Relationship of growth and puberty in beef heifers fed XXXX .

@entity6193 @entity1017 @entity291
An experiment was designed to determine the effects of dietary @entity6193 on age and weight at puberty in @entity291 crossbred beef heifers. One hundred and forty heifers were allotted to two weight classes: heavy (H) and light (L) groups, consisting of heifers above and below the average weaning weight, respectively. Heifers within each weight class were assigned to one of three diets during a 203-d winter feeding period: (1) R, 80% roughage: 20% concentrate; (2) M1, R diet plus @entity6193 (200 mg/head daily) with feed intake restricted to produce @entity1017 ( @entity1017 ) similar to R and (3) M2, R diet plus @entity6193 (200 mg/head daily). @entity1017 was higher (P less than .001) for M2 heifers than for R and M1 heifers, which performed similarly. Age and weight at puberty were similar across treatments in L heifers. However, in the H group, HM1 and HM2 heifers were younger (P less than .07) at puberty than HR heifers and this difference was not removed by covariate adjustment of either @entity1017 or body weight. Weigh at puberty was greater (P less than .01) for HM2 heifers than for HM1 or HR heifers; however, this difference was removed by covariate adjustment of either @entity1017 or body weight. Ninety-one percent of LM2 heifers and 100% of all other groups had reached puberty before the breeding season. Pregnancy rates did not differ significantly between treatment groups. Supplementation of a high roughage diet with @entity6193 decreased age at puberty of heifers in the heavy weight class and this decrease was not due to increased body weight or @entity1017 . Perhaps heifers with above average weaning weight possess a greater inherent growth potential than heifers below the average weaning weight and hence are more capable of utilizing @entity6193 to an advantage.
