Organic chromium improves immune responses in weaner pigs and reduces non-productive days in breeding sows
Kemin Industries (Asia) Pte Ltd
Chromium functions with insulin in the regulation of glucose and energy metabolism. People suffering from type II diabetes are responsive to chromium supplementation. Biologically active chromium will potentiate the action of insulin to increase the clearance of glucose out of blood and into tissue cells (Figure 1).
Figure 1. Effect of organic chromium sources on glucose clearance (% per minute) in response to an intra-venous insulin challenge test1 in growing pigs2 (Louisiana State University, USA3)
Chromium propionate increased the rate of glucose clearance out of blood in these growing pigs by 45% compared with the effect of insulin alone (P<0.01) and with a clearance rate that was 18% greater than chromium picolinate (P<0.10). Hence the source of chromium is important in relation to its physiological action.
The stress placed on piglets when weaned from the sow is associated with economic losses. Stress and disease can increase urinary excretion of chromium in people (Mertz, 1993). A recent study has shown that organic chromium may improve immune responsiveness in weaned pigs (Lien et al, National Chiayi University, Taiwan).
Thirty six piglets weaned at 4 weeks of age received either a control diet or the same diet supplemented with 200ppb of either chromium picolinate or chromium propionate (KemTRACEâ„¢ Chromium). All pigs were vaccinated against hog cholera, foot and mouth and pseudorabies. Pigs were challenged during the 4th and 8th weeks post-weaning with an intramuscular injection of an E. coli lipopolysaccharide (LPS) with changes in the white blood cell count measured from 0 to 24 hours and 0 to 6 hours post-injection after the first and second challenge respectively. Neutrophil activity in blood was measured before the 1st challenge. Blood immunoglobulin levels were also measured before the LPS challenges in the 4th and 8th weeks post-weaning.
Ear skin thickness was measured in response to a phytohaemagglutinin (PHA)
injection into the ear during the 7th week post-weaning. The results are shown in Table 1.
Table 1. Effects of chromium supplementation on immune responsiveness in weaner pigs (National Chiayi University, Taiwan; means across rows with different letters are significantly different, P<0.05)
Whilst there were no IgG or y-globulin responses for the chromium picolinate supplemented pigs at 4 weeks post-weaning, the responses were significant for chromium propionate supplemented pigs. This was also reflected in a numerically higher total globulin content for the chromium propionate supplemented pigs. Both chromium sources were associated with significantly higher total globulin contents compared with control at the second measurement. The E. coli lipopolysaccharide challenges resulted in significant white blood cell responses for the chromium supplemented pigs. The neutrophil activity response from the pigs supplemented with chromium propionate was significantly greater than the control treatment but this was not so for the picolinate source. The propionate source of chromium was also associated with a significantly greater skin thickness response to the PHA challenge than the picolinate source.
As suggested by the glucose clearance data (Figure 1), these immune responses also indicate that the chromium ligand influences physiological action (i.e. propionate compared with picolinate). On balance, supplementing the pig's diet with chromium from the propionate source showed enhanced immune responsiveness in the pig compared with the picolinate source. Improving the immune responsiveness of weaner pigs through chromium propionate supplementation (KemTRACEâ„¢ Chromium), offers the pig producer another practical tool to help young pigs through the stressful post-weaning period.
The linkage between stress and chromium response observed in transported feeder cattle may be part of the explanation for reduced liveweight loss of transported pigs supplemented with 200ppb of chromium propionate. This observation was made in a Louisiana State University trial: 2.7 hours of transportation in a truck after an 18 hour fast led to a liveweight loss of 1.6% in control pigs compared with 1.2% for chromium propionate supplemented pigs (P=0.14; chromium supplementation was from 73 to 115kg liveweight). This 24% reduction in liveweight loss was repeated in a trial with a 2 hour transport time of pigs finished at 122kg liveweight. The control pig's weight loss was 2.78% but was 2.08% for the chromium propionate supplemented pigs (KemTRACEâ„¢ Chromium). This was a 25% reduction in weight loss associated with transport and was equivalent to 0.7kg/pig which would have significant economic consequences.
The potentiation effect of chromium on the action of insulin in glucose metabolism is presumably linked to the beneficial effects of chromium on reproductive performance in sows.
Chromium supplementation has been associated with increased litter size and this effect is thought to be linked with the action of insulin on ovulation rate and embryo survival.
A recent study conducted in the U.S.A. with 65,000 sows over a 2 year period has demonstrated that 200ppb of chromium propionate (KemTRACEâ„¢ Chromium) reduced the number of non-productive days in these breeding sows. Non-productive days are those days when the gilt or sow is not pregnant or lactating. The introduction of chromium propionate was the only dietary change for the sows over the 2 year period. The 12 month period of chromium propionate supplementation was associated with an average of 32.68 non-productive days per sow compared with the previous 12 months of 37.85 days per sow without chromium supplementation (Figure 2).
Figure 2. Annual non-productive sow day rates per sow by quarter over 2 successive years; ave. 37.85 days/sow/year without chromium and ave. 32.68 days/sow/year with dietary chromium propionate supplementation
This reduction of 5.2 non-productive days (13.7%) associated with chromium propionate supplementation has favourable financial consequences due to the costs associated with maintaining sows on non-productive days, eg. housing, feeding and management costs.