The effects of supplemental sericea lespedeza pellets in lambs and kids on growth rate

Abstract

Sericea lespedeza (SL; Lespedeza cuneata), a condensed tannin rich plant, has been used in recent years to aid in the control of gastrointestinal nematodes (GIN) in sheep and goats. Grazing or feeding dried SL leads to a reduction in egg production by GIN and reduces coccidiosis. Growth rates in lambs and kids when fed SL for more than 56d has not been well characterized. The objective was to determine the effects of feeding SL leaf meal pellets on growth rate in lambs and kids. Lambs or kids weaned between 86 and 108 days of age (day 0) were supplemented with up to 900g of a control supplement (CO) or SL leaf meal pellets for 56–112 days while grazing grass pastures at the USDA, Agricultural Research Service (ARS) in Booneville, AR or Louisiana State University (LSU), Baton Rouge, LA in 2010 (ARS lambs only), 2011 (lambs only), 2012, and 2013 (kids only). Animals were weighed every 28 days for up to 112 days of supplemental feeding. Data were analyzed using GLM [average daily gain (ADG)], mixed models using repeated measures, or regression. Between days 0 and 56, ADG was greater in 2012 (P=0.01) or tended to be greater in 2010 (P=0.07) in SL than CO lambs at ARS, but lower in SL than CO ARS lambs (P<0.001) and kids in 2012 (P=0.02) and 2013 (P<0.001), and similar in LSU lambs. During the latter growth phase, ADG was reduced in SL compared with CO fed lambs and kids (P<0.01, all), except for LSU lambs in 2011 which were similar between groups. Additional studies are necessary to understand changes in growth rate of SL supplemented lambs and kids. It may be necessary to restrict the period of supplementation to less than 56 days to maximize weight gains in lambs and kids.