Centennial Review: History and husbandry recommendations for raising Pekin ducks in research or commercial production.

By some accounts, ducks were domesticated between 400 and 10,000 yr ago and have been a growing portion of the poultry industry for decades. Ducks specifically, and waterfowl in general, have unique health, housing, nutrition and welfare concerns compared to their galliform counterparts. Although there have been many research publications in regards to health, nutrition, behavior, and welfare of ducks there have been very few reviews to provide an overview of these numerous studies, and only one text has attempted to review all aspects of the duck industry, from breeders to meat ducks. This review covers incubation, hatching, housing, welfare, nutrition, and euthanasia and highlights the needs for additional research at all levels of duck production. The purpose of this review is to provide guidelines to raise and house ducks for research as specifically related to industry practices.

Effects of hydroxychloride and sulfate form of zinc and manganese supplementation on superoxide dismutase activity and immune responses post lipopolysaccharide challenge in poultry fed marginally lower doses of zinc and manganese.

Effects of hydroxychloride (OHCl) and sulfate form of zinc and manganese supplementation on immune responses of birds fed marginally lower levels of zinc and manganese during an experimental lipopolysaccharide (LPS) injection were studied. In experiment I, 30-week-old layer birds were fed 50 mg/kg Zn+45 mg/kg Mn or 100 mg/kg Zn+90 mg/kg Mn in sulfate or OHCl form and injected with 0 or 500 µg/kg LPS in a 2 (50 mg Zn+45 mg Mn and 100 mg Zn+90 mg Mn) X 2 (sulfate and OHCl) X 2 (0 and 500 µg LPS) factorial setup of treatments for 10 weeks. Among LPS-injected birds, those receiving 50 mg ZnOHCl+45 mg MnOHCl had comparable heterophil and monocyte superoxide dismutase (SOD) activity compared to the birds fed 100 mg Zn+90 mg Mn. Compared to the birds injected with PBS, LPS injection upregulated cathelicidin and IL-1 relative mRNA amounts in monocytes from birds fed 100 mg Zn+90 mg Mn, both in sulfate and OHCl form, and in birds fed 50 mg ZnOHCl+45 mg MnOHCl, but not in the birds fed 50 mg ZnSO4+45 mg MnSO4. In experiment II, one-day-old broiler birds were fed 50 mg ZnOHCl+45 mg MnOHCl, 50 mg ZnOHCl+90 mg MnOHCl, 100 mg ZnOHCL+45 mg MnOHCl, 100 mg ZnOHCl+90 mg MnOHCl, 50 mg ZnSO4+45 mg MnSO4, or 100 mg ZnSO4+90 mg MnSO4 for 21 and 42 days. Birds fed 100 mg ZnOHCl+45 mg MnOHCl form had a comparable heterophil and monocyte SOD activity and monocyte cathelicidin mRNA amounts compared to the group fed 100 mg Zn+90 mg Mn. Increasing the ZnOHCl content from 50 mg to 100 mg/kg Zn reversed (P > 0.05) the decrease in SOD activity and monocyte cathelicidin mRNA levels of the 50 mg ZnOHCl+45 mg MnOHCL fed group, and increasing the MnOHCl content from 45 mg to 90 mg/kg in the 100 mg ZnOHCl+45 mg MnOHCl group further increased SOD activity. In conclusion, birds fed diets with lower amounts of zinc and manganese in sulfate form decreased SOD activity and IL-1 and cathelicidin amounts during inflammation, and either increasing the dietary zinc and manganese content or feeding zinc and manganese in OHCl form synergistically increased the SOD activity and IL-1 and cathelicidin mRNA amounts in immune cells.

Effects of dietary vitamin E type and level on lipopolysaccharide-induced cytokine mRNA expression in broiler chicks.

Vitamin E modulates the immune response, in part by reducing inflammation. The bacterial component lipopolysaccharide (LPS) can induce an inflammatory response in chickens. The objective of this study was to evaluate immunomodulatory effects of dietary type and level of vitamin E on response of broilers to LPS. One-day-old broiler males (n=96) were placed in a vitamin E-type (synthetic, natural) × vitamin E level (22, 220 IU/kg)×LPS (LPS, saline) block design. At 22 d, LPS (or saline) was injected subcutaneously. Spleens were harvested for RNA isolation at 3 and 24 h postinjection. Relative levels of RNA expression were measured for the immune-related genes: avian ß defensin 10 (AvBD10), interleukin 6 (IL6), interferon-γ (IFN-γ), inducible nitric oxide synthase (iNOS), interleukin 10 and transforming growth factor- ß1 (TGF-ß1). Avian ß defensin 10 and iNOS are innate antimicrobial proteins. Interleukin 6 and IFN-γ are pro-inflammatory cytokines, whereas interleukin 10 and transforming growth factor-ß1 are anti-inflammatory cytokines. There were significantly higher splenic levels of IL6, IFN-γ, iNOS, and IL10 RNA expression at 3 h postinjection in chickens receiving LPS than in chickens 24 h post-LPS injection or saline-injected birds at either time. These data suggest that LPS induced an immune response that was regulated by both pro- and anti-inflammatory cytokines. Birds fed natural-type (versus synthetic) vitamin E had a significantly lower LPS-induced inflammatory response, as indicated by lower IL6 RNA expression levels, suggesting a protective effect from natural-type vitamin E when a chicken encounters a bacterial component.

Effect of NTA and EDTA on calcium metabolism of chickens and Coturnix.

Five experiments were conducted in which various levels of nitrilotriacetic acid (NTA or its salt, Na2NTA) disodium ethylenediaminetetraacetic acid (Na2EDTA) and calcium (Ca) were fed to young chicks, young quail and adult quail. The duration of trials was from 1 to 28 days of age for chicks, 7 to 49 for young quail and 167 to 210 for adult quail. Feeding 0.71% NTA or an equimolar level of Na2NTA caused a moderate decrease in chicks weight and Na2EDTA caused a drastic decrease in body weight of chicks and adult quail. Feeding Na2EDTA caused greater mortality in chicks receiving a low Ca diet than a higher level of Ca. Plasma Ca levels were significantly increased by NTA in young quail and by Na2NTA in adult quail, in contrast, they were significantly decreased by Na2EDTA in adult quail. Dietary NTA promoted greater tibia mineralization (ash/dry matter) in growing chicks. Dietary NTA increased the deposition of zinc (Zn) and manganese (Mn) in the chicks tibia, but, it decreased magnesium (Mg). On the other hand, Na2EDTA caused a significant decrease in Zn and Fe in the chicks tibia and a significant increase in Mn. Coturnix are less sensitive than chickens in responding to dietary chelates.

Lack of effect of ascorbic and citric acids on calcium metabolism of chickens.

Five experiments were carried out in which various levels of calcium and ascorbic acid or citric acid were fed to adult male chickens, young chickens, or young coturnix. Observations were made on body weight, feed efficiency, plasma calcium and tibia mineral content. One percent dietary ascorbic acid had no adverse effect on body weight, tibia ash or tibia calcium content of adult male chickens over a 224-day period, even at calcium levels as low as 0.026% of the diet. In growing chicks, body weight and plasma calcium and tibia mineral content varied with the calcium level of the diet, but were not influenced by ascorbic acid even at 0.65% of the diet. Citric acid at the same molar level was also ineffective in altering calcium metabolism in growing chickens. Growing coturnix showed differences in growth and tibia ash content with 0.4% and 0.85% calcium, but there were no pronounced effects caused by dietary ascorbic acid. There is no evidence in this work that these relatively high levels of ascorbic acid or citric acid have any adverse effect on calcium metabolism because of their chelating properties.