Rangeland Ecology & Management

Get reliable science

HOW DOES PULSE GRAZING INFLUENCE WITHIN-AND BETWEEN-GRAZING SEASON DIETARY QUALITY OF CATTLE IN SHORTGRASS STEPPE?
Author
Plechaty, Tamarah R.
Derner, Justin D.
Scasta, John D.
Augustine, David
Publisher
Society for Range Management
Publication Year
2018
Body

Pulse grazing, high stock density with short grazing periods (weeks) followed by long rest periods (months to > 1 year), is a management strategy posited to decrease selectivity and increase utilization of forage by cattle, but influences on dietary quality of grazing animals in shortgrass steppe are unknown.� We used the experimental framework of the participatory, stakeholder-led Collaborative Adaptive Rangeland Management (CARM) project at the USDA Central Plains Experimental Range to compare effects of pulse grazing to traditional rangeland management (TRM) on weekly dietary quality (based on fecal NIRS) of yearling steers for a 20-week grazing season (mid-May to early October) for two years (2015 and 2016).� Pulse grazing employed the same moderate stocking rate as TRM, but stocking density was ten-fold higher (1.85 vs. 0.185 steers per ha), and livestock were adaptively rotated among 10, 130 ha pastures within the grazing season. Across the grazing season, crude protein in cattle diets was 26-31% greater for TRM than pulse grazing in 2015 (TRM 9.7 � 0.6%, pulse grazing 7.4 � 0.5 %, mean � 1 SE) and 2016 (TRM 8.6 � 0.5 %, pulse grazing 6.8 � 0.2 %).� Dietary digestible organic matter was also greater for TRM than pulse-grazing in 2015 (TRM 62.4 � 0.3 %, pulse-grazing 61.0 � 0.4 %) and 2016 (TRM 64.0 � 0.8 %, pulse grazing 62.4 � 0.8 %). Within grazing season diet quality differences were greater between pulse grazing and TRM early in the season (mid-May through June), with these differences declining as the growing season progressed.� Adaptive management decision-making to enhance dietary quality with pulse grazing should address use of prescribed burning to increase early grazing season forage quality, matching mid-and late-season use of pastures with local precipitation patterns and amounts, and likely quicker rotations through pastures during rapid vegetation growth periods.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Reno, NV