Twenty-four pigs, 13-14 weeks of age, were studied during an experimental period of 10 weeks. The pigs were randomly divided into 3 groups. Two groups were fed a commercial feed supplemented either with a suspension of aluminium hydroxide (Al(OH)3) or aluminium phosphate (A1PO4). The third group served as a control. The same total amount of aluminium was given to each of the 2 experimental groups. After three weeks the Al(OH)3-pigs developed severe hypophosphatemia, with an average decrease in serum phosphate of 60%, a decreased growth rate and a lower concentration of 2,3-diphosphoglycerate in the erythrocytes as compared to controls. Intense hypercalcemia developed in the Al(OH)3-group during the first 6 weeks, whereas the AlPO4-pigs and the control group developed neither hypophosphatemia nor hypercalcemia. At necropsy, the consequence of the long lasting hypophosphatemia was found to be increased relative kidney weights with morphological signs of tubular damage and dyscalcification. No similar changes were observed in the AlPO4-groups and there were no organ weight deviations compared to the control group.
Tjugofyra grisar, 13–14 veckor gamla, studerades under en tio veckor lång experimentperiod. Grisarna delades slumpvis in i tre grupper. Två grupper utfodrades med ett kommersiellt foder, tillsatt lösning av, antingen aluminium-hydroxid (Al(OH)3 eller aluminium-fosfat (AlPO4). En tredje grupp utgjorde kontroller. Ungefär samma totala mängd aluminium tillfördes vardera experimentgruppen. Efter tre veckor utvecklade de Al(OH)3 behandlade grisarna hypofosfatemi, och en genomsnittlig sänkning av serumfosfat med 60% minskad tillväxthastighet och lägre koncentration av 2.3-difosfoglycerat i röda blodkroppar än kontrollerna. Hyperkalcemi utvecklades i Al(OH)3-gruppen under de första sex veckorna, medan AlPO4-grisar och kontroller inte fick vare sig hypofosfatemi eller hyperkalcemi. Vid obduktionen fann man ökad relativ njurvikt och morfologiska tecken på tubulär skada med förkalkning. Några likartade förändringar kunde inte observeras i AlPO4-gruppen och det fanns inte några avvikelser i organvikter jämfört med kontrollgruppen.