Season and location effects on serum and liver mineral concentrations of Senepol cattle on St Croix, Virgin Islands.
Serum and liver concentrations of selected macro- and trace minerals were determined in Senepol cattle at 8 sites (4 each in a high and low rainfall region) during the dry and wet season on St Croix. At each site an average of 15 mature, lactating cows, grazing native grass/legume pastures without supplementation were blood sampled each season. Liver samples were collected (n = 51) at slaughter from mature animals originating from the same sites. A preliminary analysis indicated no differences in serum mineral concentrations between mature lactating cows and growing heifers. There were differences between sites for serum magnesium (Mg) (P < 0.001), copper (Cu) (P < 0.05) selenium (Se) (P < 0.001) and zinc (Zn) (P < 0.01) in the dry season, and for Cu (P < 0.01), iron (Fe) (P < 0.001) and Zn (P < 0.01) in the wet season. Higher (P < 0.001) serum concentrations of Mg, Cu, Fe and Zn were observed in the dry season, while Se was higher (P < 0.01) in the wet season. Liver concentrations of Cu and Fe were lower (P < 0.01) and liver molybdenum (Mo) (P < 0.001) and Se (P < 0.05) higher during the dry season. The seasonal differences in serum Cu, Se and Zn concentrations have not been observed in other studies in the Central American region. More than 50% of serum samples were deficient in phosphorus (P) regardless of season, and in Cu and Zn during the wet season. Mineral supplementation should be considered.
Wildeus
S
S
University of the Virgin Islands, Agricultural Experiment Station, Kingshill, St Croix 00850.
McDowell
L R
LR
Fugle
J R
JR
D000818:Animals; D002417:Cattle / Q000097:blood* / Q000145:classification; D003300:Copper / Q000097:blood; D005260:Female; D007501:Iron / Q000097:blood; D007774:Lactation; D008099:Liver / Q000737:chemistry*; D008274:Magnesium / Q000097:blood; D012621:Seasons; D012643:Selenium / Q000097:blood; D014131:Trace Elements / Q000097:blood*; D014767:United States Virgin Islands; D015032:Zinc / Q000097:blood
D014131:Trace Elements; D003300:Copper; D007501:Iron; D012643:Selenium; D008274:Magnesium; D015032:Zinc