The gastrointestinal tract (gut) contents of male Zebu cattle (Bos indicus) were studied in the southern Sahelian zone of Mali. Measurements were carried out on 39 animals in mid-dry season (MDS) and 15 at the end of the dry season (late dry season, LDS).
After overnight fasting, the animals were weighed and then slaughtered. The different gut compartments were emptied and representative samples of their fill were analysed for contents of dry matter (all) and NDF (reticulo-rumen only).
Related to fasted live weight (FLW), gut fresh matter (FM) fill (g FM/kg FLW) increased from 165·7±4·81 g in MDS to 227·5±3·05 g in LDS (P[les ]0·001), liquid gut contents (g fluid/kg FLW) increased from 138·9±4·65 to 193·5±2·49 g (P[les ]0·001) and gut dry matter fill (g DM/kg FLW) increased from 26·8±0·88 to 34·0±0·97 g (P[les ]0·001). Fresh matter content of the reticulo-rumen accounted for 77% and 80% of the entire gut FM fill in MDS and LDS, respectively. While the NDF component in reticulo-rumen fill (g NDF/kg DM) increased from 778·5±5·63 g in MDS to 836·6±6·37 g in LDS (P[les ]0·001), the ratio between dry matter and fluid in the reticulo-rumen (g DM/g fluid) decreased from 193·2±10·17 g in MDS to 169·0±5·54 g in LDS (P[les ]0·05).
The data support the notion that African breeds of Zebu cattle adjust to deteriorating feeding conditions by increasing reticulo-rumen dry matter and fluid contents. In-depth studies are needed to quantify the physiological benefits resulting from this strategy.