Chickpea seeds have a relatively high protein and starch content and are mainly used as a concentrate, replacing soybean meal and cereal grains. The antinutritional factors in chickpea seeds were inactivated by 12-24 h of in vitro incubation with rumen liquor, and subsequently did not have a substantive effect on nutrient absorption from the small intestine of sheep (Bampidis et al., 2011).
Digestibility and rumen degradability
In sheep, estimates of OM digestibility of chickpeas were comprised between 84% (Hadjipanayiotou et al., 1985) and 92% (Bampidis et al., 2011), while energy and protein digestibility were both about 79% (Hadjipanayiotou et al., 1985). Replacing soybean meal and cereal grains by chickpea seeds in heifer, steer or lamb diets improved the apparent digestibility of crude protein and crude fat, with no adverse effect on the digestibilities of DM, fibre and energy (Hadjipanayiotou, 2002; Sommerfeldt et al., 1988; Illg et al., 1987). However, no improvement in digestibility was observed when replacing mixtures of maize grain and rapeseed meal, field peas or lentils by chickpeas in steer diets (Gilbery et al., 2007).
In growing heifers, steers and lactating cows, rumen protein degradability increased with the inclusion rate of chickpeas in replacement of soybean meal and cereal grains (Hadsell et al., 1988; Sommerfeldt et al., 1988; Illg et al., 1987). Rumen ammonia, in steers, was reported to increase with the dietary level of chickpeas in place of soybean meal and cereal grain (Gilbery et al., 2007). The effective rumen protein degradability of chickpea is comprised between 59% (ewes) and 75% (non-lactating Holstein cows) (Bampidis et al., 2011).
In lactating cows, chickpeas can be used as a substitute for soybean meal and maize grain up to 50% (DM basis) of the concentrate, or 25% (DM basis) of the whole diet. Milk protein content decreased at higher inclusion rates, though milk yield and milk fat contents increased (+ 1.2 kg milk/d). The increase in milk yield and fat content with high inclusion rates has been attributed to the relatively high fat content of chickpeas (Hadsell et al., 1988). In lactating ewes, no effect of replacing soybean meal and cereal grains with chickpeas, up to 30% (DM basis) of the concentrates, was observed on milk yield, and milk content of fat, protein, lactose and minerals (Christodoulou et al., 2005; Bampidis et al., 2011).
In growing cattle, substitution of mixtures of soybean meal, rapeseed meal and cereal grains by chickpeas resulted in higher body weight gains (Illg et al., 1987; Gilbery et al., 2007). In Holstein heifers fed a diet containing 50% of grass hay (DM basis), body weight gain was optimal when chickpeas were included at 25 to 49% of the concentrate (DM basis). Increasing chickpea inclusion rate (from 0% to 75% of concentrate DM) resulted in a linear decrease in DM intake and feed conversion efficiency (Illg et al., 1987).
In lambs and kids, the replacement of soybean meal and cereal grains with chickpeas did not affect body weight gain, intake or feed conversion ratio as long as the inclusion rate of chickpeas did not exceed 42% of the dietary DM (Hadjipanayiotou, 2002; Bampidis et al., 2011). Similarly, partial or total replacement of soybean meal and cereal grains with chickpeas did not affect carcass weight, yield, or the physical and chemical characteristics of the longissimus dorsi muscle (Lanza et al., 2003; Christodoulou et al., 2005).
Chickpea straw can be used as a ruminant feed (Bampidis et al., 2011). Compared to other straws, chickpea straw has a relatively high nutritive value (e.g. ME = 7.7 MJ/kg DM for chickpea straw vs. 5.6 for wheat) (Lopez et al., 2004; Lopez et al., 2005; Bampidis et al., 2011), but lower than that of other legume straws (Hadjipanayiotou et al., 1985; Bruno-Soares et al., 2000; Lopez et al., 2005). In sheep, DM, OM, crude protein and energy digestibilities of chickpea straw were 49%, 51%, 20% and 49%, respectively (Hadjipanayiotou et al., 1985; Bampidis et al., 2011). In rams, potential DM and NDF in sacco degradability were 45% and 39%, respectively (Bruno-Soares et al., 2000). Fed in a total mixed ration with chaffed dry groundnut forage and concentrate (700:150:150 g/kg of the total mixed ration), chickpea straw supported a BW gain of 0.38-0.42 kg/day in 10-month old camel calves (BW 187-240 kg) (Bampidis et al., 2011).
Chickpea pod husks
Chickpea pod husks contain a large rumen degradable DM fraction, above 94% (Ngwe et al., 2012). In 6-8 month old lambs and wethers, chickpea pod husks included at 10 to 20% of the diet (DM basis) replacing deoiled rice bran, or rice straw, increased the digestibilities of DM, OM, NDF and ADF (Ngwe et al., 2012; Sreerangaraju et al., 2000). A reduction in the digestibility of crude protein when chickpea pod husks were included at 10% DM was reported (Ngwe et al., 2012).