Effect of cool-season adapted chickpea varieties on physicochemical and nutritional characteristics in ruminant systems

The focus of this study was to evaluate the effect of varieties on structural, physicochemical, and nutritional characteristics of cool-season adapted chickpeas as an alternative source for protein and energy feed for ruminant livestock. The hypothesis of this study was that cool-season adapted CDC chickpeas varieties grown in Western Canada would have significant differences in nutritional characteristics and truly nutrient supply to dairy livestock. The Crop Development Center (CDC) at the University of Saskatchewan (Saskatoon, Canada) provided the experimental samples of cool-season adapted chickpeas used in this study. Three chickpea varieties, CDC Alma, CDC Cory, and CDC Frontier were collected from three locations in Saskatchewan: Elorse, Limerick, and Lucky Lake. The standard official methods from the Association of Official Analytical Chemists (AOAC) were used for chemical analyses. Energy parameters were determined using the NRC dairy-2001. An in situ technique in cannulated cows was used to evaluate rumen degradation kinetics. Intestinal digestibility was determined in vitro using the 12 h residual samples from in situ incubations. A randomized complete block design (RCBD) with variety as a fixed effect and location as a random effect was used for statistical analyses using the MIXED model procedure of SAS 9.4. Significance was declared at P < 0.05 and tendencies at 0.05 < P < 0.10. Varieties CDC Alma and CDC Cory had a higher carbohydrate content than CDC Frontier (P = 0.02). Conversely, CDC Frontier had higher crude protein (CP) (P = 0.02) and SCP (soluble crude protein) (P = 0.02) than the other chickpeas. The rumen undegraded crude protein (RUP) was higher in CDC Alma and CDC Frontier compared to CDC Cory (P = 0.01). The intestinal digested crude protein (IDP) was higher in CDC Frontier than CDC Alma and CDC Cory (P = 0.03). No differences were observed in the true protein supply (DVE value), metabolizable protein (MP), and Feed Milk Value (FMV) between the three CDC varieties (P > 0.05). In conclusion, the chemical and nutrient profiles, rumen degradation kinetics, intestinal digestibility, and true nutrient availability in lactating cows among the cool-season adapted CDC chickpea varieties have been obtained. The cool-season adapted CDC chickpea varieties had > 770 g/kg EDCP and < 230 g/kg RUCP. CDC Frontier showed better results with relatively higher CP, higher degraded protein balance (OEB, DPB), higher truly digestive protein nutrient supply (DVE, MP) to dairy cows, and higher FMV than other two varieties. In general, cool-season CDC chickpea varieties grown in western Canada can be used as an alternative energy and protein nutrient option for ruminants.