Ruminal pH and temperature, papillae characteristics and animal performance of fattening calves fed on concentrate or maize silage based diets

Raúl Bodas1*, Raquel Posado1, Daniel Jose Bartolome1, Marí­a José Tabernero de Paz1, Pedro Herráiz2, Eduardo Rebollo2, Luis Jesús Gómez3, and Juan José Garcí­a1
Feeding systems can play an important role, not only in beef farm profitability but also in animal health and performance. Fourteen Avileña-Negra Ibérica bulls, with an initial weight of 270 kg (SE 22.6 kg) and aged 223 d (SE 16.2) were used to study the effect of two feeding systems on ruminal pH and temperature and animal performance when calves were kept in loose housing conditions. Feeding systems were barley (Hordeum vulgare L.) grain-based concentrate plus barley straw (CONC) and maize (Zea mays L.) silage-based total mixed ration (TMR). Internal wireless boluses were used to collect pH and temperature values every 10 min throughout the measurement period (15 d). Diet did not modify (P > 0.10) average daily gain, carcass weight, dressing percentage, ruminal mucosa color, or papilla counts. Papilla width and papilla width/lamina propria thickness were significantly lower (P < 0.05) in TMR than in CONC animals. Time spent below ruminal pH thresholds of 7.0, 6.6, 6.2, and 5.8 and the corresponding areas under the curve were higher (P < 0.05) for animals fed under the TMR system. No significant changes were observed between experimental treatments in parameters related to ruminal temperature or estimated number of times that the animals were drinking during the day (P > 0.10). Although animal performance is not affected, feeding fattening calves on a concentrate plus barley straw diet can result in better rumen conditions than using maize silage-based TMR.
Keywords: Acidosis, feeding system, monitoring, rumen, total mixed ration.
1Instituto Tecnológico Agrario, Subdirección de Investigación y Tecnología, Finca Zamadueñas, Ctra. Burgos, km 119, 47071 Valladolid, España. *Corresponding author (bodrodra@itacyl.es).
2Asociación Española de Criadores de Ganado Vacuno Selecto de Raza Avileña-Negra Ibérica, Padre Tenaguillo, 8, 05004 Ávila, España.
3Universidad de Extremadura, Facultad de Veterinaria, Avda. de la Universidad s/n 10003 Cáceres, España.