Curva do PH bucal de equinos alimentados com dieta à base de silagem de baixo amido

Abstract

Mombasa grass silage supplemented with soybean hulls has emerged as a conserved forage option for horses, especially as a substitute for corn silage; however, its impact on oral health remains unknown. This study aimed to evaluate the oral pH curve of 12 Mangalarga Marchador mares fed Panicum maximum cv. Mombasa grass silage supplemented with soybean hulls for 90 days. Monthly collections were performed, with pH measured using a colorimetric strip. The animals were subjected to a three-hour total fast, beginning with the measurement of the baseline value (MB), followed by the provision of 500 grams of Mombasa grass silage supplemented with soybean hulls. After five minutes, oral pH was measured (M0) and subsequently recorded at 10 (M10), 30 (M30), and 60 (M60) minutes after consumption. In the first month, a significant reduction (p<0.05) in oral pH was observed after diet intake (7.75) compared with MB (8.5), with a return to baseline values at M10 (8.42). The second collection showed a significant increase (p<0.05) in oral pH at M0 (10), returning to the baseline value (MB = 9) at M10 (9) and M30 (9), but increasing significantly again (p<0.05) at M60 (10). Finally, in the third month, no differences in pH values were observed over the 60-minute period, remaining at pH 10 throughout the collection. The average baseline oral pH of Mangalarga Marchador horses was 9 after the intake of Mombasa grass silage supplemented with soybean hulls. The reduced starch content of the silage allowed saliva and biofilm to regulate transient pH decreases during intraoral digestion. Therefore, it is concluded that the silage significantly increased (p<0.05) oral pH after ingestion over the months. Thus, the ingredients of the evaluated conserved forage did not demonstrate cariogenic potential and can, from this perspective, be safely used as a substitute for corn silage.