For AFC to be about 24 months of age , first service of heifers should start from 13 months of age . Although 68 % of heifers were inseminated before 15 months of age in top herds , conception age seems to be later as only 60 % of heifers calved down before 24 months of age . It seems that it is difficult to achieve an AFC of 24 months as even in top herds only 84 % of first calving dates were below 27 months of age .
Reproduction management indicators for top herds in comparison to bottom herds showed an earlier first service , lower SPC and lower DO , being 89 vs . 104 days , 1.62 vs . 2.35 and 112 vs . 164 days , respectively . As expected the proportion of first services before 80 days-inmilk , cows pregnant before 100 and 200 daysin-milk was better for top herds in comparison to bottom herds .
The extended intervals from calving to first service could be ascribed to reproductive management of cows after calving , e . g . cows having uterine infections or reproductive problems such as cystic ovaries not detected early . Uterine infections could be caused by calving environment , i . e . wet and dirty conditions , the birth weight of calves ( poor sire selection ), presentation ( position ) of calves during the calving process , retained placentas because of nutritional imbalances , and a host of other potential causes .
Specialist workers required for reproduction management A specific person should be appointed to do heat detection ( and recording ) otherwise
everyone is under the impression that someone else is doing it . The same applies for inseminators as this technique requires special training and skills . Some inseminators seem to have a natural ability to inseminate cows successfully while others never really develop the required skills .
Heat spotters and inseminators are often not valued sufficiently or financially . While the service technique of inseminators may be correct outside the cow , the site of semen deposition is a crucial factor affecting conception . Semen deposited inside one of the uterus horns would not result in a conception when ovulation occurs in the other uterus horn . Therefore , semen should be deposited inside the uterus body . This is difficult as the uterus body is relatively small , being about 25 mm long .
The performance of these workers can also only be evaluated about six weeks after servicing cows during the pregnancy checks by the herd veterinarian .
The success rate of first service and the SPC can be used to evaluate the performance of inseminators . The inverse of SPC is conception rate or inseminator efficiency , i . e . 2 services per conception equals a 50 % conception rate . However , it is important not to use only the records of cows confirmed pregant . The number of services , except those within the last six weeks , of non-pregnant cows , should also be included . Therefore , an all services per conception estimation gives a further indication of the service efficiency
AgriKultuur | AgriCulture
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