Pregnancy and Lambing Rate Following Laparoscopic Artificial Insemination with Two Different Types of Diluent and Frozen-thawed Sperm Dose in Ewes

Abstract
| The effects with two different types of diluent (commercial Triladyl® and home-made tris based) and number of frozen-thawed ram sperm (100 × 106 and 50 × 106 sperm dose) on pregnancy and lambing rate following laparoscopic artificial insemination (LAP-AI) in indigenous ewes in Bangladesh were studied. A total of 78 non- pregnant ewes were synchronized for oestrus with two doses of 100 μg PGF2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; G1 (n = 18; commercial Triladyl®/ 100 × 106 sperm), G2 (n = 21; commercial Triladyl®/ 50 × 106 sperm), G3 (n = 20; home-made tris based/ 100 × 106 sperm) and G4 (n = 19; home-made tris based/ 50 × 106 sperm). Ewes were inseminated within 18 h to 22 h after the onset of oestrus. The non-return rate (83.3%) and pregnancy rate (72.2%) were highest with commercial Triladyl®/ 100 × 106 sperm compared to other groups. The mean gestation period ranged from 149.50 ± 3.50 days to 153.75 ± 1.03 days. The lambing rate (100%) was highest with home-made tris based/ 50 × 106 sperm compared to other groups. The multiple birth rate was highest (66.7%) with commercial Triladyl®/ 100 × 106 sperm, home-made tris based/ 50 × 106 sperm compared to other groups. The multiple birth rate ranged from 61.5% to 66.7%. The single, twin and triplet lambing was higher 38.5%, 58.3% and 18.2% with commercial Triladyl®/ 50×106 sperm, home-made tris based/ 50 × 106 sperm and home-made tris based/ 100 × 106 sperm, respectively. The lambing size ranged from 1.69 ± 0.17 to 1.82 ± 0.20. In conclusion, the home-made tris based diluent and 100 × 106 sperm dose would be the most practical method for achieving high pregnancy and lambing rate following LAP-AI in Bangladeshi ewes.