Novia Dimar  Dwitarizki, Ismaya  , Budi Prasetyo  Widyobroto, Sigit  Bintara, Tety  Hartatik, 
    Estradiol Concentration and Estrous Behaviour in Tropical Heifers
Supplemented with Undegradable Protein,
    Journal of Animal and Veterinary Advances,
    Volume 16,Issue 1,
    2017,
    Pages 24-31,
    ISSN 1680-5593,
    javaa.2017.24.31,
    (https://makhillpublications.co/view-article.php?doi=javaa.2017.24.31)
    Abstract: This research was aimed to examine the effect of Rumen Undegradable Protein (RUP) supplementation
on estradiol profile and estrous behaviour in heifers maintained in tropical climate. A total of 36 Brahman Cross
(BX) beef heifers were divided into 2 groups, control group (ration without supplemented RUP) and treatment
group (ration with supplemented RUP). The heifers were inseminated on third days after ovaries checking with
USG and synchronized with PGF<sub>2&alpha;</sub> . Blood sampling was conducted to measure the estradiol concentration in 5 points: during the estrous (0); 5; 17; 19 and 21 days. Estrous behaviour were recorded 4 times a day. Results
showed no significant effect (p&gt;0.05) of feeding RUP between control and treatment group to estradiol
concentration (130.96&plusmn;40.96; 134.75&plusmn;39.00; 137.31&plusmn;47.24; 133.48&plusmn;36.90; 143.89&plusmn;55.83 pg mL<sup>-1</sup> vs. 126.59&plusmn;34.86;
124.93&plusmn;38.82; 123.20&plusmn;42.39; 126.11&plusmn;46.45; 126.25&plusmn;32.66 pg mL<sup>-1</sup>) and estrous behaviour but there was a
significant correlation (p&lt;0.01) between estradiol concentration to estrous behaviour. In conclusion, the level
of estradiol concentration and estrous behaviour in heifers were not effected by undegradable protein
supplementation.
    Keywords: Estradiol;estrous;heifers;tropical;rumen undegradable protein