Newcombe M, Fitz-Coy S H, Harter-Dennis J M
Department of Agriculture, University of Maryland Eastern Shore, Princess Anne 21853.
Poult Sci. 1992 Sep;71(9):1442-9. doi: 10.3382/ps.0711442.
Day-old male broiler chicks were raised in floor pens. At 4 days of age, birds in 75% of the pens were inoculated with Eimeria maxima via the feed. There were four dietary treatments: uninoculated, unmedicated control (UUC), infected, unmedicated control (IUC), infected, halofuginone-medicated (3 ppm, HM), or infected, salinomycin-medicated (66 ppm, SM). At 6 days of age, birds in 50% of the pens of each treatment were restricted for 5 days to their maintenance energy intake level. The remainder consumed feed ad libitum. Medication reduced growth from 0 to 6 days of age and feed intake was depressed, irrespective of medication, in infected birds from 0 to 21 days of age. Growth, however, was improved with intake of coccidiostat over IUC from 6 to 11 days of age but did not match UUC until 28 days of age. At 42 and 49 days of age, infected birds were lighter than UUC birds. Dressing percentage for HM and SM birds was greater than that of UUC birds at 49 days of age but HM birds also had a greater percentage of abdominal fat at both 42 and 49 days of age. Feed restriction resulted in some compensatory growth immediately following refeeding. Experimental feed:gain ratio was improved in restricted birds (1.98 versus 2.03 g:g). At 42 and 49 days of age, restricted birds were lighter than birds eating ad libitum and also had a significantly greater percentage abdominal fat. A lower breast yield was observed at 42 days of age in restricted birds.
一日龄雄性肉鸡雏鸡饲养在地面围栏中。4日龄时，75%围栏中的鸡通过饲料接种了巨型艾美耳球虫。共有四种日粮处理方式：未接种、未用药对照（UUC）、感染、未用药对照（IUC）、感染、常山酮用药（3 ppm，HM）或感染、盐霉素用药（66 ppm，SM）。6日龄时，每种处理方式中50%围栏中的鸡被限制采食5天，使其维持能量摄入水平。其余鸡自由采食。用药降低了0至6日龄鸡的生长速度，并且在0至21日龄期间，无论是否用药，感染鸡的采食量均受到抑制。然而，在6至11日龄期间，摄入抗球虫药的鸡的生长速度比IUC组有所提高，但直到28日龄才与UUC组相当。在42日龄和49日龄时，感染鸡比UUC组鸡体重轻。49日龄时，HM组和SM组鸡的屠宰率高于UUC组鸡，但在42日龄和49日龄时，HM组鸡的腹部脂肪百分比也更高。限饲后再喂食时会出现一些补偿性生长。限饲鸡的实验料肉比得到改善（1.98比2.03 g:g）。在42日龄和49日龄时，限饲鸡比自由采食的鸡体重轻，腹部脂肪百分比也显著更高。42日龄时，限饲鸡的胸肉产量较低。
