Effect of Trace Mineral Levels on Growth Performance, Blood Profile, Pork Quality, and Economic Analysis in Growing to Finishing pigs

Abstract

In Korea, many swine feed companies are adding excessively large amount of trace mineral, because some experts argue that the requirements stipulated by the NRC (1998, 2012) are extremely scarce compared to actual farm situation. However, there is a lack of scientific evidence to support their insistence. This opinion leads to an increase in feed costs, resulting in increasing cost of production at swine farm. Different levels of trace mineral feeding is based on the finding whether the amount of trace mineral used are appropriate or it can bring about a maximum growth of the growing-finishing pigs. Also, the role of different levels of trace mineral impacts on efficiency of feed utilization has not been assessed. Consequently, the present study was conducted in order to evaluate the effects of trace mineral levels in diet on growth performance, blood profiles, pork quality, and economic analysis in pigs from growing to finishing. A total of 140 growing pigs ([Yorkshire × Landrace] × Duroc), 28.22 ± 4.065 kg in average body weight, were assigned into four treatment groups. Each treatment group provided different dietary mineral and treatment as followed 1) M 1: supplementation of trace mineral met the NRC (2012) requirement, 2) M 3: supplementation of trace mineral met the 3 times of NRC (2012) requirement, 3) M 6: supplementation of trace mineral met the 6 times of NRC (2012) requirement, 4) M 9: supplementation of trace mineral met the 9 times of NRC (2012) requirement. In feeding trials, the different levels of trace mineral feeding in growing-finishing pigs had no significant difference on BW and ADFI compared with NRC (2012) requirement. However, ADG was increased by additional supplementation of trace mineral in finishing period (P=0.03). Gain to feed ratio was also improved (P<0.01) as trace mineral was increased in experimental diet. The blood concentration of Fe, Cu, Zn and IgG were not affected by trace mineral supplementation and pH, color, water holding capacity, cooking loss, shear force, and proximate analysis of longissimus muscle did not show difference among treatments. In TBARS (2-thiobarbituric acid reactive substances) was increased after cooking (P<0.01) and its value was decreased in proportional to increasing of dietary mineral. Total feed cost tended to increase as dietary mineral was higher. This experiment demonstrated that ADG and G:F ratio were increased by additional supplementation of trace mineral in finishing period. However, considering the whole experimental period, excessive trace mineral feeding did not cause a positive effect on growth performance, blood profile, pork quality and economical profits in growing-finishing pigs. Moreover, excessive trace mineral in swine diet may result in higher mineral content in manure subsequently it cause an environmental pollution eventually. Therefore, dietary supplementation level of trace mineral in swine diet of NRC (2012) recommendation is enough for normal growth of growing pigs and avoiding environmental pollution.