Artificial Insemination Success Rate on Limousine Crossbred Lactation Cows

This study aimed to determine the effect of the success rate of artificial insemination (AI) in lactating Limousin crossbred cows. The materials used were 30 Limousin crossbred cows divided into two physiological statuses: lactating and non-lactating. The cows used had body condition scores (BCS) 4 and 5 on a scale of 1–9, 3–5 years old. Supplementary feeding was given for seven days at 1 kg/head/day post-AI pregnancy examination by ultrasonography (USG) after AI at 42 days of age. Variables observed were feed consumption, estrus appearance (temperature, pH, vulva color, and cervical mucus), AI results (non-return rate) NRR1, NRR2, pregnancy rate (PR) and post-AI ovary size. Data were analyzed with t-test using Microsoft Excel 2019 program, while AI results were analyzed with descriptive method. The results showed that the consumption of feed nutritional value was not significantly different between the two treatments (P > 0.05); temperature, pH, vulva color, mucus, and BCS in non-lactating cows had higher values than lactating cows. However, the results of statistical analysis showed that only the appearance of cervical mucus was significantly different (P < 0.05); non-lactating cows had higher NRR1, NRR2, and PR than lactating cows, and ovary size of lactating cows was smaller than non-lactating cows. In conclusion, the AI success rate in lactating cows was lower than in non-lactating cows, probably due to estrus display, low AI result display (NRR1, NRR2, PR) and small ovary size (length = 1.87 ± 0.13 cm; width = 1.23 ± 0.01 cm). © 2023 Friends Science Publishers