positive effect on protein digestibility and energy value (Chrysostome et al., 1998; Onu et al., 2006).
Although the results are not always consistent between experiments, it is generally observed that pigeon pea lowers performance (Oso et al., 2012; Onu et al., 2006). High inclusion rates above 20% degrade performance (Amaefule et al., 2011; Ani et al., 2011; Etuk et al., 2003) but degradation also occurs at rates as low as 5 to 10% (Babiker et al., 2006; Saeed et al., 2007; Oso et al., 2012). The effect seems to be higher in starters than in finisher broilers (Igene et al., 2012; Ani et al., 2011). Feed intake is often unaffected or even increased, which suggests that pigeon pea does not induce palatability problems (Tangtaweewipat et al., 1989). However, in this case feed efficiency is degraded. In some cases, growth performance was maintained with 10 to 20% raw pigeon pea (Ologhobo, 1992; de Oliveira et al., 2000; Tangtaweewipat et al., 1989; Iorgyer et al., 2009).
Many trials tried to improve performance with technological treatments such as thermal treatments (roasting or cooking), soaking, fermentation or dehulling (Onu et al., 2006; Abdelati et al., 2009). In most cases the growth performance of broilers is improved, with no clear advantage to one particular processing except that fermented pigeon pea did not allow good animal performance (Oso et al., 2012). Optimization of thermal treatments showed that over-processing (e.g. autoclaving at 120°C for 30 mn) led to decreased performance (Pezzato et al., 1995). Toasted pigeon pea could support growth up to 27% in finishers while performance was degraded (although non significant) in younger birds (Ani et al., 2011). Amino acid balance is important: several authors improved performance with methionine (but no lysine) addition (Amaefule et al., 2011; Babiker et al., 2006). This could be linked to the deficiency of pigeon pea in sulfur-containing amino acids (methionine and cystine) and the low digestibility of protein in raw pigeon pea. Amino acid deficiency could also explain increased feed intake in some contexts.
In summary, the general recommendation in broilers would be to limit incorporation to 10% pigeon pea in young animals. With processed (e.g. toasted) pigeon pea and in older animals, higher incorporation rates as 20% could be used. In less intensive conditions, higher rates could be tested if pigeon pea is available at low cost. However, feed efficiency can be lowered. In any case, particular attention should be paid to amino acid supply, particularly methionine.
Using pigeon pea often leads to reduced performance in laying hens. Hen-day egg production tends to decrease with raw pigeon pea (Amaefule et al., 2007b; Agwunobi, 2000; Tangtaweewipat et al., 1989) although in some experiments production is maintained with 20% pigeon pea (Udedibie et al., 1989). Feed intake increases, which leads to a degradation of feed efficiency (Amaefule et al., 2006c; Amaefule et al., 2007a). Delayed start of lay has been recorded (Amaefule et al., 2006c; Amaefule et al., 2007a). Technological treatments such as toasting or boiling can improve performance (Amaefule et al., 2006c; Amaefule et al., 2007b). Pigeon pea can be used in pullets (Amaefule et al., 2004; Amaefule et al., 2006b). Technological treatments improve the efficiency of use of pigeon pea (Amaefule et al., 2006b). The recommendations are the same as in broiler finishers.
The overall recommendation in layers is to use pigeon pea with care to avoid a degradation of feed efficiency. It should be safe to use 10% pigeon pea in layer diets, with a special care on methionine content in the diet. Higher rates (20%) can be tested especially if a technological treatment can be applied to pigeon pea.
In quails, toasted pigeon pea allowed good growth performance even at 20-30% in the diet. However, increased feed consumption led to a degradation of feed efficiency (Yisa et al., 2013).