@article{Goncharuk_2018, title={Analysis of reproductive disorders in the dairy herd}, volume={55}, url={https://abg-journal.com/index.php/journal/article/view/182}, DOI={10.31073/abg.55.25}, abstractNote={<p>The main factors that determine the effectiveness of dairy cattle are the high level of milk performance and regular reproduction of the livestock. However, often in high-productive herds there is a deterioration in the state of reproduction: the duration of service-period and period be-tween calving is prolonged, the insemination index increases, the calve output per 100 cows are emitted, the animals are culling from the herd during the first-second lactation because reproductive disorders and gynaecological diseases.</p> <p>The purpose of the study was to analyze the state of reproduction in the herd of Ukrainian Black and White dairy breed and determining the frequency of reproductive disorders, depending on age and body weight of heifers at the first mating, the number of lactation, the evaluation of ex-terior type of cows and their average daily milk yield.</p> <p>The analysis includes 569 cows of “AF Matyushi” LLC in Kyiv region, including 195 cows of the first lactation, 166 cows − the second, 208 cows − the third lactation and the older. For analy-sis cows were divided into two groups: 1) without reproductive disorders (pregnant and condition-ally healthy); 2) with reproductive disorders (not pregnant and with gynaecological diseases). The cows’ pregnancy was confirmed by ultrasound; the conditionally healthy were cows less than 83 days after calving and after the first and second inseminations before ultrasound diagnostic; not pregnant cows − cows after two or more confirmed failure inseminations.</p> <p>In 2017, the average 305-day milk yield in the herd of Ukrainian Black-and-White dairy breed in “AF Matyushi” LLC was 6583 kg, fat content 3,68% and 242 kg, milk protein content – 3,07% and 202 kg. The average service-period was 178 days, the period between calving − 458 days, the insemination index − 3,30, the coefficient of reproductive ability was 0,80. Although the herd is characterized by rather high milk performance and low level of reproductive indicators, for exam-ple, the duration of the service-period is almost twice the optimal level.</p> <p>Depending on the number of lactation, the number of pregnant cows varies within 24,1–29,5%, conditionally healthy – 32,2–34,9%, not pregnant – 2,4–7,2%, with gynecological diseases – 34,4–36,8%. The most common gynaecological diseases were metritis, hypofunction and cystic ovary, uterine abscess.In the studied herd, the age of heifers at the first mating is slightly higher than the optimal level – an average 19,6 months. Depending on the age at the first mating certain tendencies in changing the frequency of reproductive disorders were not detected. Depending on the age at the first mating of heifers, the proportion of cows without reproductive disorders varied from 52 to 63%, with reproductive disorders – from 37 to 48%.On average, live weight of heifers at the first mating was 385 kg. The analysis showed that cows, which did not have a reproductive disorders in 2017, had a significantly higher live weight at the first mating – on average by 10 kg (P &lt; 0,05). With the growth of live weight at the first mating from 350 kg and below to 441 kg and above the number of cows with reproductive disorders de-creases from 50% to 35%.</p> <p>An important part of dairy cattle breeding is a linear evaluation of exterior type of cows, be-cause the exterior is an external manifestation of the constitution of animals, their individual charac-teristics, breed type, the exterior can be judged on the direction of animal productivity, their health, reproductive ability and predict the duration of productive use in the herd.</p> <p>In the “AF Matyushi” LLC, the predominant proportion of exterior of cows was evaluated “very well” (45% of cows of the total population) and “well with the plus” (30%). Cows with a higher evaluation of exterior type were characterized by a lower frequency of reproductive disor-ders. In the group of cows without reproductive disorders, on average, the overall evaluation of the exterior type of cows was higher by 1,1 points (P &lt; 0,01) compared to animals with reproductive disorders. With increasing of the evaluation of exterior from 65–74 to 90 points and above the number of cows with reproductive disorders decreases from 54% to 31%.</p> <p>As a result of the analysis, it was found that in the group of cows with reproduction disorders there was a significantly higher average daily milk yield in the second month of lactation – 1,6 kg (P &lt; 0,05), so cows with higher milk productivity have more often reproductive disorders. How-ever, certain trends in the change in average daily milk yield in the studied groups of cows were not detected. In particular, depending on the value of the average daily milk yield in the group without reproductive disorders, the proportion of cows was 52–63%, with reproductive disorders – 37–48%. The one-factor dispersion analysis showed that the effect of the studied indicators on the frequency of reproduction disorders in the herd varied from 5,0 to 24,9%, but in all cases it was not reliable (P &gt; 0,05).</p> <p>The influence of age and body weight at first mating of heifers on the frequency of reproduc-tive disorders was 5,0% and 24,9%, respectively, lactation number – 18,2%, exterior type evalua-tion – 14,0%, average daily milk yield – 14,5%, however, in all cases this effect was unreliable (P &gt; 0,05). The unreliability of the influence of the studied factors on the reproduction in the herd proves the essential role of environmental factors.</p&gt;}, journal={Animal Breeding and Genetics}, author={Goncharuk, M. S.}, year={2018}, month={May}, pages={179-186} }