Paper and whey as a feedstuff for ruminants

Eleven papers were compared for absorption of whey and for digestibility in vitro. Papers were squared, ground, and soaked in whey for 1, 5, and 15 min and for 1, 6, 24, 48, and 72 h. Digestibility in vitro was determined on minimum and maximum whey absorption of each squared and ground paper sample. Whey absorption by squared papers increased with time. Ground samples absorbed more whey than squared ones and maximum quantities were absorbed with 1 to 5 min. Mean percent absorptions for ground telephone book covers, glossy magazines, computer cards, computer printout sheets, daily newsprint, telephone directory yellow pages, cardboard box, feedsacks, brown bags, telephone directory white pages, and coasters were: 31.0, 35.2, 35.4, 36.5, 43.9, 47.9, 51.0, 51.4, 51.7, 55.6, and 67.4. For seven papers, addition of whey increased digestibility. Four papers were either unchanged or decreased in digestibility. This depression of digestibility may have resulted from the high fat content of whey used. Based on in vitro digestibilities, we conclude that it is possible to recycle selected paper/whey combinations through ruminants.