The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance.

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

Effects of riboflavin supplementation level on health, performance, and fertility of organic broiler parent stock and their chicks.

Data from breeder hens and chicks are particularly critical for the development of vitamin B2 recommendations for organic poultry. To test safe thresholds of supplementation, 100 breeder hens (Hubbard JA 57 K) and ten cockerels were allocated to ten housing groups, with each receiving supplementation of either 4.0 (treatment CON) or 2.5 mg (treatment RED) riboflavin per kg feed. After 15 weeks of experimental feeding, 256 eggs were incubated. From the hatched chicks (Hubbard S757), 192 were allocated to four treatments based on their parents' treatment (CON- or RED-) and on their own supplementation of either 4.0 (-CON) or 2.5 mg (-RED) riboflavin per kg feed. Two groups of each combination (CON-CON, CON-RED, RED-CON, RED-RED), each with 24 chicks of both sexes, were fattened for nine weeks and slaughtered. Analysis of total riboflavin (sum of native concentrations and supplements) in the parent's feeds revealed an average, over the 15 weeks, of 7.8 and 5.8 mg per kg feed for CON and RED, respectively. Body weight, plumage integrity, gait appearance, footpad, claw and keel bone integrity, lesion scores, laying performance, and egg mass were found to be of similarly high levels for all hens without any treatment effects. Performance traits of the hens in both treatments reached the specifications of the producer for this genotype. Yolk and albumen riboflavin concentrations were not affected although yolk colour in the RED treatment group became darker. Fertility was not affected, and hatchability was 100 per cent. Total riboflavin concentrations in the broiler diets were on average, over 9 weeks, 8.2 and 6.1 mg/kg for CON and RED, respectively. In chicks, RED treatment of their parents led to significant depressions of feed intake and growth. The RED treatment of the chicks themselves also impaired growth. Growth rates of the CON-CON treatment were in line with the specifications of the producer for this genotype. Plumage scores, footpad integrity and walking appearance of the broilers, and dressing percentage of the carcasses were not affected by treatment. The RED treatment of chicks caused lower spleen and heart weights, while pancreas and liver weights, and liver riboflavin concentrations were not affected. In conclusion, supplementation of 4.0 mg/kg to organic diets did not evoke any health or performance problems for breeder hens or broiler chicks, while a supplementation level of 2.5 mg per kg feed led to reduced weight gains, although without any other riboflavin deficiency symptoms.

Ascarid eggs disappear faster from gravel and wood chips than from soil.

1. Ascarids (Ascaridia galli and Heterakis spp.) are highly prevalent in free-range laying hens. Ascarid eggs survive for long periods in soil, and one preventive measure is to add litter material to areas close to the henhouse. In this study, recovery rates of ascarid eggs from three common litter materials, namely pea gravel, beech (Fagus sylvatica) and spruce (Picea abies) wood chips were compared to recovery rates from soil. 2. Materials were mixed with faeces containing 1,408 ascarid eggs per g of faeces, placed in plastic fruit boxes and exposed to natural weather conditions in a randomised block design with six replicates per treatment. 3. Numbers of ascarid eggs were quantified at 28 time points over 3.5 years. Ascarid eggs were recovered for over three years from all materials and completely disappeared during the fourth winter of exposure. Time needed to get to a 50% reduction in ascarid eggs did not differ between litter materials and soil (242 to 269 days). A 99% reduction was reached significantly (P < 0.001) earlier in pea gravel (548 days) than in the three other materials, and earlier in the two wood chips (day 682 for beech, day 692 for spruce, P < 0.05) than in soil (1,277 days). 4. Accumulation of ascarid eggs in the area close to the henhouse can be reduced by any of the tested litter materials compared to bare soil. Adding litter to this area is highly recommended for free-range layer farmers in order to reduce numbers of infective ascarid eggs.

Enhancing dopaminergic signaling and histone acetylation promotes long-term rescue of deficient fear extinction.

Extinction-based exposure therapy is used to treat anxiety- and trauma-related disorders; however, there is the need to improve its limited efficacy in individuals with impaired fear extinction learning and to promote greater protection against return-of-fear phenomena. Here, using 129S1/SvImJ mice, which display impaired fear extinction acquisition and extinction consolidation, we revealed that persistent and context-independent rescue of deficient fear extinction in these mice was associated with enhanced expression of dopamine-related genes, such as dopamine D1 (Drd1a) and -D2 (Drd2) receptor genes in the medial prefrontal cortex (mPFC) and amygdala, but not hippocampus. Moreover, enhanced histone acetylation was observed in the promoter of the extinction-regulated Drd2 gene in the mPFC, revealing a potential gene-regulatory mechanism. Although enhancing histone acetylation, via administering the histone deacetylase (HDAC) inhibitor MS-275, does not induce fear reduction during extinction training, it promoted enduring and context-independent rescue of deficient fear extinction consolidation/retrieval once extinction learning was initiated as shown following a mild conditioning protocol. This was associated with enhanced histone acetylation in neurons of the mPFC and amygdala. Finally, as a proof-of-principle, mimicking enhanced dopaminergic signaling by L-dopa treatment rescued deficient fear extinction and co-administration of MS-275 rendered this effect enduring and context-independent. In summary, current data reveal that combining dopaminergic and epigenetic mechanisms is a promising strategy to improve exposure-based behavior therapy in extinction-impaired individuals by initiating the formation of an enduring and context-independent fear-inhibitory memory.

Impact of US Brown Swiss genetics on milk quality from low-input herds in Switzerland: interactions with grazing intake and pasture type.

This study investigated the effect of, and interactions between, contrasting crossbreed genetics (US Brown Swiss [BS] × Improved Braunvieh [BV] × Original Braunvieh [OB]) and feeding regimes (especially grazing intake and pasture type) on milk fatty acid (FA) profiles. Concentrations of total polyunsaturated FAs, total omega-3 FAs and trans palmitoleic, vaccenic, α-linolenic, eicosapentaenoic and docosapentaenoic acids were higher in cows with a low proportion of BS genetics. Highest concentrations of the nutritionally desirable FAs, trans palmitoleic, vaccenic and eicosapentaenoic acids were found for cows with a low proportion of BS genetics (0-24% and/or 25-49%) on high grazing intake (75-100% of dry matter intake) diets. Multivariate analysis indicated that the proportion of OB genetics is a positive driver for nutritionally desirable monounsaturated and polyunsaturated FAs while BS genetics proportion was positive driver for total and undesirable individual saturated FAs. Significant genetics × feeding regime interactions were also detected for a range of FAs.

Comparison of a classical with a highly formularized body condition scoring system for dairy cattle.

Body condition scoring is a common tool to assess the subcutaneous fat reserves of dairy cows. Because of its subjectivity, which causes limits in repeatability, it is often discussed controversially. Aim of the current study was to evaluate the impact of considering the cows overall appearance on the scoring process and on the validity of the results. Therefore, two different methods to reveal body condition scores (BCS), 'independent BCS' (iBCS) and 'dependent BCS' (dBCS), were used to assess 1111 Swiss Brown Cattle. The iBCS and the dBCS systems were both working with the same flowchart with a decision tree structure for visual and palpatory assessment using a scale from 2 to 5 with increment units of 0.25. The iBCS was created strictly complying with the defined frames of the decision tree structure. The system was chosen due to its formularized approach to reduce the influence of subjective impressions. By contrast, the dBCS system, which was in line with common practice, had a more open approach, where - besides the decision tree - the overall impression of the cow's physical appearance was taken into account for generating the final score. Ultrasound measurement of the back fat thickness (BFT) was applied as a validation method. The dBCS turned out to be the better predictor of BFT, explaining 67.3% of the variance. The iBCS was only able to explain 47.3% of the BFT variance. Within the whole data set, only 31.3% of the animals received identical dBCS and iBCS. The pin bone region caused the most deviations between dBCS and iBCS, but also assessing the pelvis line, the hook bones and the ligaments led to divergences in around 20% of the scored animals. The study showed that during the assessment of body condition a strict adherence to a decision tree is a possible source of inexact classifications. Some body regions, especially the pin bones, proved to be particularly challenging for scoring due to difficulties in assessing them. All the more, the inclusion of the overall appearance of the cow into the assessment process counteracted these errors and led to a fair predictability of BFT with the flowchart-based BCS. This might be particularly important, if different cattle types and breeds are assessed.

Integrated control of gastrointestinal nematodes in lambs using a bioactive feed × breed approach.

Forages rich in condensed tannins have repeatedly shown potential to reduce gastrointestinal nematode infection in sheep. Similarly, several breeds of sheep have shown a relative resistance to gastrointestinal nematodes (GIN). We hypothesised that additive or even synergic effects may arise from the combination of a relatively resistant breed and a diet rich in condensed tannins. In study I, 160 lambs of the native Red Engadine Sheep (RES) and 113 lambs of the Swiss White Alpine sheep (SWA) were artificially infected with GIN and subsequently grazed for 52 days. The lambs were then distributed to 2 groups for a 14-day experimental feeding period. One group received a diet with a proportion of 55% sainfoin and was compared to a control group on the basis of faecal egg counts (FEC). In study II, 25 RES and 27 SWA lambs grazed infectious pastures for 37 days and were subsequently fed for 13 consecutive days with approximately 100% sainfoin or control forage. In addition to the FEC determination at the start and the end of the experimental feeding, the 52 lambs in study II were slaughtered and necropsied to determine their worm burden. FEC at the end of the feeding period were significantly lower in sainfoin fed lambs compared to controls in study I (p<0.001) as well as in study II (p=0.012). Breed, animal age, live weight, sex and the interaction of breed and treatment did not affect FEC in either study. The main nematode genera found in the sacrificed lambs of study II were Haemonchus spp., Teladorsagia spp., Nematodirus spp. and Trichostrongylus spp. Overall, RES had a significantly lower Haemonchus spp. (p=0.035) and Trichostrongylus spp. (p=0.003) worm burden compared to SWA. Regardless of breed, sainfoin feeding significantly reduced Teladorsagia spp. (p=0.049) and Nematodirus spp. (p<0.001) worm burden. Although, we could not demonstrate additive or synergic effects when using an integrated breed × sainfoin approach, the finding that a proportion of only 55% sainfoin in the diet led to a lower FEC compared to controls is important with respect to the implementation on producing farms.

Performance of commercial laying hen genotypes on free range and organic farms in Switzerland, France and The Netherlands.

1. A total of 257 farmers with free ranging laying hens (organic and conventional) in Switzerland, France and The Netherlands with 273 flocks were interviewed to determine the relationships between the genotype of the hens, management conditions and performance. 2. Almost 20 different genotypes (brands) were present on the farms. In France, all birds were brown feathered hens laying brown eggs. In Switzerland and The Netherlands, there were brown, white (white feathered hens laying white eggs) and silver (white feathered hens laying brown eggs) hens. In Switzerland, mixed flocks were also present. 3. The overall effect of system (organic vs. conventional free range) on egg production and mortality was significant, with higher mortality and lower egg production among organic hens. In pair wise comparisons within country, the difference was highly significant in The Netherlands, and showed a non-significant tendency in the same direction in Switzerland and France. 4. White hens tended to perform better than brown hens. Silver hens appeared to have a higher mortality and lower production per hen housed at 60 weeks of age. 5. There were no significant relationships between production, mortality, feather condition and use of outside run or with flock size. 6. There was more variation in mortality and egg production among farms with a small flock size than among farms with a large flock size.

Poultry litter as a source of gastrointestinal helminth infections.

The aim of this study carried out in 6 commercial layer houses was to examine the effect of litter management on water content, helminth egg count and litter infectiousness with the intestinal nematodes Ascaridia galli, Heterakis gallinarum, and Capillaria spp. Three types of litter management were established in each layer house in parallel: in compartment A, litter was left undisturbed, in compartment B, wet litter was replaced and in compartment C, new litter material was added weekly. Dry matter (DM) contents of the litter and parasitological parameters (helminth egg concentration in litter samples, faecal egg counts (FECs) in the permanent layer flocks, helminth prevalence and burdens in two series of tracer animals) were determined every 4 weeks during the first 32 weeks of one laying period. DM contents of the litter varied in a broad range (48-95%); 8 weeks after onset of the study, there were significant differences between sites (P<0.001) but not between management regimes. A. galli/H. gallinarum eggs were isolated from 91% of the litter samples, whereas eggs of Capillaria spp. were only extracted from 13% of the samples. Egg concentrations in litter remained at a similar level during the observation period. Neither management regime reduced helminth egg concentrations in the litter compared to the unmanaged regime. Laying hens started excreting helminth eggs 8 weeks after introduction to the layer house. In treatment C (litter added) FECs were lower than in the unmanaged treatment A in weeks 8 (P<0.0001), 20, and 28 (both P<0.1). There was no correlation between the concentration of helminth eggs in the litter and the FECs of the layer flocks. The prevalence of A. galli in tracer animals was lower (<10%) than the prevalences of H. gallinarum (68-80%) and Capillaria spp. (30-58%). Prevalences and H. gallinarum burdens did not differ significantly between management regimes. Although high helminth egg concentrations were found in litter, the prevalence and worm burdens in tracer animals were low compared to a similar study with tracers kept in poultry runs. The reasons for this may be that poultry litter negatively affects viability and infectiousness of helminth eggs. However, underlying mechanisms need to be clarified.

Do stocking rate and a simple run management practice influence the infection of laying hens with gastrointestinal helminths?

The aim of this experiment conducted at four sites in Switzerland was to investigate the transmission and infectivity of the two main helminth parasite species of poultry (Ascaridia galli and Heterakis gallinarum) in outdoor runs with two different stocking rates. Additionally, the influence of a simple management practice (mowing of run) on helminth transmission was studied. Three run types were created on each site: runs C served as control (stocking rate 10 m(2)/hen, no management), runs B corresponded to runs C but were managed (10 m(2)/hen, management). In runs A stocking rates were doubled compared to control runs (5m(2)/hen, no management). During two subsequent layer flocks, a set of parasitological parameters (faecal egg counts (FECs), prevalence, worm burdens in hens and in tracer animals, helminth eggs in soil) as well as parameters describing the run vegetation were determined. The increased stocking rate (runs A) led to a larger proportion of bare soil and to a reduction of the average vegetation height. In runs with a lower stocking rate (B and C), the proportion of bare soil did not increase during the experimental period. Irrespective of the run type, numbers of helminth eggs in the soil decreased significantly with an increasing distance to the hen houses, while the percentage of ground coverage as well as vegetation height increased. However, across runs the correlation between the percentage of ground cover and the values of eggs per gram soil between runs was very low (r(2)=0.0007, P=0.95) indicating a non-causal relationship. Significant differences in FEC were found in flock 2 (P<0.001): FEC of hens in managed runs B were 24% lower (P<0.05) than those of the control animals. Although not significant, the corresponding prevalence was lower (-9.7%) in hens from managed runs as well. Hens from runs with a high stocking rate (A) had significantly higher FEC than hens from control runs (C). In flock 2 management (n.s.) and higher stocking rates (-62%, P<0.05) decreased the worm burdens. Tracer animals from runs with a high stocking rate (A) had significantly higher FEC than tracers from runs B and C in two tracer series. This was not reflected in the worm burdens. Overall, the stocking rate of hens in the outdoor run seemed not to influence the transmission patterns of A. galli and H. gallinarum and repeated mowing of runs did not reduce helminth infections. Lower stocking rates, however, led to a substantial improvement of the run vegetation.

In vitro screening of six anthelmintic plant products against larval Haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay.

Because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. Phytotherapy could be one of the major options to control these pathologies. Extracts or ingredients of six different plant species were tested against exsheathed infective larvae of Haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (MTT) reduction assay. Pyrantel tartrate was used as reference anthelmintic. Bromelain, the enzyme complex of the stem of Ananas comosus (Bromeliaceae), the ethanolic extracts of seeds of Azadirachta indica (Meliaceae), Caesalpinia crista (Caesalpiniaceae) and Vernonia anthelmintica (Asteraceae), and the ethanolic extracts of the whole plant of Fumaria parviflora (Papaveraceae) and of the fruit of Embelia ribes (Myrsinaceae) showed an anthelmintic efficacy of up to 93%, relative to pyrantel tartrate. Based on these results obtained with larval Haemonchus contortus, the modified MTT reduction assay could be a possible method for testing plant products with anthelmintic properties.

The anthelmintic efficacy of five plant products against gastrointestinal trichostrongylids in artificially infected lambs.

Forty-eight helminth-free lambs were divided into eight groups (A-H) of six animals. Groups A-G were infected artificially with 10,000 third stage larvae of Haemonchus contortus and 20,000 third stage larvae of Trichostrongylus colubriformis, whereas group H remained uninfected. Thirty days post-infection the lambs were treated orally with a single dosage of one of the following products: group A with 3 mg/kg body weight (BW) of an aqueous ethanol extract (70%, v/v) of the seeds of Azadirachta indica A. Juss syn. Melia azedarach L. (Meliaceae); group B with 1 g/kg BW of a raw powder of the leaves of Ananas comosus (L.) Merr. (Bromeliaceae); group C with 0.3 mg/kg BW of an aqueous ethanol extract of a 1:1 mixture (g/g) of Vernonia anthelmintica (L.) Willd. (Asteraceae) seeds and Embelia ribes Burm (Myrsinaceae) fruits; group D with 183 mg/kg BW of an aqueous ethanol extract of the whole plants of Fumaria parviflora Lam. (Fumariaceae); group E with 28 mg/kg BW of an aqueous ethanol extract of the seeds of Caesalpinia crista L. (Caesalpiniaceae); group F with 25 mg/kg BW of pyrantel tartrate and group G with 50% ethanol. Group H remained untreated. Only the ethanol extract of F. parviflora caused a strong reduction of the faecal egg counts (100%) and a 78.2 and 88.8% reduction of adult H. contortus and T. colubriformis on day 13 post-treatment. The extract was as effective as the reference compound pyrantel tartrate. Therefore, the ethanol extract itself or single constituents of F. parviflora could be a promising alternative source of anthelmintic for the treatment of gastrointestinal trichostrongylids in small ruminants.

Contrast-enhanced breast MRI for cancer detection using a commercially available system--a perspective.

The diagnosis and treatment of breast cancer are dependent upon early detection of the disease by physical examination and mammography. Although mammography is a relatively good and cost-effective method of early breast cancer detection, there are some inherent weaknesses associated with this imaging modality that limit its sensitivity and specificity. Contrast-enhanced MRI of the breasts provides the additional capability to answer questions raised or unanswered with conventional imaging methods. This paper reviews contrast-enhanced breast MRI interpretation guidelines and patient preselection criteria for diagnostic problem cases. Technical aspects using a commercially available three-dimensional (3D) spoiled gradient-echo technique are discussed.

A population model for Dermanyssus gallinae (Acari: Dermanyssidae).

A model based on a time-varying distributed delay with attrition was developed for simulating the population dynamics of the chicken mite Dermanyssus gallinae (DeGeer, 1778). The model was parametrised according to cohort life table studies conducted under constant temperature conditions and was validated with two independent data set obtained in an experimental poultry house. The predicted mite densities and the stage-structure of the population corresponded to the values observed during experimental periods of 32, and 11 weeks, respectively. Temperature and a poultry house-specific density effect were determined to control the population development.

Temperature influence on life table statistics of the chicken mite Dermanyssus gallinae (Acari: Dermanyssidae).

An age-specific life table for the chicken mite Dermanyssus gallinae (DeGeer, 1778) was based on various observations carried out at 25 degrees C. The generation time was calculated to be 16.8 days; the intrinsic rate of natural increase was 0.12 per day, and the net reproductive rate was 7.2. A nonlinear function was found satisfactory to describe the developmental rate of the different immature life-stages at temperatures below 40 degrees C. The stage-specific survival of the immature life-stages was generally high between 10 and 37 degrees C, but decreased quickly outside this temperature range. Most of the eggs were laid during the first three weeks of the adult life. The proportion of surviving females rapidly decreases after moulting to the adult stage. At a temperature of 30 degrees C, the highest number of eggs (3 eggs per day) was laid.

Prospective evaluation of physical examination of the breast.

The reliability of physical examination of the breast was evaluated by determining the extent of agreement among four experienced breast surgeons who examined the same 100 patients. The consequences of disagreements among surgeons were assessed by determining the diagnostic accuracy of each examiner. Despite differences in the frequency with which each surgeon found abnormalities or masses, or recommended mammography or biopsy, the diagnostic accuracy of the surgeons was very similar, and most disagreements concerned the findings in patients who did not have breast cancer. Breast examination carried out by more than one surgeon may reduce the frequency with which biopsy is performed in patients who do not have breast cancer.