Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/24/2006
Publication Date: N/A
Technical Abstract: The objective was to determine whether a low dose of copper oxide wire particles (COWP) would be as effective as a higher dose in reducing gastrointestinal nematodes (GIN) infection. In May 2006, 40 Boer x Spanish doe and wether kids naturally infected with GIN were weaned (97 ± 2 days of age) and assigned randomly to receive no, 0.5, 1, 2, and 4 g COWP (n = 8/treatment; Day 0). Kids grazed the same bermudagrass pasture (33 kids/ha) and were supplemented with 220 g corn/soybean meal (14% CP, DM basis)/kid daily. Body weight was determined at 0 and 28 days after COWP administration and feces and blood were collected every 7 days for FEC and PCV determination. Kids were dewormed if PCV was below 20%. Haemonchus contortus is typically the predominant GIN during summer months on this farm. On Day 0 FEC ranged between 440 (0.5 g group) and 2050 eggs/g (epg; 1 g group), but log transformed means were not different among groups on that day. FEC were similar among all doses of COWP for all dates (P > 0.10). When COWP-treated groups were pooled, FEC were lower (COWP x date, P<0.05) on Days 7 (P<0.002), 14 (P<0.004), and 21 (P<0.05) compared with untreated kids, but similar by Day 28. PCV was similar between untreated and COWP-treated kids on Days 0 and 7, but lower in untreated kids by Day 14 (COWP x date, P<0.05). Because PCV dropped below 20%, nearly one third of all kids were dewormed on Day 21 and 88% were dewormed by Day 28, independent of COWP treatment. Therefore, COWP does not appear to be effective in controlling newly acquired L4 larvae which also feed on blood, leading to decreased PCV. Average daily gain tended to increase with dose of COWP up to 2 g then decreased at 4 g (y = 93.2 + 26.3x – 6.2x2, where y = ADG in g and x = COWP dose; R2 = 0.13; P<0.07). Body weights on Day 0 were 15.3, 14.7, 13.8, 15.5, 14.4 ± 0.9 kg and on Day 28 were 18.4, 18.7, 17.3, 19.7, 17.8 ± 0.9 kg for kids administered 0, 0.5, 1, 2 and 4 g COWP (COWP x date, P<0.07). A dose as low as 0.5 g was effective in reducing FEC, but because the amount of larvae on pasture was likely very high, additional treatment was necessary within 4 weeks.