The role of feed consumption and feed efficiency in copper-stimulated growth

Abstract

Two experiments were conducted to study the role of feed intake and feed efficiency in Cu-stimulated growth of weanling pigs. In Exp. 1, 42 pigs were randomly assigned into three treatments: 1) control: ad libitum access to a corn-soybean meal-dried whey basal diet; 2) ad libitum/Cu: ad libitum access to the basal diet supplemented with 215 ppm of Cu; or 3) pair-fed/Cu: pair-fed the Cu-supplemented diet to the level of the control. Over the 14-d experiment, the ad libitum/Cu pigs had greater (P < .05) ADG and ADFI than the control pigs. The pair-fed/Cu group had an intermediate ADG. Gain:feed (GF) was not significantly affected by treatments but tended to be improved in the pair-fed/Cu pigs. Feeding copper increased (P < .05) the concentration of Cu in the serum, liver, and brain. Also, feeding Cu increased (P < .05) serum mitogenic activity and growth hormone mRNA concentrations for both feeding methods. In Exp. 2, a 2 x 2 x 2 factorial arrangement of treatments with two levels of Cu (15 vs 200 ppm), two levels of feeding (ad libitum vs restricted [85% of the ad libitum]), and two sources of Cu (Cu sulfate vs Cu lysine) was used in a 24-d experiment involving 96 pigs. Feeding copper increased (P < .05) ADG and GF. The magnitude of the Cu-stimulated growth was reduced by restricted feeding (Cu level x feeding level interaction; P < .05). The ADFI was greater (P < .05) for the pigs fed high dietary Cu only during d 1 to 6. Pigs fed Cu lysine had greater ADG and ADFI than those fed Cu sulfate (P < .05); the benefit in ADG from Cu lysine was reduced by restricted feeding (Cu source x feeding level interaction, P < .05). High dietary Cu stimulated (P < .05) serum mitogenic activity; the stimulation was greater for Cu lysine than for Cu sulfate. Feeding Cu numerically increased GH mRNA concentration. Restricted feeding reduced overall serum mitogenic activity (P < .05), but the response to high dietary Cu and Cu lysine was still evident. In summary, Cu-stimulated growth was largely dependent on a simultaneous increase in feed intake, but there were some improvements in GF. The influence of Cu on serum mitogenic activity was independent of feed intake or growth in both experiments, which indicates a direct action of Cu on the growth regulatory system.

Effects of dietary copper supplementation on nutrient digestibility, serum biochemical indices, and growth rate of young female mink (Neovison vison)

“…However, studies by Aulerich and Ringer (1976) indicated superior weight gains in male mink fed supplemental Cu at the 50 mg/kg level. Besides being an essential nutrient, Cu has received considerable attention due to its growth promoting and antimicrobial properties in animals when it has been fed at prophylactic levels (Zhou et al 1994b;Pang et al 2009;Lu et al 2010;Karimi et al 2011). Studies by Dove and Haydon (1992) and Dove (1995) have indicated that addition of 250 ppm Cu improved digestibility and utilization of the fat of weaned pigs.…”

Effect of dietary soyabean hulls and metal-amino acid chelated mineral supplementation on growth performance, nutrient digestibility and noxious gas emission in growing pigs

“…Creech et al (2004) previously reported that trace mineral sources exerted no effects on performance during the growing or gilt development phase. Coffey et al (1994) and Zhou et al (1994) previously reported that additions of Cu from copper-lysine complexes resulted in improved pig performance as compared with copper sulphate. Other researchers, however, have noted no differences in growth-promoting activity between the two Cu sources (van Heugten and Coffey, 1992).…”

Levels of copper and zinc in diets for growing and finishing pigs can be reduced without detrimental effects on production and mineral status

“…Furthermore, some studies with organic forms of Cu and Zn have also been shown to reduce mineral excretion (Creech et al, 2004) and improve performance when included at similar levels to inorganic sources (Zhou et al, 1994;Veum et al, 1995), or can be incorporated at lower dietary levels than those in the inorganic forms without negatively affecting growth performance (Mullan et al, 2002). Results from Smits and Henman (2000) indicated that Cu could be reduced from 150 mg/kg Cu sulfate to 40 mg/kg in the form of Cu proteinate amino acid chelate in grower diets, while Fremaut (2003) showed that Zn, Fe, Mn and Cu could be reduced to 36, 39, 18 and 7 mg/kg (30% of normal levels used in Belgium) if all were included in the proteinate amino acid chelate form.…”