Impact of ergot alkaloid consumption during mid and late gestation on mammary development and lactation
Britt, J., S. Adams, M. Miller Jr., C. J. Kojima, j. Andrae, and S. Duckett.  2018.  Journal of Animal Science, Volume 96, Issue suppl_3, 7 December 2018, Pages 233.

The consumption of ergot alkaloids found in endophyte-infected tall fescue [Lolium arundinaceum (Schreb.) Darbysh] reduces prolactin secretion and induces vasoconstriction. The objective of this study was to evaluate effects on maternal characteristics of parturition, mammary development, and lactation. Suffolk ewes (n = 60; 83.1kg) estimated to be carrying twins at d35 of gestation were stratified by genotype (AA, AG, GG; DRD2 SNP) to: endophyte-free tall fescue seed (E-; 0.0µg ergovaline + ergovalinine/g seed) or endophyte-infected tall fescue seed (E+; 4.14µg ergovaline + ergovalinine/g seed) during MID gestation (d 35–85) or LATE gestation (d 86–parturition). Endophyte-infected tall fescue seed provided 1772µg of ergovaline + ergovalinine/hd/d for E+ treatment while endophyte-free seed (0.0µg ergovaline + ergovalinine) was fed for E- treatment. This created four treatments: E-/E-, E-/E+, E+/E-, and E+/E+. Udder width, circumference, and teat measurements were collected at parturition. Milk tests were conducted on d1, 2, and 21 post-lambing to estimate milk production. Data were analyzed as a randomized block design with maternal genotype (AA, AG, GG), treatment (E-/E-, E-/E+, E+/E-, E+/E+), and interactions as fixed effects. There tended to be an interaction (P = 0.10) between treatment and time wherein ewes on E+/E- and E+/E+ had lighter bodyweights at d70 and E+/E+ ewes had lighter bodyweights at d98, 108, and 136 of gestation compared to E-/E- ewes. GG genotype ewes had larger (P = 0.003) udder widths compared to AA and AG ewes. Ewes receiving E+/E+ treatment had smaller (P = 0.028) udder circumferences, shorter (P = 0.029) teats, and a 64% reduction (P = 0.029) in milk production in the first two days post-lambing. Milk production at d21 post-lambing was reduced (P = 0.002) in E+/E- and E+/E+ treatments by 77% and 55%, respectively. Maternal consumption of ergot alkaloids during gestation has negative impacts on milk production.