Magnesium balance in adult cats fed a dry food rich in lactose.
The question addressed was whether lactose consumption would stimulate apparent magnesium absorption in adult cats. In a cross-over study, eight cats were fed dry diets without or with 10% lactose, which was added at the expense of the glucose component. Urine and faeces were quantitatively collected and the balance of magnesium, calcium and phosphorus was determined. Lactose feeding did not affect mineral absorption. The dry matter content of faeces was unchanged after lactose consumption. Urinary excretion of galactose represented 0.2% of the intake. It is concluded that lactose ingestion at a level of 1.2 g/kg body weight has no effect on mineral absorption and on the consistency of faeces in adult cats.
Isoenergetic substitution of dietary fat (beef tallow) for carbohydrates (cooked corn starch plus dextrin) does not affect magnesium absorption in cats
Zusammenfassung 
 
Der isoenergetische Ersatz von Kohlenhydraten (denaturierte Maisstarke plus Dextrin) durch Fett (Rindertalg) und sein Einflus auf die Magnesium-Absorption bei Katzen 
 
 
 
In einem 2 × 2-wochentlichen Cross-over-Versuch erhielten acht Katzen eine pelletierte Ration mit 10 g Fett/100 g Futter (Kontrolle) bzw. eine Ration mit 32 g Fett/100 g Futter ad libitum. Der hohe Fettgehalt wurde durch den isoenergetischen Ersatz von denaturierter Maisstarke plus Dextrin durch Rindertalg erreicht. Bei der Verabreichung der fettreichen Diat erhohte sich die Futteraufnahme und damit auch die Aufnahme an Mineralstoffen. Die prozentuale schcinbare Absorption von Magnesium, Calcium und Phosphor wurde nicht signifikant beeinflust. Dieses Ergebnis ist besonders interessant hinsichtlich von struviter Urolithiasis bei Katzen.
Acceptability and digestibility by adult cats of diets made with various sources and levels of fat.
Three experiments were conducted to determine the acceptance and digestibility by adult cats of purified diets containing various fats. In the first experiment, a two-choice trial, one female and 11 male cats (2 to 7 kg body weight) were used to determine the acceptance of diets made with bleached tallow (BT) versus six alternate fats: chicken fat (CF), yellow grease (YG), lard (L), butter (B), unbleached tallow (UT) and partially hydrogenated vegetable fat (VF). Three groups of four cats each, individually housed, were tested during four consecutive 2-week periods, giving a total of eight cats per choice. The diet made with BT was preferred (P greater than .001) over those made with B or CF. In the second experiment, a two-choice trial, 14 male and 10 female cats (2 to 5 kg body weight), individually housed, were used to determine the acceptance of diets made with 10, 25 or 50% YG. One groups of 12 cats was used to test the inclusion of 25 versus 50% YG, and another group of 12 were used to test 25 versus 10% YG. The diet made with 25% fat was preferred over diets made with 10% (P greater than .001) or 50% fat (P greater than .02). The third experiment, with 12 male and 12 female cats (2 to 5 kg body weight), examined the digestibility of purified diets made with 25% CF, BT, UT, L and B and 10, 25 and 50% YG. Each diet was fed to six cats in metabolism cages for a 5-day preliminary period and a 5-day fecal and urine collection period. Chromic oxide was included in all diets as a marker. Digestibility coefficients were computed by both the marker method and the conventional food intake and fecal collection method. Mean digestion coefficients for dry matter (DM), crude protein (CP), ether extract (EE) and energy (E) for diets made with 25% CF, YG, L, B, UT, BT, 10% YG, 50% YG were, respectively: DM-90.6, 89.5, 90.8, 89.8, 87.1, 88.0, 87.4, 90.2%; CP-91.1, 91.5, 92.7, 92.0, 90.9, 90.8, 87.0, 94.8%; EE-98.6, 98.0, 98.6, 90.9, 90.8, 87.0, 94.8%; EE-98.6, 98.0, 98.6, 90.9, 90.8, 87.0, 94.8%; EE-98.6, 98.0, 98.6, 97.5, 98.1, 98.2, 90.4, 97.9%, and E-93.8, 93.1, 93.7, 92.2, 89.5, 89.9, 88.6, 92.8%. Mean digestion coefficients calculated from total fecal collection and from chromic oxide were: 88.5 and 89.9% for DM; 90.8 and 91.9% for CP; 98.0 and 97.3% for EE, and 91.6 and 92.1 for E.