Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2003
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: The objective of the experiment was to determine the optimal dose of copper wire particles (COWP) to reduce infection of H. contortus in male lambs receiving a low or moderate level of supplement. Five to 6 months old hair breed lambs were housed on concrete, fed 454 (L) or 680 g (M; n = 25/supplement) corn/SBM with free choice access to bermudagrass hay, trace mineral and water. On Day 0, lambs were inoculated with 10,000 L3 larvae (97% H. contortus). Blood and feces were collected every 7 d for packed cell volume (PCV) and fecal egg counts (FEC) between Day 0 and day of slaughter on Day 54 (n = 25) or 63 (n = 24). Lambs were administered 0, 2, 4, or 6 g COWP on Day 28. Concentrations of copper in the liver were determined. There were no effects of supplement level on copper in the liver. Means of the 0, 2, 4, 6 g COWP treatments were 62.2, 135.7, 161.1, and 208.4 ± 13.8. Between Days 0 and 28, PCV declined in all lambs and by Day 42, PCV of all COWP treated lambs was greater than control lambs and remained higher. By Day 21, PCV was greater in the M compared with the L group of lambs and, with the exception of Day 42, remained higher in these lambs. The increase in FEC in response to inoculation was observed by Day 21. Within 7 days of COWP treatment, FEC declined from more than 8,000 eggs/g (epg) to less than 1,000 epg in all COWP treated lambs. FEC were similar between the 4 and 6 COWP lambs at all times, but FEC were greater on Day 35 in the 2 g (830 epg) vs. 4 and 6 g (75, 72 epg) COWP group. FEC were greater in L vs. M supplemented lambs and values decreased to a greater extent in H lambs when treated with COWP. The 2 g COWP was effective in alleviating H. contortus infection with the lowest concentration of copper in the liver of the COWP treatment groups. PCV values were more favorable for lambs fed the higher level of supplement, especially when FEC were greater than 8,000 epg.