Growth Rate Of Animals Research Articles

The influence of boars of producers of various breeding on the economic indicators of the use of sows

Relevance. Interbreeding or hybridization is an important factor in increasing pig productivity. As a result of the heterosis effect, the multiplicity of sows increases, the safety of offspring increases, the growth rate of young animals improves, the quality of meat improves and, as a result, the profitability of the pig industry increases.Methods. The paper evaluates the influence of boar producers from the companies PIC, Genesus Genetics and Hypor on the reproductive qualities of sows of a large white breed from the company Hypor. To implement the experiment, according to the principle of pairs of analogues, 3 groups of sows of a large white breed from the company Hypor were formed, 5 heads each. The sows of group 1 were inseminated with the seed of Landrace boars from PIC, group 2 with the seed of Landrace boars from Genesus Genetics, group 3 with the seed of Landrace boars from Hypor.Results. In scientific and economic experience, it was found that the multiplicity of sows of the 3rd group amounted to 13.0 heads, which is 7.7% less than in the 1st and 2nd experimental groups. The number of piglets at the time of weaning in groups 1 and 2 per sow was 12, which is 5.3% more than in group 3. For 1 kg of live weight gain, 9.38 EQ was spent on farrowing in the 3rd group, which is 8.1% more than in the 1st and 8.4% more than in the 2nd experimental group. Based on 1000 rubles of feed consumed, in addition, compared with the 3rd group (5.44 rubles), more live weight gain was obtained in the 1st experimental (by 0.44 rubles) and in the 2nd experimental (by 0.47 rubles) groups.

Effectiveness of integrated use of non-conventional additives in the feeding of young cattle

It is known that eff ective feed additives include pine fl our, zeolites and mineral salts. The purpose of the work was to investigate the eff ectiveness of the integrated inclusion of local non-conventional feed additives in the rations of young cattle of Simmental breed under the conditions of the Republic of Sakha (Yakutia). Scientifi c and production evaluation of the results obtained was carried out under the conditions of the Lonkur peasant farm in the Suntar district of Western Yakutia. The scientifi c and production experiment was carried out in accordance with generally accepted methodological recommendations in the fi eld of feeding of farm animals. It was found during the experiment that the integrated inclusion of non- conventional feed additives in the rations of young cattle of Simmental breed contributed to an increase in the weight growth rate of animals in the experimental group to 610 g/day (versus 560 g/day in the control group). As a result, the live weight of the animals in the experimental group was 386.8 kg, and in the control group it was 375.7 kg or the absolute gain in live weight was 128.1 and 117.6 kg, respectively, for the groups. Due to the additional gain in live weight in the experimental group (525 kg), an economic eff ect was obtained in it, which amounted to 152.25 thousand rubles or 14.5 rubles per day for 1 head. It was found as a result of experiment that in the experimental group the level of profitability was 8.21 %, while in the control group it was only 1.77 %. We note that scientific and production testing confirmed the trend that we had previously established in scientific and economic experiments. Thus, the research base was updated in terms of economic indicators with the use of experimental non-conventional feed additives when rearing of young cattle, which shows the promise and practical feasibility of their use under the conditions of Western Yakutia.

Рост и развитие бычков лимузинской породы различных генотипов в постнатальном онтогенезе

The purpose of research is to study the growth and development of Limousin bulls of various genotypes in postnatal ontogenesis. Objectives: to study of weight growth, absolute, average daily gains in live weight and relative growth rate of young animals by age periods and for the entire period of growing and fattening; to study of the linear growth of bulls in postnatal ontogenesis based on the dynamics of body measurements and body composition indices. The objects of the study are bulls of the Limousin breed of various genotypes obtained from the mating of cows of French, Australian and local selection with bulls of local reproduction. The scientific and economic experiment was carried out in 2021–2022 at LLC Meat Union of Bashkir Producers, located in the Kuyurgazinsky District of the Republic of Bashkortostan. Indicators of live weight dynamics, live weight gain, relative growth rate, body measurements and body composition indices in the age aspect were studied. Research of the weight growth of young animals of various genotypes made it possible to identify significant differences in terms of absolute and average daily gain in live weight for the entire period of growing and fattening between bulls of the 1st and 2nd experimental groups, respectively, by 32.5 kg and 59.7 g (in both cases – by 6.2 %). The highest values of measurements, indicating the formation of meat qualities and body shape, were noted in bulls of the 1st group compared with peers of the 2nd and 3rd experimental groups. Breeding animals for a long period under different housing and feeding technologies influences the characteristics of the growth and development of the descendants of local reproduction of Limousin breed cattle.

Monitoring the live weight of Hereford breeding cattle under pasture conditions

Assessing the growth potential and sustainability of breeding stock productivity makes it possible to predict effective herd management, including the duration of use of cows, significantly affecting the potential economic efficiency of raising young animals. The object of the study was data on live weight and average daily gain of Hereford cows and heifers. An assessment was made of Hereford cows’ live weight and growth rate and replacement young cattle of different years of birth, bred under conditions of year-round keeping on pasture. Assessing the growth potential of animals forming a herd for more than 15 years allows us to evaluate the trends that have led to current productivity. Keeping animals on pasture all year round, on the one hand, allows for the formation of animal resistance to environmental conditions; on the other hand, there is a tendency for the year of birth to influence the productive performance of animals, especially at the stage of raising them as replacement young animals. Still, these differences are smoothed out in the future, which today allows us to have a herd equalized by live weight. A significant influence of cows ’ birth year on their growth rates has been established. The study aimed to assess the live weight and growth rate of Hereford cows and young animals from the breeding herd, born in different years. The study’s objectives included evaluating the final weight of animals in the herd and assessing their live weight and average daily gain at the selection stage at the age of 15 months.

Assessing the Impact of Spraying an Enterococcus faecium-Based Probiotic on Day-Old Broiler Chicks at Hatch on the Incidence of Bacterial Chondronecrosis with Osteomyelitis Lameness Using a Staphylococcus Challenge Model.

Bacterial chondronecrosis with osteomyelitis (BCO) lameness is a bone disease characterized by the translocation of bacteria from the gastrointestinal tract, which colonize microfractures in broiler leg bones caused by rapid animal growth rate and weight gain, resulting in lameness. As such, BCO lameness represents a significant challenge for the poultry industry. This study aims to evaluate the effect of spraying broiler chicks on d0 at hatch with an Enterococcus faecium probiotic on the incidence of BCO-induced lameness, utilizing a Staphylococcus aureus challenge model. There were four treatments: (1) negative control (no probiotic + no challenge, NC); (2) positive control (no probiotic + challenge, PC); (3) low dosage (4.0 × 108 CFU/chick + challenge, LOW); and (4) high dosage (2.0 × 109 CFU/chick + challenge, HIGH). On d5, groups two through four were challenged with Staphylococcus aureus through the drinking water at a concentration of 1.0 × 105 CFU/mL. Cumulative lameness incidence was determined through daily evaluations and necropsies conducted on lame birds starting from d22. Data were subjected to a binomial general regression analysis (significant p < 0.05). On d56, the PC group exhibited the highest cumulative lameness incidence (58.0%; p < 0.05), followed by LOW (36.0%), HIGH (28.7%), and NC groups (25.3%), respectively. These results suggest early probiotic application at day-of-hatch successfully reduced the incidence of lameness in challenged birds, thus contributing to understanding of efficient and sustainable broiler production.

Strategies for Inducing and Validating Zinc Deficiency and Zinc Repletion

Background: According to the World Health Organization, zinc deficiency is a growing global health problem, impacting 31% of the world’s population. Zinc deficiency is a common comorbidity with many chronic diseases, from skin to kidney diseases. Given the increasing interest in zinc’s role in disease onset and progression, there is a dire need for reproducible approaches to manipulate zinc homeostasis. Here, we provide proven strategies for inducing and validating zinc deficiency and zinc repletion in a mouse model. Experimental Design: After acclimating to a ZnA (zinc adequate) diet, mice are randomly assigned to either a ZnA or ZnD (zinc deficient) diet. To replete zinc levels (ZnR), a subset of ZnD mice is returned to the ZnA diet. Animal growth rates and plasma zinc levels are assessed to validate zinc status. Results: Mice placed on the ZnD-diet have reduced body weights (26.48g ± 0.78) compared to mice maintained on the ZnA-diet (28.12g ± 0.13). However, zinc repletion promotes weight gain (27.87g ± 1.01) resulting in body weights comparable to mice maintained on the ZnA-diet. Furthermore, mice maintained on the ZnA-diet have plasma zinc levels of 3.19 μM/g Body Weight. While plasma zinc levels are 40% lower in mice place on the ZnD-diet (1.29 μM/g Body Weight). In contrast, plasma zinc levels (2.44 μM/g Body Weight) are increased in ZnR mice. Conclusion: These findings validate that the described dietary approach is an effective strategy for inducing zinc deficiency and zinc repletion. Significance: This cost-effcient approach will enhance the scientific rigor and reproducibility of studies examining the impact of zinc deficiency, and repletion on disease onset and progression. Funding Source: R21 DK119879, R01 DK-133698. 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.

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.

Strategies for inducing and validating zinc deficiency and zinc repletion.

Given the growing interest in the role of zinc in the onset and progression of diseases, there is a crucial demand for reliable methods to modulate zinc homeostasis. Using a dietary approach, we provide validated strategies to alter whole-body zinc in mice, applicable across species. For confirmation of zinc status, animal growth rates as well as plasma and urine zinc levels were evaluated. The accessible and cost-effective methodology outlined will increase scientific rigor, ensuring reproducibility in studies exploring the impact of zinc deficiency and repletion on the onset and progression of diseases.NEW & NOTEWORTHY This methods paper details dietary approaches to alter zinc homeostasis in rodents and qualitative and quantitative methods to ensure the zinc status of experimental animals. The outlined accessible and cost-effective protocol will elevate scientific rigor, ensuring reproducibility in studies exploring the impact of zinc deficiency and repletion on the onset and progression of a multitude of health conditions and diseases.

Abstract 478: Targeted combination nano-drug delivery system to enhance anti-cancer efficacy and reduce side effects

Abstract Background: Colorectal cancer (CRC) is a global health concern, with significant morbidity and mortality. Oxaliplatin (OXL) is a common treatment for CRC but its effectiveness is hampered by side effects, including gastrointestinal and neurotoxic effects. APX3330 exerts anti-angiogenic and neuroprotective effects. It is proposed that the combined use of OXL and APX3330-loaded nanoparticles (NPs) would improve drug delivery to cancer cells with enhanced therapeutic efficacy while reducing side effects of OXL. Methods: We developed dual-loaded NPs containing OXL and APX3330 linked to a cancer targeting monoclonal antibody (NPs+mAb). We characterized the physicochemical properties of the NPs and evaluated their cytotoxicity and drug release using CRC cell lines. In vivo, we assessed their therapeutic efficiency and side effects using an orthotopic CRC mouse model. Results: NPs exhibited an average size of 229±26 nm with a zeta potential of -24.1±2.1 mV. The drug loading and encapsulation efficiency were 3.3±0.2% and 71.9%, respectively. Morphological analysis via scanning electron microscopy confirmed NP structure. In vitro drug release studies showed a slower release profile from NPs compared to free OXL, with a cumulative release of 34% (w/w) after 48 hours. Notably, cytotoxicity evaluation on CT-26 cells revealed a significant reduction in the IC50 for NPs compared to free APX3330 and OXL. In vivo studies demonstrated a remarkable 31% reduction in tumor growth rate in animals treated with NPs+mAb compared to those receiving free forms of OXL and APX3330. Body weight for animals treated with NPs+mAb remained similar to the healthy group, indicating minimal systemic toxicity. Moreover, the length of the colon in healthy organs remained steady compared to animals treated with OXL, which experienced a reduction in colon length. Animals treated with the free form of OXL exhibited diarrhoea, while the stool water content for animals treated with NPs+mAb remained at a similar level as the healthy group, suggesting reduced gastrointestinal side effects. Conclusions: This study demonstrates the potential of NPs with improved retention and encapsulation efficiency for effective drug delivery. Our research validates our novel method for creating NPs with mAb conjugation, enhancing cytotoxicity against CRC cell lines. In conclusion, the designed NPs+mAb formulation improves OXL treatment efficacy, providing targeted delivery of anti-cancer drugs to the tumor site and reducing tumor size while minimizing side effects. Citation Format: Niloufar Rashidi, Majid Davidson, Vasso Apostolopoulos, Mark R. Kelley, Kulmira Nurgali. Targeted combination nano-drug delivery system to enhance anti-cancer efficacy and reduce side effects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 478.

Cultivation of microalgae in food processing effluent for pollution attenuation and astaxanthin production: a review of technological innovation and downstream application.

Valorization of food processing effluent (FPE) by microalgae cultivation for astaxanthin production is regarded as a potential strategy to solve the environmental pollution of food processing industry and promote the development of eco-friendly agriculture. In this review paper, microalgal species which have the potential to be employed for astaxanthin in FPE were identified. Additionally, in terms of CO2 emission, the performances of microalgae cultivation and traditional methods for FPE remediation were compared. Thirdly, an in-depth discussion of some innovative technologies, which may be employed to lower the total cost, improve the nutrient profile of FPE, and enhance the astaxanthin synthesis, was provided. Finally, specific effects of dietary supplementation of algal astaxanthin on the growth rate, immune response, and pigmentation of animals were discussed. Based on the discussion of this work, the cultivation of microalgae in FPE for astaxanthin production is a value-adding process which can bring environmental benefits and ecological benefits to the food processing industry and agriculture. Particularly, technological innovations in recent years are promoting the shift of this new idea from academic research to practical application. In the coming future, with the reduction of the total cost of algal astaxanthin, policy support from the governments, and further improvement of the innovative technologies, the concept of growing microalgae in FPE for astaxanthin will be more applicable in the industry.

Meat qualities of crossbred young pigs

Relevance. Interbreeding and hybridization are important factors in increasing pig productivity. As a result of the heterosis effect, the multiplicity of sows increases, the safety of offspring increases, the growth rate of young animals improves, the quality of meat improves and, as a result, the profitability of the pig industry increases.The paper presents an assessment of the meat qualities of local young pigs obtained as a result of industrial three-breed crossing.Methods. To implement the scientific and economic experience, three groups of sows of pairs of analogues of a large white breed from the Hypor company (KB Hypor) were formed. Sows of the 1st group were crossed with boars of the Landrace breed from the PIC company (Landrace Pic), the 2nd — with boars of the Landrace breed from the Genesus Genetics company (Landrace Genesus), the 3rd — with boars of the Landrace breed from the Hypor company (Landrace Hypor). As a result, two-breed crossbreeds (F1) were obtained. Next, crossbred sows (F1) of the 1st, 2nd and 3rd experimental groups were crossed with boars of the Duroc breed from Genesus Genetics, as a result, commercial young (F2) were obtained.Results. According to the research results, it was found that the highest pre-slaughter live weight was obtained from animals of the 1st group (125.12 kg), which is more than in the 2nd and 3rd experimental groups, respectively, by 5.8% and 4.0%. Studies of the chemical composition of the longest back muscle of young pigs showed that the protein content in all meat samples was in the range of 23–24% with a minimum value (23.31%) in the muscle tissue of animals of the 3rd experimental group, and the maximum (23.7%) in the 1st experimental group (the difference was 0.39%). The amount of intramuscular fat in the meat of animals of the 1st (5.57%) and 2nd (6.30%) groups was significantly higher by 1.23% and 1.96%, respectively, compared with analogues of the 3rd group. The minimum pH level of meat was noted in the 1st experimental group (5.51 pH units), the maximum — in the 2nd experimental group (5.56 pH units), the difference was 0.05 pH units. The largest mass fraction of collagen (1.11%) was obtained in the 3rd group, the smallest — in the 1st experimental group (0.66%), the difference was 0.45%.

Large scale sequence-based screen for recessive variants allows for identification and monitoring of rare deleterious variants in pigs.

Most deleterious variants are recessive and segregate at relatively low frequency. Therefore, high sample sizes are required to identify these variants. In this study we report a large-scale sequence based genome-wide association study (GWAS) in pigs, with a total of 120,000 Large White and 80,000 Synthetic breed animals imputed to sequence using a reference population of approximately 1,100 whole genome sequenced pigs. We imputed over 20 million variants with high accuracies (R2>0.9) even for low frequency variants (1-5% minor allele frequency). This sequence-based analysis revealed a total of 14 additive and 9 non-additive significant quantitative trait loci (QTLs) for growth rate and backfat thickness. With the non-additive (recessive) model, we identified a deleterious missense SNP in the CDHR2 gene reducing growth rate and backfat in homozygous Large White animals. For the Synthetic breed, we revealed a QTL on chromosome 15 with a frameshift variant in the OBSL1 gene. This QTL has a major impact on both growth rate and backfat, resembling human 3M-syndrome 2 which is related to the same gene. With the additive model, we confirmed known QTLs on chromosomes 1 and 5 for both breeds, including variants in the MC4R and CCND2 genes. On chromosome 1, we disentangled a complex QTL region with multiple variants affecting both traits, harboring 4 independent QTLs in the span of 5 Mb. Together we present a large scale sequence-based association study that provides a key resource to scan for novel variants at high resolution for breeding and to further reduce the frequency of deleterious alleles at an early stage in the breeding program.

Antibiotic Residues and Zinc Concentrations in the Livers and Kidneys of Portuguese Piglets—Relationship to Antibiotic and Zinc Resistance in Intestinal Escherichia coli

Metal ions such as zinc and copper have been used as alternatives to antibiotics, to improve animal health and growth rates in pig farming. This study aims to determine antibiotic residues and Zn concentration in piglets’ livers (n = 56) and kidneys (n = 60); and to examine the correlation between the use of Zn and antibiotics, and resistance to Zn and antibiotics of Escherichia coli isolated from piglets’ faeces (n = 60). Samples were collected from randomly selected healthy piglets (n = 60); antibiotic residues were quantified by ultra-high-performance-liquid-chromatography time-of-flight mass spectrometry (UHPLC-ToF–MS); Zn was quantified using flame atomic absorption spectrometry (FAAS); microbiological methods were used for E. coli isolation, antibiotic susceptibility, and Zn minimal inhibitory concentration; and Real-Time PCR was used for gene detection. The presence of antibiotic residues and Zn concentrations in the liver was found to be negatively correlated, whilst no significant difference was observed in the kidney. In E. coli isolated from piglet faeces considered to be susceptible or multi-drug-resistant, no significant difference was found between Zn concentrations in the liver and in the kidney, which appears to indicate that Zn accumulated in the liver and in the kidney does not promote resistance to antibiotics in E. coli. The isolates showed tolerance to Zn which would suggest that antibiotic resistance and phenotypic tolerance to Zn in these isolates are not related. The genes zitB and zntA associated to Zn tolerance, were predominantly found in the more resistant Zn isolates. The findings provide insights on how Zn use in pig production maintains antibiotic resistance and metal tolerance in bacteria, with implications for One Health.

Insights into the influence of diet and genetics on feed efficiency and meat production in sheep.

Feed costs and carcass yields affect the profitability and sustainability of sheep production. Therefore, it is crucial to select animals with a higher feed efficiency and high-quality meat production. This study focuses on the impact of dietary and genetic factors on production traits such as feed efficiency, carcass quality, and meat quality. Diets promote optimal sheep growth and development and provide sufficient protein can lead to higher-quality meat. However, establishing an optimized production system requires careful consideration and balance of dietary parameters. This includes ensuring adequate protein intake and feeding diets with higher intestinal absorption rates to enhance nutrient absorption in the gut. The study identifies specific genes, such as Callipyge, Calpastatin, and Myostatin, and the presence of causal mutations in these genes, as factors influencing animal growth rates, feed efficiency, and meat fatty acid profiles. Additionally, variants of other reported genes, including PIGY, UCP1, MEF2B, TNNC2, FABP4, SCD, FASN, ADCY8, ME1, CA1, GLIS1, IL1RAPL1, SOX5, SOX6, and IGF1, show potential as markers for sheep selection. A meta-analysis of reported heritability estimates reveals that residual feed intake (0.27 ± 0.07), hot carcass weight (0.26 ± 0.05), dressing percentage (0.23 ± 0.05), and intramuscular fat content (0.45 ± 0.04) are moderately to highly heritable traits. This suggests that these traits are less influenced by environmental factors and could be improved through genetic selection. Additionally, positive genetic correlations exist between body weight and hot carcass weight (0.91 ± 0.06), dressing percentage (0.35 ± 0.15), and shear force (0.27 ± 0.24), indicating that selecting for higher body weight could lead to favorable changes in carcass quality, and meat quality.

Simultaneous resistance to multiple anthelmintic classes in nematode parasites of cattle in New Zealand

Resistance to the benzimidazole and macrocyclic lactone anthelmintics is widespread in Cooperia spp. on cattle farms in New Zealand. Since this was first documented in 2006 little has changed in cattle farming systems except for the widespread use of levamisole to control Cooperia spp. in young cattle (i.e., parasite control has maintained an almost total reliance on use of anthelmintics). Here we report the emergence of simultaneous resistance to the benzimidazole, macrocyclic lactone and levamisole anthelmintics in Cooperia spp. and in Ostertagia spp. Anthelmintic efficacy against nematode parasites of cattle was investigated on four commercial farms following reports of poor animal growth rates and welfare, and positive faecal egg counts, despite routine treatment with combination anthelmintics, which included levamisole. Faecal egg count reduction tests involved 15 animals per treatment group, individual egg counts (paired samples) conducted pre- and post-treatment, with eggs counted to ≤ 15 eggs per g faeces and larval cultures for morphological identification. Actives tested varied between farms but always included levamisole alone and several combination products containing levamisole. Of the 20 tests conducted (i.e., 5 products on each of 4 farms) only 3 exceeded 90% efficacy against Cooperia spp. even though 8 of the products tested were combinations containing levamisole and at least one other broad-spectrum anthelmintic. Levamisole used alone achieved efficacies between 44% and 71% against Cooperia spp. across the four trials. The only product to exceed 95% efficacy against Cooperia spp. was a combination of monepantel + abamectin which was 100% effective against all parasites. Resistance to oxfendazole in Ostertagia spp. was indicated on 3 farms, while on one farm efficacy of all the tested products was ≤75% against this parasite. All the farms involved in this study were farming intensive cattle operations with an almost total reliance on anthelmintics to control parasitism. The results clearly demonstrate the emergence of simultaneous resistance to oxfendazole, levamisole and the macrocyclic lactone anthelmintics. Despite years of advice and recommendations to change farming practices away from intensive monocultures, many farmers have continued with the practice, and some are now faced with the very real possibility of being unable to control cattle parasites on their farms.

Microalgae as feed sources and feed additives for sustainable aquaculture: Prospects and challenges

AbstractAquaculture is an essential source of protein and essential fatty acids for humans. However, the sustainable development of aquaculture faces numerous challenges, including a shortage of high‐quality feed and feedstuff, and a degeneration in the safety and quality of aquatic products. This review explores how the use of microalgae as an aquafeed ingredient may help to solve these problems. Microalgae are a vital food source for larval bivalves, shrimps, and fish due to their high nutritional value and suitable cell size. Particularly, bivalves rely on microalgae as a direct feed source throughout their entire life cycle. Microalgae are also indispensable food sources or nutrient supplements for secondary live prey, including rotifers, Artemia, and copepods. Microalgae containing a large amount of protein and lipid can be used as alternatives to fishmeal and fish oil in aquafeed. Moreover, microalgae are rich in ω‐3 polyunsaturated fatty acids, carotenoids, vitamins, and β‐glucan. These bioactive substances can be used as feed additives to improve the growth rate, skin coloration, antioxidant capacity, immunity, and survival rate of aquatic animals. However, the high production cost of microalgae limits its widespread application in aquaculture. Recent advancements in the technology used to culture microalgae intensively, especially fermentation technology, have significantly improved the production efficiency and decreased the production cost. Therefore, accelerating the use of microalgae as aquafeed is crucial if sustainable aquaculture is to be achieved. The review concludes by discussing the opportunities and challenges involved in integrating microalgae into sustainable aquaculture and suggests a way forward.

Improving the productive performance of growing lambs using prebiotic and probiotic as growth promoters

The feed additives (prebiotics and probiotics) are used to stabilize the healthy gut microbiome by supporting beneficial microorganisms, thereby improving the animal growth rate. Thirty growing lambs, with around 20.50 ± 0.65 kg live weight were placed into five equal groups (6 animals each). The concentrate feed mixture (CFM) + roughage was given to the control groups. The treatments (T) of T1, T2, and T3 treatments were fed the control ration with three levels of prebiotic supplementation: 0.50, 1.00, and 1.50 g/kg CFM of mannan oligosaccharids + beta glucan, respectively. The T4 received the control ration and was supplemented with 1.0 g/kg CFM probiotic (3.0 × 108 CFU/g, Bacillus amyloliquefaciens). The roughage was provided ad libitum, and the animals were supplemented with CFM at 2.00% of the body weight. A digestibility trial was conducted at the end of the 150-day feeding trial. The results demonstrated that increasing the prebiotic to 0.15% enhanced average daily gain and feed efficiency (P < 0.05) when compared to the control group. Although daily gain and feed efficiency in probiotic-fed animals were higher (P < 0.05) than in the control group, they were lower in prebiotic-fed lambs. The blood parameters were within normal range. The animals that received 0.10% prebiotic had the highest economic feed efficiency when compared to the other groups. Prebiotic treatment improved nutrient digestibility and nutritive values; however, the results for control and probiotic treatment were practically identical. Additionally, further research is needed to investigate the effects of prebiotics, probiotics and synbiotics as feed additives on productive and reproductive performance in ruminants.

Production of nutrient-rich foods for carnivorous animals: a sustainable approach using Amazonian by-products of fishing and fishing processing

The animal feed manufacturing industry faces ongoing challenges in providing nutritionally balanced diets for a wide range of species, particularly carnivorous animals. The prevalent use of plant-based ingredients in commercial feeds often leads to significant nutritional limitations for these species, driven by cost and availability considerations. This study aims to develop an innovative process for producing nutrient-rich feed for carnivorous animals using Amazonian by-products of fishing and fishing processing as the primary source of high-quality animal-derived nutrients. Additionally, it evaluates the feasibility and effectiveness of this process, examining its impacts on the health and growth of animals fed with these diets. Furthermore, it explores the environmental and economic benefits arising from the intelligent utilization by-products of fishing and fishing processing in the animal feed industry. The research involved the formulation and production of animal feed utilizing by-products of fishing and fishing processing through pelletization and extrusion techniques. These feeds were then subjected to comprehensive nutritional analysis and performance evaluations with carnivorous species. The study also considered the cost-effectiveness of this approach by assessing raw material costs. The research successfully demonstrated the production of nutrient-rich feeds with elevated utilization of animal-derived nutrients, contributing to improved nutrition for carnivorous animals. The experimental diets showed promising results in terms of animal health, growth, and survival rates during the preliminary performance evaluation.

Dynamics of indicators of replacement heifers rearing under the conditions of an animal husbandry enterprise

One of the conditions for high productivity of cows is proper, balanced feeding during the rearing of replacement heifers. The purpose of the work was to study the dynamics of indicators of the rearing of replacement heifers under the conditions of an animal husbandry enterprise where Holstein cattle are bred. The results of the analysis of the indicators of the rearing of replacement heifers and their dynamics over 5 years of production activity of the farm breeding Holstein cattle have been presented in the article. It was established that the fi rst insemination of replacement heifers in 2021 was carried out at the age of 13 months with a live weight of 401 kg. The live weight of heifers was 69,7 % of the live weight of fi rst-calf heifers and 69,1 % of the live weight of mature cows, which corresponded to the norm. The live weight of the first-calf heifers during the analyzed period decreased from 580 kg in 2017 to 575 kg in 2021, i. e. by 5 kg or 0,9 %. The live weight of mature cows increased from 557 kg in 2017 to 680 kg in 2021, i. e. by 23 kg or 4,1 %. The live weight of all groups of animals met the minimum requirements for the Holstein breed. Thus, for 5 years of the production activity of the milk production enterprise, it was established that in the farm under study, the growth, development, and age of the fi rst insemination indicators corresponded to the standards for Holstein breed, which indicated a fairly high level of breeding work carried out by the specialists of the farm. An increase in the growth rate of young animals allows us to inseminate heifers at the age of 14–15 months, which reduces the age of the fi rst calving and increases the efficiency of the dairy cattle industry.

Effects and mechanism of microplastics on organic carbon and nitrogen cycling in agricultural soil: A review

AbstractAt present, microplastics (MPs) are a kind of emerging pollutants of concern in the environment, and have a wide and far‐reaching impact on terrestrial ecosystems. This article summarizes the latest research progress of the impact of MPs pollution on the biogeochemical cycle of carbon (C) and nitrogen (N), and summarizes the current situation of MPs pollution in agricultural soil. On the basis of summarizing the effects of MPs on soil physicochemical properties, soil microorganisms and soil plants and animals, this article focuses on how soil MPs affect the C and N cycles by changing these factors. MPs can alter organic matter degradation and C and N cycles by changing the soil physicochemical properties, as well as the soil microbial and enzymatic activities. MPs may alter plants' nutrient uptake processes, which in turn affects the ability of plants to photosynthesize and absorb C and N elements. MPs can affect the survival rate, the growth rate and intestinal injury of soil animals, therefore indirectly affecting the soil C and N cycles. At the same time, this article compares the different effects of conventional plastics and biodegradable plastics on soil, and looks forward to the current research deficiencies and the future research directions of ecotoxicology of MPs on C and N cycle.