Factors affecting milk intake of kittens

Quantitative information on suckling behaviour and milk intake of kittens is very limited. Kittens nurse frequently and measuring milk intake is complicated because neonatal kittens are stimulated to urinate and defecate by grooming of the queen just before and during suckling. To evaluate the effect of time between suckling bouts and maternal diet on milk production, milk intake was assessed by the "weigh-suckle-weigh" method for 48 h once a week. Kittens were separated from their queens for 2 h at 1 wk, 3 h at 2 wks, 4 h at 3 wks and 5 h at 4 wks of age. Kittens (n=91) were nursed by queens (n=20) fed commercial extruded diets containing approx. 10% (1,984 observations) or 20% fat (1,184 obs.). Kittens were noted to retain a set teat order during suckling which was more rigid in larger litters. No obvious diurnal effect on suckling behaviour was observed. Milk intake/kitten was not affected by the number of kittens (n=3-6). Weight gain of kittens during milk intake measurements was lower than that of kittens not separated from queens, suggesting an effect of either stress or lower milk intake during the procedure used. Higher milk intake was found in kittens suckling on queens fed the high fat diet (27-35 vs 10-16 g/d, respectively). Our results indicate that age has less influence (1 vs 4 wk, p<0.01, wks 2 and 3 ns) on milk production than maternal diet composition (p<0.001). These results are being confirmed using an alternative method (D₂O dilution).