The stress of weaning influences serum levels of acute-phase proteins, iron-binding proteins, inflammatory cytokines, cortisol, and leukocyte subsets in Holstein calves

The purpose of our study was to investigate changes in immunological parameters induced by weaning stress (including milk restriction) in calves. Fifteen Holstein calves were subjected to weaning at 6 weeks of age. Blood samples were collected at -14, -7, -2, 1, 3, and 5 days post-weaning (DPW; 0 DPW = 42 days). Weaning caused significant (p < 0.01) increases in the neutrophil (NE):lymphocyte (LY) ratio at 5 DPW with a significant (p < 0.05) reduction of LYs. The concentration of acute-phase proteins (haptoglobin and serum amyloid A) also increased significantly (p < 0.05) at 3 and 5 DPW compared to -2 DPW. Levels of the iron-binding protein lactoferrin decreased significantly (p < 0.05) after weaning. Serum tumor necrosis factor-α and cortisol levels were elevated (p < 0.05) at 3 DPW, while those of serum interferon-γ decreased (p < 0.05) at 1 and 3 DPW compared to levels observed before weaning. Weaning significantly (p < 0.05) decreased the percentage of CD25⁺ T cells in the peripheral blood. In conclusion, weaning stress affected the NE:LY ratio along with the levels of acute phase proteins, lactoferrin, cortisol, and inflammatory cytokines in the peripheral blood of calves. Weaning stress may induce an acute phase response possibly through the elevation of cortisol production and modulation of inflammatory cytokines.     

Intra-arterial delivery of triolein emulsion increases vascular permeability in skeletal muscles of rabbits

Background

To test the hypothesis that triolein emulsion will increase vascular permeability of skeletal muscle.

Methods

Triolein emulsion was infused into the superficial femoral artery in rabbits (triolein group, n = 12). As a control, saline was infused (saline group, n = 18). Pre- and post-contrast T1-weighted MR images were obtained two hours after infusion. The MR images were qualitatively and quantitatively evaluated by assessing the contrast enhancement of the ipsilateral muscles. Histologic examination was performed in all rabbits.

Results

The ipsilateral muscles of the rabbits in the triolein group showed contrast enhancement, as opposed to in the ipsilateral muscles of the rabbits in the saline group. The contrast enhancement of the lesions was statistically significant (p < 0.001). Histologic findings showed that most examination areas of the triolein and saline groups had a normal appearance.

Conclusion

Rabbit thigh muscle revealed significantly increased vascular permeability with triolein emulsion; this was clearly demonstrated on the postcontrast MR images.     

MRSA CC398 in the pig production chain

In 2005, a distinct clone of methicillin resistant Staphylococcus aureus (MRSA CC398) was found in pigs and people in contact with pigs. The structure of the pig production chain in high technology pig husbandry enables pathogens to spread during animal trading, with an increasing prevalence in herds further down the chain. The objective of this study was to quantify the effect of the MRSA status of the supplying herd on the MRSA status of the receiving herd in order to gain more insight into the role of animal trading as a transmission route for MRSA CC398. Nasal samples (60-80 pigs per herd) were collected from 38 herds; in 20 herds, environmental samples were collected as well. Ten MRSA-positive herds (based on the results of nasal swabs of 10 individual pigs per herd) from a prior study were included in the data analysis. Herds were classified as MRSA positive if at least one sample tested positive. The 48 herds were part of 14 complete (40 herds) and 4 incomplete (8 herds) pig production chains. Fifty-six percent of the herds were classified as MRSA positive. MRSA-positive herds were observed at the start (breeding herds), middle (farrowing herds) and the end (finishing herds) of the pig production chain. All of the herds in 8 chains tested MRSA positive;, all of the herds in 5 chains tested MRSA negative and in the remaining 5 chains, MRSA-positive and MRSA-negative herds were detected. Seven spa types were found, which were all previously confirmed to belong to CC398. All of the isolates were susceptible to mupirocin, linezolid, rifampicin, fusidic acid and cotrimoxazole. Resistance against tetracycline, erythromycin and clindamycin was found in 100, 74 and 76% of the isolates, respectively. Seventy-nine percent of herds with a MRSA-positive supplier of pigs were MRSA positive, whereas 23% of herds with a MRSA-negative supplier were MRSA positive (OR=10.8; 95% CI: 1.5-110.1; P=0.011). The presence of entirely MRSA-positive and MRSA-negative chains and the strong association between the MRSA status of herds and their suppliers illustrates a large risk associated with purchasing pigs from MRSA-positive herds; a top-down strategy for future control programs is, therefore, a basic requirement. However, 23% of herds with a MRSA-negative supplier were MRSA positive and furthermore, 46% of the herds at the top of the pig production chain without a supplier tested MRSA positive. This underlined the need for the identification of additional risk factors for MRSA.     

Effect of day and night temperatures during long photoperiods on the vegetative growth and flowering of Chrysanthemum morifolium Ramat

The influence of day and night temperatures in the range of 10–17°C on the vegetative growth under long days of 17 year-round cultivars of chrysanthemum was studied. The after-effect of the temperature regime on the time of flowering at 17°C under short days was also recorded.A decrease of the day or night temperature reduced growth, but the effect of the day temperature was much stronger than that of the night temperature. The temperature during the vegetative period had hardly any effect on the time of flowering at 17°C.The consequences for production and breeding are discussed.     

Horizontal transmission of Mycobacterium avium subsp. paratuberculosis in cattle in an experimental setting: calves can transmit the infection to other calves

In September 2001, two subsequent transmission experiments both lasting 3 months were carried out to study cow-calf transmission of Mycobacterium avium subsp. paratuberculosis (Map) (Period 1), followed by calf-calf transmission of the infection (Period 2). Every 2 weeks, serum, heparinised blood and faecal samples were collected from all animals. After these experiments, the 20 calves were housed individually for more than 3 years to be able to detect the infection status and excretion pattern of each animal. In autumn 2004, the animals were inseminated, to observe a possible increase in faecal excretion of Map shortly before expected calving. One month before the expected calving date in 2005, animals were slaughtered and several tissues per cow and unborn calf were sampled for culture. The results indicate that horizontal cow-calf transmission is readily achieved (Period 1). At the highest infection pressure (six shedding cows of which three high shedders in Period 1) all five calves excreted Map in their faeces during Period 1 (shortly after infection), and four of these calves during Period 2 (when the shedding cows were absent). After that, excretion became less frequently. Horizontal calf-calf transmission did take place (Period 2), as the four donor-calves infected two receiver-calves. Transmission rates during the 3 months periods were quantified as a reproduction ratio R. The R [95% CI] of cow-calf and calf-calf transmission were estimated as 2.7 [1.1, 6.6] and 0.9 [0.1, 3.2] new infections per infectious animal during 3 months.     

A review of porcine reproductive and respiratory syndrome virus in Dutch breeding herds: population dynamics and clinical relevance

Understanding the spread of porcine reproductive and respiratory syndrome virus (PRRSV) in pig populations is essential to the development of effective PRRS prevention and control strategies. Moreover, knowledge of the field dynamics of PRRSV in pigs will provide insights into the clinical relevance of PRRS, and will enable the targeting of interventions. This review of PRRSV includes discussion on the occurrence of outbreaks, the persistence of infection and the fade-out of infection in Dutch breeding herds. The dynamic character of PRRSV infections in endemically infected herds and the relevance of the disease under Dutch field conditions are also highlighted. Furthermore, several strategies aimed at controlling the spread of PRRSV are discussed.     

Greenhouse gas emissions between 1993 and 2002 from land-use change and forestry in Mexico

In this paper we present the Mexican inventory of greenhouse gas (GHG) emissions from the land-use sector. It involved integration of forest inventory, land-use and soil data in a GIS to estimate the net flux of GHG between 1993 and 2002.     

Participatory agroforestry development for restoring degraded sloping land in DPR Korea

Participatory approaches in agroforestry combine land, labor, and knowledge, by blending local experience with external expert support for sloping land restoration. We describe and analyze over a decade of bottom-up agroforestry development processes that today are influencing national policies. In the 1990s, after economic upheaval following the collapse of trade with the USSR (Soviet Union) rapid conversion of sloping lands to agriculture, in association with heavy rainfall events, caused widespread erosion and landslides. In response, pilot scale ??user groups?? obtained rights-to-use, rights-to-harvest and rights-to-plan or access to sloping lands for tree products and food. All three rights were novel in the DPR Korea and jointly contributed to success, together with active research support. Innovations in double-cropping annual food crops together with non-competitive contour strips of valuable fruits (aronia berry: Aronia melanocarpa) and/or high-value timber (larch: Larix leptolepis) emerged as preferred local agroforestry systems. Broad support for agroforestry practices has now emerged within the Ministry of Land and Environmental Protection as well as a number of universities and research centres. Further development will require increased engagement with agricultural and horticultural agencies, while the social dimensions of participatory agroforestry continue to provide rich learning.     

Fungal inoculation induces agarwood in young Aquilaria malaccensis trees in the nursery

Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.