Large White and Duroc semen was used to form a three-breed cross from Large White x Norwegian Landrace dams. A pair of sibs from each litter was fed ad libitum and a further pair on a time-based scale at the Meat and Livestock Commission testing station at Stirling, Scotland. A total of 241 litters was tested. At the end of testing the pigs were slaughtered and standard carcass measurements were made. One side of the carcass of each of a sample of 60 pigs was fully dissected. The Duroc progeny grew faster and had better food conversion efficiency than the Large White progeny when fed ad libitum but there was no difference between the breeds when feeding was restricted. The Large White progeny produced a better trimming yield and were slightly longer. There was no significant difference in fat depths. The proportions of lean, fat and bone tissues did not differ greatly between the breeds although the Large White progeny had slightly more lean tissue and the Duroc progeny were more heavily boned and had more intermuscular fat. The Duroc terminal sires gave an economic advantage of £1·70 per pig when fed ad libitum but a loss of £0·35 when fed to a restricted scale. This was primarily due to the superior growth rate and food conversion efficiency of the Duroc progeny when fed ad libitum.

This study was carried out to investigate breeds, age and sex effect on haematological and biochemical profiles of ducks. A total of one hundred and twenty (120) day old ducklings of two breeds (60 Muscovy and 60 Mallards) were used for the study. The ducks were divided into four (4) groups centered on the breeds and sexes designated as Muscovy males, Muscovy females, Mallard males and Mallard females. At 4 and 8 weeks, blood samples were collected from the experimental group and analysed. The experiment was 2 × 2 × 2 factorial in a Randomized Complete Block Design with two breeds (Mallard and Muscovy), sex and age. Results obtained showed significant effect (P < 0.05) of breeds on Packed Cell Volume, Haemoglobin, Red Blood Cells (RBC), White Blood Cells, Platelets, Total Proteins, Albumin, Globulin and Tryglycerides while no significant effect of breeds (P > 0.05) was observed on Urea, Creatinine and Glucose in the two breeds of ducks. Result indicated that Muscovy recorded higher values for Haemoglobin (10.35 ± 0.52g/dl) and RBC (4.62 ± 0.24 × 1012/ L) than Mallard which recorded Haemoglobin (10.10 ± 0.62 g/dl) and RBC (4.43 ± 0.27 × 1012/ L). Significant effects of Sex and age (P < 0.05) were observed on haematological and biochemical profiles. It is therefore concluded that the two breeds of ducks studied can be successfully raised in Rivers State, Nigeria without adverse effect on their health since their haematological and biochemical values compared favorably with standard reference values. Values obtained in this investigation could also serve as a baseline data of these breeds in humid tropical environment.