Open AccessHypoglycin A absorption in sheep without concurrent clinical or biochemical evidence of disease
Author(s) -
GonzálezMedina Sonia,
Bevin William,
AlzolaDomingo Rafael,
Chang YuMei,
Piercy Richard J.
Publication year - 2021
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.16077
Subject(s) - rumen , ingestion , grazing , zoology , subclinical infection , bioavailability , horse , medicine , meal , biology , food science , agronomy , pharmacology , paleontology , fermentation
Background Hypoglycin A (HGA) intoxication after ingestion of Acer spp. tree material has never been confirmed in domesticated ruminants despite their similar grazing habitats. Objectives To investigate whether sheep have low HGA bioavailability caused by rumen HGA breakdown. Animals Stomach and rumen fluid samples from 5 adult horses and 5 adult sheep respectively. Residual serum samples from 30 ewes and lambs. Methods Experimental and retrospective cohort study. Hypoglycin A concentration was quantified in horse gastric and sheep ruminal samples after in vitro incubation with Acer pseudoplatanus seeds. Serum samples from grazing sheep (n = 20) and nursing lambs (n = 10) obtained before and after their release onto pastures with and without Sycamore seedlings were analyzed for HGA and methylenecyclopropyl‐acetic acid carnitine, and serum biochemistry. Results Neither ovine rumen nor equine gastric fluid affected HGA content in samples incubated for up to 2 hours. Despite HGA's detection in serum from sheep (n = 13/15; median, 23.71 ng/mL; range, 5.62‐126.4 ng/mL) grazing contaminated pastures and in their nursing lambs (n = 2/5; median, 12.5 ng/mL; range, 8.82‐15.67 ng/mL), there was no apparent clinical or subclinical disease. Conclusions and Clinical Importance Any reduced sensitivity to HGA intoxication in sheep seems unrelated to ruminal degradation. Serum HGA concentrations in sheep were similar to those of subclinically affected atypical myopathy horses. Any reduced sensitivity of sheep to HGA might be related to greater metabolic resistance rather than selective grazing habits or lower bioavailability. Hypoglycin A was found in nursing lambs, suggesting that HGA is excreted in milk.