Efficiency of in vivo embryo production according to temporary hypo-nutrition and Body Condition Score condition in Hanwoo donors

The study sought to investigate the in vivo embryos and the number of transferable embryos produced under transient hypo-nutrition conditions and with different body condition scores (BCS) in a multiple ovulation treatment applied to Hanwoo cows. Seventy cows were selected and categorized into control, high-nutrition, and low-nutrition groups based on their feeding levels, and the study was conducted for 23 days. The total number of recovered embryos per group was 6.87±1.34, 10.67±2.00, and 11.78±1.16, respectively. The number of transferable embryos per group was 4.40±1.02, 7.33±2.18, and 8.20±0.97, respectively. This was significantly higher (p<0.05) in the low-nutrition group than in the other two groups. The number of recovered embryos according to the BCS was 4.50±4.50 in the BCS 2.0 group, 11.19±1.34 in the BCS 2.5-3.0, and 14.58±2.38 in the BCS 3.5 group. The number of transferable embryos was 10.75±2.33 in the BCS 3.5 group, which was significantly higher (p<0.05) than 2.50±2.0 in the BCS 2.0 and 7.59±1.05 in the BCS 2.5~3.0 group. In conclusion, maintaining the BCS level of donors above 2.5 is recommended, and temporary hypo-nutrition treatment was found to be effective for fertilized egg production, especially in cows with BCS above 3.5.