Determination of true absorption and fecal endogenous loss of zinc in goats

Abstract

We determined the true absorption and endogenous fecal loss of zinc (Zn) in goats using its stable isotope. Three goats were fed with the diet containing 50 mg/kg Zn twice a day for 17 days. In the morning of day 11, the goats were given a meal labeled by (67) Zn as the tracer with dysprosium as the unabsorbed marker. Then the goats were given unlabeled diet as the rest of the morning feed. We measured dietary and fecal Zn concentration, (67) Zn abundance and dysprosium concentration in feces. The excretion pattern of the tracer Zn into feces differed from that of dysprosium. Therefore, we directly calculated the true absorption of Zn from Zn concentration and (67) Zn abundance in fecal samples collected after the labeled diet was given. The apparent absorption of Zn was -0.009 ± 0.016 mg/kg bodyweight (fractional absorption, -1.07 ± 1.85%). The true absorption of Zn was 0.162 ± 0.018 mg/kg bodyweight (fractional absorption, 18.25 ± 2.01%). The endogenous fecal loss of Zn was 0.172 ± 0.004 mg/kg bodyweight and the intestinal secretion of Zn was 0.210 ± 0.009 mg/kg bodyweight. The present experiment indicates that stable isotopic Zn is a powerful tool for examining Zn metabolism in ruminants.

Ruminal Solubility and Bioavailability of Inorganic Trace-Mineral Sources and Effects on Fermentation Activity Measured In Vitro

“…This finding indicates that only a small part of the added Zn solubilized during the 70hrs fermentation, and if solubilized, Zn could be assimilated by the rumen bacteria (19-38% of total Zn). The percentage of the total Zn in the BACT found in this study (19-38% of total Zn), was quite close to the intestinal apparent absorption of Zn in ruminants, in the interval of 15-30% [49]. Regarding the differences between ZnO and ZnSO4 solubility, after 22hrs of Zn exposure (ZnO_48h and ZnS_48h treatments), 19 % of the Zn was recovered in the SOL with the sulfate source, while only 10 % with the oxide source (p<0.05), indicating a higher solubility of the sulfate form.…”

Ruminal Solubility and Bioavailability of Inorganic Trace Mineral Sources and Effects on Fermentation Activity Measured in Vitro

“…This finding indicates that only a small part of the added Zn solubilized during the 70 h fermentation, and if solubilized, Zn could be assimilated by the rumen bacteria (19-38% of total Zn). The percentage of the total Zn in the BACT found in this study (19-38% of total Zn) was quite close to the intestinal apparent absorption of Zn in ruminants, in an interval of 15-30% [51]. Regarding the differences between ZnO and ZnSO 4 solubility, after 22 h of Zn exposure (ZnO_48 h and ZnS_48 h treatments), 19% of the Zn was recovered in the SOL with the sulfate source, while only 10% with the oxide source (p < 0.05), indicating higher solubility in the sulfate form.…”

Detecting animal by-product intake using stable isotope ratio mass spectrometry (IRMS)

“…However, to obtain such information, studies on the isotopic assimilation of organic matter in different animal tissues need to be carried out (Martins et al, 2012). There are few descriptions of turnover in biological samples and/or tissues from sheep, and they are focused on turnover involving C3 and C4 plant diets (Zazzo et al, 2008;Harrison et al, 2011;Martins et al, 2012) and lipid metabolism studies (Hattori et al, 2010;Richter et al, 2012).…”