Weight Gain Of Animals Research Articles

Impacts of environmental feedbacks on the production of a Central Queensland beef enterprise in a future climate

CONTEXTUnderstanding climate change impacts on beef production enterprises in northern Australia is challenging due to the complexity of the system, which involves biophysical processes such as pasture and animal production, herd management, economics, emissions, and the interaction among these things. Modelling is a powerful tool to help the beef industry understand the impacts of climate change and to develop adaptation plans to help ensure enterprises remain economically viable over the long term. OBJECTIVEWe assess climate change impacts on a single specialised beef enterprise south-east of Moura (24.59°S, 150.09°E) in northern Australia's Central Queensland region. This is achieved by comparing enterprise performances during a 2030s climate and a 1975–2013 baseline period. METHODSWe used a calibrated pasture model called GRASP to simulate the farm's pasture growth under multiple scenarios for land conditions, grass basal areas and stocking rates for the baseline and 2030s climates and to construct pasture growth databases – known as datacubes. The datacubes provide a simplified representation of mean coupling between the herd dynamics and livestock production model (Crop Livestock Enterprise Model). The coupled whole-of-farm model was parameterised using enterprise data collected through interviews with the property owner and allowed for feedback between the pasture and livestock systems. The feedback capability allowed us to consider changes in land condition through stocking rates and their effect on pasture growth, animal weight gain, profit and CO2 emissions. RESULTS AND CONCLUSIONSWe found that warmer and drier climatic conditions during 2030s will reduce pasture growth in austral spring and summer but increase pasture growth in winter and autumn. Increased pasture growth in winter and autumn cannot compensate for the reduction in pasture growth in the warm seasons but can improve animal liveweight gain in winter and early spring. This leads to an overall increase in annual weight gain of steers (the cattle class that provides the main income source for this farm) while the CO2 emission intensity remains similar to the baseline period. Maintaining land condition under the 2030s climatic conditions considered will require a reduction in sustainable herd size, leading to lower beef production and lower profit under current pasture and herd management strategies. Impacts will likely differ from those described if a drier future is not realised. SIGNIFICANCEThis study provides a climate change impact assessment on a specialised beef enterprise (i) being distilled from individual ruminants, and (ii) considering environmental feedbacks in the interaction between pasture and livestock systems.

Nursery pigs fed with feed contaminated by aflatoxin B1 (Aspergillus flavus) and anti-mycotoxin blend: Pathogenesis and negative impact on animal health and weight gain

The present study aimed to evaluate whether a moderate dose of aflatoxin B1 in pigs' diet interferes with pigs' growth and health in the nursery phase and whether an anti-mycotoxin mixture minimizes the adverse effects of the toxin. One blend with Saccharomyces cerevisiae lysate, zeolite, silicon dioxide, propylene glycol, Carduus marianus extract, soy lecithin, and carbonate was used as an anti-mycotoxin. Four treatments, with six repetitions per treatment and three pigs/pen: Afla0-AntiMyc0 - negative control (without aflatoxin); Afla500-AntiMyc0 - positive control (500 ppb of aflatoxin); Afla0-AntiMyc1000 - 1000 mg/kg of anti-mycotoxin blend; Afla500-AntiMyc1000 - 500 ppb aflatoxin +1000 mg/kg of anti-mycotoxin blend. It was observed that pigs in the positive control (Afla500-AntiMyc0) had lower body weight and weight gain when compared to the other treatments during the experimental period. Also, pigs from Afla500-AntiMyc0 had lower feed intake between days 1–20 and 1 to 30 than Afla0-AntiMyc0. The pigs from Afla500-AntiMyc0 had higher levels of liver enzymes aspartate aminotransferase and alanine aminotransferase compared to other treatments. The pigs from Afla500-AntiMyc0 had higher villus height than the other treatments, while the folded size was smaller in this treatment. Crypts were deeper in the intestines of pigs in both treatments that consumed aflatoxin. In general, it is concluded that the intake of aflatoxin B1 by nursery pigs has negative impacts on the health and, consequently, the animals' growth performance; however, the addition of the contaminated feed with an anti-mycotoxin blend was able to protect the pigs, minimizing the adverse effects caused by the mycotoxin.

Comparative analysis of body weight gain in laboratory animals with different routes of administration of Lcarnitine

In recent years, several studies have been published that suggest that L-carnitine supplementation may affect weight in some animal species and humans, and may also affect the body composition of growing animals. Currently, only a few results are available on the effects of L-carnitine on weight loss and body composition in animals. Therefore, the purpose of this study was to find out whether injections of L-carnitine can influence the dynamics of the weight of laboratory animals. Toxicity studies were conducted on outbred rats in October 2021 in the vivarium of the St. Petersburg State University of Veterinary Medicine. The study involved females weighing 190-210 grams, purchased from the Federal State Unitary Enterprise “Nursery of Laboratory Animals “RAPPOLOVO”. When studying subchronic toxicity after subcutaneous and intramuscular administration, L-carnitine was administered at 2 dose levels. Doses were determined based on the results of the acute toxicity experiment: 1/5 and 1/10 of the maximum tolerated dose. The first experimental group (n=10) received the drug intramuscularly at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg). The second experimental group (n=10) received the drug intramuscularly at a dose of 0.04 mg/kg (1/10 of 2000 mg/kg). The third experimental group received subcutaneous L -carnitine at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg), the fourth experimental group received subcutaneous L-carnitine at a dose of 1/10 of the maximum tolerated (2000 mg/kg body weight). Group 5 was the control group (n=10) and received sodium chloride 0.09% intramuscularly at a dose of 1/5 of 2000 mg/kg, group 6 was the control group and received sodium chloride 0.09% subcutaneously at a dose of 1/5 of 2000 mg /kg. As a result of studies of subchronic toxicity on laboratory animals of the drug L-carnitine for veterinary use with subcutaneous and intramuscular administration, it was established that a dosage of 1/5 of the maximum tolerated, and a dosage of 1/10 of the maximum tolerated, does not cause changes in the dynamics of body weight animals.

The use of lupin variety “Deco” in the feeding of pigs

The purpose of this research was to study the effect on the digestibility of dietary nutrients and livestock parameters of young pigs of different doses of an alternative feed source such as lupine grain of the variety “Deco” instead of full-fat soybeans in the composition of compound feed. The studies were carried out on young pigs of DanBred genetics under conditions of a pig-breeding enterprise. Clinically healthy pigs were selected for the research. The method of analogues was used when selecting animals into groups, taking into account age, live weight, sex, etc. Four groups of animals were formed to conduct the experiment. There were 48 pigs in each group. The duration of the experiment was 124 days. The control group of young pigs was fed compound feed with full-fat soybeans. Herdmates in the 1st experimental group were fed compound feed with 50 % of full-fat soybeans replaced with the variety “Deco” lupine, in the 2nd experimental group with 75 %, in the 3rd experimental group full-fat soybeans were completely replaced with lupine grain. In relation to full-fat soybeans lupine grain of the variety “Deco” contained more dry matter by 0,08 abs.%, crude protein by 2,45 abs.%, crude ash by 0,35 abs.%, nitrogen-free extractive substances by 2,38 abs.%, the studied amino acids by 1,75 abs.%. Partial or complete replacement of full-fat soybeans in the compound feed with the lupine variety “Deco” led to the increase in the digestibility of nutrients in the body of young pigs with the following results: dry matter was digested more by 0,41–1,15 abs.%, organic matter by 0,23–1,00 abs.%, crude fat by 0,17–1,52 abs.%, crude protein by 0,92–1,83 abs.%, crude fi ber by 2,04–3,21 abs.%, nitrogenfree extractive substances by 0,12–0,43 abs.% compared to the pigs of the control group. The use of nitrogen, calcium and phosphorus taken with compound feed in animals was greater in relation to analogues from the control group by 0,76–1,61 abs.%, 0,72–1,61 and 0,19–1,26 abs.%, respectively. At the age of 180 days, the live weight of pigs in the control group was 131,04 kg, and in the experimental groups it was 2,82–3,96 kg higher. There was the decrease in feed expenditures per 1 kg of live weight gain in animals of the experimental groups by 2,57–3,49 % in comparison with control analogues. In order to expand the feed supply in pig farming, increase the nutritional value of compound feed and reduce their cost, as well as increase the meat productivity of pigs we recommend input alkaloid-free lupine of the variety “Deco” into compound feed.

Microencapsulated Probiotics in Feed for Beef Cattle are Better Alternative to Monensin Sodium

The use of antibiotics and other growth-promoting agents in animal feed has been a common practice in the animal industry for many years. However, concerns about the potential risks associated with these agents have led to increased interest in alternative approaches, such as the use of probiotics. This research evaluated the potential benefits associated with the use of microencapsulated probiotics in feed salt for beef cattle compared to the commonly used ionophore antibiotic, monensin sodium. The results of the in vitro test showed that the microencapsulated probiotic treatment led to higher degradability of several dietary components, including dry matter (11% higher) and organic matter (8% higher). An in vivo test was performed on 270 animals on different farms, revealing a higher daily weight gain (115 g/day/animal) in animals fed the microencapsulated probiotics over the monensin sodium treatment. Significant differences in body weight gain among the diets were found using Monte Carlo simulation, which allows us to infer that the diets with a better feed conversion index offered a better gross margin. Overall, the use of microencapsulated probiotics in feed salt for beef cattle shows promise as a potential alternative to monensin sodium.

Fasciola hepatica antioxidant and protease-inhibitor cocktail recombinant vaccines administered five times elicit potent and sustained immune responses in sheep but do not confer protection

Our laboratory’s vaccine development strategy against the livestock parasite Fasciola hepatica centres around disrupting key biological processes by combining groups of antigens with similar/complementary functional actions into a single vaccine cocktail. In this study the focus was on antioxidant protein vaccines and a protease inhibitor vaccine aimed at disrupting the parasite’s ability to defend against oxidative stress and protease-inhibitor balance, respectively. Two combinations of recombinantly expressed antioxidants were assessed, namely peroxiredoxin (rFhPrx), thioredoxin (rFhTrx) and thioredoxin-glutathione reductase (rFhTGR) (Group 1) and rFhPrx, rFhTrx, and two superoxide dismutases (rFhSOD1 and rFhSOD3) (Group 2). The protease inhibitor vaccine cocktail included representatives of each of the key secreted protease inhibitor families, namely a Kunitz-type inhibitor (rFhKT1), a serpin (rFhSrp1) and a stefin, (rFhStf1) (Group 3). The vaccine combinations were formulated in adjuvant Montanide 61VG administered at five timepoints; two before experimental challenge with 60 F. hepatica metacercariae and three after infection. The vaccine combinations did not reduce the liver fluke burden, and only Group 2 displayed a marginal reduction in egg viability (8.2%). Despite previous results showing an effect of liver fluke vaccines on overall weight gain in infected animals, no significant (P value >0.05) impact on weight gain was observed in this study. Antibodies were elicited against all the vaccine antigens within the cocktails and were maintained at high levels to the end of the trial, due to our strategy of continuing vaccine administration after infection. However, these responses were not boosted by the challenge F. hepatica infection. A comparative analysis with previous vaccine data using a protease inhibitor vaccine found no repeat of the promising outcomes associated with this vaccine, indicating that the addition of rFhSrp1 to the vaccine cocktail did not improve vaccine efficacy. Assessment of liver pathology across the two trials using a modified liver enzyme score (glutamate dehydrogenase to platelet ratio) at eight weeks post infection suggests an association with liver fluke burden above 45 flukes, which could be used to predict liver pathology in future trials. The results reported in this study highlight the ambiguousness in liver fluke vaccine development and the difficulty in obtaining consistent and repeatable protection. This work stresses the need for repetition of trials and the use of sufficiently sized groups to assess vaccine efficacy with adequate statistical power.

Recombinant Myostatin: Isolation and Use in Vaccines

Protein myostatin is not only a potential target for therapeutic effects in pathologies of the muscular system, but also a tool for biotechnological regulation of the meat productivity of farm animals. The action of myostatin can be blocked by inducing autoantibody synthesis using recombinant myostatin (rMST) as an antigen. E. coli producer strain Bl21/pET28-MSTN was obtained with a high level of recombinant protein expression in inclusion bodies. Purified rMST was used to immunize sheep and rabbits. Using the created ELISA test system for the detection of antibodies to myostatin in the blood of sheep, it was shown that rMST is immunogenic (the working titer of sera is 1/400–1/800). As a result of vaccination of rabbits over a monthly period, the average body weight and average daily weight gain in animals of the experimental groups was observed to increase compared to the control group.

Differential depot-specific effects of long-term fructose intake on lipoprotein lipase activity and adipose tissue development in lean and obese+NIDDM SHR/Ntul//-cp rats

To determine the effects of a lower glycemic index, fructose-rich diet on parameters of weight gain and adipose tissue cellularity in principle fat depots, groups of congenic lean and obese+NIDDM SHR/tul//-cp rats were fed nutritionally complete isoenergetic diets where 54% of the calories were present as cooked cornstarch (CCS diet) or equal parts CCS and fructose (the CCSF diet) plus essential fats, proteins, minerals and dietary fibers from one until 9 months of age. Initial body weights were similar in all groups. Net weight gain and final body weights of obese >>>lean and demonstrated only a modest trend toward a greater weight gain in obese animals fed the CCSF diet. Differential effects on adipocyte size and number including marked hyperplasia and hypertrophy were observed in retroperitoneal and dorsal fat pads, while the mass and cellularity of the epididymal depots were similar in all dietary and phenotype groups. Tissue Lipoprotein Lipase activity (LPLA) was similar in EPI, RP, and Dorsal fat depots in both phenotypes, but LPLA in IBAT of lean >>> obese and demonstrated a modest diet effect (CSS > CSSF) in both phenotypes. These results indicate that the long-term consumption of the high fructose diet was neither substantially beneficial nor ameliorative in contributing to the modest excess weight gain and adiposity in WAT depots of the obese phenotype of this strain, despite the lower glycemic index and slower luminal digestibility of fructose vs cornstarch when fed in isoenergetic proportions in the diet. In contrast, IBAT mass and cellularity of obese >>> lean, while IBAT LPLA of lean >>> obese, suggestive of improved insulin sensitivity. These results suggest that the excess weight gain and adiposity often attributed to the consumption of excess dietary fructose sources may be at least in part a reflection of net caloric intake and insulinogenic responses rather than the type of carbohydrate consumed. In addition, the greater IBAT mass, cellularity, and percent lipid content of the obese are consistent with early onset hyperphagia and an impaired capacity for energy expenditure via non-shivering thermogenesis and thus represent a likely contributor to the epigenetic expression and development of obesity in the obese phenotype of this strain.

Influence of succinic acid Acidum succinicum on chinchilla growth in postembryonic period

In animal husbandry, special attention is paid to biological additives and natural metabolites used in the development of feeds that ensure productivity of animals and increase resistance to adverse environmental factors. Such additives actively influence energy metabolism and do not harm even in case of an overdose, due to the absence of xenobiotic effects inherent in a large number of synthetic drugs. The purpose of the research was to study growth dynamics of chinchillas against the background of drug Succinic acid forte. The experiments were carried out on chinchillas 55-61 days old. At the same time, succinic acid (Acidum succinicum) was given to the chinchillas of the experimental group for 30 days in addition to the main diet - 20 mg/kg of live weight, pre-mixed with a small amount of water, then chinchillas were fed individually from the syringe. Determination of the dynamics of live weight was carried out using individual weighing of animals at the beginning of the experiment when forming groups, and then every ten days before feeding. When analyzing the main productive indicators, a direct pattern was noted - use of succinic acid in the diet of young chinchillas led to an increase in growth rate. So, 20 days after the start of the experiment, indicators of absolute gain in live weight of experimental animals were 32.07 % (p = 0.001), and after 30 days - 45.34 % (p = 0.001) more than in the control, where in the feeding of chinchillas, only the main diet was used without additional introduction of succinic acid.

Estimation of acute oral toxicity of the drug "Mastigard®"

The parameters of acute oral toxicity of Mastigard® are presented. The drug was introduced intragastrically to rats at a dose of 2000 mg/kg. During the study, the tested dose did not cause signs of intoxication and death of animals. Physiological parameters of rats remained within the species norm. Also no changes in the behavior of animals were noted, the reaction to tactile, pain, sound and light irritants was adequate. Autopsy of animals at the end of observation did not reveal pathological and anatomical changes in internal organs and tissues. Regular control of body weight of rats testified to uniform weight gain of all experimental animals during 14 days of observation, no body weight loss was observed during all periods of weighing. Thus, the LD50 of Mastigard® is more than 2000 mg/kg. Mastigard® belongs to the 5th class of toxicity according to the GHS and the 4th class of danger (substances of little danger) according to GOST 12.1.007-76.

Impact of Feed Quality on Livestock Productivity

Abstract
 Purpose: The aim of the study was to investigate impact of feed quality on livestock productivity.
 Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries.
 Findings: High-quality feed rich in essential nutrients, such as protein and energy, plays a crucial role in enhancing the growth, reproduction, and overall health of livestock. Research consistently demonstrates that access to nutritious feed leads to increased weight gain in meat-producing animals, higher milk yields in dairy cattle, and improved reproductive performance in breeding stock. Conversely, poor-quality feed or inadequate nutrition can lead to stunted growth, lower milk production, reduced fertility, and increased susceptibility to diseases. Therefore, optimizing feed quality through proper nutrition management is a fundamental factor in maximizing livestock productivity and ensuring sustainable agricultural practices.
 Unique Contribution to Theory, Practice and Policy: Nutrient Utilization Theory, Liebig's Law of the Minimum and Optimal Foraging Theory may be used to anchor future studies on impact of feed quality on livestock productivity. Livestock producers should implement stringent quality control measures to ensure the consistency and safety of animal feeds. Government agencies and industry associations can develop educational programs and training initiatives for livestock farmers.

Multiomics analysis reveals the molecular basis for increased body weight in silkworms (Bombyx mori) exposed to environmental concentrations of polystyrene micro- and nanoplastics

IntroductionMicro- and nanoplastics (MNPs) are emerging environmental pollutants that have raised serious concerns about their potential impact on ecosystem and organism health. Despite increasing efforts to investigate the impacts of micro- and nanoplastics (MNPs) on biota little is known about their potential impacts on terrestrial organisms, especially insects, at environmental concentrations. ObjectivesTo address this gap, we used an insect model, silkworm Bombyx mori to examine the potential long-term impacts of different sizes of polystyrene (PS) MNPs at environmentally realistic concentrations (0.25 to 1.0 μg/mL). MethodsAfter exposure to PS-MNPs over most of the larval lifetime (from second to last instar), the endpoints were examined by an integrated physiological (growth and survival) and multiomics approach (metabolomics, 16S rRNA, and transcriptomics). ResultsOur results indicated that dietary exposures to PS-MNPs had no lethal effect on survivorship, but interestingly, increased host body weight. Multiomics analysis revealed that PS-MNPs exposure significantly altered multiple pathways, particularly lipid metabolism, leading to enriched energy reserves. Furthermore, the exposure changed the structure and composition of the gut microbiome and increased the abundance of gut bacteria Acinetobacter and Enterococcus. Notably, the predicted functional profiles and metabolite expressions were significantly correlated with bacterial abundance. Importantly, these observed effects were particle size-dependent and were ranked as PS-S (91.92 nm) > PS-M (5.69 µm) > PS-L (9.7 µm). ConclusionOverall, PS-MNPs at environmentally realistic concentrations exerted stimulatory effects on energy metabolism that subsequently enhanced body weight in silkworms, suggesting that chronic PS-MNPs exposure might trigger weight gain in animals and humans by influencing host energy and microbiota homeostasis.

The use of biologically active additives in feeding of pigs

Probiotics and phytobiotics are a modern alternative to antibiotics in animal husbandry. Numerous studies confirm the effectiveness of probiotic additives in diets of pig, including improved growth rates, feed conversion effi ciency, modulation of the intestinal microbiota, nutrient utilization, intestinal health and regulation of the immune system. Probiotics have been proposed and used as the best alternative to the use of antibiotics as a remedy for diarrhea after weaning piglets and as growth stimulants. The purpose of the work was to study the reproductive traits of sows and the meat productivity of their off spring through the use of phytobiotic “Intebio” and probiotic “Profort” in the diets. In the fi rst scientifi c and economic experiment, the eff ect of the phytobiotic “Intebio” and the probiotic “Profort” on the reproductive traits of two-breed sows (F1) obtained as a result of crossbreeding sows of Yokshire breed with boars of Landrace breed, which were crossbred with boars of Duroc breed to obtain commercial young animals. In the second scientifi c and economic experiment, the effect of feed additives and their aftereff ect on the productive traits of the obtained three-breed off spring (F2) was studied. As a result of research to improve the reproductive traits of sows, increase the productivity of young animals and improve the quality of pork, we recommend using the phytobiotic “Intebio” in a dose of 120 g/t and the probiotic “Profort” in a dose of 500 g/t of feed according to the following scheme: for sows 30 days before farrowing and during the suckling period, for piglets from 7 to 105 days of rearing. The use of these additives will increase the prolificy of sows by 1,9–2,3 %, increase the livability of piglets by 4,0–6,1 abs.%, increase the absolute gain in live weight of young animals by 3,4–6,3 %.

Feet and legs malformation in Nellore cattle: genetic analysis and prioritization of GWAS results.

Beef cattle affected by feet and legs malformations (FLM) cannot perform their productive and reproductive functions satisfactorily, resulting in significant economic losses. Accelerated weight gain in young animals due to increased fat deposition can lead to ligaments, tendon and joint strain and promote gene expression patterns that lead to changes in the normal architecture of the feet and legs. The possible correlated response in the FLM due to yearling weight (YW) selection suggest that this second trait could be used as an indirect selection criterion. Therefore, FLM breeding values and the genetic correlation between FLM and yearling weight (YW) were estimated for 295,031 Nellore animals by fitting a linear-threshold model in a Bayesian approach. A genome-wide association study was performed to identify genomic windows and positional candidate genes associated with FLM. The effects of single nucleotide polymorphisms (SNPs) on FLM phenotypes (affected or unaffected) were estimated using the weighted single-step genomic BLUP method, based on genotypes of 12,537 animals for 461,057 SNPs. Twelve non-overlapping windows of 20 adjacent SNPs explaining more than 1% of the additive genetic variance were selected for candidate gene annotation. Functional and gene prioritization analysis of candidate genes identified six genes (ATG7, EXT1, ITGA1, PPARD, SCUBE3, and SHOX) that may play a role in FLM expression due to their known role in skeletal muscle development, aberrant bone growth, lipid metabolism, intramuscular fat deposition and skeletogenesis. Identifying genes linked to foot and leg malformations enables selective breeding for healthier herds by reducing the occurrence of these conditions. Genetic markers can be used to develop tests that identify carriers of these mutations, assisting breeders in making informed breeding decisions to minimize the incidence of malformations in future generations, resulting in greater productivity and animal welfare.

Development of a body condition index to estimate adiposity in ponies and horses from morphometric measurements.

There is a high prevalence of obesity in ponies and pleasure horses. This may be associated with equine metabolic syndrome and an increased risk of laminitis. Body condition scoring (BCS) systems are widely used but are subjective and not very sensitive. To derive a body condition index (BCI), based on objective morphometric measurements, that correlates with % body fat. Retrospective cohort study. Morphometric measurements were obtained from 21 ponies and horses in obese and moderate body condition. Percentage body fat was determined using the deuterium dilution method and the BCI was derived to give the optimal correlation with body fat, applying appropriate weightings. The index was then validated by assessing inter-observer variation and correlation with % body fat in a separate population of Welsh ponies; and finally, the correlation between BCI and BCS was evaluated in larger populations from studies undertaken in Australia, the United Kingdom and the United States. The BCI correlated well with adiposity in the ponies and horses, giving a Pearson r value of 0.74 (P < 0.001); however, it was found to slightly overestimate the % body fat in leaner animals and underestimate in more obese animals. In field studies, the correlation between BCI and BCS varied particularly in Shetlands and miniature ponies, presumably due to differences in body shape. Further work may be required to adapt the BCI to a method that is more applicable for Shetlands and miniature ponies. This BCI was able to provide an index of adiposity which compared favourably with condition scoring in terms of accuracy of estimating adiposity; and was more consistent and repeatable when used by inexperienced assessors. Therefore, this may be a useful tool for assessing adiposity; and may be more sensitive than condition scoring for tracking weight gain or weight loss in individual animals.

Formation and Replacement of Bone and Tooth Mineralized Tissues in Green Iguanas (Iguana iguana) Revealed by In-Vivo Fluorescence Marking.

Hard tissue formation patterns and rates reveal details of animal physiology, life history, and environment, but are understudied in reptiles. Here, we use fluorescence labels delivered in vivo and laser confocal scanning microscopy to study tooth and bone formation in a managed group of green iguanas (Iguana iguana, Linné 1758) kept for 1.5 years under experimentally controlled conditions and undergoing several dietary switches. We constrain rates of tooth elongation, which we observe to be slow when enamel is initially deposited (c. 9 µm/day), but then increases exponentially in the dentin root, reaching c. 55 µm/day or more after crown completion. We further constrain the total timing of tooth formation to ∼40-60 days, and observe highly variable timings of tooth resorption onset and replacement. Fluorescent labels clearly indicate cohorts of teeth recruited within Zahnreihen replacement waves, with faster sequential tooth recruitment and greater wave sizes posteriorly, where each wave initiates. Fluorescence further reveals enamel maturation after initial deposition. Rates of hard tissue formation in long bones range from 0.4 to 3.4 µm/day, correlating with animal weight gain and cortical bone recording the entire history of the experiment. We suggest additional labeling experiments to study hard tissue formation patterns in other reptiles, and propose strategies for chemical analyses of hard tissues in order to extract temporal information about past environments, behaviors, and diets from reptilian fossils throughout the Phanerozoic.

Socio-cultural practices on the use of beetle grubs as food and feed in western Kenya

We examined the socio-cultural practices on the use of beetle grubs as food and feed in western Kenya by interviewing 211 randomly selected households and conducting seven focus group discussions in Bungoma, Kakamega, Busia, and Trans Nzoia counties. The grubs were used as food and feed in ~ 39% and 78% of the households, respectively. The perceived benefits of the grubs for human consumption were nutritiousness and no linkage to allergies. The grubs were perceived to enhance animal weight gain and increase poultry egg laying. They were also perceived to recycle nutrients from organic waste, and clean the environment. Toasting and roasting were the dominant methods of preparing the grubs. Lack of knowledge on the grub nutritional benefits and stigma were key deterrents to their consumption. About 66% of the respondents expressed willingness to farm the grubs if the market and rearing protocols are available. Almost 98% of the respondents lacked knowledge of the beetle biology, indicating limited capacity to conserve them. The practices on the use of beetle grubs as food and feed differed across counties and by gender, age, marital status and education level. Strategies for sustainable use of the grubs as food and feed have been proposed and new research directions highlighted.

Combined use of recombinant interlekin-2 and anthelmintic drugs for the treatment of helminthiasis of animals

Relevance. The widespread occurrence of helminthiasis leads to significant economic damage: loss of production, decreased fertility, significant costs for therapeutic and preventive measures, culling and mass death of domestic animals (especially young animals). Parasitization of helminths observed in farm animals is associated with the development of immunodeficiency. Deworming, as a rule, also leads to certain negative changes in the immune system.Methods. The use of combination therapy, including the use of anthelmintic drugs in combination with recombinant interleukin-2 (Roncoleukin®) for the treatment of helminthiasis of animals of various etiologies.Results. The use of anthelmintics in combination with pathogenetic therapy with recombinant interleukin-2 promotes the restoration of immunoreactivity of animals, reduces the likelihood of adverse reactions and improves the results of deworming. The use of combination therapy in cattle, horses and pigs increases the effectiveness of the treatment of helminthiasis: there is a significant decrease in the intensity of invasion by 2, 8, 19 times and the extent of invasion by 7, 13, 21%, an increase in the values of intensity effectiveness by 8, 13, 25% and extensivity by 7, 16, 21%. The use of the combined deworming method contributes to a significant increase in the average daily weight gain of animals in comparison with monotherapy with anthelmintic drugs.

Chronic Restraint Stress Alters Rat Behavior Depending on Sex and Duration of Stress.

Chronic restraint stress (CRS) can have different behavioral effects depending on variables associated with the stressor and the organism. This study aimed to verify the effect of the interaction between sex and duration of the CRS protocol in rats. Sprague-Dawley rats were divided by sex, intervention (CRS; control), and CRS duration (11 days; 22 days). Rats exposed to CRS showed better spatial learning than controls in the Morris water maze test, regardless of sex and stress duration. Males exposed to CRS for 11 days showed a higher rate of behaviors associated with anxiety than males exposed to 22 days of CRS at the elevated plus maze test, but the same was not observed in females. The weight gain of animals exposed to stress decreased in the first 11 days, showing a recovery from day 11 to day 22 of intervention. No effects of CRS were observed on behaviors associated with depression in the sucrose preference test. The results suggest habituation to the protocol, with a progressive decrease in the harmful effects of stress on and maintenance of the beneficial effects. It is possible that females are more resistant to the harmful effects of CRS on anxiety.

L-2-Oxothiazolidine-4-Carboxylate, a Cysteine Precursor, Stimulates Growth and Normalizes Tissue Glutathione Concentrations in Rats Fed a Sulfur Amino Acid-Deficient Diet

The efficiency of L-2-oxothiazolidine-4-carboxylate, a cysteine precursor, in stimulating glutathione synthesis and growth was evaluated in growing rats. Animals were fed a sulfur amino acid-deficient diet (0.25% L-methionine and no cysteine) supplemented with L-2-oxothiazolidine-4-carboxylate (0.35%) for 3 wk and compared with age-matched animals receiving the sulfur amino acid-deficient diet alone. Rats fed the sulfur amino acid-deficient diet had lower glutathione concentrations in bronchoalveolar lining fluid, lung, lymphocytes, and liver than rats fed a sulfur amino acid-deficient diet supplemented with L-2-oxothiazolidine-4-carboxylate. Rats fed the supplemented diet had normal tissue and bronchoalveolar lining fluid glutathione levels. Central venous plasma glutathione concentrations, mostly reflecting liver excretion, were less affected by L-2-oxothiazolidine-4-carboxylate supplementation. Rats fed L-2-oxothiazolidine-4-carboxylate supplementation had normal weight gain compared with a much lower weight gain in animals fed the sulfur amino acid-deficient diet alone. Thus, L-2-oxothiazolidine-4-carboxylate increased tissue glutathione concentrations and stimulated growth in rats. The lung glutathione status of the rats was reflected by glutathione concentrations in lymphocytes and the bronchoalveolar lining fluid, but not by the central venous plasma glutathione concentrations.