The objectives of this research were 1) to evaluate
CuS04 and a CU lysine complex (CuLys) as growth promotants
for weanling pigs, 2) to assess the effects of feeding
growth stimulating levels of Cu from both sources on dry
matter digestibility (DMO) and mineral balance of finishing
pigs, and 3) to examine the effect of feeding elevated CU on
serum growth hormone and IGF-1 levels. Two trials (176
pigs) were conducted in which pigs were fed 0, 100, 150, or
200 mg/kg Cu from CUS04 or CuLys. Elevated Cu increased
daily gain and feed intake linearly, with no difference
between the sources. Dietary CU linearly increased liver,
kidney (P < .001), and brain (P < .05) Cu stores. In the
liver, the linear response between the sources was different
(P < .001); pigs fed 200 mg/kg Cu from CuLys had the highest
CU concentration. Serum CU increased linearly with no
difference between the two sources. Serum mitogenic
activity increased linearly during wk 1 to 2 and 1 to 5 (P < .05), with no difference between the two sources. Twenty-four
barrows were used to examine the effect of Cu additions
from both Cu sources on digestibility and mineral balance.
Pigs fed Cu from CuLys tended to have greater DMD when
compared with controls (P < .10), but percentage of Cu
absorbed was not different among the treatments. Pigs fed
Cu from both sources absorbed more eu than controls (P <
.01), with no difference between sources. Pigs fed CuS04 (P < .027) and CuLys (P < .101) absorbed more Fe than controls
but Zn balance was not affected. Twelve pigs were
cannulated after 7 wk of growth to quantify the effect of
elevated dietary Cu on circulating growth hormone and IGF-1
levels. Growth performance was not improved by added Cu,
but efficiency of gain was greater for pigs fed Cu when
compared with controls (P < .101). Baseline growth hormone
secretion was greater in pigs fed Cu (P < .06) for three of
four days; however, average concentrations were not affected
by diet. Concentrations of IGF-1 were higher in control
pigs (P < .05).
next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.
