Gürbüz Daş

Research Institute for Farm Animal Biology

Background Density related effects, both inverse density- and density-dependent, contribute to regulating population dynamics of parasites. We investigated whether density related effects are directly controlling lifetime fecundity of Heterakis gallinarum. Methods Daily total numbers of H. gallinarum eggs in faeces samples (N = 1365) from chickens...

Background: Classical faecal egg counts (FEC) provide less reliable diagnostic information for nematode infections in chickens. We developed an ELISA based on Ascaridia galli antigens and tested two hypotheses, as follows: (i) IgY antibodies developed against A. galli will also be useful to identify Heterakis gallinarum infections, and (ii) circula...

Worm expulsion is known to occur in mammalian hosts exposed to mono-species helminth infections, whilst this phenomenon is poorly described in avian hosts. Mono-species infections, however, are rather rare under natural circumstances. Therefore, we quantified the extent and duration of worm expulsion by chickens experimentally infected with both As...

Mineral and heavy metal accumulation in black soldier fly (Hermetia illucens) larvae (BSFL) is of growing interest. The bioaccumulation of elements in BSFL is usually assessed by a bioaccumulation factor (BAF), which is the ratio between the concentration of an element in the organism and in its feeding substrate. Recently, a new index, i.e. bioacc...

Background A coproantigen enzyme-linked immunosorbent assay (ELISA) has recently been proposed for detecting ascarid infections in chickens. The excretion pattern of ascarid antigens through chicken faeces and the consistency of measurements over the course of infections are currently unknown. This study evaluates the pattern and repeatability of w...

During parasite infections, the liver may prioritise immune-related pathways over its metabolic functions. Intestinal infections caused by Ascaridia galli and Heterakis gallinarum impair feed intake, nutrient absorption, and weight gain. Histomonas meleagridis, vectored by H. gallinarum , can also damage liver tissues, potentially impairing liver f...

We investigated if feeding earthworms (EW) or vermicompost (VC) to broilers improves performance and aids in coping with dietary challenges from a soluble non-starch polysaccharide (NSP)-enriched diet (negative control diet; CON-). Newly-hatched male Cobb-500 birds (N = 480) were fed either a positive (+) control diet (CON+, n = 240) or CON+ supple...

Black soldier fly larvae (BSFL) can accumulate minerals, including P and Ca, from sewage sludge recyclates (SSR), and may therefore be used as a protein- and mineral-enriched component in poultry rations. In this study, the effects of supplementing SSR mineral-enriched BSFL on broiler performance and health were investigated. BSFL were grown on a f...

The recycling of minerals is crucial for the future circular agriculture. Black soldier fly larvae (BSFL) can accumulate minerals in their body. This study investigated the effects of adding mineral-enriched BSFL, grown on substrates containing sewage sludge recyclates (SSR), to broiler feed to reintroduce minerals from waste streams currently subj...

Global rock phosphorus sources are finite and expensive. New recycling technologies (e.g. Ash2Phos) are emerging. Black soldier fly larvae (BSFL) accumulate minerals from sewage sludge recylates (SSR). Mineral-enriched BSFL can make up to 20% of broiler rations.

Background Gut infections of chickens caused by Ascaridia galli and Heterakis gallinarum are associated with impaired host performance, particularly in high-performing genotypes. Heterakis gallinarum is also a vector of Histomonas meleagridis that is often co-involved with ascarid infections. Here, we provide a first insight into the alteration of...

Phosphorous (P) resources are finite. Sewage sludge recyclates (SSR) are not only of interest as plant fertilizer but also as potential source of minerals in animal nutrition. However, besides P and calcium (Ca), SSR contain heavy metals. Under EU legislation, the use of SSR derivatives in animal feed is not permitted, but given the need to improve...

Reports of Ascaridia galli in laying hens in Europe have increased since the ban on conventional battery cages in 2012. As this parasite is transmitted directly via the faecal-oral route by parasite eggs containing a larva, it is reasonable to assume that the escalating problem is related to the increased exposure now occurring in modern welfare-fr...

A feeding experiment was conducted to investigate the impact of feeding defrosted whole black soldier fly larvae (BSFL) to broilers in increasing levels in the ration on blood metabolites, carcass characteristics (CC) and on changes in fatty acid (FA) composition in plasma, muscle and abdominal fat. Day-old chicks (Ross-308; n=252) were assigned to...

In recent years, interest in the larvae of black soldier fly (BSF) ( Hermetia illucens ) as a sustainable protein resource for livestock feed has increased considerably. However, knowledge on the nutritional and physiological aspects of this insect, especially compared to other conventional farmed animals is scarce. This review presents a critical...

Whole BSFL can be fed to broilers not only for decreasing soybean-protein in diets but also to improve animal welfare. How much whole BSFL could be fed to broilers is however unknown. We assessed apparent interest of broilers in eating BSFL when offered with either 10% (L10), 20% (L20) or 30% (L30) of voluntary feed intake (FI) of control chickens...

A reliable method of diagnosing the most prevalent helminth infections in chickens is vital for developing effective control strategies. A. galli and H. gallinarum are phylogenetically close nematode species that can elicit the development of cross-reactive antibodies in chickens. Therefore, an enzyme-linked immunoassay (ELISA) based on Ascaridia g...

Meal of Black Soldier Fly Larvae (BSFL), which requires extraction of protein and fat, is a novel protein source for poultry, while unprocessed whole BSFL could even directly be fed to chickens. Newly hatched Ross-308 chicks (n = 252) received whole BSFL at 10% (L10), 20% (L20) or 30% (L30) of voluntary feed intake (FI) of control chickens (CON) th...

Soybean meal in poultry diets can be replaced by defatted black soldier fly larvae (BSFL) meal without affecting performance [1]. However, whole BSFL could be fed to chickens directly without processing [2]. We investigated the effects of different inclusion levels of unprocessed BSFL in broiler diets on metabolism, immune status, carcass character...

Black Soldier Fly larvae (BSFL) are known for their high Ca content [1]. They are one of only a few insect species to contain a wide calcium (Ca):phosphorus (P) ratio of up to 8.2:1 [2] [3]. We hypothesized that inclusion of up to 30% unprocessed BSFL in broiler diets have a positive influence on mineralization, in particular the ash, Ca and P cont...

Protein imbalance during pregnancy affects women in underdeveloped and developing countries and is associated with compromised offspring growth and an increased risk of metabolic diseases in later life. We studied in a porcine model the glucose and urea metabolism, and circulatory hormone and metabolite profile of offspring exposed during gestation...

Background Histomonosis is a severe re-emerging disease of poultry caused by Histomonas meleagridis , a protozoan parasite which survives in the environment via the cecal worm Heterakis gallinarum . Following infection, the parasites reside in the ceca and are excreted via host feces. In the present work, male birds of conventional broiler (Ross 30...

Nematode infections may induce immune-modulatory effects and influence host-immune responses to other pathogens. The aim of the study was to investigate whether a mixed nematode-infection influences non-specific and vaccine-induced humoral immunity against Newcastle Disease Virus (NDV), Infectious Bronchitis Virus (IBV), and Avian Metapneumovirus (...

Here, we describe the first transcriptomic investigation of the peripheral blood of chickens exposed to Ascaridia galli and Heterakis gallinarum infections. We investigated differentially expressed gene (DEG) patterns in two chicken genotypes with either a higher (Lohmann Brown Plus, LB) or lower (Lohmann Dual, LD) laying performance level. The hen...

Insect larvae are part of the natural diet of poultry. In recent years, the meal of the Black Soldier Fly Larvae (BSFL; Hermetia illucens L.) has been suggested as an alternative source of protein to soybean and hence, as a potential ingredient for chicken feed (1). The inclusion of BSFL-meal in the poultry diets implies the extraction of protein a...

Faecal egg counting techniques (ECTs) are useful tools for assessing anthelmintic efficacy and selecting hosts resistant to parasite infection. McMaster (MM) is one of the most commonly used ECTs, but it suffers from low sensitivity and precision. Mini-FLOTAC (MF) has been proposed to replace MM, but so far has not been evaluated for gastro-intesti...

Dysregulated skeletal muscle metabolism (DSMM) is associated with increased inter- and intramuscular fat deposition in low birth weight (L) individuals. The mechanisms behind DSMM in L individuals are not completely understood but decreased muscle mass and shifts in lipid and carbohydrate utilisation may contribute. Previously, we observed lower fa...

The present invention relates to a method for predicting the methane (CH4) emission of a dairy cow comprising: a) determining the total amount of milk of a dairy cow per one day; b) determining the energy corrected milk value (ECM) of the milk of the dairy cow of the same day as in a); c) determining the percentage amount of saturated fatty acids (...

Modern chickens have been genetically developed to perform high under optimal conditions. We hypothesized that high-performance is associated with a higher sensitivity to environmental challenges in laying hens. By using nematode infections as an environmental stressor, we assessed performance-level associated host responses in a high (i.e. Lohmann...

The aim of this study was to test the effect of the animal to feeding place ratio on behavior of meat goats during gestation. In one group (FP-1.0; n=10) every goat had a single feeding place while in the other group (FP-0.5; n=10) two goats had to share one feeding place. Behaviors were analyzed with the continuous sampling method for 24h for each...

Fast growing broilers are less able to cope with fitness related challenges. As the allocation of metabolic resources may be traded off between performance and defence functions in parasitized hosts, we hypothesized that fast growing broilers are more sensitive to mixed nematode infections compared with slower growing genotypes under the same envir...

Milk fatty acids (MFA) are a proxy for the prediction of CH4 emission from cows, and prediction differs with diet. Our objectives were (1) to compare the effect of diets on the relation between MFA profile and measured CH4 production, (2) to predict CH4 production based on 6 data sets differing in the number and type of MFA, and (3) to test whether...

Background Worm expulsion is known to occur for some helminth species residing in mammalian hosts (VALLANCE et al., 1997; DOLD and HOLLAND, 2011). However for avian species such a phenomenon has only poorly been described so far. Thus, the aim of this study was to investigate whether and how efficiently worm expulsion takes place in chickens infect...

Periodicity in nematode egg excretion may be of evolutionary origin as it can favour dispersal of the eggs in the environment. We investigated whether egg excretion by Heterakis gallinarum shows a repeatable pattern of periodicity. The faecal egg concentration and total number of eggs excreted within 4-h intervals were significantly affected by the...

In Europe, poultry husbandry systems have recently shifted from cage to floor rearing or free range systems resulting in increased prevalence of Ascaridia galli and Heterakis gallinarum. Benzimidazole (BZ) resistance in nematodes has been reported in ruminants and horses. Using different molecular methods, resistance was linked with presence of thr...

Ruminant enteric methane emission contributes to global warming. Although breeding low methane-emitting cows appears to be possible through genetic selection, doing so requires methane emission quantification by using elaborate instrumentation (respiration chambers, SF6 technique, GreenFeed) not feasible on a large scale. It has been suggested that...

Factors affecting the development of Ascaridia galli–specific humoral responses and their protective roles are largely unknown. We investigated the effects of time and infection dose on A. galli–specific IgY antibody levels following experimental infection. The acquisition and development of new infections and reinfections were also monitored by us...

Figure S1. In silico secondary structure determination of S‐CPHB‐S and S‐CPHB‐A2 was carried out using the Phyre2 server (Kelley and Sternberg, 2009; Kelley et al., 2015). Figure S2. Chromatogram of the ß‐Asp‐Arg dipeptide after enzymatic degradation of cyanophycin with cyanophycinase and subsequent enzyme removal (blue); Asp and Arg signals afte...

Data S1. Detailed experimental procedure.

Table S1. Body weight, intakes of pellets, cyanophycin (CPG), cyanophycinase (CPGase), and free Asp and Arg, as well as concentrations of plasma Asp, ß‐Asp‐Arg dipeptide, Arg, and Orn in four groups of mice fed protein‐free pellets supplemented with CPG, CPG+CPGnase, Asp+Arg, or none of these (control; CON). Table S2. Sequence of primers used in t...

Experimental setups for physiological research, in which acute operative interventions need to be performed, can require inclusion of general anesthesia (GA), which may interfere or confound with the effects of the experimental factors of interest on measured variables. It was recently shown that the most commonly used sedatives/anesthetics in pigs...

Experimental setups for physiological research, in which acute operative interventions need to be performed, can require inclusion of general anesthesia (GA), which may interfere or confound with the effects of the experimental factors of interest on measured variables. It was recently shown that the most commonly used sedatives/anesthetics in pigs...

Food supplementation with the conditionally essential amino acid arginine (Arg) has been shown to have nutritional benefits. Degradation of cyanophycin (CGP), a peptide polymer used for nitrogen storage by cyanobacteria, requires cyanophycinase (CGPase) and results in the release of β-aspartic acid (Asp)-(Arg) dipeptides. The simultaneous productio...

Maternally derived antibodies can provide partial protection against certain bacterial and viral infections. We investigated whether chicks descending from nematode-infected hens are more resistant against Ascaridia galli, a prevalent gastrointestinal nematode, than chicks from nematode-free mothers. One-day-old chicks (N = 153) from infected (mab+...

The porcine model has been utilized by researchers to study human developmental aspects, surgical procedures, disease impacts, and nutritional interventions for over 60 yr. However, when it comes to investigating how nutrients regulate human gastrointestinal tract (GIT) function and health, and nutritional research evolves from dietary composition...

Physiological research with swine often includes sedation or general anesthesia (GA), which may influence the basal physiological responses of experimental animals and may have the potential to confound or interfere with the effects of experimental factors of interest. Using 6 adult female pigs, we investigated whether selected plasma metabolites a...

Heat stress is known to influence sow reproduction, but it is unknown to which extent under temperate climates. Therefore, the impact of temperature and temperature-humidity index (THI) on the reproductive performance of sows during summer months from 2009 to 2011 were studied. Reproductive parameters of 22 264 inseminations and 21 610 resulting fa...

Flavonoids are secondary plant metabolites with several health promoting effects. As dairy cows often suffer from metabolic imbalance and health problems, interest is growing in health improvements by plant substances such as flavonoids. Our group has recently shown that the flavonoids quercetin and rutin (a glucorhamnoside of quercetin) are bioava...

Experimental infection models for Ascaridia galli rely on the use of eggs isolated either directly from worm uteri or from host faeces. We investigated whether A. galli eggs isolated from the two sources differ in their embryonation ability. A. galli eggs originating from 12 worm infrapopulations were isolated both from faeces of the living host (f...

Abstract 1. Genetic parameters were determined for the worm burden of the most common gastro-intestinal nematodes in two chicken genotypes after being exposed to free-range farming conditions for a laying period. 2. Seventeen-week-old hens of two brown genotypes, LB plus (n = 230) and LB classic (n = 230), were reared for a laying period and subjec...

In modern husbandry systems, feed rations for laying hens may contain high levels of dietary fibre, which may only be fermented intestinally. Depending on fermentation properties, the type of dietary fibre may influence the intra-caecal environment constituting the predilection site of Heterakis gallinarum. We investigated egg production dynamics a...

Although the climate in Germany is moderate, heat stress conditions may occur during summer months. However, it is unknown to what extent sow fertility and piglet survival are affected under moderate climatic conditions in indoor systems. Therefore, this study estimated effects of temperature and temperature–humidity index (THI) on sow fertility an...

The objective of this study was to monitor establishment and development of gastro-intestinal helminth infections in chickens over two production years (PY) on a free-range farm in Lower Saxony, Germany. The data were collected between July 2010 and June 2011 (PY1) and July 2011 and January 2013 (PY2), respectively. During PY1, Lohmann Brown classi...

With regard to the growing concerns on global climate change, this study aimed at describing basic climatic conditions in sow barns. On 10 piglet producing farms, temperature and relative humidity were measured in the farrowing, servicing and waiting compartments from July 2011 to August 2012. Based on that, the temperature-humidity-index (THI) was...

Isoflurane-anaesthesia combined with an analgesic represents a welfare-friendly method of pain mitigation for castration of piglets. However, it requires an inhaler device, which is uneconomic for small farms. Sharing a device among farms may be an economical option if the shared use does not increase labour time and the resulting costs. This study...

It was hypothesized that chickens with extremely varying body weights (BW) from an otherwise homogeneous host sample cope differently with Ascaridia galli (Schrank 1788) infection. Small and large birds, falling into either the lower or the upper 5 % quantiles of BW distribution of a parent stock flock, were selected at an age of 4 weeks, housed se...

Castration of piglets with the use of isoflurane-anaesthesia in combination with an analgesic has been proven to be a welfare-friendly approach. However, castration is performed with an equipped anaesthetic device which is not profitable for small farms. Thus, this study aimed at investigating whether sharing the anaesthetic device among farms resu...

Eighty Lohmann White laying hens were used to investigate the effect of dietary inclusion of Bacillus subtilis and inulin, individually or in combination, on egg production, eggshell quality, tibia traits, Ca retention, and small intestine morphology and microflora composition from 64 to 75 weeks of age. Hens were randomly distributed into 4 treatm...

It is well documented that global warming is unequivocal. Dairy production systems are considered as important sources of greenhouse gas emissions; however, little is known about the sensitivity and vulnerability of these production systems themselves to climate warming. This review brings different aspects of dairy cow production in Central Europe...

This study investigated whether infectivity of Capillaria obsignata eggs depends on media culture used for embryonation. Intact female worms were kept in one of following four media: 0.5 % formalin, 2 % formalin, 0.1 % potassium dichromate and 0.1 N sulfuric acid. Embryonation rates of the eggs were quantified either daily in intact females for 16...

The investigation aimed at examining if the composition of grassland silage affects the microbial nitrogen assimilation in the rumen of sheep. The silages were made of vegetative summer re-growths consisting of 48% grasses, 28% legumes and 24% other forbs (GCF) or of pure grass (G). Silage GCF contained more intermediately degradable non-structural...