کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10973682 1108017 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Short communication: Test for nonpregnancy in dairy cows based on plasma progesterone concentrations before and after timed artificial insemination
ترجمه فارسی عنوان
ارتباط کوتاه: آزمایش عدم بارداری در گاوهای شیری مبتنی بر غلظت پروژسترون پلاسما قبل و بعد از تلقیح مصنوعی به موقع
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
چکیده انگلیسی
Timed artificial insemination (AI) programs have increased reproductive efficiency in dairy herds. A low timed AI pregnancy per AI is partially explained by cows that fail to respond optimally to the series of treatments that are designed to synchronize ovulation for AI. We hypothesized that testing cows for plasma progesterone concentrations during a timed AI protocol could be used as an early diagnostic test for nonpregnancy. Lactating Holstein cows (n = 160) in 2 confinement-style dairies were used. Cows were treated with Presynch Ovsynch 56 for timed AI. Concentrations of progesterone in plasma were measured at −3, 0, 7, and 25 d relative to timed AI. Progesterone data were analyzed and receiver operating characteristic curves were generated by using logistic regression. The area under the receiver operating curves for a progesterone test for nonpregnancy on d −3 (PGF2α), 0 (AI), 7, and 25 d relative to timed AI were 0.68, 0.52, 0.55, and 0.89, respectively. The cutpoints and sensitivity (respectively) for the progesterone test were 0.51 ng/mL (lower = nonpregnant) and 28.2% for the day of PGF2α, 0.43 ng/mL (greater = nonpregnant) and 17.9% for the day of AI, 1.82 ng/mL (lower = nonpregnant) and 23.1% for 7 d after AI, and 2.67 ng/mL (lower = nonpregnant) and 76.0% for 25 d after AI. The false positive rate was less than 5% for all tests. Analysis of a second data set from a published study gave approximately the same cutpoints and sensitivity. When both studies were combined, approximately 20% of nonpregnant cows could be identified with a single test that was done before or shortly after AI with a false positive rate of less than 5%. When 2 and 3 tests were applied sequentially, the sensitivity for identifying nonpregnant cows increased from 38.4 to 50.5%. The pregnancy per AI for those cows that met the established progesterone criteria was approximately 3 to 4 times greater than those that failed to meet the criteria. The conclusions were that cows destined to be nonpregnant after timed AI can be identified before or shortly after AI. Testing for nonpregnancy before or shortly after AI may have utility with respect to eliminating a nonproductive AI (cows identified before AI) or shortening the time to reinsemination (cows identified by 1 wk after AI).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 99, Issue 7, July 2016, Pages 5858-5865
نویسندگان
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