Heifers were grouped by BW (i.e., 4 heifers per group) and there was a 2-wk interval between the starting date for group 1 and group 2 because only 4 respiration chambers were available for enteric methane measurements.
Heifers were grouped by BW (i.e.,4 heifers per group) and there was a 2-wk interval betweenthe starting date for group 1 and group 2 becauseonly 4 respiration chambers were available for entericmethane measurements.