Corn grain rehydration methods: Water vs. cactus pear in the diet for feedlot lambs

The goal was to evaluate the productive performance, nutrient digestibility, nitrogen balance and blood parameters of feedlot lambs fed silages of corn grain rehydrated with water or cactus pear. Thirty male intact lambs, mixed breed, and with an average initial weight of 22 +/- 4.29 kg were assigned to a completely randomized design with three treatments and ten replications. The treatments were defined as diet containing ground dry corn grain - CG (Control); diet containing corn grain silage rehydrated with water (CW) and; diet containing corn grain silage rehydrated with cactus pear (CCP). No significant differences were observed (P > 0.05) among the treatments in terms of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrate (TCHO), and metabolizable energy (ME). However, the ME content (P = 0.0204) of the diets containing rehydrated corn grain silage (CW) (2.57 Mcal/kg DM) was significantly higher than that of the CG diets (2.29 Mcal/kg DM). This difference in ME was associated with improved digestibility of DM (P = 0.0148), OM (P = 0.0032), and TCHO (P = 0.0027) in the CW diets. Animals fed the CG diets exhibited lower total weight gain, daily weight gain, and reduced feed efficiency. Additionally, a higher percentage of starch was found in the feces of animals consuming CG diets. In contrast, animals fed the CCP diet had higher plasma glucose concentrations (P = 0.0177). The inclusion of rehydrated corn grain silage in the diets proved to be a valuable nutritional strategy to enhance the overall nutritive value of corn grain for lambs, leading to improved animal performance. Furthermore, the utilization of cactus pear as a source of rehydration for grain silage can be particularly advantageous in regions where water resources are limited.