The Effect of Three Types of Buffering Supplements on Growth Performance, Fermentation, and Some Blood Parameters in Fattening Mehraban Lambs

Background and Objective: In fattening lambs, acidosis leads to reduced dry matter intake and growth performance. Dietary buffering supplements are one of the tools to control rumen acidity, especially in fattening lambs and high-producing livestock. This study aimed to investigate the effects of three types of buffering supplements on growth performance, feed intake, rumen fermentation, rumen pH, protozoal population, and blood parameters in fattening lambs fed a 70% concentrate diet.
Materials and Methods: The experiment was conducted using 18 Mehraban breed fattening lambs (29 ± 1 kg, 3 months old) in a completely randomized design with three groups and six replicates over a 75-day period. The experimental groups included: 1) Control group (sodium bicarbonate buffer), 2) RuminoBuffer group (a synthesized compound), and 3) Behdam-Roshd Khorasan commercial buffer group. The studied traits in live animals included growth performance (initial weight, final weight, daily weight gain, feed conversion ratio, and dry matter intake), rumen fermentation (pH, ammonia nitrogen, total volatile fatty acids), protozoal population, and blood parameters (biochemical and enzymatic). Additionally, in vitro gas production parameters and digestibility were evaluated.
Results: The results showed no significant difference among the three buffering supplements in terms of average daily weight gain and dry matter intake in fattening lambs (P > 0.5). Rumen pH, ammonia nitrogen, and total volatile fatty acids remained stable and unchanged in all three buffer types on days 30 and 60 (P > 0.5). In vitro digestibility and total gas production in the second group (Ruminobuffer) were significantly lower compared to the other two groups (P < 0.5), while the Behdam-Roshd commercial buffer group was similar to the control group. The protozoal population decreased in both the Ruminobuffer and Behdam-Roshd groups compared to the control (P < 0.05). The total protozoal population in lambs fed the Behdam-Roshd buffer was significantly lower than in the other two groups (P < 0.05). Lambs fed the Behdam-Roshd buffer had lower blood glucose levels compared to the other two groups, and blood triglyceride levels decreased in lambs fed Ruminobuffer compared to the control (sodium bicarbonate) (P < 0.05). Alanine aminotransferase (ALT) increased in both the Ruminobuffer and Behdam-Roshd groups compared to the control (sodium bicarbonate), while aspartate aminotransferase (AST) decreased in the Ruminobuffer group compared to the other two groups (P < 0.05).
Conclusion: The use of these buffers in a high-concentrate (70%) fattening diet helped control and prevent rumen pH from dropping below six. Given the similar daily and total growth performance across all three groups, and considering the price per kilogram of each buffer, it is recommended to use the more cost-effective buffer.
Keywords: Volatile fatty acids, Buffer, Fattening lambs, Growth performance, Ammonia nitrogen.