Age structure of fertilization of heifers and its influence on the frequency of complication of calving in first-calf cow and their culling from the herd

Abstract

During the analysis of the age of heifers, in which they became pregnant, it was found that 28.5% of animals were fertilized before 14 months of age. However, 45.2% of heifers became pregnant from 14 till 17 months. At the age from 17 till 20 months, 23.6% of heifers became pregnant. At least 2.7% of heifers were inseminated after reaching the age of more than 20 months. A frequency analysis of calving complicated course firstborn depending on age heifers during fertilization showed that it has noted and a third of fertilized heifers under 14 months of age and a group of 17 and up to 20-months. The frequency of complicated calving was lower by 7.9% in first-born cows that were fertilized at the age of heifers from 14 to 17 months., Than heifers first and third groups. In firstborn fertilized after 20 months of age and complications is calving were recorded in 50.0% of cases. Analysis of spread of Art and complicated course calving cows of different age groups depending on the number of previous families showed that it observed in 24.7% of all cows animals that calved. The largest of the share was 16.3% firstborn. Cows at the second calving or impeded his progress noted a 4.9 times fewer animals and in cows third calving share its complications decreased 12.5 times relatively firstborn. Animals of the fourth and subsequent calving we are number of complications was smaller group of first fruits of 4.3 times (p ˂0,001). The frequency of culling cows in the herd was 23.7%. And the analysis of the structure of culled cows depending on the age and period of lactation showed that during 90 days of lactation 57.5% of cows dropped out. Every fourth cow dropped out at the end of lactation. First-born 47.2% of all culled cows were most often culled of all cows rejected. Animal second lactation dropped to 1.55 times (p ˂0,01) less or the same first-born, and cows third and fourth lactations or more dropped to 2.8 - 2.6 times (p ˂0,01) less than cows of the second lactation. Most first-born 24.2% were culled during 90 days of lactation, cows of the third and fourth and more lactations dropped out 3.6 and 3.3 times (p ˂0.05) less. At the end of lactation, 15.3% of first-born cows dropped out, which is 9.7% more than cows of the second lactation and 12.9% more than cows of the third and fourth and more lactations.

Морфогістоархітектоніка Органів Статевої Системи Корів За Симптоматичної Неплідності

“…Нині існує значна кількість наукових повідомлень стосовно поширеності неплідності великої рогатої худоби, зокрема дослідники стверджують, що у корів цей показник коливається в межах від 20 до 90 % [1][2][3][4]. Важливо зауважити, що неплідність у корів частіше зумовлюється віковими та індивідуальними особливостями організму, умовами їх годівлі, утримання та експлуатації [5][6][7].…”