Feeding Conditions Research Articles

Eggceptional variances: Exploring immunomodulation across commercial caged, free-range, and Tibetan environments

The nutritional quality of poultry eggs is altered at different geographic altitudes, seasonal latitudes, and feeding conditions, which in turn affect the immune function of the consumer. The main objective of this study was to investigate how different environments (caged, free-range, and Tibetan farming) affect the nutritional composition of eggs, subsequently influencing the immune status of the organism and establishing a correlation between environment, food, and health. The results demonstrated that the three types of eggs significantly enhanced the health status of immunocompromised mice. Eggs efficiently protect immune organs, prevent decline in immune cell activity, and improve the body's resilience to external stimuli by regulating the secretion of cytokines, immunoglobulins, and the differentiation of lymphocyte subpopulations. Moreover, all three types of eggs enhanced digestion and nutrient absorption by repairing the damaged intestinal barrier. Notably, the caged egg showed effective regulation of interleukin (IL)-2, IL-6, interferon-γ, and tumor necrosis factor-α. Besides regulating cytokine levels, free-range eggs significantly increased lymphocytes and erythrocyte concentrations. Meanwhile, Tibetan eggs primarily exerted their immunological effects by stimulating cytokine secretion and repairing the intestinal barrier. This study provides a comprehensive understanding of how eggs from diverse environments affect the immune system, providing an essential theoretical basis for egg production and guiding consumers in dietary choices.

112 Nutritional, feed safety, and environmental benefits and limitations of using soybean co-products in swine diets

Abstract Various types of soybean co-products are used in swine diets which have benefits and limitations related to protein quality, environmental impact, and feed safety. To address these concerns for sustainable pork production, methodologies have evolved. Soybean processing and storage methods affecting protein oxidation have been studied less than lipid oxidation. Protein carbonyl concentrations were measured and compared among diverse samples of soybeans and soybean meal from different regions of the US and processed by mechanical or solvent extraction. Mechanically extracted soybean meal had greater concentrations of protein carbonyls than solvent extracted soybean meal which were associated with a greater concentration of residual oil. Soybeans and their co-products also contain antioxidants that may protect against more extensive lipid and protein oxidation. Understanding the interactions between natural antioxidants and oxidation of lipid and proteins in soy co-products is important for optimizing nutritional efficiency and health in sustainable pork production systems. Because soybean meal is a major component of swine diets, its origin and environmental footprint affects the environmental impact of feed, manure, and pork production. Using a spatially explicit lifecycle assessment of feed ingredients and regional manure management programs, we compared the effect of using four feeding programs on greenhouse gas (GHG) emissions, land use, and embedded water consumption in 3 major U.S. pork production regions assuming they would provide equal growth performance and carcass composition. Although environmental impacts varied among regions, the corn-soybean meal feeding program resulted in the greatest land and water use of all grower-finisher feeding programs, and more GHG emissions than feeding low protein amino acid supplemented (LP) diets and diets containing 8% supermarket food waste, but less overall GHG emissions than the distiller’s dried grains with solubles (DDGS) feeding program. Results from a subsequent study showed that feeding corn-soybean meal diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with feeding DDGS and LP diets. Lastly, the extended survival of infectious agents such as African swine fever virus in feed ingredients has important implications for biosecurity and prevention of transboundary transmission of swine diseases. We developed a risk-free in situ surrogate non-animal assay (RISNA) to estimate survival of ASFV in various feed ingredients and conditions, and results indicate greater thermal stability than previously observed, and comparable extended survival among corn- and soybean-based ingredients. These new insights will be useful in revising feed biosecurity protocols to prevent introduction and transmission of ASFV in feed supply chains. In conclusion, holistic assessments of feed ingredients, like our evaluation of soybean co-products, are needed to achieve a more sustainable, One Health approach to pork production.

Phosphorus removal from fermented dairy manure concurrent with polyhydroxybutyrate-co-valerate synthesis under aerobic conditions

Wastewater phosphorus removal achieved biologically is associated with the process known as enhanced biological phosphorus removal (EBPR). In contrast with canonical EBPR operations that employ alternating anaerobic–aerobic conditions and achieve asynchronous carbon and phosphorus storage, research herein focused on phosphorus removal achieved under aerobic conditions synchronously with volatile fatty acid (VFA) storage as polyhydroxybutyrate-co-valerate (PHBV). 90.3 ± 3.4 % soluble phosphorus removal was achieved from dairy manure fermenter liquor; influent and effluent concentrations were 38.6 ± 9.5 and 3.7 ± 0.8 mgP/L, respectively. Concurrently, PHBV yield ranged from 0.17 to 0.64 mgCOD/mgCOD, yielding 147–535 mgCODPHBV/L. No evidence of EBPR mechanisms was observed, nor were canonical phosphorus accumulating organisms present; additionally, the polyphosphate kinase gene was not present in the microbial biomass. Phosphorus removal was primarily associated with biomass growth and secondarily with biomass complexation. Results demonstrate that concurrent PHBV synthesis and phosphorus recovery can be achieved microbially under aerobic dynamic feeding conditions when fed nutrient rich wastewater.

Dynamic simulation and analysis of dichloromethane-acetone, dichloromethane-trichloromethane and dichloromethane-toluene VOC mixture abatement systems under transient feed conditions

Minimisation of environmental footprint in line with sustainability goals rests at the top of the agenda of the pharmaceutical industry. Volatile Organic Compounds (VOCs), while essential to primary pharmaceutical manufacturing, are solvents whose emissions pose a risk to human health and ecosystems. Adsorption on activated carbon beds is an established technology for end of pipe emissions control, which, however, faces efficiency limitations by quick and irregular bed saturation due to complex, transient feeds. This study employs a validated nonisothermal, multicomponent adsorption model to quantitatively assess the exact effect and potential value of waste stream feed sequencing towards activated carbon bed utilisation optimisation. Our results indicate that gradual increase of dichloromethane feed concentration in combination with a low, constant inlet concentration of the strongly adsorbing component leads to the latest breakthrough onset for the dichloromethane-acetone, dichloromethane-chloroform and dichloromethane-toluene mixtures. Transient vs. constant feeds usage and their interplay clearly affects bed behaviour, paving the way to industrial VOC emission abatement scheduling and process optimisation.

Machine learning-assisted prediction and optimization of solid oxide electrolysis cell for green hydrogen production

The solid oxide electrolysis cell (SOEC) holds great promise to efficiently convert renewable energy into hydrogen. However, traditional modeling methods are limited to a specific or reported SOEC system. Therefore, four machine learning models are developed to predict the performance of SOEC processes of various types, operating parameters, and feed conditions. The impact of these features on the SOEC's outputs is explained by the Shapley additive explanations and partial dependency plot analyses. The preferred model is integrated with a genetic algorithm to determine the optimal values of each input feature. Results show the improved extreme gradient enhanced regression (XGBoost) algorithm is the core of the machine learning model of the process since it has the highest R2 (> 0.95) in the three outputs. The electrolytic cell descriptors have a greater impact on the system performance, contributing up to 54.5%. The effective area, voltage, and temperature are the three most influential factors in the SOEC system, contributing 21.6%, 16.6%, and 13.0% to its performance. High temperature, high pressure, and low effective area are the most favorable conditions for H2 production rate. After conducting multi-objective optimization, the optimal current intensity and hydrogen production rate were determined to be 1.61 A/cm2 and 1.174 L/(h·cm2).

Feeding Status Transiently Alters the Phosphorylation of Enzymes in the PI3K/Akt/GSK3β Pathway but not Phosphorylated Tau in the Cortex of Male Obese Zucker Rats

Metabolic syndrome (MetS) fosters pathological brain markers such as excess phosphorylated tau (ptau) to produce neuronal dysfunction. Activation of the PI3K/Akt/GSK3β pathway by increasing pAkt-Ser473 and pGSK3β-Tyr216 promotes phosphorylation of tau at residues such as Ser396. Insulin also increases pGSK3β-Ser9 to limit phosphorylation of tau. Deficient insulin signaling has been proposed to reduce pGSK3β-Ser9 and promote pathological excess ptau-Ser396. However, studies of these pathways in rodent models of MetS report both elevated and reduced expression of pAkt-Ser473 and pGSK3β-Ser9, raising the question of the predictive value and role of altered pGSK3β-Ser9 expression in producing excess ptau. Studies reporting reduced pGSK3β-Ser9 in insulin resistant and diabetic rodents often used fasted animals for tissue collection, but other studies without reported fasting showed increased pGSK3β-Ser9. However, elevated ptau was consistently observed under both conditions. Because short-term changes in insulin and glucose alter pAkt-Ser473 and pGSK3β-Ser9 expression, we hypothesized that phosphorylation was related to the feeding status at time of tissue collection rather than the chronic disease state, and excess ptau was resistant to these short-term changes. We examined whether fasting altered pAkt-Ser473, pGSK3β-Tyr216, and pGSK3β-Ser9, and ptau-Ser396 levels in 18-week-old male obese (OZR) and lean (LZR) Zucker rats. After measurement of blood glucose by tail sample in their home cage, fasted (16 hours) and non-fasted rats were euthanized for tissue collection. Though baseline glucose was higher in OZRs vs. LZRs in the fed state (202.4±21.9 vs. 115.9±2.7 mg/dl, t-test) and fasted state (169.4±5.8 vs. 95.3±3.8 mg/dl, t-test), fasting significantly reduced glucose in OZRs but not LZRs (2-way ANOVA with Tukey’s post hoc, P=0.023 for OZRs and P=0.143 for LZRs, n=5-8/group). Protein expression in the cerebral cortex was measured by Western blotting and normalized to actin (n=3-5 for all groups). Expression of ptau-Ser396/total tau was significantly elevated in OZRs vs. LZRs in both feeding conditions (p<0.001) and was not altered by fasting in either phenotype. Expression of pAkt-Ser476 was elevated in non-fasted OZRs vs. LZRs (p<0.001). Fasting greatly reduced pAkt-Ser476 in OZRs (p<0.001) but not LZRs (P=0.741), making expression in fasted OZRs and LZRs comparable (P=0.674). Expression of pGSK3β-Ser9 was significantly elevated in fed OZRs vs. LZRs (p<0.001). Fasting reduced expression of pGSK3β-Ser9 only in OZRs (p<0.001 in OZRs, P=0.952 in LZRs), but expression of was still elevated in fasted OZRs vs. LZRs (P=0.009). Expression of pGSK3β-Tyr216 was significantly elevated in fed OZRs vs. LZRs (p<0.001) but significantly lower in fasted OZRs vs. LZRs (p<0.001). These data show that feeding status does not alter the ptau-Ser396 in the cerebral cortex of OZRs vs. LZRs, but phosphorylation of the enzymes of the PI3K/Akt/GSK3β signaling pathway are greatly affected by MetS and feeding status at time of tissue collection. Thus, when OZRs have access to food, elevated pGSK3β-Tyr216 may contribute to the GSK3β-mediated rise in ptau-Ser396 despite elevated pGSK3β-Ser9. Supported by R01Hl132568S1, JES Edwards Foundation, and Summerfield G. Roberts Foundation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Degradation of edible mushroom waste by Hermetia illucens L. and consequent adaptation of its gut microbiota

The edible fungus industry is one of the pillar industries in the Yunnan–Guizhou Plateau, China. The expansion of the planting scale has led to the release of various mushroom residues, such as mushroom feet, and other wastes, which are not treated adequately, resulting in environmental pollution. This study investigated the ability of black soldier fly (Hermetia illucens L.) larvae (BSFL) to degrade mushroom waste. Moreover, this study analyzed changes in the intestinal bacterial community and gene expression of BSFL after feeding on mushroom waste. Under identical feeding conditions, the remaining amount of mushroom waste in Pleurotus ostreatus treatment group was reduced by 18.66%, whereas that in Flammulina velutipes treatment group was increased by 31.08%. Regarding gut microbial diversity, compared with wheat bran-treated control group, Dysgonomonas, Providencia, Enterococcus, Pseudochrobactrum, Actinomyces, Morganella, Ochrobactrum, Raoultella, and Ignatzschineria were the most abundant bacteria in the midgut of BSFL in F. velutipes treatment group. Furthermore, Dysgonomonas, Campylobacter, Providencia, Ignatzschineria, Actinomyces, Enterococcus, Morganella, Raoultella, and Pseudochrobactrum were the most abundant bacteria in the midgut of BSFL in P. ostreatus treatment group. Compared with wheat bran-treated control group, 501 upregulated and 285 downregulated genes were identified in F. velutipes treatment group, whereas 211 upregulated and 43 downregulated genes were identified in P. ostreatus treatment group. Using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we identified 14 differentially expressed genes (DEGs) related to amino sugar and nucleotide sugar metabolism in F. velutipes treatment group, followed by 12 DEGs related to protein digestion and absorption. Moreover, in P. ostreatus treatment group, two DEGs were detected for fructose and mannose metabolism, and two were noted for fatty acid metabolism. These results indicate that feeding on edible mushroom waste can alter the intestinal microbial community structure of BSFL; moreover, the larval intestine can generate a corresponding feedback. These changes contribute to the degradation of edible mushroom waste by BSFL and provide a reference for treating edible mushroom waste using BSFL.

Nano vitamin E improved the antioxidant capacity of broiler chickens.

Vitamin E (VE) is a potent nutritional antioxidant that is critical in alleviating poultry oxidative stress. However, the hydrophobic nature and limited stability of VE restrict its effective utilization. Nanotechnology offers a promising approach to enhance the bioavailability of lipophilic vitamins. The objective of this experiment was to investigate the effects of different sources and addition levels of VE on the growth performance, antioxidant capacity, VE absorption site, and pharmacokinetics of Arbor Acres (AA) broilers. Three hundred and eighty-four 1-d-old AA chicks were randomly allocated into four groups supplemented with 30 and 75 IU/kg VE as regular or nano. The results showed that dietary VE sources had no significant impact on broiler growth performance. However, chickens fed 30 IU/kg VE had a higher average daily gain at 22 to 42 d and 1 to 42 d, and lower feed conversion ratio at 22 to 42 d than 75 IU/kg VE (P < 0.05). Under normal feeding conditions, broilers fed nano VE (NVE) displayed significantly higher superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) enzyme activities and lower malonic dialdehyde (MDA) concentration (P < 0.05). Similarly, NVE had a higher antioxidant effect in the dexamethasone-constructed oxidative stress model. It was found that nanosizing technology had no significant effect on the absorption of VE in the intestinal tract by examining the concentration of VE in the intestinal tract (P > 0.05). However, compared to broilers perfused with regular VE (RVE), the NVE group displayed notably higher absorption rates at 11.5 and 14.5h (P < 0.05). Additionally, broilers perfused with NVE showed a significant increase in the area under the concentration versus time curve from zero to infinity (AUC0-∞), mean residence time (MRT0-∞), elimination half-life (t1/2z), and peak concentration (Cmax) of VE in plasma (P < 0.05). In summary, nanotechnology provides more effective absorption and persistence of VE in the blood circulation for broilers, which is conducive to the function of VE and further improves the antioxidant performance of broilers.

Hematological parameters of blood of the heifers of different lines of the Kazakh white-headed breed

The experience of importing high-yielding foreign producers has shown the disadvantages of this practice due to low adaptation of the imported animals and difficulties in their full acclimatization to new conditions of housing and feeding. As a result, at best it prevents them from realizing their potential, at worst it contributes to their rapid drop out of the reproduction process. Domestic breeds are adapted to Russian conditions, but need to improve their productive qualities. Therefore, selection and breeding work is of key importance in the technological development of the beef cattle breeding industry of our country. We conducted studies on the heifers of the Kazakh white-headed breed of the Donguz 7139, Korol 13682NV-6 and Zolotoi 3423 lines in the conditions of the APC (collective farm) "Anikhovsky" of the Adamovsky district of the Orenburg region. Blood sampling of the heifers at 15 months of age (n = 18) was carried out in the morning before feeding from the jugular vein, for morphological studies – in vacuum tubes with an anticoagulant, for biochemical – with a coagulation activator. It was found that the heifers of the Zolotoi 3423 line surpassed the animals of the Donguz 7139 line in blood content of total protein (79,9 g/l) by 5.6%, albumins (36,8 g/l) by 6.35%, AST (27,8 Un/l) by 4.27%, ALT (105,0 Un/l) by 14.2%, erythrocytes (5,67 ∙ 10[1]2 cells/l) by 15.24% and hemoglobin (79,6 g/l) by 12.42%, that indicates a high rate of metabolism and redox processes in their body and eliminates the hidden risks of stability, adaptability of the gene pool of a new breeding form. Taking into account the productivity indicators given in the previous article, as well as the results obtained in the course of the present study, the creation and increase in the number of animals of the Zolotoi 3423 line is promising in breeding and breeding work with a herd of the Kazakh white-headed cattle in the APC (collective farm).

ELECTRODE WIRE FEEDER FOR MIG/MAG AND TIG WELDING PROCESSES

The electrode wire feeding mechanisms of welding machines are designed to transport the electrode wire from the spool to the welding zone at a constant, predetermined speed or at a speed that varies according to a given law. One of the most promising areas for improving arc welding and surfacing equipment is to control the transfer of electrode metal by pulsing the electrode wire. Therefore, the feeding mechanisms of welding machines must ensure compliance with the conditions of continuous feeding at a constant speed or pulsed feeding with an intermittent movement. The problem of forming pulses with the required parameters can be solved by feeding mechanisms with a vibration drive. The main advantage of such a technical solution is the ability to produce pulsed motion with controllable frequency and amplitude parameters. Due to the high resolution of movement and high dynamic properties in transient motion modes, vibration-driven feeding mechanisms are able to provide high accuracy of bar material feeding into the working area of technological equipment. The principle of operation of such a mechanism is based on the transformation of spatial vibrations into linear displacements. The analytical dependencies obtained in this work allow us to determine the parameters of electrode wire movement by the vibratory feeding mechanism. The proposed technical solution makes it possible to provide different movements of the wire along its axis, and changing the pulsation mode is made possible by adjusting the oscillation frequency of the drive.

Combined Metabolomics and Biochemical Analyses of Serum and Milk Revealed Parity-Related Metabolic Differences in Sanhe Dairy Cattle.

The production performance of dairy cattle is closely related to their metabolic state. This study aims to provide a comprehensive understanding of the production performance and metabolic features of Sanhe dairy cattle across different parities, with a specific focus on evaluating variations in milk traits and metabolites in both milk and serum. Sanhe dairy cattle from parities 1 to 4 (S1, n = 10; S2, n = 9; S3, n = 10; and S4, n = 10) at mid-lactation were maintained under the same feeding and management conditions. The milk traits, hydrolyzed milk amino acid levels, serum biochemical parameters, and serum free amino acid levels of the Sanhe dairy cattle were determined. Multiparous Sanhe dairy cattle (S2, S3, and S4) had a greater milk protein content, lower milk lactose content, and lower solids-not-fat content than primiparous Sanhe dairy cattle (S1). Moreover, S1 had a higher ratio of essential to total amino acids (EAAs/TAAs) in both the serum and milk. The serum biochemical results showed the lower glucose and total protein levels in S1 cattle were associated with milk quality. Furthermore, ultra-high-resolution high-performance liquid chromatography with tandem MS analysis (UPLC-MS/MS) identified 86 and 105 differential metabolites in the serum and milk, respectively, and these were mainly involved in amino acid, carbohydrate, and lipid metabolism. S1 and S2/S3/S4 had significantly different metabolic patterns in the serum and milk, and more vitamin B-related metabolites were significantly higher identified in S1 than in multiparous cattle. Among 36 shared differential metabolites in the serum and milk, 10 and 7 metabolites were significantly and strongly correlated with differential physiological indices, respectively. The differential metabolites identified were enriched in key metabolic pathways, illustrating the metabolic characteristics of the serum and milk from Sanhe dairy cattle of different parities. L-phenylalanine, dehydroepiandrosterone, and linoleic acid in the milk and N-acetylornithine in the serum could be used as potential marker metabolites to distinguish between Sanhe dairy cattle with parities of 1-4. In addition, a metabolic map of the serum and milk from the three aspects of carbohydrates, amino acids, and lipids was created for the further analysis and exploration of their relationships. These results reveal significant variations in milk traits and metabolites across different parities of Sanhe dairy cattle, highlighting the influence of parity on the metabolic profiles and production performance. Tailored nutritional strategies based on parity-specific metabolic profiles are recommended to optimize milk production and quality in Sanhe cattle.

Regularities of Growth and Development of Buffaloes

Based on the research, an analysis of the biological characteristics of the growth and development of buffaloes in certain periods and stages was carried out. The growth rate of animals of all ages depends on feeding conditions, time of year and other environmental factors. The stage of onset of sexual activity in animals differs sharply from all periods of growth and development. It has been revealed that timely mating of animals, on the contrary, naturally lengthens the maturation period and makes it possible to breed larger animals and obtain greater productivity in the future. For normal processes of growth and development in the body of animals, it is necessary to improve the external environmental conditions and, above all, the conditions of feeding, housing and care. It is necessary to build a breeding business in an exemplary manner and thus increase the weight and milk and meat productivity of livestock.

A New Method for Treating Pododermatitis in Cows

Hoof disease in cattle has a negative impact on their productivity. There are many causes of the disease. Thus, as a result of unsatisfactory feeding and maintenance conditions, untimely implementation of preventive veterinary and sanitary measures, complications of infectious diseases, as well as improper hoof care, pododermatitis occurs in animals. There are various methods for treating claw diseases in animals. However, despite this, our new treatment method is different from other treatments. As a result of the disease, heat shock proteins (HSP70) with a molecular weight of 70 kilodaltons were obtained, which restore the damaged structure of proteins in the body and were used to treat pododermatitis in cattle and small cattle. Many scientists have conducted research and obtained good results using dihydropyrimidinase-like protein 2 (DPB2) to produce this HSP70 in the body to treat various diseases.

Some plasma biomarkers of residual feed intake in beef cattle remain consistent regardless of intake level

This study investigated whether plasma biomarkers of residual feed intake (RFI), identified under ad libitum feeding conditions in beef cattle, remained consistent during feed restriction. Sixty Charolais crossbred young bulls were divided into two groups for a crossover study. Group A was initially fed ad libitum (first test) and then restricted (second test) on the same diet, while Group B experienced the opposite sequence. Blood samples were collected from the 12 most divergent RFI animals in each group at the end of the first test and again after the second test. 12 plasma variables consistently increased, while three consistently decreased during feed restriction (FDR < 0.05). Only two metabolites, α-aminoadipic acid for Group A and 5-aminovaleric acid for Group B, were associated with RFI independent of feed intake level (FDR < 0.05), demonstrating moderate-to-high repeatability across feeding levels (intraclass correlation coefficient ≥ 0.59). Notably, both metabolites belong to the same metabolic pathway: lysine degradation. These metabolites consistently correlated with RFI, irrespective of fluctuations in feed intake, indicating a connection to individual metabolic processes influencing feed efficiency. These findings suggest that a portion of RFI phenotypic variance is inherent to an individual’s metabolic efficiency beyond variations in feed intake.

Plankton in the Gulf of Alaska and its contribution to feeding of pacific salmons in spring of 2020

Results of the plankton survey conducted in the Gulf of Alaska, including EEZ of Canada, aboard RV Pacific Legacy No. 1 in March-April of 2020 are presented. The samples of plankton were collected in regular grid of stations and processed according to the methodologies adopted in TINRO. The mean total biomass of zooplankton was estimated as 301.9 mg/m3 , of phytoplankton — as 41.9 mg/m3 . The large-sized fraction of zooplankton dominated (on average 214.6 mg/m3 , or 71 % of the total biomass), the portions of the smalland medium-sized fractions were 16 % and 13 %, respectively. Because of spring blooming development, both phyto- and zooplankton biomasses were increased southward from 3.2 and 188.3 mg/m3 in the northern area of the gulf to 87.9–34.6 and 305.4–397.7 mg/m3 in its central and southern areas, on average. The biomass of small- and medium-sized fractions (presented by copepods Pseudocalanus, Oithona similis, eggs and nauplii of copepods, copepodites, juvenile pteropods, hyperiids and euphausiids, and larvae of siphonophore) had slightly increased in the southern area to 50–60 and 35–38 mg/m3 , respectively, whereas the biomass of largesized fraction presented mainly by copepods (49 %) and arrowworms (36 %) had increased from 118.9 mg/m3 in the north to 293.6 mg/m3 in the south. Boreal species, as Neocalanus cristatus, N. plumchrus/N. flemingeri, Eucalanus bungii, and Metridia pacifica dominated in the zooplankton biomass.The total stock of zooplankton in the Gulf of Alaska in March-April of 2020 was amounted in 39798 . 103 t that was higher than in February-March of 2019 (25517 . 103 t), obviously because of the spring bloom beginning. Correspondingly, distribution density of phyto- and zooplankton was 8.5 and 61.4 t/km2 in March-April of 2020 against 1.0 and 36.6 t/km2 in February-March of 2019. The largest increasing was noted for the small-sized fraction (in 2 times, to 9.7 t/km2 ) and medium-sized fraction (in 4 times, to 8.0 t/km2 ), whereas the increasing for large-sized animals was moderate — from 31.0 t/km2 in 2019 to 43.6 t/km2 in 2020, and the density of euphausiids did not increase (0.8 t/km2 in both years for Euphasia pacifica). The total stock of large-sized fraction had increased from 21650 . 103 t in 2019 to 28920 . 103 t in 2020.The diet of pacific salmon corresponded with the species composition and biomass of the large-sized fraction of zooplankton, with predominance of euphausiids, pteropods, jellyfish, hyperiids, and oikopleura. The main consumers were the most abundant fish groups, as chum salmon with size of 35–60 cm and coho salmon of 30–50 cm found mainly in the central and southern areas of the gulf. E. pacifica were the favorite prey for all salmon species (67–80 % of food weight), except coho salmon — this species preferred squids (77.6 %). Monthly grazing of zooplankton by salmons in the Gulf of Alaska is estimated as 30.175 . 103 tons that is an insignificant portion of its large-sized fraction stock, so the feeding conditions during the survey are considered as favorable for pacific salmons. However, the consumption is possibly underestimated because of low biomass of consumers in the winter-spring season. Spatial and temporal variations of fish aggregations driven by variability of water temperature and other abiotic factors should be accounted for adequate evaluation of the feeding conditions.

Thermal conditions in the marine coastal waters as a factor favorable for formation of extra-strong year-classes of Karaginsky pink salmon

Variability of the timing for downstream migration of juvenile pink salmon from the Hailulya River to the adjacent coastal waters of Karaginsky Bay is considered and influence of the coastal water temperature on strength of the year-classes for two generative lines of pink salmon spawning in the Karaginsky Bay is analyzed for 1978–2020. The optimal conditions for the downstream migration in the period after 2002 are determined as the mean weighted per migration intensity water temperature &gt; 5.6 o C (up to 7.8 о С on average with the maximum 9.9 о С in some years) and a stable increasing of the temperature during migration. The factor of food availability for juveniles became less important for formation of the Karaginsky pink salmon year-classes since the late 2000s, in comparison with the temperature. Statistical model is proposed for the year-class strength dependence on the temperature of coastal waters in late June and the parents number (R2 = 0.791). The modeled hindcasts of the pink salmon returns in 2021–2023 were rather satisfactory. Given these new results, the limits of pink salmon escapement to spawning grounds could be reconsidered and fishery management models should be adjusted to modern conditions of unrestricted juvenile feeding to get and rationally exploit super-strong year-classes of this species.

A New Bacillus velezensis Strain CML532 Improves Chicken Growth Performance and Reduces Intestinal Clostridium perfringens Colonization.

Bacillus velezensis has gained increasing recognition as a probiotic for improving animal growth performance and gut health. We identified six B. velezensis strains from sixty Bacillus isolates that were isolated from the cecal samples of fifteen different chicken breeds. We characterized the probiotic properties of these six B. velezensis strains. The effect of a selected strain (B. velezensis CML532) on chicken growth performance under normal feeding and Clostridium perfringens challenge conditions was also evaluated. The results revealed that the six B. velezensis strains differed in their probiotic properties, with strain CML532 exhibiting the highest bile salt and acid tolerance and high-yield enzyme and antibacterial activities. Genomic analyses showed that genes related to amino acid and carbohydrate metabolism, as well as genes related to starch and cellulose hydrolysis, were abundant in strain CML532. Dietary supplementation with strain CML532 promoted chicken growth, improved the gut barrier and absorption function, and modulated the gut microbiota. Under the C. perfringens challenge condition, strain CML532 alleviated intestinal damage, reduced ileal colonization of C. perfringens, and also improved chicken growth performance. Collectively, this study demonstrated that the newly isolated B. velezensis strain is a promising probiotic with beneficial effects on chicken growth performance and gut health.

Relationship between feed efficiency and gut microbiota in laying chickens under contrasting feeding conditions

The gut microbiota is known to play an important role in energy harvest and is likely to affect feed efficiency. In this study, we used 16S metabarcoding sequencing to analyse the caecal microbiota of laying hens from feed-efficient and non-efficient lines obtained by divergent selection for residual feed intake. The two lines were fed either a commercial wheat-soybean based diet (CTR) or a low-energy, high-fibre corn-sunflower diet (LE). The analysis revealed a significant line x diet interaction, highlighting distinct differences in microbial community composition between the two lines when hens were fed the CTR diet, and more muted differences when hens were fed the LE diet. Our results are consistent with the hypothesis that a richer and more diverse microbiota may play a role in enhancing feed efficiency, albeit in a diet-dependent manner. The taxonomic differences observed in the microbial composition seem to correlate with alterations in starch and fibre digestion as well as in the production of short-chain fatty acids. As a result, we hypothesise that efficient hens are able to optimise nutrient absorption through the activity of fibrolytic bacteria such as Alistipes or Anaerosporobacter, which, via their production of propionate, influence various aspects of host metabolism.

The influence of environmental change and seasons on the sperm quality of breeding boars after relocation

This study aimed to determine the impact of relocation as a potential stress factor on the reproductive properties of breeding boars, as well as the impact of the new environment on the quantity and quality of the semen obtained during different seasons. At the beginning of spring, 16 breeding boars (Large White (n=3), German Landrace (n=4), Swedish Landrace (n=6) and Pietrain (n=3)) were relocated from old to new housing conditions and exposed to loading, transport, unloading, and rehousing in a new environment. They had the same conditions of feeding, care, sexual exploitation and keeping, before and after relocation. The health status of all breeding boars was carefully monitored and controlled. No significant differences were observed in the total and average number of doses produced between seasons. There was a significantly higher value of total ejaculate volume and density during the spring compared to the values obtained in other seasons (P&lt;0.01). Differences in the average percentage of mobility between autumn and winter were not significant (P=0.983), as in spring and summer (P=0.737). Ventilation rate, gas concentrations of ammonia, nitrous oxide and carbon dioxide in the boar enclosure were similar before and after relocation. Two days after relocation, one boar (ID 172) showed signs of illness and was treated, but his sperm was rejected due to sperm agglutination and reduced motility, so he was culled. Individual analysis of the production indicators showed that there was no significant change in the spermatogenesis of healthy boars, even though they were relocated.

Effect of the feeding condition and number of dominant follicles on oestrus synchronization in Swamp buffalo

The research aimed to assess how feeding conditions and the number of the dominant follicles (DF) influence oestrus synchronization in swamp buffaloes. A total of 170 swamp female buffaloes raised in semi-grazing and housekeeping were included in the study. The synchronization used CIDR method and the follicles on the day of CIDR (Controlled Internal Drug Releasing) insert and removal were tracked by sonography. The results indicated that the age of first mating, age at first calving, and caving interval showed no significant differences in the two feeding conditions. The number of follicles at CIDR insertion and removal decreased in semi-grazing, but increased in housekeeping buffaloes. The percentage of buffalo without DF, one DF, and two DFs at CIDR withdrawal did not differ statistically. The percentage of estrus was 100% in both groups. Pregnancy rates were 53.18% in semi- grazing and 52.63% in housekeeping. The onset of oestrus was similar, but the duration of oestrus was longer in the buffaloes without DF than those with one or two DFs. The percentage of pregnant buffaloes in the group without DF was significantly lower than that in the other two groups. In summary, the efficiency of oestrus synchronization did not differ between semi-grazing and housekeeping methods. Buffaloes without DF displayed longer oestrus periods and lower pregnancy rates compared to those with one or two DFs in the ovarian system.