Relative Availability of Iron in Mined Humic Substances for Weanling Pigs

Abstract

Humic substances include several biological active and inactive compounds that are commonly used for improving soil fertility. Use of humic substances in swine diets is a novel concept. Humic substances contain 8,700 mg/kg of iron but its bioavailability is unknown. This study was conducted to test the bioavailability of iron in humic substances for nursery pigs. One hundred twenty five pigs (Newsham, Colorado Springs, CO) were not given supplemental iron while nursing for 21 d. Pigs were weaned on d 21 and allotted to one of five treatments (four control treatments with different levels of supplemented iron; 0, 30, 70 and 88 mg/kg from FeSO 4 and one treatment with 70 mg/kg iron from humic substances). Pigs were fed diets for 5 wk ad libitum and water was accessible freely. Body weight and feed intake were measured weekly. Blood samples were taken from pigs on d 28 to measure the number of red blood cells and hemoglobin concentration. Pigs fed a diet with the humic substances grew faster (p<0.05) during the first week postweaning, but performance was not different during the entire 5 wk period. Feed intake and gain/feed were the same among treatments. The slope ratio technique was used to estimate relative iron bioavailability. The concentration of blood hemoglobin did not respond to dietary iron levels using this model. However, the number of red blood cells (106/µl) was modeled by 4.438+0.017× 'iron (mg/kg) from FeSO 4 '+0.012×'iron (mg/kg) from the humic substances'. Based on the comparison between the slopes (0.012 from humic substances and 0.017 from FeSO 4 ), iron in humic substances was 71% as available as the iron in FeSO 4 . The slopes for dietary feed intake of FeSO 4 and the iron in humic substances did not differ (p>0.05). Humic substances can replace FeSO 4 as an alternative iron source for pigs at 71% relative bioavailability.

Effects of humic substances supplementation provided through drinking water on performance, carcass traits and meat quality of broilers

“…Based on these values and results, the results with respect to chemical composition, mineral contents and colour characteristics of breast and thigh meats suggest that humic acid at the tested doses did not affect on CIE lightness values as follows: lighter (pale) or darker (dark) than normal, but slightly increased L* and a* values of these meats and did not affect b* value. In the present study, the enhanced Fe content of the meats may explain the fact that the humic acid particles and/or minerals from HS preparations may be absorbed (Visser, 1973; Fuchs et al., 1990; Büsing et al., 2005) and the HS can replace FeSO 4 as an alternative iron source for animals, including pigs (Kim et al., 2004; Ji et al., 2006), because the relative bioavailability of the iron in HS has been reported as 71% of iron sulphate (Kim et al., 2004). Thus, our result with regard to a* values was clearly due to differences in Fe content of breast and thigh meats.…”

“…(2006) reported that there was a trend for reduction in the serum concentrations of Ca, Mg, Fe and P by humic acid, contrary to the augmentation in the meat concentrations of Ca, Fe and Cu at the higher level of humic acid offered in this study. Such a case may be due to a metal chelating effects of humic, which is affected by large number of carboxylic acid side chains (Peña‐Mèndez et al., 2005; Rath et al., 2006) and the mineral content of HS used in the present study (Kim et al., 2004; Ji et al., 2006).…”

Prophylaxis of post-weaning diarrhoea in piglets by zinc oxide and sodium humate

“…The present study found no significant effect of ZnO and HNa treatment on blood cells, haematocrit and haemoglobin. Rupic et al (1998) reported that inorganic Zn in the diet of fattening pigs appears to be responsible for the increase in the values of erythrocytes, haemoglobin and haematocrit and Kim et al (2004) observed significantly increased erythrocyte values in pigs supplemented with HS. We observed non-significantly higher erythrocytes and haematocrit in ZnO2.5 and HNa + ZnO1.7 as well as non-significantly higher haemoglobin levels in the ZnO2.5 group after three weeks of treatment.…”

Fermented soybean meal as a vegetable protein source for nursery pigs: I. Effects on growth performance of nursery pigs

“…The RBV of FSBM to PP was 99.1% when the 3-wk period was considered, and there was no difference in growth response between FSBM and PP. A slope-ratio assay is an effective method to compare RBV of nutrients from different sources (Hahn et al, 1990;Kim and Easter, 2001;DeRouchey et al, 2002;Kim et al, 2004). In this experiment, 3.7% PP was replaced by 4.9% FSBM, with the addition of Lys, Thr, Met, and Trp to match AA profiles.…”