Intake, Digestibility, and Ruminal Degradability of Shredded Hay

¹ Experimental Farm, Agriculture Canada, La Pocatière, PQ, Canada G0R 1Z0
² Research Station, Agriculture Canada, Ste-Foy, PQ, Canada G1V 2J3
³ Université Laval, Département de génie rural, Ste-Foy, PQ, Canada G1K 7P4
⁴ Departamento de Zootecnia, Universidade Estadual de Maringa, 87020-900 Maringa, Parana, Brazil
⁵ Centre for Food and Animal Research, Agriculture Canada, Ottawa, ON, Canada K1A 0C6

Thirty-two Outaouais intact male lambs averaging 39.1 kg were assigned randomly to a 2 x 2 factorial arrangement of treatments consisting of two forages and two methods of harvesting to determine intake and digestibility. The four treatments fed during the experiment consisted of alfalfa and timothy hays harvested with either a prototype mat maker or a conventional mower conditioner. Hays were fed for ad libitum intake for the entire experiment, and data on digestibility and intake were collected for 9 d after a 21-d adaptation. Ruminal degradability of DM, N, and ADF of hays was estimated with two fistulated cows using nylon bags incubated up to 96 h. Harvesting with the prototype mat maker compared with the conventional mower generally increased intake and digestibility of alfalfa and timothy hays. Ruminal degradability of DM and the potentially degradable fraction of DM and ADF was higher when hay was harvested with the prototype mat maker than with the conventional mower. The increased digestibility of hay harvested with the prototype mat maker could be explained by the increased digestibility in the rumen because harvesting with the prototype mat maker increased the potentially degradable fraction of DM and ADF. These results suggest that the digestible energy content of hay was increased by shredding.

Key Words: hay • digestion • shredding • maceration

Submitted on December 30, 1993
Accepted on May 27, 1994