Adrenal responsiveness to a low-dose ACTH challenge in early and late lactating dairy cows.

To improve the evaluation of the chronic stress conditions, the adrenal responsiveness to low dose ACTH stimulation, in different lactation stages, was checked in 56 multiparous dairy cows from 2 herds (25-350 days in milk). Cows were retrospectively ranked in 3 stages: early (150 DIM) lactation. Herd B (vs. herd A) showed higher basal cortisol and frequency of inflammation. Early stage (vs. others) showed higher basal cortisol, bilirubin, ceruloplasmin and haptoglobin, as well as lower ones of cholesterol and lower rise of plasma cortisol during ACTH challenge (P<0.001). Cortisol peak was also correlated negatively with ceruloplasmin, bilirubin, ROM, and positively with cholesterol, vitamin A and E. Both, basal cortisol and cortisol response to ACTH, are associated to inflammation but in opposite way: basal cortisol positively and cortisol response negatively. This latter results are likely due to lower transcortin synthesis, that could be ensued in early lactating cows suffering inflammation

Plasma cortisol variations in dairy cows after some usual or unusual manipulations

The increase of blood cortisol is a common consequence of the acute stress; this has generally positive effects, despite not completely understood (Sapolsky et al. 2000). However, at least in human beings under chronic stress, the hypothalamic-pituitary-adrenal system – responsible of cortisol release – is deregulated, resulting in pathophysiological changes, which may develop into various types of disorders (Tafet and Bernardini, 2003)

Anti-inflammatory treatments in calving dairy cows: effects on haematological and metabolic profiles

High yielding dairy cows are particularly vulnerable during the transition period to any event able to stimulate immune system. In contrast, response to these events is easily controlled in other stages of lactation

Potential dietary feed additives with antibacterial effects and their impact on performance of weaned piglets : a meta-analysis

This meta-analysis evaluated the use of potential dietary feed additives (pDFA) with antibacterial effects and their impact on the perfomance of weaned piglets. Twenty-three peer-reviewed in vivo studies, comprising 50 trials, were identified between January 2010 and January 2017. The pDFA in these studies could be grouped in 5 classes: antimicrobial peptides, chitosan, lysozyme, medium chain fatty acids/triglycerides and plant extracts. Mixed-effect meta-analyses with type of pDFA as fixed effect were performed for the growth parameters 'average daily gain' (ADG) and 'feed conversion ratio' (FCR), which are the two most important and used economic performance parameters for farmers. For each class of pDFA, results of the meta-analysis showed significantly higher average daily gain in the group with pDFA compared to the negative control group, while no significant difference with the positive control group was observed. Furthermore, a positive effect on FCR was found, i.e. significantly less feed was needed to gain 1 kg of body weight in the group with pDFA compared to the negative control group. No significant differences with positive control groups were observed for each class of pDFA, except for plant extracts, where the FCR was also significantly reduced in the treatment group. These results suggest that pDFA could reduce the use of antimicrobials without significant negative effects on performance indicators

Change of digesta passage rate in dairy cows after different acute stress situations

Six dairy cows received 3 treatments after morning meal, in a double Latin square design. Treatments were ACTH challenge (SYN), hoof trimming (TRIM) and saline (CTR). Measurements included: plasma cortisol and metabolic profile during the 24 h after treatments; the rate of digesta passage, faecal dry matter and pH. Both acute stress situations vs CTR caused a rapid and similar rise in plasma cortisol (P<0.001), while plasma glucose increased only in response to TRIM. Plasma concentrations of urea and BHB were increased for several hours after both stress situations. Most importantly, the transit time of digesta was reduced with SYN and TRIM (P<0.05). Our data demonstrate a reduced forestomach motility during acute stress and confirm a possible negative linkage between stress and gut functions, perhaps independent of diet composition. The mechanism seems linked to increased ACTH or cortisol rather than corticotrophin-releasing factor

Potential dietary feed additives with antibacterial effects and their impact on performance of weaned piglets: A meta-analysis

This meta-analysis evaluated the use of potential dietary feed additives (pDFA) with antibacterial effects and their impact on the perfomance of weaned piglets. Twenty-three peer-reviewed in vivo studies, comprising 50 trials, were identified between January 2010 and January 2017. The pDFA in these studies could be grouped in 5 classes: antimicrobial peptides, chitosan, lysozyme, medium chain fatty acids/ triglycerides and plant extracts. Mixed-effect meta-analyses with type of pDFA as fixed effect were performed for the growth parameters ‘average daily gain’ (ADG) and ‘feed conversion ratio’ (FCR), which are the two most important and used economic performance parameters for farmers. For each class of pDFA, results of the meta-analysis showed significantly higher average daily gain in the group with pDFA compared to the negative control group, while no significant difference with the positive control group was observed. Furthermore, a positive effect on FCR was found, i.e. significantly less feed was needed to gain 1 kg of body weight in the group with pDFA compared to the negative control group. No significant differences with positive control groups were observed for each class of pDFA, except for plant extracts, where the FCR was also significantly reduced in the treatment group. These results suggest that pDFA could reduce the use of antimicrobials without significant negative effects on performance indicators

Blood inflammatory indices in goats around kidding

AbstractThe transition period of goats is often characterized by serious metabolic problems, mainly before parturition. These troubles are related to negative energy balance status, however all causes are not totally defined. To improve the knowledge about pathogenesis in this phase we have monitored the changes of some blood indices of lipomobilization and inflammation. Six blood samples were collected from 10 primiparous and 25 multiparous "Camosciata delle Alpi" goats after morning milking. Samples were collected around 20 and 7 days before parturition and on days 0, 3, 6 and 12 of lactation. Albumin, total protein, haptoglobin, ceruloplasmin, total cholesterol, NEFA, β-OH-butyrate (BHB), Ca, Mg and Zn were determined. Goats were grouped according to their BHB level before parturition: low (≤0.6 mmol/l; LOB), average (0.6÷1.09; AVB) and high (≥1.09 mmol/l; HIB) level. Furthermore, the AVB group was divided according to plasma haptoglobin level before parturition: low (<0.5 g/l) or high. The statistical..

Modelling of broadband light sources based on InAs / INxGA1-xAS metamorphic quantum dots

We propose a design for a semiconductor structure emitting broadband light in the infrared, based on InAs quantum dots (QDs) embedded into a metamorphic 4-step-graded InxGa1- xAs buffer with x = 0.10, 0.20, 0.30, 0.40. We developed a model to calculate metamorphic QD energy levels based on realistic QD parameters and on strain-dependent material properties: results of simulations were validated against experimental values. By simulating the broadband metamorphic structure, we demonstrated that its light emission can cover the whole 1.0 - 1.7 μm range with a bandwidth of 550 nm at 10K. The emission spectrum was then assessed under realistic electrical injection conditions, at room temperature, through device-level simulations based on a coupled drift-diffusion and QD dynamics model. As metamorphic QD devices have been already fabricated with satisfying performances we believe that this proposal is a viable option to realize broader band light-emitting devices such as superluminescent diodes

Broadband light sources based on InAs/InGaAs metamorphic quantum dots

We propose a design for a semiconductor structure emitting broadband light in the infrared, based on InAsquantum dots(QDs) embedded into a metamorphic step-graded InxGa1−xAs buffer. We developed a model to calculate the metamorphic QD energy levels based on the realistic QD parameters and on the strain-dependent material properties; we validated the results of simulations by comparison with the experimental values. On this basis, we designed a p-i-n heterostructure with a graded index profile toward the realization of an electrically pumped guided wave device. This has been done by adding layers where QDs are embedded in InxAlyGa1−x−yAs layers, to obtain a symmetric structure from a band profile point of view. To assess the room temperature electro-luminescenceemission spectrum under realistic electrical injection conditions, we performed device-level simulations based on a coupled drift-diffusion and QD rate equation model. On the basis of the device simulation results, we conclude that the present proposal is a viable option to realize broadband light-emitting devices