Increase in erythrocyte osmotic resistance following polyunsaturated fatty acids (PUFA) supplementation in show jumper horses

Effects of dietary camelina, flaxseed, and canola oil supplementation on plasma fatty acid concentrations and health parameters in horses

Camelina (Camelina sativa) is a hardy, low-input oilseed crop that provides a rich source of the n-3 fatty acid, α-linolenic acid (ALA). The primary purpose of the present study was to assess the effects of dietary camelina oil (CAM) consumption on various health parameters, as compared to horses fed canola oil (OLA) or flax oil (FLX). Secondly, to determine how dietary CAM, FLX, and OLA alter circulating plasma total lipids across time. Thirty horses, from three separate herds, were used for this study [14.9 years ± 5.3 years; 544 ± 66 kg calculated BW (mean ± SD)]. After a 4-week gradual acclimation period using sunflower oil mixed with soaked hay cubes, horses were balanced by location, age, sex, weight, and breed and randomly allocated to one of three treatment oils (CAM, OLA, or FLX) at an inclusion of 370 mg of oil/kg BW/day. Horses had ad libitum access to hay and/or pasture for the duration of the study. Body condition score (BCS), BW, oil intake, complete blood counts, plasma biochemical profiles, and plasma total lipids were measured on weeks 0, 2, 4, 8, and 16 throughout the 16-week treatment period. BW, BCS, and oil intake were analyzed using an ANOVA using PROC GLIMMIX in SAS Studio. Complete blood counts and biochemical profiles were analyzed using an ANCOVA, and fatty acids were analyzed using an ANOVA in PROC MIXED in SAS Studio. No differences were observed among treatment groups for BW, BCS, oil intake, complete blood counts, and biochemical parameters. Individual fatty acids that differed among treatments and/or across time were largely reflective of the different FA profiles of the oils provided. Most notably, plasma ALA was greater for FLX than OLA, but neither differed from CAM (P = 0.01). Linoleic acid did not differ among treatments or over time (P > 0.05). The n-6:n-3 ratio decreased over time for both CAM and FLX, and ratios were lower for FLX than OLA at week 16, but not different from CAM (P = 0.02). These results suggest that dietary CAM had no adverse effects on health parameters and that daily supplementation of CAM and FLX at 370 mg of oil/kg BW/day induces positive changes (a decrease) in the n-6:n-3 status of the horse. Consequently, CAM may be considered as an alternative oil to FLX in equine diets.

Effect of dietary krill oil supplementation on horse red blood cell membrane fatty acid composition and blood parameters

Supplementation with marine-derived n-3 long-chain polyunsaturated fatty acids (LC PUFAs), eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) is linked to beneficial health effects in both humans and horses. Krill oil (KO), which is extracted from the Antarctic krill (Euphausia superba), is well documented as a safe and biologically available dietary supplement in humans and several animal species, but there is a lack of documentation regarding its effect as a dietary ingredient for horses. The objective of this study was to test whether KO as a dietary supplement had the ability to raise horse red blood cell (RBC) membrane EPA and DHA, expressed as the n-3 index. Five nonworking Norwegian cold-blooded trotter horse geldings (body weight [BW]: 567 ± 38 kg) were supplemented with KO (10 mL/100 kg BW) for 35 days in a longitudinal study. Blood samples were analysed for RBC membrane fatty acid (FA) profile, haematology and serum biochemistry every 7th day. KO was well accepted by all horses, and no adverse health effects were observed during the 35-day trial period. KO supplementation affected the RBC membrane FA profile by increasing the n-3 index from Day 0 to 35 (Day 0: 0.53% vs. Day 35: 4.05% of total RBC FAs). The observed increase in the sum of EPA and DHA (p < 0.001), total n-3 FAs (p < 0.001) and the reduction of n-6 FAs (p < 0.044) resulted in a lower n-6:n-3 ratio (p < 0.001) by Day 35 of KO supplementation. In conclusion, the RBC n-3 index was increased and the general n-6:n-3 ratio was decreased in horses receiving 35-day dietary KO supplementation.

Characterization of exercise-induced hemolysis in endurance horses

Exercise-induced hemolysis occurs as the result of intense physical exercise and is caused by metabolic and mechanical factors including repeated muscle contractions leading to capillary vessels compression, vasoconstriction of internal organs and foot strike among others. We hypothesized that exercise-induced hemolysis occurred in endurance racehorses and its severity was associated with the intensity of exercise. To provide further insight into the hemolysis of endurance horses, the aim of the study was to deployed a strategy for small molecules (metabolites) profiling, beyond standard molecular methods. The study included 47 Arabian endurance horses competing for either 80, 100, or 120 km distances. Blood plasma was collected before and after the competition and analyzed macroscopically, by ELISA and non-targeted metabolomics with liquid chromatography-mass spectrometry. A significant increase in all hemolysis parameters was observed after the race, and an association was found between the measured parameters, average speed, and distance completed. Levels of hemolysis markers were highest in horses eliminated for metabolic reasons in comparison to finishers and horses eliminated for lameness (gait abnormality), which may suggest a connection between the intensity of exercise, metabolic challenges, and hemolysis. Utilization of omics methods alongside conventional methods revealed a broader insight into the exercise-induced hemolysis process by displaying, apart from commonly measured hemoglobin and haptoglobin, levels of hemoglobin degradation metabolites. Obtained results emphasized the importance of respecting horse limitations in regard to speed and distance which, if underestimated, may lead to severe damages.

Measuring Biochemical Variables and Serum Amyloid A (SAA) in Working Mules in Central Italy

According to FAO reports, the global mule population counts about 9 million mules. This hybrid cross of a male donkey and a female horse is mainly used for draft purposes because they are thought to be strong and hardy animals. Most consider mules to be less susceptible to disease and fatigue compared to horses. Therefore, the aim of this study was to investigate the effects of fieldwork on biochemical variables and serum amyloid A in working mules. Blood samples were collected from 10 healthy, female, working mules before and after 8 h of fieldwork. According to statistical analysis, a significant influence (p < 0.05) of fieldwork was found on mules’ electrolyte profile with increased levels of sodium, chloride, and calcium, as well as on blood urea nitrogen and creatinine. After a day of fieldwork, serum sodium, chloride, calcium, urea, and creatinine concentrations were increased, supporting decreases in body water and renal blood flow. However, without comparison to a group of mules that were not exercised yet maintained under similar ambient conditions, it is uncertain whether these changes can be attributed to exercise. Further, no change in SAA concentration was found after exercise, indicating that the work performed did not result in systemic inflammation.

Selected Alternative Feed Additives Used to Manipulate the Rumen Microbiome

Simple Summary

The continuous intensification of ruminant production drives towards the expansion of feed components and additives that are utilizes for the coverage of animal’s demand for nutrients. Additionally, in recent years, studies are focused on the investigation of how feed additives affect the microbiome of the digestive system in order to obtain improved performance and/or reduce methane emissions by ruminants. The use of additives such as algae, probiotics, fermented feed or essential oils can serve as an alternative to antibiotics or other synthetic compounds that may pose a danger to the environment.

Abstract

In recent years, a boost in the ruminant population has been observed, and consequently, an increase in the animals’ demand for nutrients and methane emissions. Methane emission is generated during the microbial fermentation of feed in the rumen, and a percentage even up to 12% of the energy obtained by this process can be wasted. In addition, the use of antibiotics in animal husbandry is being increasingly restricted. restricted. As a result, there is a continuous search for innovative feed additives that can serve as alternatives to antibiotics, and will also be safe for both people and the environment. In the present review article, additives were selected on basis that, according to studies conducted so far, may positively affect the microbiome of the digestive system by improving indicators and/or reducing methane production. Among them, probiotics, prebiotics or their combination—synbiotics are at the forefront of research. However, additives in the form of algae or plant origin are also gaining ground in popularity, such as essential oils, fermented wheat straw or Gelidium amansii, due to their general recognition as safe (GRAS) for both humans and environment.

Assessment of Response to Moderate and High Dose Supplementation of Astaxanthin in Laying Hens

Simple Summary

With the increasing use of carotenoids, especially astaxanthin as a feed additive in the poultry industry, the concern about the health status of the laying hen and efficacy to improve egg quality in the case of overdosing was raised. Thus, we aimed to evaluate the effects of either moderate or high dose dietary supplementation of astaxanthin on eggs and laying hens’ health status. The results revealed that, at moderate dose increment, astaxanthin is well deposited in egg yolk, efficiently improves egg yolk color, and contributes to ameliorate the general health status of laying hens. Besides, the high dose supplementation presented positive effects on the coloration and enrichment of egg yolk and the health status of laying hens with no significant difference with the moderate doses to some extents. We concluded that it would be beneficial to add astaxanthin to laying hens feed at a moderate dose rather than high dose.

Abstract

In this study, we evaluated the impact of moderate and high dose dietary supplementation of astaxanthin on production performance, quality of eggs, and health status of laying hens. The experiment involved 480 laying hens, divided into four groups of eight replicates. The different groups named A1, A2, A3, and A4 were allocated the same diet supplemented with Haematococcus pluvialis powder to provide 0, 21.3, 42.6, and 213.4 mg of astaxanthin per kilogram of feed, respectively. One-way ANOVA and linear and quadratic regression analysis were used to assess the differences between the groups. The results showed that the production performance of laying hens and the physical quality of eggs did not significantly differ between the groups (p > 0.05). Astaxanthin distribution in tissues was typical per bird, whereas the egg yolk coloration and astaxanthin concentration increased with the supplementation dose (p < 0.001). However, there was a decrease in concentration and coloration efficacy of astaxanthin at high dose supplementation (213.4 mg/kg) compared to moderate doses (21.3 and 42.6 mg/kg). Blood biochemical tests showed some discrepancies that were not ascribed to the effect of diets, and the increase in liver weight in the A4 group compared to others was equated with an adaptation of laying hens to the high dose supplementation. Astaxanthin improved superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and diminished malondialdehyde (MDA) content in both liver and serum; meanwhile, the activities of SOD and GSH-Px in serum were similar between the moderate doses and high dose supplementation. Additionally, astaxanthin alleviated interleukin 2, 4, and 6 (IL-2, IL-4, and IL-6, respectively) in serum, showing the best effect in A3 and A4 groups. Besides, immunoglobulin G and M (IgG and IgM), as well as tumor necrosis factor-alpha and beta (TNF-α and TNF-β), were not much affected. It was concluded that although astaxanthin has no obvious adverse effect on the performance and health status of laying hens, it may not be valuable for egg fortification and health status improvement of laying hens at high dose supplementation. The high dose astaxanthin supplementation up to 213.4 mg/kg in the diet might be avoided.

Venous Blood Acid-Base Status in Show Jumper Horses Subjected to Different Physical Exercises

The aim of this study was to assess whether acid-base profile exhibits changes in regularly trained show jumping horses undergoing increasing exercise workloads. Seven female Italian saddle horses were subjected to three different physical exercise trials of increasing workload identified as three exercise phases (EPs). During EP_I horses were subjected to a standardized exercise test consisting of 15 minutes of treadmill, during EP_II horses were subjected to a show jumping test (height, 0.9-1.1 m; course length, 300 m), during EP_III horses underwent two jumping sessions carried out over two consecutive days. Blood samples were collected at rest (T_PRE), after exercise (T_POST), and 30 minutes after the end of exercise (T_POST30). The values of pH, partial pressure of carbon dioxide (Pco₂), partial pressure of oxygen (Po₂), bicarbonate level (HCO₃^-), hemoglobin (Hb), and hematocrit (Hct) were measured. A significant effect of exercise workload and time (P < .001) on Po₂, Pco₂, HCO₃^-, Hb, and Hct values was found. The variation in the studied parameters resulted mostly reversible within T_POST30 in horses when subjected to EP_I and EP_II, whereas Po₂, Hb, and Hct remained higher at T_POST30 than T_PRE in horses when subjected to the second day of jumping section (EP_III) indicating a failure to recover. The results suggest that jumping sessions carried out over two consecutive days represent extra workload for horses, and this should be taken into account by veterinarian to prevent acid-base imbalance and for the maintenance of health and performance in equine athletes.