Impact of corn grind diameter and housing environment on performance and presence

将白色来航母鸡饲养在传统的蛋鸡笼中， 10层母鸡/笼（403 cm 2/鸟）的甲板系统或带地板的自由放养房屋 围栏上的垫料，可进入栖息地或适当的自由放养环境。FDA AHU援助将 不需要参加这项合作研究。皮埃蒙特研究站 北卡罗来纳州农业部和家禽科学部 大学将提供实验动物（白色来航母鸡）、实验饲料、饲养 和动物护理超过6周的实验时间框架。此外，所有畜牧业（喂养， 提供水、维护住房）将由北卡罗来纳州皮埃蒙特研究站提供 部农业部，将进行每周体重的收集和记录。的 试验设计包括2 × 2析因试验设计，以饲料谷物为变量 大小（细与粗）在捣碎饮食和住房（传统笼与自由放养）为8 周龄（20周龄至28周龄）。实验饲料将使用最低成本的 线性规划，以满足或超过NRC（1994）蛋鸡的营养需求。的 包含在饲料中的玉米将被研磨得很细或很粗以用于实验性饮食处理。 在精细研磨的醪饲料中的玉米将在配备有3毫米粉碎机的锤磨机中研磨。 平均粒径为560日元的筛网。粗磨玉米用于替代 通过使用4-mm筛网研磨并随后在60英寸的筛中筛分来制备饮食。 使用平均粒径大于3000日元的16 mm筛的分离器。这些饮食 治疗将不包含抗微生物剂或抗球虫剂。蛋鸡将每天进行检查 有视力健康问题或身体状况不佳的鸟类将被人道地安乐死， 颈椎脱位并记录死亡率。从生产母鸡收集的鸡蛋将 在4摄氏度下储存最多24小时，随后在 家禽科学，用于分析。在第6周，通过颈椎脱位对所有母鸡实施安乐死 由皮埃蒙特研究站（Salisbury NC）的畜牧团队和 将无菌采集以下组织：脾脏、母鸡生殖道（卵巢和/或 子宫阴道区域）和盲肠。这些组织将储存在无菌冰冷缓冲蛋白胨中 在家禽科学系处理，用于分析 沙门氏菌的微生物分析此外，环境微生物分析将 对从每种实验笼舍类型（传统笼舍与 自由放养栖息地）、饮用水和饲料。环境测试将在现场进行 在实验的第3周和实验的第8周（终止）。

White Leghorn hens will be housed in either conventional layer hen battery cages, in a quad- deck system with 10 layer hens/cage (403 cm2/bird) or housed free range housing with floor pens on litter with access to roosts or suitable free-range environment. FDA AHU assistance will not be required for this collaborative study. Piedmont Research Station, North Carolina Department of Agriculture and the Department of Poultry Science, North Carolina State University will provide experimental animals (White Leghorn Hens), experimental diets, housing and animal care over the 6 week experimental time frame. Also, all animal husbandry (feeding, providing water, maintenance of housing) will be provided by Piedmont Research Station, NC Dept. Agriculture, which will perform the collection and recording of weekly bodyweights. The experimental design consists of a 2 X 2 factorial experimental design with variables of feed grain size (fine versus coarse) in a mash diet and housing (conventional cages versus free-range) for 8 weeks (20 weeks to 28 weeks of age). The experimental diets will be formulated using least-cost linear programming to meet or exceed NRC (1994) nutrient requirements for layer hens. The corn included in the feed will be either ground fine or coarse for experimental dietary treatments. The corn in the finely ground mash diet will be ground in a hammermill equipped with a 3-mm screen with an average particle size of 560 yen¿. Coarsely ground corn utilized in the alternative diet will be prepared by grinding using a 4-mm screen with subsequent sieving in a 60 in. separator using a 16-mm sieve with an average particle size greater than 3000 yen¿. These dietary treatments will not contain antimicrobials or coccidiostats. Laying hens will be inspected daily and birds with visual health problems or poor body condition will be humanely euthanized by cervical dislocation and recorded for mortality rates. Eggs collected from production hens will be stored at 4¿¿C for a maximum of 24 hours and subsequently, processed at the Department of Poultry Science, for analysis. At week 6, all hens will be euthanized by cervical dislocation performed by animal husbandry team at Piedmont Research Station, Salisbury NC and the following tissues will be aseptically collected: spleen, hen reproductive tract (ovaries and/or uterovaginal region) and cecum. These tissues will be stored in sterile ice cold buffered peptone water in stomacher bags and processed at the Department of Poultry Science, for analysis for microbial analysis for Salmonella. Additionally, environmental microbial analysis will be conducted on samples collected from each experimental housing type (conventional cage versus free range roost), drinking water and feed. Environmental testing will be conducted at the onsite of the experimentation, at week 3 of experiment, and at week 8 of experimentation (termination).