Effect of laying parity and sex ratio on reproduction performance and biochemical parameters of White Roman geese kept in an environmentally controlled house

1. This study aimed to investigate the effect of the first and third parities and one male: four females (1 M:4F) and 1 M:6F sex ratios of White Roman geese on their reproductive performance and biochemical parameters in an environmentally controlled house.2. Ganders (<i>n</i> = 136) and geese (<i>n</i> = 656) from the first and third parity were randomly placed into eight pens. These eight pens were assigned to one of four treatments in a 2 × 2 factorial arrangement (two sex ratio groups × two parity groups). The first and third parity treatment groups had 1 M:4F (each pen containing 20 ganders and 80 geese) and 1 M:6F (each pen containing 14 ganders and 84 geese) sex ratio treatment groups, respectively, replicated twice.3. Blood samples were collected from the geese at different time points: upon entering the house (ST), the beginning of the lighting regime of 7 L:17D for six weeks (LC6W), lighting adjustment to 9 L:15D for 6 weeks (9C6W), the peak of egg production (PEP) and the end of egg production (EEP).4. The first parity group had a longer laying period than the third parity (274 vs.191 days). First parity had a lower egg production rate than third parity during whole stage (18.7 vs. 25.4%). Fertility in 1 M:4F group was significantly higher than in 1 M:6F rate group (54.7 vs. 45.1%) at all periods.5. Plasma levels of total protein, albumin, globulin, triglycerides, calcium and phosphorus concentrations were significantly higher for whole laying period in first parity geese compared to third parity birds.