Eva Moors

Is the FAMACHA chart suitable for every breed? Correlations between FAMACHA scores and different traits of mucosa colour in naturally parasite infected sheep breeds.

Infections with gastrointestinal nematodes, in particular Haemonchus contortus, are worldwide one of the most important factors causing high economic losses in sheep production. Different methods for detecting infections with H. contortus have been described, such as, e.g. the FAMACHA system, which categorises the colour of the conjunctivae from red to pale. When H. contortus is not the predominant parasite, the FAMACHA chart might not be suitable to detect nematode infections, because of the lack of a blood feeding parasite. Otherwise breed-specific differences in the colour of the mucosa could be responsible for the limitations of the FAMACHA system. The aim of the study was to compare different methods of measuring mucosa colour in the German sheep breeds Black Head Mutton (BH) and Leine sheep (LE). In a total of 232 6-months-old lambs, the colour of mucosa was measured using the FAMACHA chart (conjunctivae) as well as the colour analyser Minolta Chroma Meter CR-200b (gingivae). Faeces and blood samples were taken at the same time to determine faecal egg counts per gram faeces (FEC) and the packed cell volume (PCV), respectively. Lambs grazed on contaminated pastures and no anthelmintic treatment was used. Lambs were moderately infected with gastrointestinal nematodes with no significant difference between the two breeds (P>0.05). The prevalence of H. contortus was 23%, based on larvae differentiation of coproculture. There was no significant correlation between FEC and PCV, nor FEC and FAMACHA (P>0.05). Significant differences (P<0.05) were found between the BH and LE lambs with regard to the colour measurement traits Chroma, hue-angle and FAMACHA. Beside the relatively low parasite pressure, these differences in the mucosa colour between the two breeds could be responsible for the limitations of the FAMACHA chart as a useful indicator of a nematode infection. Measuring the colour of the mucosa by using a colour analyser seems to be more suitable to detect less developed anaemic situations in sheep (PCV> or =0.27l/l), as shown by significant correlation coefficients between PCV and Chroma and HA, respectively. It can be concluded, that the measurement of mucosa colour with a colour analyser is more sensitive in detecting anaemic states in sheep, compared to the FAMACHA chart. However, because the colour analyser is not suited for measurements in the field, an adaptation of the FAMACHA colour scales for different sheep breeds might be required.

Genetic resistance to Heterakis gallinarum in two chicken layer lines following a single dose infection.

Groups of White Leghorn and New Hampshire male and female chicks were reared under helminth-free conditions and divided into two groups at an age of 8 weeks. One group was artificially infected with 100 embryonated Heterakis gallinarum eggs, while the other group was kept as uninfected control. After 8 weeks all animals were harvested and worm burden was established. Maximum of 60 worms per bird randomly selected were measured for length. Body weights were recorded at 8 and 16 weeks of age. Total worm burden was significantly (P<0.0001) higher in infected males than in infected females. Furthermore, White Leghorns showed a significantly (P=0.011) higher number of worms when compared with New Hampshire animals. Average worm lengths were not significantly different between the breeds (P=0.155) and sexes (P=0.062). Correlations between worm burden and worm length was 0.08 (P=0.140). The daily weight gains between 8 and 16 weeks of age of the infected animals were significantly (P=0.038) lower when compared with the control group. There was no significant correlation between daily weight gain and worm burden. The estimated heritabilities for logarithm (ln) worm burden were 0.41 (S.E.+/-0.086) in White Leghorn and 0.31 (S.E.+/-0.126) in New Hampshire, respectively. Based on the estimated heritabilities it is possible to select for H. gallinarum resistance in both genetically distinct chicken breeds. This approach may be of importance for chickens kept in floor husbandry systems.

Tandem affinity depletion: a combination of affinity fractionation and immunoaffinity depletion allows the detection of low-abundance components in the complex proteomes of body fluids.

Protein biomarker discovery in the low concentration range of human body fluids requires the enrichment of the proteins of interest. Here we report on a tandem affinity strategy: In the first step, we isolated a human plasma glyco-subproteome of healthy individuals by wheat germ agglutinin (WGA) lectin affinity chromatography. In the second step, the proteins of this subproteome were used to raise antibodies in llama (Lama glama). The heavy-chain fraction of the llama antibodies was used to deplete from the WGA lectin binding fraction all proteins normally found in human plasma. In this way, we selectively enriched the glycoprotein, CEA, a known cancer marker which had been spiked into normal plasma. As a proof of concept, we applied this method to the analysis of plasma sample from colon cancer patients. We could demonstrate the selective enrichment of CEA by a factor of 600-800.

Effects of castration and weaning conducted concurrently or consecutively on behaviour, blood traits and performance in beef calves

The objectives of this study were to evaluate the effects of Burdizzo castration and abrupt weaning on the behaviour, blood traits and performance of beef calves when weaning was conducted concurrently or consecutively to castration. In total, 64 male beef calves aged between 6 and 7 months were assigned to a 2×2 factorial design with the following treatment groups (n=16 animals per treatment): (1) castrated and concurrently weaned in week 0 (CAS-WEA); (2) castrated in week 0 and weaned in week 4 (CAS-CON); (3) bulls weaned in week 0 (BUL-WEA); and (4) bulls weaned in week 4 (BUL-CON). The behaviour of the calves was observed for 3 days following weaning. Blood was collected weekly from weeks 0 to 5 and analysed for the acute-phase protein haptoglobin, and neutrophil and lymphocyte percentages. BW was recorded weekly from weeks 0 to 7. Animals were slaughtered at 17 months and weight, dressing percentage and carcass classifications were recorded. On day 1 after weaning, the number of vocalizations (calls/10 min) was higher in BUL-WEA (7.2) and CAS-WEA (5.4) than in calves of CAS-CON (2.8) and BUL-CON (2.9) groups (P<0.05). From days 1 to 3 vocalizations decreased in all groups. CAS-CON and BUL-CON animals spent 20% lying on day 1 after weaning compared with 40% in CAS-WEA and BUL-WEA calves (P<0.05). The haptoglobin concentration decreased during the first 5 weeks after weaning in all groups independent of the castration, weaning group or its interaction (P>0.05). WEA groups showed an increased average daily gain (ADG) during weeks 0 to 3 and a reduced ADG during 4 to 7 weeks in comparison with CON animals. At slaughter, bulls were about 80 kg heavier than castrates and had a superior dressing percentage and carcass classification (P>0.05). In conclusion, weaning had a greater effect on the number of vocalizations, standing/walking and lying behaviour and ADG compared with Burdizzo castration. In comparison with undertaking the procedures separately, concurrent castration and weaning neither affected behaviour and haematological parameters nor impaired performance. There was no evidence that the concurrent application of both treatments markedly increased the stress response compared with their application at intervals of a few weeks.

Is the establishment rate and fecundity of Haemonchus contortus related to body or abomasal measurements in sheep

The relationship among parasitological parameters, abomasal size and body size measurements was investigated in lambs following an experimental infection with Haemonchus contortus. In total, 100 lambs from five different genotypes (German Merino (GM), Texel × GM, Suffolk × GM, German Blackhead Mutton × GM and Ile de France × GM) were experimentally infected with 5000 infective third stage larvae of H. contortus at the time of weaning at 12 weeks of age. Four and six weeks after infection, individual faecal samples were collected for estimation of faecal egg counts (FECs). Furthermore, wither height, shoulder width, heart girth, loin girth and body length were taken at 18 weeks of life. Lambs were slaughtered and necropsied 7 weeks post-infection, and worm counts, abomasal volume and surface area were determined. Positive correlations were found between different body size parameters, body weight and abomasal sizes. FEC and worm counts were not significantly correlated either with body size parameters or with abomasal size. The mean worm burden was higher in GM than in crossbred lambs. There was no significant difference in abomasal size between GM and crossbred lambs. The results suggest that the variations between animals in worm burden following an experimental infection with H. contortus (worm resistance) are not influenced by body size parameters or abomasal sizes. Therefore, other factors, including genetic-based differences in resistance, must cause these findings between and within breeds.