Table 5.

Amount of faeces, DM of the faeces, mineral concentrations in the faeces and faecal mineral excretion of cats fed a diet with a varying protein concentration and quality (Mean values with their standard errors; n 8 per diet)

	Protein concentration				Protein quality†
	HQ 35 %	HQ 44 %	HQ 57 %	sem	HQ 57 %	LQ 55 %	sem
Amount of faeces (g/kg BW per d)	5·25a	4·46a	7·35b	0·53	7·35	5·74	0·64
DM of the faeces (%)	44·2a,b	42·4b	39·3a	0·83	39·3	49·0	2·23
Amount of faeces (g DM/kg BW per d)	2·33b	1·85a	2·83b	0·19	2·83	2·88	0·31
Faecal concentrations (mg/g DM)
Ca	72·1b	63·0a	77·2b	1·62	77·2	68·2*	2·06
P	48·8b	33·2a	50·9b	1·81	50·9	41·1*	1·44
Mg	6·10b	5·24a	7·12b	0·20	7·12	4·72*	0·35
K	2·16a	4·48b	2·36a	0·37	2·36	1·08*	0·28
Na	2·13b	1·98a	2·35b	0·13	2·35	2·21	0·15
Cl	1·50	1·64	1·78	0·21	1·78	1·35	0·27
Faecal excretion (mg/kg BW per d)
Ca	167b	117a	224c	16·9	224	166*	21·5
P	112b	62·2a	144b	10·8	144	115	12·5
Na	5·27a,b	3·70a	6·93b	0·68	6·93	6·65	1·07
Mg	14·3b	9·76a	20·1b	1·49	20·1	13·2*	1·77
K	5·91	8·91	7·27	1·14	7·27	2·94*	1·10
Cl	3·69	3·32	5·58	0·77	5·58	4·11	1·12

HQ 35 %, high protein quality diet with 35 % crude protein content; HQ 44 %, high protein quality diet with 44 % crude protein content; HQ 57 %, high protein quality diet with 57 % crude protein content; LQ 55 %, low protein quality diet with 55 % crude protein content; BW, body weight.

^a,b,c Mean values within a row with unlike superscript letters were significantly different (P ≤ 0·05).

* Mean value was significantly different from that for HQ 57 % (P ≤ 0·05).

† Protein quality differed depending on the amounts of greaves meal in the diets: HQ 35 % and HQ 44 %, 10 % greaves meal; HQ 57 %, 11 % greaves meal; LQ 55 %, 34 % greaves meal.