http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Growth and reproductive development of Angus, Brahman, Bonsmara, Romosinuano, Tuli, and Wagyu bulls
xii, 113 leaves : illustrations ; 28 cm.
The purpose of these experiments was to evaluate growth and reproductive development of: fall (F; n=7) versus spring (S; n=10) born Brahman bulls (Experiment I), and Angus (n=7) and Brahman bulls (n=10) in comparison to Bonsmara (n=8), Romosinuano (n=10), Tuli (n=10), and Wagyu (n=10; Experiment II). Treatment regimens were similar between the two trials. Bulls were maintained together and fed a 3:1 (corn:soybean meal) supplement containing lasalocid. The supplement was fed at 1.5% of BW and bulls had free access to coastal bermudagrass hay, water, and a salt/mineral mix. Measurements were taken at 14-d intervals until bulls reached sexual maturity (SM; ejaculate with [>] 500x10⁶ sperm with [>] 50% motility). Measurements included BW, body condition score (BCS), hip height (HH), scrotal circumference (SC), and testis length. Upon attaining a 21 cm SC, ejaculates were collected and continued through SM. Stages of reproductive development were first sperm, puberty (50x10⁶ sperm/ejaculate; P), and SM. No differences (P>0.10) were found in Experiment I for BW, BCS, SC, or paired testis volume (PTV) between seasons of birth at FS or P. Age at FS tended (P<0.08) to be greater in F (418±13d) than S (382±12d), was similar at P, and was delayed (P<0.05) at SM for F (546±17d) versus S bulls (481±14d). F had (P<0.05) greater SC (34.2±.7 vs. 31.5±.6cm) and PTV (608±33 vs. 451±27cc) than S. Interval from FS to P was similar but interval from P to SM was greater (P<0.05) in F (82±10d) than in S bulls (54±8d). Brahman bulls born in the fall have SM retarded during the cold months with short photoperiods compared with spring born bulls who reached maturity during longer photoperiods. In experiment II, Angus and newly introduced breeds were younger (P<0.05) at FS, P, and SM than Brahman bulls which were heavier and taller (P<0.05) than all other breeds at each stage. Angus, Bonsmara, and Brahman bulls had similar (P>0.10) scrotal circumference throughout the trial while Wagyu bulls had the smallest scrotal circumference at each stage, with Romosinuano and Tuli falling intermediate. Newly introduced breeds developed competitively to Angus and more rapidly than Brahman bulls.
"Major subject: Physiology of Reproduction"
Issued also on microfiche from Lange Micrographics.
Includes bibliographical references (leaves 100-112).