Interaction of vitamin A supplementation level with ADH1C genotype on intramuscular fat in beef steers.
Previously, the single nucleotide polymorphism in alcohol dehydrogenase (ADH1C c.-64T>C) was shown to have an association with intramuscular fat (IMF) in the longissimus thoracis (LT) muscle when vitamin A was limited in finishing rations of beef steers. The purpose of this study was to determine the optimum vitamin A supplementation level, in combination with ADH1C genotype, to increase IMF of the LT muscle. In total, 45 TT genotype, 45 CT and 27 CC Black Angus crossbred steers were backgrounded on a commercial ration containing 3360 IU vitamin A/kg dry matter (DM). During finishing, the steers were randomly assigned to one of three vitamin A treatments at 25%, 50% and 75% of the National Research Council recommendation of 2200 IU/kg DM. Treatments were administered via an oral bolus. Carcass quality was evaluated and a sample from the LT muscle was collected for analysis of IMF. A treatment×genotype interaction (P=0.04) was observed for IMF; TT steers on the 75% treatment had higher IMF relative to CT and CC steers on the same treatment. Western blot analysis showed that TT steers had higher (P=0.02) ADH1C protein expression in hepatic tissue. Previously, TT steers exhibited increased IMF when fed limited vitamin A. In the current study, the lack of variation in IMF between treatments and genotypes at the lower vitamin A treatment levels was likely due to the majority of the steers grading Canada AAA (USDA Choice). However, the western blot data supports that TT steers are expected to have higher IMF deposition, due to an increased production of ADH1C. The interaction between ADH1C genotype and vitamin A supplementation level has the potential for use in marker-assisted management programs to target niche markets based on increased marbling.
1Department of Animal and Poultry Science,University of Saskatchewan,Saskatoon,SK,Canada S7N 5A8.
K G
KG
Krone
2College of Medicine,University of Saskatchewan,Saskatoon,SK,Canada S7N 5E5.
A K
AK
Ward
1Department of Animal and Poultry Science,University of Saskatchewan,Saskatoon,SK,Canada S7N 5A8.
K M
KM
Madder
3Department of Large Animal Clinical Sciences,Western College of Veterinary Medicine,Saskatoon,SK,Canada S7N 5B4.
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S
Hendrick
1Department of Animal and Poultry Science,University of Saskatchewan,Saskatoon,SK,Canada S7N 5A8.
J J
JJ
McKinnon
1Department of Animal and Poultry Science,University of Saskatchewan,Saskatoon,SK,Canada S7N 5A8.
F C
FC
Buchanan
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000235:genetics*; D000818:Animals; D001823:Body Composition / Q000187:drug effects* / Q000235:genetics*; D050218:Body Fat Distribution; D002170:Canada; D002417:Cattle; D019587:Dietary Supplements; D005838:Genotype; D008099:Liver / Q000201:enzymology; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D000069466:Red Meat / Q000032:analysis; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*
D014801:Vitamin A; D000426:Alcohol Dehydrogenase
alcohol dehydrogenase; beef cattle; intramuscular fat; vitamin A