Effect of complex catalytic supplementation with non-protein nitrogen on the ruminal ecosystem of growing goats pasturing on shrub land in Mexico

Abstract Thirty-eight young Alpine goats, 16.1 (±0.370) kg body weight (BW), were reared at Queretaro, Mexico, grazing on a semi-arid woody brush ( Caducifolio espinoso ) range land. The experimental goats ( n  = 20) were pastured daily and supplemented with 200 g/day of a complex catalytic feed (CCF). It consisted of molasses (14–18%), urea (8–10%), salt (3–4%), limestone (3–4%), cottonseed meal (13–18%), rice polishing (10–13%), corn (11–12%), poultry litter (9–10%), commercial mineral salt (1.3%), ammonium sulfate (0.3–0.5%), cement kiln dust (1.5%), and animal lard (10–15%). The control goats ( n  = 18) were supplemented daily with 300 g of a balanced concentrate (BC), containing 1.5% commercial mineral salt, 60% corn, 32.5% wheat bran, and 4% soybean oil meal. Stocking rates varied from 1.45 to 1.85 AU/ha and daily stocking rate from 36.4 to 58.6 AU/ha. At all times, fibrous forages were available exceeding the voluntary dry matter intake. One fistulated goat was kept in each group. Growth of the experimental goats averaged 95 g/day (±3) compared to 76 g/day (±5) of the controls ( P 3 mg/l) in ruminal liquid of CCF goats was higher ( P