PSX-10 High protein and energy feed supplementation enhance gastrointestinal parasite resilience in organic farming sheep.

Abstract The management of gastrointestinal parasite (GIP) in organic sheep is a challenging issue as chemical anthelmintic drugs is prohibited use in organic production. This trial was to evaluate the high protein and energy feed supplementation effect on the GIP status in post-lactation ewes. The five-acre pasture paddock was subdivided into one acre grazing plots by an electric flexi net fence. Thirty mixed-age ewes were selected and divided into five subgroups each with six ewes and grazed on one-acre plots for four weeks respectively, with dry hay and water supply at libitum. The experimental use of animals in this trial was approved by Lincoln University’s Institutional Animal Care and Use Committee (ACUC21-6). The organic grain feed mixture was purchased locally (Peterson Organic Feeds, MO) and fed in groups on troughs within grazing plots daily. Organic grain supplemental level was defined and assigned as control (TC, 0/d), low (T1, 227 g/d), moderate (T2, 340 g/d), moderate high (T3, 454 g/d), and high-level supplementation (T4, 567 g/d) groups. Animal growth and production performance traits were recorded for live weight (LW, kg), average daily gain (ADG, g/d), body condition score (BCS, 1-5), FAMACHA® score (FMS, 1-5), fecal egg count (FEC/g), hematocrit (HCT%) and ultrasound scanned back fat depth (BFD, mm), loineye muscle death (LED, mm) and loineye muscle area (LEA, cm²). The carcass traits were measured live on longissimus dorsi muscle over the 12-13th ribs of animals using an ultrasonographic equipment (ExAgo) fitted on a linear transducer. Means of LW, BFD, ADG, and LEA were significantly increased for organic grain supplemental groups over animals in control group (P< 0.05). The organic grain supplementation has decreased FEC (P< 0.05) in supplemental group animals (T1, T2, T3, T4) from the prior feeding (day 0) to the end of supplementation (day 28) whereas, animals in control group (T0) have shown remaining as initial fecal egg count status. The result indicated that a short-term supplementation of high protein and energy feeds enhance GIP resilience in post-lactation ewes and production performance.