Submitted to: Livestock Research for Rural Development
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/31/2001
Publication Date: 12/31/2001
Citation: PHILLIPS, W.A., RAO, S.C. DIGESTIBILITY AND NITROGEN BALANCE OF DIETS CONTAINING COTTONSEED MEAL, ALFALFA, OR PIGEON PEA AS THE PROTEIN SOURCE.LIVESTOCK RESEARCH FOR RURAL DEVELOPMENT. 2001. Available from: http://www.cipav.org.co/lrrd/lrrd13/6/phill36.htm. Interpretive Summary: Pigeonpeas are a new crop that can be grown during the summer and has the potential to add economic diversity to winter wheat production systems used in the Southern Great Plains. Pigeonpeas are high in protein content but have not be evaluated as a protein supplement in diets fed to cattle or sheep. Diets containing commonly used protein supplements, such as cottonseed meal, soybean meal and dehydrated alfalfa, were compared to a diet containing pigeonpeas to determine the nutritive value of raw cracked pigeonpeas. We determined that one pound of pigeonpeas is equivalent to 0.6 pounds of corn plus 0.4 pounds of cottonseed meal.
Technical Abstract: The objective of this study was to determine the DM and protein digestibility and N balance of diets containing alfalfa (Medicago sativa), cottonseed meal (Gossypium), soybean meal (Glycine max) or raw cracked pigeonpea (Cajanus cajan) as the protein source. Twenty-four lambs were blocked by genotype (Dorset x Dorset, St. Croix x St. Croix or reciprocal crosses) and within block assigned to one of four diets. All diets were formulated to provide similar amounts of CP, which was equal to the daily CP requirement for a lamb with an average BW of 38 kg; diets provided adequate energy to support an ADG of 75 g. Lambs were confined to metabolism stalls for the 28-d experiment and limit-fed each diet once daily. A 5-d total collection of feces and urine was conducted at the end of the experimental period. Dry matter digestibility was similar among the diets containing pigeonpea, cottonseed meal or alfalfa, but protein digestibility for the pigeonpea diet was lower (P<0.05) than for the diet containing alfalfa. However, N retention (g/d) was not different among these three diets, although fecal N was higher in lambs fed pigeonpeas. From these data, we conclude that pigeonpeas can be used as protein source in the diets of lambs and that one unit of raw pigeonpea can replace 0.6 units of corn and 0.4 units of cottonseed meal without lowering diet digestibility and N retention.