Lactational and Ruminal Response of Dairy Cows to Ten and Twenty Percent Dietary Newspaper

Abstract
Fifteen lactating Holstein cows in a 3 × 3 Latin square experiment determined effects of ground newspaper in the diet. Test components of the rations were: A) 20% cottonseed hulls; B) 10% paper and 10% cottonseed hulls; C) 20% paper. All animals received 2.3 kg of long alfalfa hay daily. Proximate analysis and gross energy determinations indicated that the paper rations contained more crude fiber, ether extract, and gross energy and less crude protein and ash. Ink in the paper appar- ently caused higher gross energy values and probably increased ether extract. Estimates of dry matter digestibility by an in vitro technique were not significantly different being 77.4, 77.4, and 77.5 for the control, 10% paper, and 20% paper rations. Aver- age daily ration intakes were significantly different among rations with intakes of 21.5, 17.0, and 12.5 kg per day for the control, 10% paper, and 20% paper. Paper at 20% of the ration significantly lowered actual milk yields but did not significantly lower fat-corrected milk yield during the six weeks. Average daily fat-corrected milk yields for control, 10% paper, and 20% paper treatments were 15.9, 16.9, and 16.3 kg. Milk fat percentages were 2.6, 3.1, and 3.4 with significant differences between treatments. Milk protein and solids-not-fat were not significantly different; however, there was an inverse linear response be- tween treatment and milk protein percent- age. There were small differences in ruminal volatile fatty acids with a significantly