Studies on the relationship between lower-cost low protein complexity feed and genetics with health and growth performance in pigs

通过替代饲养策略降低生产成本是养猪业的研究重点。我们最近的研究表明，只要猪不患病，低成本的动物蛋白（低蛋白质复杂性）饲粮可以喂给苗猪，对其生产性能没有负面影响，直至市场体重。我们还确定了猪的基因型与提高生长速度和抗传染病能力相关，但在商业养殖条件下，饲料质量、基因型和健康对猪生长性能的累积影响尚不清楚。本研究将检验低成本饲粮的应用情况，并调查提高了对传染病遗传抗性的猪在这些饲粮/条件下的表现是否更好。在2个不同的季节，猪将分别饲喂成本较低的动物低复杂蛋白日粮或常规日粮。猪将多次称重并监测疾病；病猪将被尸检以诊断疾病病因。血液、粪便和鼻拭子将被检测猪病原体的存在，血清免疫/生长生物标志物将被分析，并对猪的先天抗病基因缺陷进行基因分型。在屠宰时，将评估一部分猪的胴体屠宰率和瘦肉产量，以确定日粮对胴体质量的影响。我们将确定在商业环境中使用成本更低的动物蛋白替代饲料的可行性。我们还将确定在商业条件下影响生长性能的参数，以及在生长的各个阶段对传染性病原体的抵抗力，并将这些参数与生产力与市场重量和胴体质量联系起来，以帮助最大限度地提高这种替代的廉价苗圃饲料的经济效益。这项研究将为生产者和饲料和遗传公司提供有用的宝贵知识，以使用更便宜的饲料，以及选择更健壮的猪基因型和/或具有优异生长性能的猪。对加拿大人来说，结果将是一个更强大的养猪业，改善动物福利，更安全的猪肉消费，减少抗菌剂的使用，从而有助于对抗抗菌素耐药性。

Reduction of production cost via alternate feeding strategies is a research priority of the swine industry. Our recent study showed lower cost reduced animal-protein (low protein complexity) diets can be fed to nursery pigs without negative impacts on performance up to market weight as long as pigs do not become diseased. We have also identified pig genotypes associated with improved growth rate and infectious disease resistance, but the cumulative impact of feed quality, genotype, and health on pig growth performance under commercial farming conditions is unclear. This study will examine the application of lower-cost diets, and investigate whether pigs with improved genetic resistance to infectious diseases perform better under these diets/conditions. Pigs on commercial farms will be fed either a lower cost reduced animal low complexity protein diet or conventional diet during 2 different seasons. Pigs will be weighed multiple times and monitored for disease; sick pigs will be necropsied to diagnose disease etiologies. Blood, feces and nasal swabs will be tested for the presence of swine pathogens, and serum immune/growth biomarkers will be analyzed, and pigs genotyped for defects in innate disease resistance genes. At slaughter a subset of pigs will be evaluated for carcass dressing percentage and lean yield to determine the impact of the diets on carcass quality. We will determine the feasibility of using alternative lower cost reduced animal protein diets in a commercial setting. We will also identify parameters that impact growth performance under commercial conditions and resistance to infectious agents during the various stages of growth and relate these to productivity up to market weight and carcass quality, to help maximize the economic benefits of this alternative less expensive nursery diet. This study will provide valuable knowledge usable by producers and feed and genetics companies towards the use of less expensive feeds as well as selection of more robust pig genotypes and/or pigs with superior growth performance. The result for Canadians will be a stronger swine industry with improved animal welfare, safer pork for consumption, and reduced use of antimicrobials thus helping in the war on antimicrobial resistance.