Abstract: Objective: To investigate the effect of dietary supplementation of composite buffer on the milk quality
and health status of lactating goats fed a high concentrate diet. Methods: Eight mid-lactating Saanen dairy goats with
similar body weights were randomly divided into high concentrate diet group (HG, concentr ate:forage ratio = 60:40)
and buffering agent group (BG, fed high concentrate diet added with). The experiment lasted for 20 weeks. The milk
production and milk composition were measured weekly during the period, and on week 19, rumen fluid and blood
samples were collected for the measurement of rumen fluid pH and lipopolysaccharide (lipopolysaccharides, LPS) content
as well as blood biochemical indices. Results: The average daily milk yield, and protein, fat and lactose percentages of
dairy goats from the BG were higher than those of the HG, especially milk fat percentage (P < 0.05). The rumen fluid
pH of dairy goats in the HG was persistently lower than that of the BG and the occurrence of subacute ruminal acidosis
was found in the former. Additionally, the LPS content of the rumen fluid of dairy goats in the HG was significantly
higher than that in the BG (P < 0.01). Biochemical analysis showed that the activities of alkaline phosphatase and alanine
aminotransferase and aspartate transaminase in the blood of HG goats were significantly higher than those in BG goats
(P < 0.05). Conclusion: Dietary supplementation of composite buffer could improve the milk quality and yield of lactating
goats fed a high concentrate diet. The mechanism involved may be due to decreased rumen fluid pH, reduced production of
abnormal metabolites and consequent improved health status in response to dietary composite buffer.

Key words: composite buffer, lactating goats, subacute ruminal acidosis, milk quality, body health