Allelopathy in the rhizosphere and amended soil of Chenopodium murale L.

Soil infested with Chenopodium murale and amended with it were investigated to verify their allelopathic effects on seedling emergence and some growth and physiological parameters of five test species, Trifolium alexandrinum, Triticum aestivum, Melilotus indicus, lycopersicum esculentum and Cucumus sativus. The two types of soil exhibited phytotoxic effects on the seedling emergence of the test species. Growth and physiological parameters were significantly inhibited when the soil was amended with a high concentration of C. murale tissues. Soil amended with shoot tissue had more inhibitory effects than soil amended with root tissue, at the same concentration. M. indicus was more inhibited than the other species in relation to leaf area, dry matter, pigment, carbohydrates and protein contents.     

Influence of preservation methods on the quality of colostrum sourced from New Zealand dairy farms

Abstract

AIMS: To assess the effect of two temperatures (ambient temperature and 4°C), three preservation methods (no preservative, yoghurt and potassium sorbate), and two periods of storage (3 and 7 days) on Brix and total bacterial and coliform counts of colostrum collected from New Zealand dairy farms.

METHODS: One litre of colostrum destined to be fed to newborn calves was collected from 55 New Zealand dairy farms in the spring of 2015. Six aliquots of 150 mL were obtained from each colostrum sample, with two aliquots left untreated, two treated with potassium sorbate and two with yoghurt, and one of each pair of aliquots stored at ambient temperature and the other at 4°C. All samples were tested for Brix, total bacterial counts and coliform counts before treatment (Day 0), and after 3 and 7 days of storage. The effect of preservation method and storage temperature on the change in Brix, bacterial and coliform counts after 3 or 7 days of storage was analysed using multivariable random effects models.

RESULTS: For all outcome variables there was a temperature by preservation interaction. For aliquots preserved with potassium sorbate, changes in Brix and bacterial counts did not differ between aliquots stored at ambient temperature or 4°C, but for aliquots preserved with yoghurt or no preservative the decrease in Brix and increase in bacterial counts was greater for aliquots stored at ambient temperature than 4°C (p<0.001). For aliquots preserved with potassium sorbate, coliform counts decreased at both temperatures, but for aliquots preserved with yoghurt or no preservative coliform counts increased for aliquots stored at 4°C, but generally decreased at ambient temperatures (p<0.001). There was also an interaction between duration of storage and temperature for bacterial counts (p<0.001). The difference in the increase in bacterial counts between aliquots stored at 4°C and ambient temperature after 3 days was greater than between aliquots stored at 4°C and ambient temperature after 7 days.

CONCLUSIONS AND CLINICAL RELEVANCE: Use of potassium sorbate to preserve colostrum for 3 or 7 days resulted in little or no reduction in Brix and a lower increase in total bacterial counts than colostrum stored without preservative or with yoghurt added. Colostrum quality was not affected by storage temperature for samples preserved with potassium sorbate, but storage at 4°C resulted in better quality colostrum than storage at ambient temperatures for colostrum with no preservative or yoghurt added.     

Accelerated vaccination schedule provides protective levels of antibody and complete herd immunity to equine influenza

Reasons for performing study: During the 2007 Australian equine influenza (EI) outbreak, an accelerated primary course 14 day intervaccination schedule was proposed, but not widely implemented. Expert opinion was divided as to the efficacy of such a schedule given the lack of published data. This study determined the level and duration of humoral immunity following administration of a recombinant canarypox‐vectored vaccine (ALVAC‐EIV) with a primary intervaccination interval of 14 days and booster at 105 days. Objectives: To examine whether protective levels of immunity of adequate duration were achieved following a primary course reduced from a minimum interval of 28 to 14 days. Antibody responses to 2 H3N8 American lineage virus strains (including A/equine/Sydney/6085/2007) were assessed and compared to previous challenge studies using ALVAC‐EIV at conventional intervaccination intervals. Methods: Fourteen Thoroughbred horses and 2 ponies from a rural racehorse training property in Victoria, Australia, were vaccinated with ALVAC‐EIV on Days 0, 14 and 105. Serial blood samples were collected over the next 32 weeks and tested with haemagglutination inhibition and single radial haemolysis (SRH) in full assays to evaluate the serological response. Results: All horses and ponies responded to the accelerated ALVAC‐EIV vaccination schedule. Mean SRH antibodies remained above those consistent with clinical protection for the duration of the study period. All vaccinates demonstrated high SRH antibodies 14 days following V2, thereby achieving 100% herd immunity to homologous viral challenge. Conclusions: An accelerated vaccination schedule conferred long‐lasting protective antibody levels despite a >50% reduction in the recommended V1–V2 interval. Potential relevance: High levels of rapidly acquired herd immunity are critical in containing an outbreak of such a highly contagious pathogen as EIV. In a strategic vaccination programme, it is important that horses remain protected for sufficient time to allow control programmes to succeed. An accelerated 14 day primary course intervaccination interval and booster at 105 days achieves both of these objectives.     

New durum wheat with Hessian fly resistance from Triticum araraticum and T. carthlicum in Morocco

Hessian fly is an important pest of wheat on the North American continent and the temperate Mediterranean drylands. Yield losses caused by this insect in Morocco are the heaviest in the Mediterranean region and are estimated to be 36% on average. Genetic resistance to Mediterranean Hessian fly biotypes has not been found in durum wheat, although large numbers of durum accessions were screened. Genes for resistance were found in common wheat; some of which are transferable to durum. However, there is a need to broaden the genetic base for resistance in durum wheat. The objective of this work was to introgress resistance from selected Triticum araraticum and T. carthlicum accessions using multiple backcross methodology. The experimental recipient durum wheat included numerous adapted and high‐yielding lines. Testing for Hessian fly resistance under controlled conditions and field yield data showed that this programme yields Hessian fly‐resistant durum lines with good yields and adaptation.     

Evaluation of Cow Pea Seed Meal,Vigna sinensis,as a Dietary Protein Replacer for Nile tilapia,Oreochromis niloticus (L.), Fingerlings

The main objectives of this study were to evaluate the effect of partial and total replacement of fish meal (FM) protein by cow pea seed meal (CPSM) protein in practical diets on growth performance, feed utilization, and body composition of Nile tilapia, Oreochromis niloticus (L.). Fish of an average initial weight of 4.6 ± 0.2 g were stocked in 15 glass aquariums (80 L each) at a rate of 15 fish per aquarium. FM protein (30% of the diet) was used as the sole source of animal protein in the control diet. Percent replacement of FM by CPSM on the basis of crude protein were as follows: 0% (control diet A), 25% (diet B), 50% (diet C), 75% (diet D), and 100% (diet E). Diets were fed to fish at a rate of 4% of the total fish biomass daily, for a period of 16 wk. The results of this study revealed that the fish fed control diet A (100% FM) had the best average final body weight, specific growth rate (SGR %/d), weight gain (g/fish), weight gain %, while the poorest results for all parameters were obtained with fish fed diet E (100% CPSM). The same parameters of fish fed diets B (25% CPSM) and C (50% CPSM) were not significantly different (P > 0.05) from those of fish fed the control diet A. Feed utilization parameters of fish fed diets A, B, C, and D were better than for diet E. Proximate composition of whole‐body moisture and ash contents were not significantly different (P > 0.05) among all experimental diets and control diet. Whole‐body protein contents for fish fed diets B and C were superior to the control diet A. Incorporation of CPSM in the diets significantly increased whole‐body fat content. Incorporation of CPSM in the diets significantly decreased apparent digestibility coefficient of crude protein crude fat and energy. Diets B and C were not significantly different from control diet A. Therefore, these findings suggest that up to 50% of FM protein can be replaced by CPSM protein in Nile tilapia diets without any adverse effects on growth performance, feed utilization, body composition, and digestibility.     

The Impact of Reproductive Technologies on Stallion Mitochondrial Function

The traditional assessment of stallion sperm comprises evaluation of sperm motility and membrane integrity and identification of abnormal morphology of the spermatozoa. More recently, the progressive introduction of flow cytometry is increasing the number of tests available. However, compared with other sperm structures and functions, the evaluation of mitochondria has received less attention in stallion andrology. Recent research indicates that sperm mitochondria are key structures in sperm function suffering major changes during biotechnological procedures such as cryopreservation. In this paper, mitochondrial structure and function will be reviewed in the stallion, when possible specific stallion studies will be discussed, and general findings on mammalian mitochondrial function will be argued when relevant. Especial emphasis will be put on their role as source of reactive oxygen species and in their role regulating sperm lifespan, a possible target to investigate with the aim to improve the quality of frozen–thawed stallion sperm. Later on, the impact of current sperm technologies, principally cryopreservation, on mitochondrial function will be discussed pointing out novel areas of research interest with high potential to improve current sperm technologies.