Importance of animal husbandry and production management on food safety in livestock production systems

Production and management systems do significantly effect animal health and therewith the use of drugs and prophylactic treatments. This may lead to residues and a change for the worse in food safety. The consequent implementation and use of hygiene and management tools and measures is needed, as well as a combination of these measures with effective programmes (e.g. vaccination, procedure with cleaning and disinfection, all in all out etc.) in order to limit the use of drugs in sick animals so they are used only when absolutely necessary. A better education among producers is also an important step towards higher food safety on farm level

Untersuchungen zu genetisch bedingten Unterschieden in der Parasitenresistenz von Legehennen – Testung unter den Bedingungen einer Stations- und Feldprüfung

Die in der ökologischen Geflügelhaltung genutzten genetischen Herkünfte eignen sich aus verschiedenen Gründen in unterschiedlichen Maß für diese Verfahren. Die Bewertung der Eignung reduziert sich bisher im Wesentlichen auf Aspekte der Leistung (u.a. Eizahl, Eigewicht, Futterverwertung) sowie in gewissem Maße des Verhaltens (u.a. Kannibalismus). Aspekte der Tiergesundheit werden häufig auf Mortatiltätsraten reduziert, so dass u.a. subklinisch verlaufende Erkrankungen unberücksichtigt bleiben. In ökologischen Haltungsverfahren für Legehennen zählen die Parasitosen, insbesondere die Helminthosen, vor allem verursacht durch Ascaridia galli, Capillaria-Arten und Heterakis gallinarum, zu den bedeutendsten Erkrankungen (KAUFMANN und GAULY, 2009). Der notwendige Medikamenteneinsatz verursacht Kosten, führt zu Wirkstoffresistenzen, bedingt Rückstandsprobleme und belastet die Umwelt, was den elementaren Zielsetzungen ökologischer Tierhaltung widerspricht. In der Nutzung genetisch bedingter Unterschiede in der Parasitenresistenz kann ein erfolgsversprechender Ansatz zur Reduktion der Problematik gesehen werden. Es wurden bereits züchterisch nutzbare Resistenzen gegenüber Endoparasiteninfektionen bei verschiedenen Tierarten und Rassen beschrieben (ISRAEL, 1975; GAULY et al., 2002). Die Arbeiten beziehen sich allerdings bisher ausschließlich auf künstliche Infektionen mit nur einem Innenparasit (Monoinfektion) und wurden darüber hinaus nur an wenige Genotypen durchgeführt. Entsprechend ist die Einbeziehung weiterer im ökologischen Landbau eingesetzter Herkünfte notwendig. In einem zusätzlichen Schritt muss auch die Schätzung der Resistenz unter Feldbedingungen, d.h. unter der Situation von Mischinfektionen erfolgen. Möglicherweise lassen sich daraus unterschiedliche Empfehlungen ableiten. Das Gesamtziel des Projekts ist es, genetisch bedingte Unterschiede in der Resistenz gegenüber Wurminfektionen an Legehennen verschiedener genetischer Herkünfte auf der Basis einer experimentellen (Stationsprüfung) und anschliessend einer natürlichen Infektion (Feldprüfung) darzustellen und damit deren Eignung für die Bedingungen der Boden- bzw. Freilandhaltung zu bewerten. Die daraus resultierenden Ergebnisse sollen praktischen Landwirten des ökologischen Landbaus als Entscheidungshilfe bei der Genotypenwahl dienen und Zuchtunternehmen mögliche Perspektiven der Gestaltung von Zuchtprogrammen aufzeigen

Review: Challenges for dairy cow production systems arising from climate changes.

The so-called global change refers to changes on a planetary scale. The term encompasses various issues like resource use, energy development, population growth, land use and land cover, carbon and nitrogen cycle, pollution and health, and climate change. The paper deals with challenges for dairy cattle production systems in Europe arising from climate change as one part of global changes. Global warming is increasing, and therefore ecosystems, plant and animal biodiversity, and food security and safety are at risk. It is already accepted knowledge that the direct and indirect effects of global warming in combination with an increasing frequency of weather extremes are a serious issue for livestock production, even in moderate climate zones like Central Europe. The potential and already-measurable effects of climate change (including increase in temperature, frequency of hot days and heat waves), in particular the challenges on grassland production, fodder quality, nutrition in general, cow welfare, health as well as performance of dairy production, will be reviewed. Indirect and direct effects on animals are correlated with their performance. There are clear indications that with selection for high-yielding animals the sensitivity to climate changes increases. Cumulative effects (e.g. higher temperature plus increased pathogen and their vectors loads) do strengthen these impacts. To cope with the consequences several possible adaptation and mitigation strategies must be established on different levels. This includes changes in the production systems (e.g. management, barn, feeding), breeding strategies and health management

Relationship between herd size and measures of animal welfare on dairy cattle farms with freestall housing in Germany

The objective of this study was to examine the association of herd size with animal welfare in dairy cattle herds. Therefore, 80 conventional dairy cattle farms were classified by the number of cows into 4 herd size classes, C1 (100 cows), C2 (100-299 cows), C3 (300-499 cows), and C4 (≥500 cows), and assessed using multiple animal-based measures of the Welfare Quality Assessment protocol for dairy cattle. Data were recorded from April 2014 to September 2016 by an experienced single assessor in northern Germany. Each farm was visited 2 times at an interval of 6 mo (summer period and winter period) to avoid seasonal effects on the outcome. The average herd size was 383 ± 356 Holstein-Friesian cows (range 45 to 1,629). Only farms with freestall (cubicle) housing and a maximum of 6 h access to pasture per day were included in the study. Data were statistically analyzed using a generalized linear mixed model. None of the farms reached the highest overall rating of "excellent." The majority of the farms were classified as "enhanced" (30%) or "acceptable" (66%), and at 6 assessments the farms were rated as "not classified" (4%). Regarding single indicators, mean trough length per cow, percentage of cows with nasal discharge, and vulvar discharge increased with increasing herd size, whereas it was vice versa for displacements of cows. Percentage of lean cows, percentage of dirty lower legs, and duration of the process of lying down showed a curvilinear relationship with the number of cows per farm. Herd size was not associated with any other measures of the Welfare Quality protocol. In conclusion, herd size effects were small, and consequently herd size cannot be considered as a feasible indicator of the on-farm animal welfare level. Housing conditions and management practices seem to have a greater effect on animal welfare than the number of dairy cows per farm

Confinement of sows for different periods during lactation: effects on behaviour and lesions of sows and performance of piglets.

Alternatives to farrowing crates with continuous confinement of the sow are urgently needed because the animal welfare is negatively impacted. Given the increase of herd sizes, practical experience with loose-housing is needed to force the implementation of these systems in the field. Next to aspects of labour efficiency, detrimental piglet mortality rates that may occur during the first days postpartum (pp) is a major criticism. Therefore, loose-housing after a crating period limited to the first days pp might be a feasible alternative to improve welfare under intensive production conditions. The aim was to investigate the effect of crating sows during lactation for different periods on their behaviour and integument alterations and on piglets' performance. Gilts from a commercial herd were observed from 5 to 26 days pp and housed in farrowing crates (1.85×2.50 m) that could be altered between confinement crates and loose-housing pens. Animals were divided into three groups, that were either crated continuously from birth until weaning (Group A, n=55), until 14 days pp (Group B; n=54) or 7 days pp (Group C, n=59). The behaviour of six randomly selected gilts per group was video recorded from 5 to 26 days pp and analysed by time sampling technique. Lesions on the legs, shoulder and lumbar vertebra were scored on days 7, 14 and 25 pp. Piglets were weighed weekly, causes of losses recorded and weight losses of gilts measured. Not different between groups (P>0.05), animals spent 72 to 76% lying laterally, 14 to 17% lying in abdominal or semi-abdominal position, 9 to 10% standing and 1 to 3% sitting. B-sows were lying longer in week 3 and 4 of lactation compared to A- and C-sows (P0.05), whereas almost 90% of the losses occurred in the first week pp. In conclusion, loose-housing of lactating gilts after a reduced postnatal crating period of 7 days affected neither the activity level of the gilts and lesions on the integument nor pre-weaning mortality. Therefore, it is recommended to allow sows to move around to some extent during the later lactation period

Immune Response of Bos indicus

Antigens of anti-tick vaccines are more efficacious for homologous challenge with local tick strains. cDNA clones encoding for Bm91 from local Rhipicephalus (Boophilus) microplus strains were developed to immunize Bos indicus cattle under field conditions. Three groups of six animals each were injected with the antigen Bm91, saline, and adjuvant, respectively. Animals were immunized three times at 3-week intervals and a fourth time after six months. The anti-Bm91 antibody level, measured by ELISA, was monitored for 7 months and the reproductive performance of naturally infested R. (B.) microplus was determined. Bm91-immunized animals developed a strong immune response expressed by high anti-Bm91 levels remaining on high levels until the end of the study. Western blot analysis confirmed that Bm91 is immunogenic. Compared to control animals, the reproductive efficiency index and the egg viability were 6% and 8%, respectively, lower in the Bm91 group (P<0.05). In conclusion, it was demonstrated that Bm91 induced a long-lasting immune response. However, the effect on the tick reproduction was not sufficient for an efficient tick control. Further studies under field conditions are warranted to enhance the effect on the tick reproduction by optimizing the immunization regimen, alone or in combination with other vaccine candidate antigens

Assessment of welfare indicators in dairy farms offering pasture at differing levels.

In terms of animal welfare, farming systems of dairy cows are perceived positively by consumers when compared to pigs or poultry. A main reason is that the majority of consumers associate dairy farming with pasture, which in turn they relate with benefits for animal health and welfare. However, holistic scientific assessments of the effects of pasturing on animal welfare are rare. Hence, it was the aim to study the animal welfare level in 61 German loose housing dairy farms by using the measures of the Welfare Quality® protocol for dairy cattle (WQP). Data were collected twice per farm at the end of the pasture season (July to October) and approximately 6 months later at the end of the barn season (December to April). Farms were classified based on the duration cows had access to pasture per day during the pasture season: group 1 (G1)>10 h; group 2 (G2) 6 to 10 h; group 3 (G3)<6 h and group 4 (G4) without pasture access. The average herd size was 129 Holstein-Friesian or Red-Holstein cows (range 58 to 527). In addition to WQP data, performance data were gathered from routine herd data recordings. The indicators were aggregated to criteria applying the scoring system of the WQP. G4 received lower scores at the first than at the second visit for the criterion absence of hunger, while there were no differences between visits in the other groups (P=0.58 – group×farm visit effect). All pasturing groups were scored better at the end of the pasture season than G4 for the criterion comfort around resting (P<0.01). Compared with G1 for both farm visits and G2 for the end of the barn season, G4 reached inferior scores for the criterion absence of injuries, including indicators such as hairless patches, lesions, and swellings and lameness. At both assessments G2 was scored higher than the other groups for the criterion absence of diseases (P=0.04). In conclusion, pasture access had positive effects only on selected welfare indicators, however, these effects were not maintained throughout the barn season

Association study in naturally infected helminth layers shows evidence for influence of interferon-gamma gene variants on Ascaridia galli worm burden

Single nucleotide polymorphisms (SNPs) in the genes for interleukin-4, -13 and interferon-gamma, and 21 additional SNPs which previously had been significantly associated with immune traits in the chicken, were genotyped in white and brown layer hens and analyzed for their association with helminth burden following natural infections. A nucleotide substitution located upstream of the promoter of the interferon-gamma gene was significantly associated with the log transformed number of Ascaridia galli in the brown layer line (genotype CC: 6.4 ± 1.0 worms; genotype CT: 11.7 ± 2.2 worms). Therefore, IFNG seems to be a promising candidate gene for further studies on helminth resistance in the chicken

Plant Traits Relevant for Multi-Functionality of Grassland Swards for Free-Range Chicken Husbandry

The sward of the outdoor run serves multiple important functions in free-range chicken husbandry systems. Vegetation ground cover is crucial for soil conservation. Moreover, by providing a foraging enrichment it is relevant for animal welfare (Shimmura et al. 2008). Scientific knowledge of the plant-animal interactions of swards in outdoor chicken runs is only just emerging. An understanding of these will help to improve swards both in view of the conservation of an intact vegetation cover, and for fostering animal welfare. In the present field study, we investigated: (1) the growth of a number of grassland plant species under conditions of chicken stocking in order to identify species that provide a durable greening of run areas; and (2) the foraging behaviour of chickens on swards of different botanical composition and canopy cover. Based on these data, our aim was to determine properties of plants that are particularly suitable for greening outdoor chicken runs

Prevalence of Gastrointestinal Helminths in Thai Indigenous Chickens Raised Under Backyard Conditions in Northern Thailand

SUMMARY This study aimed to evaluate the prevalence and worm burden of gastrointestinal parasites in Thai indigenous chickens (Gallus gallus domesticus) kept under extensive backyard conditions in Northern Thailand. A total of 211 male (N = 98) and female (N = 113) chickens from 11 smallholder farms were selected randomly between December 2016 and May 2017. At slaughter, fecal samples were collected to estimate fecal egg counts (presented as eggs per gram of feces) and oocyst counts (oocyst per gram of feces). The gastrointestinal tract of each animal was examined for the presence of parasites. The percentage of FEC- and FOC-positive samples was 33.7 and 55.4%, respectively. On average, 111 ± 328 ascarid eggs and 2,983 ± 11,641 coccidian oocysts were found. From the post mortem examination, 3 nematode species and cestodes were recovered. A total of 156 (73.9%) of the sampled chickens were infected with at least 1 helminth species. Average worm burden per chicken was 46.7 (SD = 50.9, median = 30). The most prevalent species were the nematodes Heterakis gallinarum (70.6%) followed by Ascaridia galli (60.2%) and Capillaria spp. (44.1%). The overall prevalence of cestodes was 27.7%. Apart from A. galli with higher prevalence in males than in females (P ≤ 0.05), gender did neither affect prevalence nor worm burden (P > 0.05). Growth performance was not negatively affected by helminth infections. In conclusion, the vast majority of Thai native chickens are subclinically infected with at least 1 helminth species under the studied backyard conditions