Do increased stocking periods affect animal performance and weed population in Southern Wisconsin?

Authors: FRANCO DUARTE, ARTHUR - University Of Wisconsin; KOHMANN, MARTA - University Of Wisconsin; RENZ, MARK - University Of Wisconsin; Jaramillo, David

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2024
Publication Date: 11/12/2024
Citation: Franco Duarte, A., Kohmann, M., Renz, M., Jaramillo, D.M. 2024. Do increased stocking periods affect animal performance and weed population in Southern Wisconsin?. ASA-CSSA-SSSA Annual Meeting Abstracts. ASA-CSSA-SSSA Meetings, San Antonio, TX, November 10-13, 2024.

Interpretive Summary:

Technical Abstract: Rotational stocking is used in pastures across the Midwest with daily to weekly stocking periods. Variations in stocking periods can influence pasture and animal responses, as well as weed population dynamics. We evaluated three stocking periods (1-, 4-, and 8-d; 32-d rest period across treatments) in a randomized complete block design with three replicates. The experiment was conducted in southwestern Wisconsin on a multi-species pasture composed of perennial cool season grass and legume species [orchardgrass (Dactylis glomerata L.), tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.), white and red clovers (Trifolium repens L. and T. pratense L.)]. Weed species were dandelion (Taraxacum officinale Weber ex Wigg.), Canada thistle (Cirsium arvense (L.) Scop.), and yellow foxtail (Setaria pumila (Poir.) Roem. & Schult). Holstein-Angus crossed heifers were rotationally stocking using variable stocking rates. Pasture botanical composition was assessed pre- and post-grazing by collecting biomass from four 0.25-m2 quadrats to 10-cm stubble height. Samples were separated into grass, legume, or weeds, dried, and weighed. Animal performance was assessed by weighing the animals after 12-h of food and water restriction every 28-d. Weed biomass was minimal and similar across treatments during the first and second grazing cycles. However, increases in weed biomass were detected at the third grazing cycle with two and eleven-fold greater biomass in the 4- and 8-d stocking period treatments compared to the 1-d move, respectively (P<0.01). Animal average daily gain was similar across treatments and grazing cycles (0.44 kg/d), but below the average expected for the region likely due to severe drought in 2023. Difference in weed proportion did not result in differences in animal performance, probably because some of the dominant weed species like dandelions are often preferred by grazing cattle. Overall, weed populations were low and did not affect animal performance. Furthermore, stocking period did not affect pasture productivity or animal performance.