Anticoccidial Vaccination Is Associated with Improved Intestinal Health in Organic Chickens

Simple Summary

In recent years, the number of organic chicken farms has increased. Chickens can be infected by single-cell parasites, coccidia, which cause lesions in the lining of the intestine leading to poor growth and sometimes death (coccidiosis). This infection can also lead to overgrowth in the intestine of a bacterium, Clostridium perfringens, that may cause further damage (necrotic enteritis). Prevention is often achieved by adding substances in the feed that will slow down the development of parasites and bacteria, but this is not allowed in organic farming. The aim of this study was to investigate if vaccination against coccidia can prevent these diseases in organic chickens. Vaccinated chickens developed milder gut lesions, had fewer and less damaging C. perfringens, and had similar or higher body weight compared to unvaccinated chickens six weeks after vaccination. No deaths from coccidiosis or necrotic enteritis occurred among vaccinated chickens while some unvaccinated chickens died from these diseases. We conclude that vaccination against coccidia benefits organic chickens. This study provides knowledge supporting further development of the organic chicken industry. The results are also of relevance to the management of coccidiosis and necrotic enteritis in conventional broilers.

Abstract

Eimeria spp. and Clostridium perfringens (CP) are pathogens associated with coccidiosis and necrotic enteritis (NE) in broiler chickens. In this study we evaluated the effect of anticoccidial vaccination on intestinal health in clinically healthy organic Ross 308 chickens. On each of two farms, one unvaccinated flock (A1 and B1) was compared to one vaccinated flock (A2 and B2) until ten weeks of age (WOA). Faecal oocysts were counted weekly, and species were identified by PCR (ITS-1 gene). Lesion scoring, CP quantification and PCR targeting the CP NetB toxin gene were performed at three, four, and six WOA and chickens were weighed. Necropsies were performed on randomly selected chickens to identify coccidiosis/NE. Oocyst shedding peaked at three WOA in all flocks. Later oocyst shedding (E. tenella/E. maxima) in unvaccinated flocks at 5–7 WOA coincided with coccidiosis/NE. Although results differed somewhat between farms, vaccination was associated with lower intestinal lesion scores, reduced caecal CP counts, lower proportions of netB-positive CP, lower body weight at three–four WOA, and similar or slightly increased body weight at six WOA. In conclusion, the intestinal health of organic broilers can benefit from anticoccidial vaccination when oocyst exposure levels are high.

An overview of health challenges in alternative poultry production systems

Due to consumer demand and changing welfare standards on health, ecology, equity, and safety concepts, poultry production has changed markedly over the past 20 y. One of the greatest changes to poultry production standards is now offering poultry limited access to the outdoors in alternative and organic poultry production operations. Although operations allowing access to the outdoors are still only a small portion of commercial poultry production, it may impact the gastrointestinal (GIT) health of the bird in different ways than birds raised under conventional management systems. The present review describes current research results in alternative systems by identifying how different poultry production operations (diet, environmental disruptive factors, diseases) impact the ecology and health of the GIT. Various research efforts will be discussed that illustrate the nutritional value of free-range forages and how forages could be beneficial to animal health and production of both meat and eggs. The review also highlights the need for potential interventions to limit diseases without using antibiotics. These alternatives could enhance both economics and sustainability in organic and free-range poultry production.

Using stochastic dynamic modelling to estimate the sensitivity of current and alternative surveillance program of Salmonella in conventional broiler production

Since 2018, the EU commission has declared the Danish broiler industry to be Salmonella free. However, there is continuous Salmonella pressure from the environment, and a number of parent flocks and broiler flocks become infected annually. When a parent flock becomes infected, the infection can be transmitted vertically to the broiler flocks, before the parent flock is detected and destroyed, including the eggs at the hatchery. To address this issue, we developed stochastic dynamic modelling of transmission of Salmonella in parent flocks and combined that with the relation between flock prevalence and test sensitivity for environmental samples in the flock. Results suggested that after 10 and 100 infected hens were seeded, the likelihood of detecting an infected parent flock within the three first weeks after the infection was strongly influenced by the taking of five boot swabs (95% CI 70–100) instead of two (95% CI 40–100) or the supplementing of the two boot swabs by a dust sample (95% CI 43–100). Results suggest that the likelihood of detecting the broiler flock as infected in the program was estimated to at least 99% in broiler flock even if only one chicken was initially infected. These findings are of relevance for managing parent flocks and eggs at the hatchery in case of Salmonella infection in parent flocks in the Danish poultry.

Husbandry Practices, Health, and Welfare Status of Organic Broilers in France

Simple Summary

Organic poultry production has grown rapidly in Europe for the past several years in the context of sustainable development within farming. The authors carried out a field study in France between 2014 and 2015 concerning 85 organic broiler flocks that showed a wide diversity of farming management systems from independent farmers set up for direct sales of poultry to farmers under contract with a company for product sales. Health and welfare characteristics did not significantly differ between these two farming systems, except slightly dirtier feathers and more footpad dermatitis on the independent farms, related to the poultry housing conditions in mobile houses. A mortality rate of 2.8% was found, with digestive problems mainly being observed. Better knowledge of husbandry practices, health, and the welfare status of organic poultry is of primary importance to improve the management of organic production and to help in characterizing farming sustainability.

Abstract

Organic poultry production has increased sharply with growing consumer demand in the context of sustainable development. A study was conducted in 85 organic broiler flocks between 2014 and 2015 to describe the husbandry practices and the health and welfare status of organic broilers in France, and to study farming diversity by comparing independent farms (Ind farms, n = 15) with direct sales to farms working with companies (Comp farms, n = 70). Each flock was visited at 3 and 11 weeks of age to collect data on farming conditions, health disorders, and mortality. Welfare notation of 30 broilers per flock and parasitic examination of 5 broilers per flock was also performed. Findings showed significantly different farming management between Ind farms and Comp farms, with smaller flocks on the Ind farms (476 broilers/house vs. 3062 broilers/house, p < 0.01) more frequently in mobile houses. The mean mortality rate was 2.8%, mainly involving digestive disorders. Helminths were detected in 58.8% of the flocks. On average, 21.9% and 5.8% of broilers in a flock had footpad dermatitis and dirty feathers, respectively. The health and welfare characteristics of organic broilers on Ind farms vs. Comp farms were not significantly different, except dirtier feathers and more footpad dermatitis on Ind farms (19.1% vs. 2.9%, p = 0.03 and 39.6% vs. 18.1%, p = 0.02, respectively), associated with poultry housing conditions in mobile houses (p < 0.01). This study provides greater insight into farming sustainability aspects related to the husbandry practices, and the health and welfare of organic broilers in France.

Production traits of artificially and naturally hatched geese in intensive and free-range systems - II: slaughter, carcass and meat quality traits

1. This study investigates the slaughter, carcass and meat quality traits of artificially and naturally hatched geese in intensive and free-range production systems. 2. The study was conducted with 114 naturally hatched and 102 artificially hatched geese. From each replicate of the intensive and free-range systems, one female and one male goose were slaughtered at the ages of 14, 16 and 18 weeks (a total of 32 geese per slaughter week). 3. Artificially hatched geese had higher slaughter weights (5280 vs. 4404 g), carcass weights (3520 vs. 2863), dressing percentages (66.6-65.2% vs. 65.0-63.6%) and carcass part, feather and edible inner organ weights. The ratio of both edible inner organs and abdominal fat was higher in naturally hatched geese. Breast meat L*, a* and pH values and thigh meat dry matter values were higher in artificially hatched geese, whereas thigh meat b* and pH values were higher in naturally hatched geese. 4. Intensively reared geese had higher slaughter weights (4900 vs. 4783 g), carcass weights (3253 vs. 3130 g) and abdominal fat weights (280 vs. 250 g), as well as higher dressing percentages (66.3-64.9% vs. 65.3-63.9%). Breast meat b* and thigh meat L* values were higher in the intensive system, while breast and thigh pH values, dripping loss and cooking loss were higher in the free-range system. Water-holding capacity was higher in the intensive system. 5. In conclusion, artificially hatched, intensively reared geese had the highest slaughter weights; however, both artificially and naturally hatched geese raised in a free-range system reached acceptable slaughter weights and can thus be recommended for use with this type of production system.

Feed intake and activity level of two broiler genotypes foraging different types of vegetation in the finishing period

A study was performed with 2 broiler genotypes (slow and medium growth) restricted in supplementary feed and foraging 2 different mixed vegetations (grass/clover or chicory) to identify possible benefits of herbage on nutrition during the finishing period (80 to 113 d of age). Three hundred birds were included in a 2 × 2 factorial design with groups of 25 birds replicated 3 times. The use of outdoor areas, performance, and forage intake were investigated. To identify possible differences in foraging activity, the use of the range was monitored one day per week at 4 different times of the day. Feed intake from foraging was estimated by killing 4 birds per plot (2 males and 2 females) in the morning and in the evening on 3 d during the experiment and measuring crop content. Vegetation type did not influence broiler use of the free-range area, feed intake, or performance. Differences in the use of the range area, activity level, and feed content in the crops were observed in relation to genotype, sex, age of broilers, and also the time of day. Foraging activity was positively correlated with age. Medium-growth broilers spent more time inside and closer to the broiler houses during the day with increased foraging activity during evenings, in contrast to the slow-growing broilers that showed a more uniform activity during the day. Based on the measurement of crop content it was estimated that the slow-growing genotype had a daily intake of 5 to 8 g of forage per day, whereas the medium-growing genotype had an intake of 9 g for females and 20 g for males. In conclusion, limitation of supplemented protein feed in the finishing period may be acceptable for broilers that have access to highly nutritious vegetation.