Bioavailability of manganese from manganese proteinate, manganese sulfate and manganese oxide in broilers reared under heat distress

The relative bioavailabilities of manganese from manganese monoxide/ manganese sulfate and Mn-proteinate were compared in two different environmental conditions. Birds were raised at a cycling temperature of 18.3 to 23.9 °C or at a cycling temperature of 23 to 35 °C. Experimental animals used were day-old male commercial broiler chicks (Arbor Acre X Arbor Acre). Treatments were prepared from a starter and a grower diet (26 ppm Mn dry matter basis) which were supplemented with 0, 1000, 2000, and 3000 ppm Mn as Mnproteinate, manganese sulfate or manganese monoxide. Birds had ad libitum access to feed and water. Bone was the most sensitive tissue followed by kidney to manganese supplementation from all sources. Tibia manganese concentration increased linearly (P \u3c 0.05). Based on ratios of slopes from multiple linear regression analysis of bone manganese on manganese intake from various sources, the relative bioavailabilities were 120 and 91% from manganese proteinate and manganese oxide, respectively, compared with 100% from manganese sulfate in three-week old chicks and 125 and 83% from manganese proteinate and manganese oxide, respectively, compared with 100% from manganese sulfate in chicks older than three weeks. All values were significantly different from 100% (P \u3c 0.05). Heat distress was observed to increase the manganese bioavailabilities of the various manganese sources (P \u3c 0.05) . Manganese from Mn-proteinate was more available than manganese from manganese sulfate followed by manganese oxide under each environmental temperature regimen