RELATIONSHIPS BETWEEN FORCE-FEEDING AND SOME PHYSIOLOGICAL PARAMETERS IN GEESE BRED FOR FATTY LIVER
The susceptibility of geese of different genotypes and sexes to force-feeding, some plasma biochemical parameters (thyroid hormones, cholesterol, retinoids, total protein and albumin) of force-fed geese, and the relationship between force-feeding, fat storage and the above-mentioned
parameters were studied. Sixty (30 male and 30 female) geese of three genotypes (Hungarian, Landes and their crossbred called Babat Hybrid) were divided in two groups at 12 weeks of age. Geese in one group (5 males and 5 females from each genotype) received mixed feedingad libitum. Birds in
the other group were force-fed with maize. After 3 weeks all birds were bled, blood samples were taken, and the above-mentioned plasma parameters were determined. Thyroxine (T4) levels were significantly lower in force-fed (11.6 ± 3.5 ng/ml) than in control geese (22.7 ± 4.09 ng/ml).
Plasma triiodothyronine (T3) level was also lower in the force-fed than in the control group, but the difference was not significant (1.87 ± 0.23 ng/ml and 2.11 ± 0.28 ng/ml, respectively). Plasma total protein (TP, 45.2 ± 4.5 g/l), albumin (ALB, 16.51 ± 2.8 g/l),
(-carotene (BC, 3504 ± 3107 µg/l), retinol (ROL, 1160 ± 505 µg/l), retinyl palmitate (RP, 1745 ± 405 µg/l) and total cholesterol (TCh, 4.32 ± 0.55 mmol/l) levels were elevated in the force-fed group as compared to the control (TP = 36.4 ±
5.1 g/l, ALB = 15.6 ± 0.9 g/l, BC = 1657 ± 1681 µg/l, ROL = 687 ± 375 µg/l, RP = 1398 ± 607 µg/l, and TCh = 2.83 ± 1.98 mmol/l). All differences were significant except those found for albumin and (-carotene. No significant sex-
or genotype-related effects were observed for these parameters.