Dose Responses to Supplemental Polyacrylamide on Digestion, Metabolism, and Ruminal Digestive-Enzyme Activities in...

In recent years, in response to the demand for the livestock industry to enhance cattle production performance, scholarly inquiries have centered on elucidating the underlying mechanisms by which feed additives modulate rumen microenvironment and metabolic efficacy, thereby facilitating nutrient absorption and augmenting production performance in cattle. This study was undertaken to evaluate the impacts of surfactant polyacrylamide (PAM) supplementation on digestive processes, metabolic dynamics, and ruminal digestive enzyme activities in cattle. Four ruminally cannulated crossbred cows (~3 years, 350 kg, non-pregnant/lactating) were utilized in a 4 × 4 Latin square design. The animals were fed a basal diet supplemented with polyacrylamide (PAM) at concentrations of 0, 1.0, 2.0, and 6.0 g/kg across four 22-day experimental periods, each consisting of a 16-day adaptation phase and a 6-day sampling phase. Supplementation with polyacrylamide (PAM) at levels ranging from 1.0 to 6.0 g/kg of diet significantly increased voluntary dry matter intake (VFI) in cattle by a maximum of 13.7% (p < 0.05), with peak effects at 2.0 g/kg. The digestibility of dry matter, crude protein, cellulose, and energy was significantly improved (p < 0.05 to p < 0.01), reaching maximum increases by 12.6%, 12.8%, 17.5%, and 11.7%, respectively. Nitrogen, calcium, and phosphorus retention increased substantially (p < 0.01 to p < 0.05), with calcium retention showing the highest improvement (55.7%). Rumen cellulase activities (endocellulase, exocellulase, cellobiase, and xylanase) were significantly enhanced (p < 0.01), peaking at 37.3% for cellobiase. However, pectase, amylase, and protease activities remained unaffected. Optimal benefits were observed at 2.0 g/kg PAM, highlighting its potential to improve feed efficiency and nutrient utilization in cattle.