Effect of field peas, chickpeas, and lentils on rumen fermentation, digestion, microbial protein synthesis and feedlot performance in receiving diets for beef cattle

¹ Department of Animal & Range Sciences North Dakota State University, Fargo, ND 58105
² North Dakota State University, Carrington, ND

^* To whom correspondence should be addressed. E-mail: gregory.lardy{at}ndsu.edu.

	Abstract

Two experiments were conducted to evaluate the use of pulse grains in receiving diets for cattle. In Exp. 1, 8 Holstein (615 ± 97 kg initial BW) and 8 Angus-crossbred steers (403 ± 73 kg initial BW) fitted with ruminal and duodenal cannulae were blocked by breed and used in a randomized complete block design to assess the effects of pulse grain inclusion in receiving diets on intake, ruminal fermentation, and site of digestion. Experiment 2 was a 39-d feedlot receiving trial in which 176 mixed breed steers (254 ± 19 kg initial BW) were used in a randomized complete block design to determine the effects of pulse grains on DMI, ADG, and G:F in newly received feedlot cattle. In both studies, pulse grains (field peas, lentils, or chickpea) replaced corn and canola meal as the grain component in diets fed as a total mixed ration. Treatments included: 1) corn and canola meal (control); 2) field pea; 3) lentil; and 4) chickpea. Preplanned orthogonal contrasts were conducted between control vs. chickpea, control vs. field pea, and control vs. lentil. In Exp. 1, there were no differences among treatments for DMI (11.63 kg/d, 2.32% of BW daily; P = 0.63) or OM intake (P = 0.63). No treatment effects for apparent ruminal (P = 0.10) and total tract OM digestibilities (P = 0.40) were detected when pulse grains replaced corn and canola meal. Crude protein intake (P = 0.78), microbial CP flow (P = 0.46), total tract CP digestibility (P = 0.45), and microbial efficiency (P = 0.18) were also not influenced by treatment. Total tract ADF (P = 0.004) and NDF (P = 0.04) digestibilities were greater with field pea vs. control. Total VFA concentration was lower for field pea (P = 0.009) and lentil (P < 0.001) compared to control. Chickpea, field pea, and lentil had lower (P 0.03) acetate molar proportion than CON. Ruminal pH (P = 0.18) and NH₃ (P = 0.14) were not different among treatments. In Exp. 2, calves fed chickpea, field pea, and lentil had greater overall DMI (7.59 vs. 6.98 kg/d; P 0.07) and final weight (332 vs. 323 kg; P 0.04), whereas chickpea and lentil had greater ADG (1.90 vs. 1.71 kg/d; P 0.04) than control. Gain efficiency (P = 0.18) did not differ among treatments. Steers fed pulse grains had similar CP and OM digestibilities compared to a combination of corn and canola meal in receiving diets. Pulse grains are a viable alternative for replacement of protein supplements in receiving diets for beef cattle.

Key Words: Chickpeas, Digestion, Field peas, Lentils, Receiving, Steers