Abstract :
The objective of three experiments was to determine the influence of high condensed tannin
(CT) grain sorghum on gastrointestinal parasite fecal egg counts (FEC). Sixteen naturally
infected Boer crossbred mixed-sex goats were used. Animals that were supplemented with
grain daily were removed from pasture and placed in individual pens and fed treatment
diets for 21 or 14 days (Experiment 3). Goats were allowed ad libitum access to water and
diets containing high or low CT cracked grain sorghum. On day 0 and every 7 days thereafter,
PCV, FEC and FAMACHA® eyelid color scores (EYE; Experiment 1 only) were recorded.
For Experiment 1, percentage of animals dewormed, PCV and EYE were not influenced
by treatment and averaged 13.6±4.5% per treatment period, 23.4±0.8% and 3.2±0.12,
respectively, for all animals. The FEC increased after day 0 for control but not high tannin
grain sorghum fed goats (treatment by day interaction, P < 0.02). As expected, EYE and PCV
were negatively related (r =−0.45; P < 0.0005). For Experiment 2, there was no influence
of diet on PCV or FEC, but there was an effect of day on FEC (P < 0.002) in which all goats
had higher FEC on day 0 (1956±219 eggs/g) than any other sampling day. For Experiment
3, there was no effect of feeding high CT grain sorghum on FEC (2992±591 eggs/g) or PCV
(25.1±0.5%). In these studies, high CT grain sorghum did not consistently influence FEC
and did not impact PCV or number of animals requiring chemical anthelmintic treatment.
