Treating Bos indicus bulls with rumen transfaunation after 24 hours of transportation does not replete muscle glycogen

Abstract

Twelve Bos indicus bulls were allocated to one of two treatment groups: rumen transfaunation (n = 6) given 10 kg of rumen fluid after transport or Control (n = 6), given 10 kg of deionised water after transport. Glycogen concentrations of the M. semimembranosus, M. semitendinosis and M. longisimus dorsi were measured before transport on Day –7 and after transport on Day 0, Day 1, Day 4 and Day 9. Feed intake, liveweight gain, plasma metabolites and electrolytes were recorded on the sampling days. Rumen transfaunation increased the dry matter intake of treated bulls compared with the bulls treated with deionised water. Rumen transfaunation had no effect on glycogen concentrations of the M. semimembranosus, M. semitendinosis and M. longisimus dorsi compared with the bulls treated with deionised water. The M. semimembranosus and the M. semitendinosis decreased in glycogen concentration immediately after transport on Day 0 but repleted to pre-transportation concentrations within 1 day. However, the M. longisimus dorsi demonstrated no change in glycogen concentration between the pre-transportation sample on Day –7 and Day 0 or Day 1 after transportation. The M. longisimus dorsi of the bulls increased in glycogen concentration between Day 1 and Day 4 after transportation. The bulls in this experiment demonstrated that muscle glycogen, as measured at the M. longissimus dorsi, cannot recover to sufficient concentrations (40–45 µmol of glycogen concentration per gram muscle) to ensure normal meat quality until between 1 and 4 days of rest when feeding Rhodes grass hay ad libitum.