Changes in the Hematological Variables in Pigs Supplemented With Yeast Cell Wall in Response to a Salmonella Challenge in Weaned Pigs

Antimicrobial properties of Limosilactobacillus reuteri strains for control of Escherichia coli and Salmonella strains, diarrhoea cause in weaning pigs

This study aimed to use lactic acid bacteria isolated from piglet faeces to develop probiotics, allowing for the effective control of Escherichia coli and Salmonella. Lactic acid bacteria were isolated from the faeces of suckling piglets and identified by 16S rRNA sequencing, then examined for haemolysis; gelatinase activity; and resistance to acid, bile, and pancreatin. The antimicrobial activity of selected lactic acid bacteria isolates was examined for 8 E. coli and 7 Salmonella strains. One-hundred and sixty-four lactic acid bacteria isolates were identified from 118 piglet faecal samples, and 13 lactic acid bacteria isolates were selected from analyses of haemolysis; gelatinase activity; and resistance to acid, bile, and pancreatin. Of the selected 13 lactic acid bacteria isolates, Limosilactobacillus reuteri PF20-3 and PF30-3 strains had the highest antibacterial activity against E. coli and Salmonella.

In-feed nutritional additive probiotic Saccharomyces boulardii RC009 can substitute for prophylactic antibiotics and improve the production and health of weaning pigs

Background and Aims

Non-therapeutic antibiotic use is associated with the current decrease in antibiotic therapeutic efficiency and the emergence of a wide range of resistant strains, which constitutes a public health risk. This study aimed to evaluate the use of Saccharomyces cerevisiae var. boulardii RC009 as a nutritional feed additive to substitute the prophylactic use of antibiotics and improve the productive performance and health of post-weaning piglets.

Materials and Methods

Four regular nutritional phases were prepared. Post-weaning pigs (21-70 days old) received one of two dietary treatments: T1-basal diet (BD-control group) with in-feed antibiotics as a prophylactic medication (one pulse of Tiamulin in P3 and one pulse of Amoxicillin in P4); and T2-BD without in-feed antibiotics but with Saccharomyces boulardii RC009 (1 × 1012 colony forming unit/T feed). The feed conversion ratio (FCR), total weight gain (TWG-kg), and daily weight gain (DWG-kg) were determined. A post-weaning growth index (GI) was calculated and animals (160 days old) from each treatment were analyzed at the abattoir after sacrifice for carcass weight and respiratory tract lesions.

Results

Pigs consuming probiotics had higher TWG and DWG than the control group. The group of animals with low body weight obtained the same results. Saccharomyces boulardii administration decreased diarrhea, and FCR reduction was related to a GI improvement. A significant increase in carcass weight and muscle thickness reduction was observed in animals received the probiotic post-weaning.

Conclusion

Saccharomyces boulardii RC009, a probiotic additive, was found to improve the production parameters of pigs post-weaning and enhance their health status, indicating that it may be a promising alternative to prophylactic antibiotics.

Improving growth performance and blood profile by feeding autolyzed yeast to improve pork carcass and meat quality

The 63 commercial pigs were divided into three groups consisting of seven replicates of three piglets each. The experimental diets were (1) control diet, (2) diet with autolyzed yeast (AY) 0.5%, and (3) diet with AY 1.0%. Compared to the control group, using AY 0.5% in the diet reduced average daily feed intake (ADFI) and improved feed conversion ratio (FCR) (p < 0.05). The blood urea nitrogen (BUN) and neutrophil/lymphocyte ratio (N/L) in blood decreased with the addition of AY 0.5% (p < 0.05). The pH at 6-h postmortem of meat in the 0.5% AY diet group was higher than for the control group (p < 0.05). Backfat thickness (p = 0.09) and P2-backfat thickness (p = 0.07) tended to decrease, while the fat free index (FFI; p = 0.07) tended to increase with 0.5% AY supplementation. The protein percentage (p = 0.07) and the a* value (redness) (p = 0.08) in the meat tended to increase, and the springiness increased with 0.5% AY supplementation (p < 0.05). An appropriate level of AY supplementation can impact positively on the physiological functions in swine with a consequent seems to improve in qualitative traits of the meat quality.

Effect of functional oils or probiotics on performance and microbiota profile of newly weaned piglets

The study aimed to evaluate a commercial blend of functional oils based on liquid from the cashew nutshell and castor oil as a growth promoter in newly weaned piglets. A total of 225 piglets, castrated males and females with 28 days of age were randomly distributed in pens with 15 animals composing three treatments and five repetitions. The treatments were: control (without the inclusion of additives), probiotics, or functional oils. The performance was evaluated. At 50 days of age, a pool of fresh feces from 3 animals/repetition was collected to perform the sequencing of microbiota using the Illumina MiSeq platform. Supplementation with functional oils improved the piglets' daily weight gain and feed conversion ratio (P < 0.05) in the first weeks of the experiment, which resulted in higher final live weight (P < 0.05) in the phase when compared to the control treatment (24.34 kg and 21.55 kg, respectively). The animals that received probiotics showed an intermediate performance (23.66 kg final live weight) at the end of the 38 experimental days. Both additives were effective in increasing groups essential for intestinal health, such as Ruminococcaceae and Lachnospiraceae. The functional oils were more effective in reducing pathogenic bacteria, such as Campylobacter and Escherichia coli. In conclusion, the use of functional oils optimized performance and effectively modulated the microbiota of newly weaned piglets.

Salmonella Bacterin Vaccination Decreases Shedding and Colonization of Salmonella Typhimurium in Pigs

Since the occurrence of swine salmonellosis has increased over time and control strategies other than biosecurity are highly recommended, the present study aimed to evaluate the efficacy of vaccination with Salmonella Choleraesuis and Salmonella Typhimurium bacterins in pigs. Two experimental groups were formed: G1, animals immunized with two doses of a commercial vaccine (n = 20); G2, control group (n = 20). After vaccination, all pigs were orally challenged (D0) with 10⁸ CFU of Salmonella Typhimurium and evaluated for 40 days. Every 10 days after D0, five piglets from each experimental group were euthanized and submitted to the necroscopic examination, when organ samples were collected. Blood samples and rectal swabs were collected before the first dose of the vaccine (D−42), before the second dose (D−21), before the challenge (D0), and thereafter, every three days until D39. Blood count, serum IgG measurement by ELISA, and the excretion of Salmonella Typhimurium in feces were evaluated. While the results from blood count and serum IgG concentration did not differ, the detection and excretion of Salmonella between G1 and G2 differed (p < 0.05). Therefore, it was observed that this vaccine partially protected the animals against experimental infection with Salmonella Typhimurium, reducing the excretion of bacteria in feces.

Alternatives to Antibiotics: A Symposium on the Challenges and Solutions for Animal Health and Production

Antibiotics have improved the length and quality of life of people worldwide and have had an immeasurable influence on agricultural animal health and the efficiency of animal production over the last 60 years. The increased affordability of animal protein for a greater proportion of the global population, in which antibiotic use has played a crucial part, has resulted in a substantial improvement in human quality of life. However, these benefits have come with major unintended consequences, including antibiotic resistance. Despite the inherent benefits of restricting antibiotic use in animal production, antibiotics remain essential to ensuring animal health, necessitating the development of novel approaches to replace the prophylactic and growth-promoting benefits of antibiotics. The third International Symposium on “Alternatives to Antibiotics: Challenges and Solutions in Animal Health and Production” in Bangkok, Thailand was organized by the USDA Agricultural Research Service, Faculty of Veterinary Science, Chulalongkorn University and Department of Livestock Development-Thailand Ministry of Agriculture and Cooperative; supported by OIE World Organization for Animal Health; and attended by more than 500 scientists from academia, industry, and government from 32 nations across 6 continents. The focus of the symposium was on ensuring human and animal health, food safety, and improving food animal production efficiency as well as quality. Attendees explored six subject areas in detail through scientific presentations and panel discussions with experts, and the major conclusions were as follows: (1) defining the mechanisms of action of antibiotic alternatives is paramount to enable their effective use, whether they are used for prevention, treatment, or to enhance health and production; (2) there is a need to integrate nutrition, health, and disease research, and host genetics needs to be considered in this regard; (3) a combination of alternatives to antibiotics may need to be considered to achieve optimum health and disease management in different animal production systems; (4) hypothesis-driven field trials with proper controls are needed to validate the safety, efficacy, and return of investment (ROI) of antibiotic alternatives.

Influence of Yeast Products on Modulating Metabolism and Immunity in Cattle and Swine

Nutritional supplementation has been used by livestock producers for many years in order to increase animal performance, improve animal health, and reduce negative effects associated with enteric and/or respiratory pathogens. Supplements such as yeast and yeast-based products have broad applications across many livestock production systems, including poultry, aquaculture, cattle, and swine and have been shown to benefit animal production at various stages. These benefits include improvement in milk production, weight gain and feed conversion, as well as immune function. Initial research into the mode of action for these effects has focused on stimulation of the immune system by the β-glucan fractions of yeast. However, emerging studies have revealed that some of the beneficial effects of yeast products may stem from altering metabolism, including the availability of glucose and fatty acids. These changes in metabolism, and potentially energy availability, may partially explain differences in immune function observed in yeast-supplemented livestock, as the energy demands of an activated immune system are extremely high. Thus, this paper explores the influence of yeast products on metabolism in cattle and swine, and how changes in metabolism and energy availability may contribute to improvements in immune function in supplemented animals.

Animal Models of Type III Secretion System-Mediated Pathogenesis

The type III secretion system (T3SS) is a conserved virulence factor used by many Gram-negative pathogenic bacteria and has become an important target for anti-virulence drugs. Most T3SS inhibitors to date have been discovered using in vitro screening assays. Pharmacokinetics and other important characteristics of pharmaceuticals cannot be determined with in vitro assays alone. In vivo assays are required to study pathogens in their natural environment and are an important step in the development of new drugs and vaccines. Animal models are also required to understand whether T3SS inhibition will enable the host to clear the infection. This review covers selected animal models (mouse, rat, guinea pig, rabbit, cat, dog, pig, cattle, primates, chicken, zebrafish, nematode, wax moth, flea, fly, and amoeba), where T3SS activity and infectivity have been studied in relation to specific pathogens (Escherichia coli, Salmonella spp., Pseudomonas spp., Shigella spp., Bordetella spp., Vibrio spp., Chlamydia spp., and Yersinia spp.). These assays may be appropriate for those researching T3SS inhibition.