Four Holstein-Friesian crossbred dairy cows were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design to study the effect of banana flower powder (BAFLOP) and sodium bicarbonate (NaHCO3) supplementation as rumen-buffering agents on rumen fermentation and milk production. The first factor was two ratios of roughage to concentrate (R : C) at 60 : 40 and 40 : 60, whereas the second was two sources of buffering agent (BAFLOP and NaHCO3) supplemented at 20 g/kg of dry matter intake. All cows were fed total dry matter intake at 25 g/kg bodyweight and untreated rice straw was used as a roughage source. Feeding R : C at 40 : 60 increased nutrient digestibilities, nitrogen absorption, allantoin excretion and absorption, microbial nitrogen synthesis, microbial crude protein and efficiency of microbial nitrogen synthesis in both BAFLOP- and NaHCO3-supplemented groups. BAFLOP supplementation could maintain ruminal pH as NaHCO3. Blood urea nitrogen, total volatile fatty acid and propionate, and milk yield increased in cows fed R : C at 40 : 60 both in BAFLOP and NaHCO3 supplementation, whereas acetate was relatively high in cows consuming R : C at 60 : 40. However, rumen microorganisms were similar among treatments whereas milk compositions were unchanged by the dietary treatments, except milk fat and total solids were the highest in cow consumed R : C at 60 : 40. The results suggested that feeding R : C at 40 : 60 resulted in improvement of nutrient digestibility, rumen fermentation efficiency and milk production, and supplementation of BAFLOP showed similar buffering capacity as NaHCO3. Therefore, BAFLOP could be used efficiently as a dietary rumen-buffering agent and promisingly deserves a replacement for bicarbonate sources in lactating dairy cows fed on a high concentrate diet.
The effect of concentrate supplementation type on milk production, dry matter intake, rumen fermentation, and nitrogen excretion in late-lactation, spring-calving grazing dairy cows
