Performance by Katahdins grazing stockpiled toxic tall fescue, non-toxic tall fescue, or "Persist" orchardgrass: 1-year summary

Abstract Text:   Grazing stockpiled forages during the winter months may provide small ruminant producers a cheaper alternative to buying expensive feedstuffs.  However, limited research has been conducted comparing the effects of stockpiling endophyte-infected tall fescue [Lolium arundinaceum (Screb.) Darbysh; E+], novel endophyte-infected tall fescue (NE+), and Persist orchardgrass (Dactylis glomerata L.) on performance and reproductive rates by Katahdin ewes.  A total of 48 spring-born Katahdin ewes (22 ± 0.67 kg initial BW, 2.6 ± 0.09 initial BCS) were stratified by weight and BCS and allocated randomly to 1 of 6 groups representing 3 treatments: 1) E+; 2) NE+; or 3) Persist orchardgrass.  Each treatment consisted of 2 replications (0.4 ha per replication) and 8 animals per replication.  Data were analyzed using PROC MIXED of SAS with two preplanned orthogonal contrast statements to evaluate ewe performance: 1) the mean of E+ vs. the mean of NE+ and Persist orchardgrass and 2) the mean of NE+ vs. the mean of Persist orchardgrass.  Pregnancy rates and percentage of multiple births were analyzed by the Chi-square procedure of SAS.  Excess forage was grazed in early August and 54 kg N/ha was applied on September 17, 2013.  Beginning on November 14, 2013, grazing of stockpiled pastures was initiated and lasted a total of 77 d.  At the beginning of the breeding season (December 16, 2013), one Katahdin ram that had passed a breeding soundness exam was introduced and remained in each group for 39 d.  Ewe weights, BCS, and ADG did not differ (P ≥ 0.12) across treatments.  Pregnancy rates did not differ (P ≥ 0.19) across treatments.  Percentage of multiple births tended (P = 0.07) to be greater from NE+ and Persist orchardgrass compared with E+ (19 vs. 0%, respectively) and tended (P = 0.07) to be greater from NE+ compared with Persist orchardgrass.  Therefore, grazing stockpiled endophyte-infected tall fescue, novel endophyte-infected tall fescue, or Persist orchardgrass during the winter months may result in similar ewe performance and pregnancy rates, but grazing stockpiled novel endophyte-infected tall fescue may improve the percentage of multiple births.  This work was supported by the USDA National Institute of Food and Agriculture, Evans-Allen project #227400.

Keywords: sheep, fescue, stockpiling