The objective of this experiment was to investigate the effect of annual forages on the growth and parasite resilience of growing, fall-born lambs. We hypothesized that lambs grazing annual forages would increase their body weight (BW) at a greater rate and be more resilient to parasitic infection when compared with lambs grazing on stockpiled pasture. A total of 54, 60-day-old Dorset and Suffolk × Dorset crossbred lambs (24 ± 4.9 kg) were stratified by sex, weight, and randomly assigned to one of three grazing treatments with all lambs weaned at an average of 60 days of age and placed on either: 1.) Avena sativa (oat), 2.) Brassica rapa subsp. Rapa (turnip), or 3.) Schedonorus arundinaceus (Schreb.) (permanent tall fescue-based) pastures. In terms of lamb growth, lambs grazing turnips demonstrated greater BW on days 42 and 56 when compared with lambs grazing oat and stockpiled pastures. In addition, lambs grazing turnips had a greater average daily gain (ADG) on days 28 and 42 when compared with lambs grazing oat and stockpiled pastures. Furthermore, on day 42, lambs grazing stockpiled pastures had a greater ADG when compared with lambs grazing oat pastures. For indices of parasitism, there were no differences shown between treatments for lamb FAMACHA© eye score, packed cell volume, and total plasma protein concentration. However, lambs grazing oat pastures had less eggs per gram of feces on days 28, 42, and 56 when compared with lambs grazing turnips and stockpiled pastures. Annual forages can play a critical role in the growth and resilience to parasitic infection of grazing lambs, as lambs grazing on turnips demonstrated the greatest BW and ADG whereas lambs grazing on oat pastures shed fewer fecal eggs per gram of feces.

该实验的目的是研究年生饲草对生长中的秋天羔羊生长和寄生虫弹性的影响。我们假设，与在牧场上放牧的羔羊相比，每年放牧的羔羊会以更大的速度增加体重（BW），并且对寄生虫感染的抵抗力更强。共有54只60天大的多塞特郡和萨福克×多塞特郡的杂交羔羊（24±4.9千克）按性别，体重进行分层，并随机分配到三种放牧处理中的一种，所有羔羊平均断奶60天。年龄，并放在以下任何一个上：1.）Avena sativa（燕麦），2.）Brassica rapa subsp。拉帕（萝卜）或3.）Schedonorus arundinaceus（Schreb。）（基于永久性羊茅的永久性）牧场。就羔羊的生长而言，相比于放牧燕麦和堆放牧场的羔羊，放牧萝卜的羔羊在第42天和第56天表现出更大的体重。此外，与放牧燕麦和堆放牧场的羔羊相比，放牧萝卜的羔羊在第28天和第42天的平均日增重（ADG）更高。此外，在第42天，与放牧燕麦牧场的羔羊相比，放牧储存牧场的羔羊的平均日增重更高。对于寄生虫指数，羔羊FAMACHA©眼评分，细胞堆积量和血浆总蛋白浓度的处理之间没有差异。但是，与放牧萝卜和储存牧场的羔羊相比，放牧燕麦牧场的羔羊在第28、42和56天每克粪便中的鸡蛋更少。