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The type of gum arabic affects interactions with soluble pea protein in complex coacervation
No full textComplex coacervation is an encapsulation process involving two oppositely charged biopolymers. Since different compositions of gum arabic may affect its interaction with protein, we studied the complex coacervation of two types of gum arabic (GA) (Acacia senegal-GA1 and Acacia seyal-GA2) with soluble pea protein (SPP) through Zeta potential, turbidity, morphology, the secondary structure of SPP, UV/vis absorbance and thermodynamic parameters. The maximum formation of coacervates occurred at SPP:GA 3:1 (w/w) and pH 3.5–4.0 with changes in the secondary structure of SPP. GA1 combination resulted in higher binding constant, implying a stronger affinity between SPP and GA1. Entropy of 0.7 and 0.5 kJ/mol.K, and enthalpy of −151 and −95.5 kJ/mol were obtained for SPP:GA1 and SPP:GA2. The complex coacervation was spontaneous as proved by the negative values of the Gibbs free energy. GA1 resulted in stronger interactions with SPP, offering new alternatives for encapsulation of bioactive compounds
Developing pathway for practical deployment of DNA based selection strategies in potato breeding
No full textAssessing the ability of nisin A and derivatives thereof to inhibit gram-negative bacteria from the genus Thermus
Get PDFpeer-reviewNisin is a bacteriocin that is globally employed as a biopreservative in food systems to control gram-positive, and some gram-negative, bacteria. Here we tested the bioactivity of nisin A-producing Lactococcus lactis NZ9700 and producers of bioengineered variants thereof against representatives of the gram-negative genus Thermus, which has been associated with the pink discoloration defect in cheese. Starting with a total of 73 nisin variant-producing Lactococcus lactis, bioactivity against Thermus was assessed via agar diffusion assays, and 22 variants were found to have bioactivity greater than or equal to that of the nisin A-producing control. To determine to what extent this enhanced bioactivity was attributable to an increase in specific activity, minimum inhibitory concentrations were determined using the corresponding purified form of these 22 nisin A derivatives. From these experiments, nisin M17Q and M21F were identified as peptides with enhanced antimicrobial activity against the majority of Thermus target strains tested. In addition, several other peptide variants were found to exhibit enhanced specific activity against a subset of strains
Risk Factors for Antimicrobial Use on Irish Pig Farms
Get PDFpeer-reviewedThe threat to public health posed by antimicrobial resistance in livestock production means
that the pig sector is a particular focus for efforts to reduce antimicrobial use (AMU). This study
sought to investigate the risk factors for AMU in Irish pig production. Antimicrobial use data were
collected from 52 farrow-to-finish farms. The risk factors investigated were farm characteristics
and performance, biosecurity practices, prevalence of pluck lesions at slaughter and serological
status for four common respiratory pathogens and vaccination and prophylactic AMU practices.
Linear regression models were used for quantitative AMU analysis and risk factors for specific AMU
practices were investigated using logistic regression. Farms that milled their own feed had lower total
AMU (p < 0.001), whereas higher finisher mortality (p = 0.043) and vaccinating for swine influenza
(p < 0.001) increased AMU. Farms with higher prevalence of pericarditis (p = 0.037) and lung abscesses
(p = 0.046) used more group treatments. Farms with higher prevalence of liver milk spot lesions
(p = 0.018) and farms practising prophylactic AMU in piglets (p = 0.03) had higher numbers of
individual treatments. Farms practising prophylactic AMU in piglets (p = 0.002) or sows (p = 0.062)
had higher use of cephalosporins and fluoroquinolones. This study identified prophylactic use and
respiratory disease as the main drivers for AMU in Irish pig production. These findings highlight
areas of farm management where interventions may aid in reducing AMU on Irish pig farms.Department of Agriculture, Food and the Marine, Irelan
Cross-sectional analyses of a national database to determine if superior genetic merit translates to superior dairy cow performance
Get PDFpeer-reviewedVarious studies have validated that genetic divergence in dairy cattle translates to phenotypic differences; nonetheless, many studies that consider the breeding goal, or associated traits, have generally been small scale, often undertaken in controlled environments, and they lack consideration for the entire suite of traits included in the breeding goal. Therefore, the objective of the present study was to fill this void, and in doing so, provide producers with confidence that the estimated breeding values (EBV) included in the breeding goal do (or otherwise) translate to desired changes in performance among commercial cattle; an additional outcome of such an approach is the identification of potential areas for improvements. Performance data on 536,923 Irish dairy cows (and their progeny) from 13,399 commercial spring-calving herds were used. Association analyses between the cow's EBV of each trait included in the Irish total merit index for dairy cows (which was derived before her own performance data accumulated) and her subsequent performance were undertaken using linear mixed models; milk production, fertility, calving, maintenance (i.e., liveweight), beef, health, and management traits were all considered in the analyses. Results confirm that excelling in EBV for individual traits, as well as on the total merit index, generally delivers superior phenotypic performance; examples of the improved performance for genetically elite animals include a greater yield and concentration of both milk fat and milk protein, despite a lower milk volume, superior reproductive performance, better survival, improved udder and hoof health, lighter cows, and fewer calving complications; all these gains were achieved with minimal to no effect on the beef merit of the dairy cow's progeny. The associated phenotypic change in each performance trait per unit change in its respective EBV was largely in line with the direction and magnitude of expectation, the exception being for calving interval. Per unit change in calving interval EBV, the direction of phenotypic response was as anticipated but the magnitude of the response was only half of what was expected. Despite the deviation from expectation between the calving interval EBV and its associated phenotype, a superior total merit index or a superior fertility EBV was indeed associated with an improvement in all detailed fertility performance phenotypes investigated. Results substantiate that breeding is a sustainable strategy of improving phenotypic performance in commercial dairy cattle and, by extension, profit
Effect of multicarbohydrase enzymes containing α-galactosidase on the growth and apparent metabolizable energy digestibility of broiler chickens: a meta-analysis
Get PDFpeer-reviewedExogenous enzyme supplementation is a valid strategy to improve nutrient availability and growth performance in broilers. Traditional carbohydrases, such as xylanase and β-glucanase, are well-researched solutions to increase the nutritional value of cereal grains, whilst reducing any negative impact of associated viscous polysaccharides. The feeding value of soybean meal and other protein rich oilcakes may not be fully exploited with traditional enzymes, as structures such as galacto-oligosaccharides and pectins require specific α-galactosidase, mannanase and other hemicellulolytic enzymes. This study aimed to summarize, in a meta-analysis, the results from independently run randomized controlled studies in various global locations that evaluated the effect of two distinct multicarbohydrase formulations, in which an α-galactosidase was combined with either xylanase (AGX) or β-glucanase (AGB). Through meta-regression analysis, the mean difference effects of AGX and AGB supplementation on broiler final body weight (BW), feed conversion ratio (FCR) and nitrogen-corrected apparent metabolizable energy (AMEN) were calculated for each relevant study. Fixed and random-effects models were used to compute the standardized mean difference (SMD) and confidence intervals, with corrective actions taken to ensure compliance with publication bias and heterogeneity by the Egger test and the Cochran Q test. Adjusted models showed that the AGX supplementation increased broiler BW (SMD=+30 g; 95 % CI: 0.08_0.48; P = 0.006) and improved FCR (SMD=−0.01 g/g; 95 % CI: -0.51_-0.11; P = 0.002). A composite evaluation of independent studies showed increased AMEN in broilers supplemented with AGX (SMD=+58 kcal/kg; 95 % CI: 0.45_1.10; P < 0.001). Furthermore, meta-analysis confirms that AGB supplementation increased BW (SMD=+56 g; 95 % CI: 0.32_0.91; P < 0.001), improved FCR (SMD=−0.04 g/g; 95 % CI: −0.76_−0.20; P = 0.006) and increased AMEN (SMD=+49 kcal/kg; 95 % CI: 0.30_1.07; P < 0.001). Overall, this meta-analysis found that dietary supplementation of broiler diets with the multicarbohydrases containing α-galactosidase considered in this evaluation, improved broiler growth during rearing periods of 35 days or more. These improvements may be supported by increases in energy utilization, as found in this study
Quantifying genetic differences between exported dairy bull calves and those sold for domestic beef production
Get PDFpeer-reviewedSelection bias is introduced when selection among individuals exists but the information used to inform that selection decision is not considered in downstream genetic evaluations. Genetic evaluations are undertaken in several countries for carcass-related metrics in prime cattle; no consideration is generally taken for animals that are harvested at a younger age for veal production and thus do not express the prime carcass phenotype. Although no veal industry exists in Ireland, dairy calves are routinely exported to continental Europe for veal production. The objective of the present study, based on a cross-sectional analysis of calf export data, was to determine quantitatively if genetic variability exists in whether purchased dairy-bred bull calves are immediately exported or retained within the country for domestic production. Also of interest was whether such a genetic difference was associated with differences in carcass weight, conformation score, and fat score in prime cattle relatives. Editing criteria were imposed to consider only Holstein-Friesian bull calves. Post-editing, the fate of 43,890 Holstein-Friesian bull calves (<100 d of age) was available; variance components for the binary phenotype (sold for export or not) were estimated using both linear and threshold animal models, and genetic correlations with carcass traits from 56,366 prime cattle were estimated. The heritability (standard error) of whether or not a calf was exported was 0.04 (0.01) on the linear scale and 0.07 (0.02) on the threshold scale. Although no explicit maternal genetic effect was detected, the proportion of the phenotypic variance due to maternal effects was 0.03 to 0.07. The genetic correlation (standard error) between the export phenotype with carcass weight, conformation score [scale 1 (poor) to 15 (excellent)], and fat score [scale 1 (thin) to 15 (fat)] in prime cattle was 0.002 (0.12), −0.25 (0.12), and −0.32 (0.11), respectively. The low heritability of the calf export phenotype and lack of a strong genetic correlation with carcass metrics suggest that other calf features might be greater determinants of the eventual fate of the calf. Accounting for the export phenotype in genetic evaluations of carcass traits in prime cattle had a negligible effect on the estimated breeding values for carcass merit
Sire contribution to fertilization failure and early embryo survival in cattle
Get PDFpeer-reviewedDespite passing routine laboratory tests of semen quality, bulls used in artificial insemination (AI) exhibit a significant range in field fertility. The objective of this study was to determine whether subfertility in AI bulls is due to issues of sperm transport to the site of fertilization, fertilization failure, or failure of early embryo or conceptus development. In experiment 1, Holstein-Friesian bulls (3 high fertility, HF, and 3 low fertility, LF) were selected from the national population of AI bulls based on adjusted fertility scores from a minimum of 500 inseminations (HF: +4.37% and LF: −12.7%; mean = 0%). Superovulated beef heifers were blocked based on estimated number of follicles at the time of AI and inseminated with semen from HF or LF bulls (n = 3–4 heifers per bull; total 19 heifers). Following slaughter 7 d later, the number of corpora lutea was counted and the uteri were flushed. Recovered structures (oocytes/embryos) were classified according to developmental stage and stained with 4′,6-diamidino-2-phenylindole to assess number of cells and accessory sperm. Overall recovery rate (total structures recovered/total corpora lutea) was 52.6% and was not different between groups. Mean (± standard error of the mean) number of embryos recovered per recipient was 8.7 ± 5.2 and 9.4 ± 5.5 for HF and LF, respectively. Overall fertilization rate of recovered structures was not different between groups. However, more embryos were at advanced stages of development (all blastocyst stages combined), reflected in a greater mean embryo cell number on d 7 for HF versus LF bulls. Number of accessory sperm was greater for embryos derived from HF than for LF bulls. The aim of experiment 2 was to evaluate the effect of sire fertility on survival of bovine embryos to d 15. Day 7 blastocysts were produced in vitro using semen from the same HF (n = 3) and LF (n = 3) bulls and transferred in groups of 5–10 to synchronized heifers (n = 7 heifers per bull; total 42 heifers). Conceptus recovery rate on d 15 was higher in HF (59.4%,) versus LF (45.0%). Mean length of recovered conceptuses for HF bulls was not affected by fertility status. In conclusion, while differences in field fertility among AI sires used in this study were not reflected in fertilization rate, differences in embryo quality were apparent as early as d 7. These differences likely contributed to the higher proportion of conceptuses surviving to d 15 in HF bulls
The effect of machine traffic zones associated with field headlands on soil structure in a survey of 41 tilled fields in a temperate maritime climate
Get PDFpeer-reviewedMachinery traffic imposes a negative effect on soil structure, leading to soil compaction. Studies to date have primarily focused on the influence of applied wheel loads on soil structure. Few studies have assessed the impact of commercial farm operations on soil structure and crop performance, particularly on field headlands in a temperate maritime climate such as Ireland. A survey was conducted on 41 conventionally managed field sites to investigate the effect of field position (field edge, turning, transition and in-field zones) in relation to machinery operations on soil structure. Soil texture classes ranged from sandy loam to clay loam. All sites used plough-based crop establishment. Soil structural condition was assessed visually using the visual evaluation of soil structure method (VESS) for the topsoil (0−250 mm), and Double Spade below plough depth (250−400 mm). Quantitative soil measurements such as shear strength, bulk density and porosity using soil cores post-harvest, and soil cone penetration resistance were taken at two time points in the crop growth cycle. For most measurements of soil structure, the in-field zone of least machinery traffic produced the best scores (Sq 2.81 & DS 2.48), and the turning zone returned the poorest scores in the 0−250 mm soil layer (Sq 3.31 & DS 2.91). The strongest quantitative scores for the in-field and turning zones, respectively, were for trowel penetration resistance in the upper (2.49 & 3.20) and lower (3.41 & 4.05) soil depth layers and for shear vane (38.17 & 53.59 kPa) for the same zones. The visual assessments and some of the quantitative measurements (0−250 mm soil layer) followed the zone order trend of: turning, field edge, transition and in-field, for increasing machinery traffic. The results show that the visual soil indicators used in this study are more sensitive than quantitative soil measurements such as soil bulk density (ρb) or porosity (TP and MP) at detecting soil structural differences between zones, particularly below plough depth (>250 mm soil depth)
The ultra-structural, metabolomic and metagenomic characterisation of the sudanese smokeless tobacco ‘Toombak’
Get PDFpeer-reviewedToombak is a smokeless tobacco produced from the Nicotiana rustica tobacco plant from Sudan. Pre-prepared and ready to buy Toombak samples were analysed using mass spectrometry (heavy metals), gas and liquid chromatography (metabolomics), 16S rRNA metagenomic sequencing (microbiome) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and pH analysis.Chromium, cobalt, and copper were high in the pre-prepared form of Toombak while iron, tobacco specific nitrosamines (TSNAs), formaldehyde and acetaldehyde were high in both types. Firmicutes and Actinobacteria dominated Toombak. Samples of ready to buy Toombak showed inter-variational differences depending on place of purchase. We found Virgibacillus were increased in the pre-prepared form while Corynebacterium casei, Atopococus tabaci, Atopostipes suicloacalis, Oceanobacillus chironomi and Staphylococcus gallinarum were the most abundant species in the ready to buy forms. PICRUSt analysis highlighted increased activity of metal transport systems in the ready to buy samples as well as an antibiotic transport system. SEM-EDX highlighted large non-homogenous, irregular particles with increased sodium, while pH of samples was in the alkaline range.The final composition of Toombak is affected by its method of preparation and the end product has the potential to impart many negative consequences on the health of its users. TSNA levels observed in Toombak were some of the highest in the world while the micro-environment of Toombak supports a distinct microbiota profile