Feed Additive Research Articles

Phytogenic feed additives as an alternative to control postpartum problems in organic dairy farming

Organic dairy farming presents unique challenges, particularly regarding postpartum problems in dairy cows. This article explores the potential of phytogenic feed additives as an alternative solution to control such issues in organic dairy farming. Postpartum problems, including retained placenta, metritis, and mastitis, can have serious consequences for dairy cow health and productivity. The conventional treatment methods, such as antibiotics and anti-inflammatory drugs, are restricted in organic farming, necessitating the search for alternative solutions. Phytogenic feed additives, derived from plant sources, offer a promising alternative to conventional treatments. They provide anti-inflammatory, immunomodulatory, antimicrobial, and antioxidant effects, which can help prevent and manage postpartum problems in dairy cows. Studies have shown the efficacy of various plant-based remedies in treating specific postpartum issues, such as retained placenta, uterine prolapse, uterine infections, repeat breeding, mastitis, and post parturient hypocalcemia. The use of herbal remedies for postpartum problems aligns with the principles of organic farming, offering sustainable and environmentally friendly solutions. By exploring the potential of phytogenic feed additives, this article aims to contribute to the advancement of natural and eco-friendly practices in organic dairy farming, promoting the health and welfare of dairy cows while ensuring farm sustainability and profitability. In conclusion, phytogenic feed additives have shown promising results in controlling postpartum problems in organic dairy farming. They offer a safe, effective, and sustainable alternative to conventional allopathic treatments, helping to address the unique challenges faced by organic dairy farmers. However, more research and professional guidance are necessary to fully harness the potential of phytogenic feed additives in organic dairy farming.

PSXI-22 Effects of a palatability enhancer and olive bioactives on performance and physiological status of veal calves after farm reception

Abstract Veal calves have to deal with several stressors early in life, such as transport and commingling with animals of unknown health histories from multiple different origins; making the reception a possible critical period where animals should adapt to all these challenges. Previous studies in unweaned rosée calves have shown that the use of feed additives (FA) to enhance intake and immunity at farm arrival could be a strategy to minimize the negative effects of stress and feed restriction during transportation. The aim of this study was to evaluate the effects of a palatability enhancer (PE) and olive bioactives (OB) on performance and serum biomarkers in veal calves. Dairy beef calves [n = 252; BVD-free; body weight (BW) = 44.6 ± 3.63 kg] coming from auction market were distributed in 3 treatments (84 animals/tr) during 8 wk: i) calves fed concentrate and MR without FA (negative control, NC); ii) calves fed concentrate and MR with a PE based on sweeteners (PE); and iii) calves fed concentrate with PE and MR with PE and OB (PEOB). On farm arrival animals were housed individually until 5 wk of age, when animals were grouped in pens of 4 calves. Performance was monitored during the trial and serum samples were collected 48 h after the mixing (25 animals/tr) to analyze several biomarkers related to immune system (MILLIPLEX MAP Kit) and energy status (BHBA). Performance data were analyzed with a mixed-effects model and serum biomarkers by One-Way Anova with Fisher’s LSD correction for multiple comparisons (normally distributed data) or by non-parametric Kruskal-Wallis test with Dunn’s correction (data not normally distributed). Final BW was greater (P = 0.01) in PE and PEOB groups compared with NC (+2.2 kg and +2.6 kg, respectively). Concentrate feed intake (FI) during first 4 wk tended (P = 0.06) to be greater in PEOB compared with NC (+15%); however, after grouping (wk 5 to wk 8), PE showed a ldecreased FI compared with NC (-9.5%, P = 0.01). Forty-eight hours after animal grouping, PEOB showed reduced concentration of tumor necrosis factor (TNF) α than NC and PE (P = 0.03). Moreover, PEOB and PE had a greater concentration of interleukin (IL) 36Rα (P < 0.05) and IP10 (P < 0.01) compared with NC. Besides PEOB tended (P < 0.15) to have decreased concentrations of MIP1α, IL1α, and BHBA compared with PE. In conclusion, the addition of a PE and OB improved the adaptation of veal calves after reception, resulting in greater final BW. The improvement in early FI and the immunomodulatory effect in challenging situations displayed by the treatments may partially explain the observed benefits.

PSXII-24 Use of a commercial blend of tannins as feed additive for feed lot cattle on large pen trial improves carcass weight and carcass feed conversion

Abstract The utilization of commercial tannin extracts as feed additives holds promise for enhancing animal performance and health within commercial feedlot settings. This study aimed to assess the impact of a commercial tannin blend, SilvaFeed BX (Indunor, Buenos Aires, Argentina), sourced from quebracho and chestnut extracts along with saponins, on the performance of beef cattle. Nelore bullocks (n = 1,198) were allocated to 12 pens in a completely randomized block design, stratified by initial date, at a commercial feedlot facility in Goias State, Brazil. Each pen served as an experimental unit, with 10 pens housing 100 animals each and 2 pens containing 99 animals each. The experimental treatments included a Control diet with monensin alone [25 ppm/kg dry matter (DM)] or treated with BX (0.7 g/kg DM) on top of the control diet. Individual body weights (BW) were recorded at processing (initial BW; IBW) and shipment (final BW; FBW), while DM intake (DMI) was averaged per pen throughout the study duration. Carcass weight (CW) was individually measured at the packing plant, and carcass gain was calculated as the discrepancy between carcass weight and the estimated initial carcass weight, set at 50% of the IBW, aligning with customary practices for negotiating feeder cattle in Brazil. Statistical analyses were conducted using Proc Glimmix in SAS, treating pens and treatments as fixed effects and blocks as random effects, with IBW considered as a covariate. Residuals were assessed for normality, identifying three outliers. Mean comparisons were facilitated using LSMEANS. The results indicated that BX-treated cattle exhibited increased FBW (502.17 vs. 493.64 kg, P = 0.0992), carcass weight (275.76 vs. 268.78 kg, P = 0.0343), total carcass gain (107.52 vs. 100.54 kg, P = 0.0343), and improved carcass feed conversion (10.46 vs. 11.45 kg DM/kg; Table). Despite numerical differences, the limited number of replications were not enough to detect significant differences between treatments in average daily gain (P = 0.2419), DMI (P = 0.5508), feed conversion (P = 0.2641), or dressing (P = 0.3757). In conclusion, BX, a blend of tannins, exhibits potential for enhancing carcass weight and feed conversion efficiency in Nelore bullocks. Further investigations employing larger sample sizes are warranted to comprehensively elucidate its effects on other performance parameters.

PSXI-7 Effects of selected feed additives on feedlot cattle performance when fed diets containing rehydrated corn grain silage

Abstract The use of additives makes it possible to improve body weight (BW) gain and muscle growth, the efficiency of nutrient use, in addition to reducing the incidence of metabolic disorders. The objective of the study was to evaluate the performance, feed intake and carcass production of feedlot Nelore cattle, fed with a high concentrate diet, using different feed additives. Nelore bulls [n = 48; initial BW (BWi = 378.1 kg ± 8.92 kg; 20 mo of age), were used. Bulls were allocated in a collective pen, randomly distributed in two treatments: 1) Sodium Monensin (MON), 26 mg/kg DM; and2) CRINA + RUMISTAR + Hy-D (CRD), blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25 hydroxyvitamin D3, 1 mgּ animal-1ּ d-1 . The experiment lasted 101 d, the animals were weighed fasting (± 16 h) at the beginning and end of the experiment, at the end of the experiment the animals were subjected to carcass ultrasound, dry matter intake (DMI) was measured daily individually using electronic troughs with selector doors (Intergado, PONTA, Betim, MG-Brazil). The initial carcass weight (195.6 kg, P = 1.0) was estimated using the equation HCWi = 0.6587*BWi-53.44 (R² = 0.993), obtained through the reference slaughter of 9 animals, and the final carcass weight measured in the refrigerator. The “step-up” adaptation protocol lasted 15 d, followed by the finishing diet until the end of the experimental period, consisting of ground corn, rehydrated corn grain silage, cottonseed cake, whole cottonseed, sugarcane bagasse, urea and vitamin-mineral supplement. Data were analyzed by SAS PROC ANOVA, using BWi as a covariate when significant. Animals fed CRD had a greater final BW (534.0 vs 515.6 kg, P = 0.003) and increased average daily gain (ADG) by 0.180 kg/d (1.54 vs 1.36 kg/d, P = 0.003). DMI was greater (10.2 vs 9.3 kg/d, P < 0.001) as well as DMI:BW (2.24 vs 2.09 %BW/d, P < 0.001). The feed efficiency did not differ between treatments (P = 0.21). Animals fed CRD presented heavier HCW (305 vs 291 kg, P = 0.004) and ADG carcass (1.08 vs 0.95 kg/d, P = 0.004). The carcass conversion, calculated as kg DM/15 kg carcass produced (143.5 vs 152.6, P = 0.11), carcass yield (P = 0.15), 12th ribeye area (P = 0.52) and 12th rib fat (P = 0.12), were similar among the treatments. Feeding CRD tended to improve marbling (1.67 vs 1.45%, P = 0.08). These results underscore the potential of CRD as an effective alternative to traditional additives in enhancing the performance and carcass quality of feedlot cattle.

PSXIII-1 Sensory additives improved the recovery of commercially marketed and transported unweaned dairy beef calves at rearing farm arrival

Abstract Calf recovery after arrival at the rearing farm in unweaned calves is impaired by periods of stress, feed restriction and fasting during marketing and transportation. The use of feed additives to enhance intake at arrival could be a strategy to minimize those negative effects. A total of 72 calves (71.4 ± 1.72 kg) gathered in a commercial assembly center and transported 9 h to a rearing farm were used to evaluate the effect of a sensory additive (SA) on performance in calves fed 2 L of milk replacer twice daily at 12.5% and ad libitum concentrate feed. Calves were allocated in 8 pens and distributed in 2 treatments (4 pens/treatment): calves fed a concentrate without SA since the beginning of the study (arrival to the rearing farm after transport) until weaning (CON; n = 36); calves fed a concentrate containing SA (SEN; n = 36) from arrival until weaning. Calf body weight (BW) and pen intake were recorded weekly. On d 21 of the study, calves were partially weaned and only milk replacer was offered in the morning, and on d 28 all calves were completely weaned. The study lasted 35 d. Data were analyzed with a mixed-effects model. Average daily gain was greater (P = 0.04) for SEN calves compared with CON calves (0.68 ± 0.019 kg/d and 0.61 ± 0.019 kg/d, respectively). Final BW of SEN calves (95.5 ± 0.89 kg) tended (P = 0.06) to be greater compared with BW of CON calves (93.1 ± 0.89 kg). Finally, average concentrate intake was greater for SEN calves (0.89 ± 0.023 kg/d) compared with CON calves (0.79 ± 0.023 kg/d). Unweaned dairy beef calves receiving sensory additive improved concentrate intake and growth at farm arrival improving their recovery.

133 Effect of feeding two different feed additives (Prime Force and Optipartum C+) on finishing cattle performance and carcass characteristics

Abstract A feedlot study was conducted to evaluate the effect of two feed additives, Prime Force (Furst-McNess Company, Rockford, IL) and Optipartum C+ (AB Vista, Plantation, FL), on finishing cattle performance and carcass characteristics. In this experiment, steers [n = 320; 390 ± 9.5 kg of body weight (BW)] were used and four treatments were evaluated in a total of 32 pens, with 10 steers per pen and 80 steers per treatment. Treatments were arranged in a 2 × 2 factorial and included a control diet with no additives; a diet containing Prime Force targeted at 68 g/steer daily; a diet containing Optipartum C+, targeted at 20 g/steer daily; and a diet containing a combination of both products (68 g/steer Prime Force and 20 g/steer Optipartum C+). Cattle were fed for 151 d, but treatments were imposed the last 67 d before slaughter (i.e., fed control diet to all cattle until d 84). Performance is for the total 151-d feeding period. No interaction between feed additives was observed for performance or carcass traits (P ≥ 0.41), therefore main effects are presented. Feeding Prime Force increased final BW (P < 0.04) when compared with cattle not fed Prime Force. A tendency was observed for greater adjusted final BW (P = 0.06) and ADG (P = 0.08) for cattle fed Prime Force compared with cattle fed no Prime Force. Cattle fed Prime Force had numerically greater intake (P = 0.11) than cattle fed no Prime Force, therefore gain to feed (G:F) was not impacted (P = 0.54). Ribeye area and fat depth were not different (P ≥ 0.17) for cattle fed Prime Force versus cattle that had no Prime Force added to the diet, but marbling was numerically improved (P = 0.11) due to Prime Force. Carcass-adjusted final BW (P = 0.11) was numerically greater for cattle fed Optipartum C+ and ADG tended (P = 0.09) to be greater for cattle fed Optipartum C+ compared with cattle fed no Optipartum C+. Dry matter intake was not different (P = 0.54) for cattle fed Optipartum C+ versus cattle with no Optipartum C+ in the diet, therefore G:F was numerically improved (P = 0.13) by the increase in ADG for cattle fed Optipartum C+. Ribeye area, fat, and marbling were not different (P ≥ 0.30) between cattle fed Optipartum C+ and those that did not receive Optipartum C+ in the diet. Incidence of liver abscesses was not affected by feeding either additive (P = 0.40). Based on results from this study, adding Prime Force to a finishing diet tended to improve BW and ADG compared with cattle not fed Prime Force. Feeding Optipartum C+ tended to increase ADG and improve G:F due to equal DMI when compared with diets with no Optipartum C+ added.

Glucose Metabolism-Modifying Natural Materials for Potential Feed Additive Development.

Glucose, a primary energy source derived from animals' feed ration, is crucial for their growth, production performance, and health. However, challenges such as metabolic stress, oxidative stress, inflammation, and gut microbiota disruption during animal production practices can potentially impair animal glucose metabolism pathways. Phytochemicals, probiotics, prebiotics, and trace minerals are known to change the molecular pathway of insulin-dependent glucose metabolism and improve glucose uptake in rodent and cell models. These compounds, commonly used as animal feed additives, have been well studied for their ability to promote various aspects of growth and health. However, their specific effects on glucose uptake modulation have not been thoroughly explored. This article focuses on glucose metabolism is on discovering alternative non-pharmacological treatments for diabetes in humans, which could have significant implications for developing feed additives that enhance animal performance by promoting insulin-dependent glucose metabolism. This article also aims to provide information about natural materials that impact glucose uptake and to explore their potential use as non-antibiotic feed additives to promote animal health and production. Further exploration of this topic and the materials involved could provide a basis for new product development and innovation in animal nutrition.

Determination and evaluation of canthaxanthin and β-apo-8’-carotenoid ethyl ester in chicken eggs and meat in Tianjin

Canthaxanthin and β-apo-8’-carotenoid ethyl ester are widely used as feed additives in poultry feed for enhancing the color of poultry products. The excessive intake of the two colorants can cause health damage. According to the European Food Safety Authority (EFSA), the acceptable daily intake (ADI) of canthaxanthin and β-apo-8’-carotenoid ethyl ester are 0.03 mg/kg·bw and 0.015 mg/kg·bw, respectively. Ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) was used to determine two colorants in chicken eggs and meat. A PRiME HLB solid-phase extraction cartridge was used to extract and clean-up the sample. BEH C18 column was used as the separation column, with water containing 0.1% formic acid and acetonitrile as the mobile phase. The limit of detection (LOD) was 0.05 mg/kg, and the limit of quantification (LOQ) was 0.1 mg/kg. The recoveries were between 90% and 104%. The daily intake of two colorants in chicken eggs and meat was evaluated based on the detection data, food consumption data and weight data of the population. The mean estimated daily intake (EDI) values of canthaxanthin through chicken eggs and meat were 1.09 µg/(kg·bw·d) and 0.013 µg/(kg·bw·d), respectively. The mean EDI value of β-apo-8’-carotenoid ethyl ester through eggs was 0.44 µg/(kg·bw·d). The results showed that eggs were the main contributor to the daily intake of two colorants. The mean hazard quotients (HQ) values of two colorants through chicken eggs and meat was within a safe range.

34 The influence and interaction of nutrition with the immune system in companion animal models

Abstract Understanding the impacts of nutrients in a species-specific manner has both practical and academic benefits for improving animal health. Therefore, species-specific animal models and research reagents are crucial to understanding molecular and physiological pathways. However, limitations in repeatable, descriptive models, sample size, and the ethics of companion animal research result in often needing to make inferences from human, murine, and other related immunology and nutrition research models. Recent companion animal work has focused on the impact of key nutrients in animal diets, including fat-soluble vitamins D, and E, omega-3 polyunsaturated fatty acids (PUFA), overall amino acid and energy balance over the lifespan, minerals including zinc and selenium, and feed additives such as probiotics and beta glucans. The selected research model, samples able to be collected, and available reagents for sample analysis will impact potential outcomes and inferences made from the data, including both acute to chronic impacts. From a theoretical standpoint, the balance between nutrient supplementation and impact includes understanding nutrients and responses of a model system in both deficiency and therapeutic level settings. For example, when supplementing Vitamin D, Vitamin E, or omega-3 polyunsaturated fatty acids, inclusion above currently recommended levels may optimize immune function, such as pathogen clearance, improved vaccine titer responses, or reduce inflammation. For other nutrients associated with immunomodulation such as zinc, additional chronic pharmacological supplementation may inhibit certain aspects of immune function, much like a deficiency scenario. Overstimulation of the immune system through nutrient supplementation may also impact the necessary modulation and repair roles that immune cells such as macrophages play in wound healing and anti-inflammatory responses. Continued work in nutritional immunology will further enhance our understanding of the power of nutrition and diet to improve health in companion animals.

94 Associative effects of two potent anti-methanogenic Moringa oleifera accessions mixed at various proportions on in vitro rumen fermentation and methane inhibition

Abstract Moringa is an important anti-methanogenic plant with a potential to develop as multipurpose feed additives. Previous studies identified two potent accessions (accession 07633 designated as A3 and accession collected from Pretoria designated as A11) with high methane (CH4) inhibition characteristics. Two metabolite ion features (MIFs) 4.44_609.1462 and MIF 4.53_433.1112 were identified as bioactive MIFs associated with greater methane inhibition in Moringa accession A3 and A11, respectively. Two separate studies were conducted with an aim to name the MIF associated with methane inhibition and evaluate the benefit of mixing plant extract from A3 and A11 in different proportions to exploit their additive or synergistic effect in inhibiting CH4 emission. In study 1, software and online tools such as MS-DIAl, MS-FINDER, and the mass bank database were used to identify the MIF 4.44_609.1462 and MIF 4.53_433.1112, and the two MIFs were tentatively named as Hesperidin and Isovitexin, respectively (Figure 1). In study 2, the Moringa plant extracts from A3 and A11 were mixed in the following proportion A3100:A110, A380:A1120, A360:A1140, A350:A1150, A340:A1160, A320:A1180, and A30:A11100 proportions (A3:A11), and applied at a rate 50 mg/kg DM of Eragrostis curvula hay incubated in an Incoshake incubator to determine their effect on in vitro gas production and CH4, and in vitro organic matter digestibility (IVOMD) of the hay. In each incubation run, the sole or a mixture of the Moringa plant extract treatments were added to the test feed and incubated in 125 mL serum bottles with four replications per treatment, and the incubation was repeated for three runs. A Chi–square (☐2) test were used to determine the presence of an associative effect for mixtures combined at different proportion. Generally, the mixture resulted in less (P < 0.05) CH4 volume, slightly improved or no effect on IVOMD, propionate concentration decreased acetate while increasing propionate concentration, with higher CH4 inhibition, and % CH4 inhibition was significantly greater when the two accessions were mixed in 50% proportion (Figure 2). Specifically, associative effects were recorded when the two accessions are mixed in 50% proportion in terms of greater CH4 inhibition, propionic acid concentration and total volatile fatty acid production (TVFA), as well as reduction in CH4 per unit TVFA and C2:C3 ratio (Table 1). Therefore a 50% binary cocktail of M. oleifera accession A3 and A11 (A350:A1150) plant extracts can be used as feed additive for CH4 inhibition without affecting the feed fermentation adversely when compared with the sole accession leaf extracts or other proportions of binary cocktails. Detailed mechanisms of action, however, need to be confirmed.

48 Dietary functional fiber properties for improved health and disease outcomes in pigs

Abstract In swine production, using feed antibiotics as antimicrobial growth promotants has been reduced; thus, feed alternatives to manage gut health are required. Dietary fiber and similar carbohydrate structures such as resistant starch, oligosaccharides, and exopolysaccharides are nutritional tools that may enhance gut health in pigs. Dietary fiber may have a role to alleviate diarrheal diseases including in pigs post-weaning but can also reduce constipation in sows, but specific functionality depends on fiber properties. Antibiotics are hypothesized to influence gut health via modulation of intestinal microbial profiles; fermentation and intestinal inflammation are considered important mechanisms. Dietary fiber sources differ in a key functional property: fermentability. Rapid fermentation of fiber and oligosaccharides is associated with changes in microbial profiles and increased metabolite production. Recently, microbial composition was hypothesized to be less important and combined output of metabolites should be the focus. Fiber properties may also manipulate retention time and physico-chemical properties of the undigested residue; hence, non-fermentable fiber may prevent constipation in sows. The fiber-like structure resistant starch is not digested and acts as fermentable fiber but has unique properties, because it specifically increases intestinal abundance of bifidobacteria, which are associated with improved gut health. Using crop breeding, feed processing, and feed additives, the structure of fiber and starch can be altered thereby changing its degradation kinetics and affecting its prebiotic activity. Finally, fiber-like structures such as exopolysaccharides from Limosilactobacillus reuteri and unique oligosaccharides may serve as receptor analogues for pathogenic bacteria, e.g., enterotoxigenic Escherichia coli (ETEC). These receptor analogues block lectin domains of bacterial adhesins and thus prevent adherence of pathogens to the gut wall, thereby avoiding initiation of post-weaning diarrhea. In conclusion, dietary fiber and similar structures possess important functional properties that may also provide important solutions to maintain gut health in pigs.

489 Antibiotic Resistance of cecal Escherichia coli isolates from Lohmann LSL lite pullets and laying hens fed omega-3 fatty acids or yeast bioactives, reared at different spacing allowance

Abstract Poultry diets provide components that alter gut microbiota composition. We investigated antimicrobial resistance (AMR) phenotypes of E. coli isolates from ceca digesta of pullets and hens reared at different spacing allowance (SA) and dietary source of omega-3 fatty acids (N-3 FA) and yeast bioactives (YB) from placement to 17 wk of age (woa). A total of 2,632-day old chicks were placed in cages at two SA (24 cages each): High SA (HSA, 348 cm2/bird; ~50 birds/cage) and Low SA (LSA, 284 cm2/bird; ~68 birds/cage). Birds were fed corn and soybean-based diets (C), C + 3% co-extruded full fat flaxseed and pulse mixture (N-3 FA) and C + 0.05% YB processed with β-1,3-glucan hydrolase. At 4, 16 and 35 woa, ceca samples were collected to isolate E. coli using Chromocult agar. Their susceptibility to 14 antibiotics were determined by automated Sensititre system according to CLSI and CIPARS guidelines to determine their antimicrobial susceptibility profile. Number of antibiotics resistant E. coli isolates were analyzed using general linear mixed model procedure of SAS with diets, SA, sampling age and associated interactions as fixed factors. Cochran-Mantel-Haenszel test was used to determine the relationship between these treatments, and differences between treatments were considered significant at P < 0.05. Out of 428 presumptive E. coli isolated, 153 of 428 isolates (35.7%) were resistant to one antimicrobial class but no resistance against ciprofloxacin, azithromycin and nalidixic acid were detected. The prevalence of antimicrobial resistant E. coli decreased as the birds aged from wk 4–35 (P < 0.05). At wk 4 (P = 0.002) and 16 (P = 0.011), the least prevalence of ampicillin (AMP) resistance was in ceca digesta from N-3 FA-fed birds. At 35 woa, no AMP and cefoxitin (FOX) resistance were detected in birds fed YB (Table 2). At 16 woa, the prevalence of streptomycin resistance was greater in N-3 FA-fed than in YB-fed birds (P = 0.02), which was less than control-fed birds. Of the 428 isolates, 59 (13.8%) were resistant to more than two antimicrobial classes, with most from TIO-FOX-AMP-TET and STR-SULF-TET. At wk-4, SA had a significant effect on multiple resistance spectrum with LSA having the lowest MDR E. coli (P = 0.02) mainly from N-3 FA-fed pullets. This study showed an overall low AMR prevalence which decreases with age of the bird. This study is the first to report that feed additives (N-3 FA or YB) influence the AMR profile of cecal E. coli in pullets and layers. Prevalence of AMP resistance was least in N-3 FA-fed birds, whereas least STEP- and SULF resistance was observed in YB-fed birds. Our next study would help understand the molecular and evolutionary aspect of this resistant E. coli and their potential to cause colibacillosis.

464 Awardee Talk: Gastrointestinal tract physiology in young pigs

Abstract It is indeed a great privilege to have been awarded the 2024 American Feed Industry Association Award in Nonruminant Nutrition Research. I am honored to follow in the footsteps of many great non-ruminant nutritionists in the industry. I commenced my career in the pork industry with a PhD in digestive nutritional physiology focusing on the newly weaned piglet that, some 35 yr later, is still the subject of significant interest amongst researchers, veterinarians and practitioners, and producers alike. My research was amongst the first to demonstrate direct relationships between voluntary feed intake after weaning and structure and function of the small intestine, corresponding to production consequences. To circumvent intestinal tract disturbances after weaning, antibiotic growth promotors (AGPs)/prophylactic levels of antibiotics and mineral compounds (e.g., ZnO) were routinely included in diets. With the withdrawal of AGPs and in some jurisdictions, in-feed medications and ZnO, the commercial importance of maximizing feed intake in the post-weaning period, with appropriate inclusion of fiber and selected feed additives, has become even more apparent. Some of the more recent work I have been involved in, still involving the gastrointestinal tract, has explored the interrelationships as to why progeny born to first-litter sows perform worse than progeny born to multiparous sows. This is a global issue for the pork industry, especially in view of increasing litter size, yet remains one that has been relatively underexplored. A series of Australian studies using primiparous and multiparous sows, and their progeny conducted on commercial farms confirmed these findings, and reported some significant physiological, immunological, and anatomical differences between piglets born to different parity mothers. Piglets born to first-litter sows are born and weaned lighter than their counterparts born to older sows, suggesting they suffer poorer acquisition of maternal immunity and delays in intestinal tract development and skeletal muscle both in utero and soon after birth, and around weaning. Piglets born to first-litter sows enter weaning with reduced intestinal tract integrity and show some signs of reduced immunocompetence, which taken together, may impede their ability to cope with the stressors of weaning. Weaned piglets are typically treated collectively and are not managed by parity, but lifelong consequences of being born to a first-litter sow suggests further work needs to be done in this field. Gastrointestinal tract structure and function in piglets, and indeed in all neonates, is intricately associated with ‘gut health’, which was a term not even in the lexicon of the pork industry when I began my career. It is pleasing to see that the study of the gastrointestinal tract continues today, stronger than ever, as advances in science and methodologies allow for greater introspection of this organ and its multi-directional influences on the biology of the pig.

Lemongrass essential oil in silage and as a feed additive has limited effect on animals feed intake and rumen fermentation

ABSTRACT This study aimed to evaluate the effects of lemongrass essential oil (LEO) addition during the ensiling and subsequent sheep feed intake, particle selection, in vitro rumen fermentation, total-tract apparent digestibility and nitrogen balance. Eight Dorper lambs 19.4±2.40 (mean±SD) kg of body weight were used in a trial using a 4 × 4 Latin Square design to evaluate: I. LEO addition during the whole-plant sorghum ensiling: 0 (EN−) and 4 (EN+) mL per kg of sorghum dry matter (DM); and II. LEO supply during the animals feeding: 0 (F−) and 1.6 (F+) mL per kg of diet DM. Treatments showed no effect on feed intake and particle size selection. Ensiling with LEO increased ammonia-N when LEO was not added during incubation. LEO addition during incubation decreased neutral detergent fibre (NDF) degradation when LEO was not added during the ensiling. In addition, LEO addition increased fermentation gas production and decreased digestibility. LEO addition in sheep feeding tended to decrease crude protein digestibility. Treatments did not affect nitrogen balance and the average daily gain. Thus, LEO supply during ensiling and sheep feeding does not affect feed intake, particle selection and nitrogen balance.

Probiotic Feed Additives Mitigate Odor Emission in Cattle Farms through Microbial Community Changes

Probiotic Feed Additives Mitigate Odor Emission in Cattle Farms through Microbial Community Changes

The bacterial and yeast microbiota in livestock forages in Hungary

BackgroundAlong bacteria, yeasts are common in forages and forage fermentations as spoilage microbes or as additives, yet few studies exist with species-level data on these fungi’s occurrence in feedstuff. Active dry yeast and other yeast-based products are also common feed additives in animal husbandry. Here, we aimed to characterize both fermented and non-fermented milking cow feedstuff samples from Hungary to assess their microbial diversity in the first such study from Central Europe.ResultsWe applied long-read bacterial metabarcoding to 10 fermented and 25 non-fermented types of samples to assess bacterial communities and their characteristics, surveyed culturable mold and yeast abundance, and identified culturable yeast species. Fermented forages showed the abundance of Aerococcaceae, Bacillaceae, Brucellaceae, Lactobacillaceae, Staphylococcaceae, and Thermoactinomycetaceae, non-fermented ones had Cyanothecaceae, Enterobacteriaceae, Erwiniaceae, Gomontiellaceae, Oxalobacteraceae, Rhodobiaceae, Rickettsiaceae, and Staphylococcaceae. Abundances of bacterial families showed mostly weak correlation with yeast CFU numbers, only Microcoleaceae (positive) and Enterococcaceae and Alcaligenaceae (negative correlation) showed moderate correlation. We identified 14 yeast species, most commonly Diutina rugosa, Pichia fermentans, P. kudriavzevii, and Wickerhahomyces anomalus. We recorded S. cerevisiae isolates only from animal feed mixes with added active dry yeast, while the species was completely absent from fermented forages. The S. cerevisiae isolates showed high genetic uniformity.ConclusionOur results show that both fermented and non-fermented forages harbor diverse bacterial microbiota, with higher alpha diversity in the latter. The bacterial microbiome had an overall weak correlation with yeast abundance, but yeasts were present in the majority of the samples, including four new records for forages as a habitat for yeasts. Yeasts in forages mostly represented common species including opportunistic pathogens, along with a single strain of Saccharomyces used as a feed mix additive.

Modulatory effects of Enteromorpha prolifera powder and its enzymatic hydrolysate on growth performance, antioxidant capacity, and non-specific immunity of Trachinotus ovatus

The excessive proliferation of the genus Enteromorpha serves as the primary catalyst for the occurrence of red tides. Nonetheless, this genus is abundant in sulfated polysaccharides, phenolic compounds, peptides, and alkaloids, which exhibit remarkable efficacy in antioxidation, anti-inflammation, and immune response modulation. Consequently, Enteromorpha-derived products hold promising application prospects as aquatic feed additives. The primary objective of this study was to evaluate the impact of E. prolifera powder (EPM) and its enzymatic hydrolysate (EPH) on the growth, antioxidant capacity, intestinal morphology, and immunity of juvenile Trachinotus ovatus. Four isonitrogenous and isolipidic diets were formulated with varying levels of Enteromorpha products: 0 % (Control), 0.1 % EPH (EPH0.1), 0.3 % EPH (EPH0.3), and 3 % EPM, and were administered to juvenile T. ovatus for eight weeks. The findings revealed that growth performance in the EPH0.3 and EPM groups surpassed that of the control group, concomitant with increased feed intake and elongated intestinal villi. Notably, Enteromorpha-derived products supplementation significantly bolstered the antioxidant capacity of T. ovatus through activation of the Nrf2-Keap1 signaling pathway, leading to elevations in antioxidant enzymes such as SOD and CAT, as well as T-AOC. Conversely, MDA levels were conspicuously reduced in the Enteromorpha-treated groups. Moreover, Enteromorpha-derived products supplementation exhibited pronounced anti-inflammatory effects, marked by the downregulation of proinflammatory cytokine expression and upregulation of anti-inflammatory cytokines, along with decreased apoptotic gene expression. These observations highlight the potential anti-inflammatory properties of EPM and EPH, which may contribute to the preservation of hepatic tissue health and homeostasis. In summary, the optimal growth performance and antioxidant capacity were achieved with 0.3 % EPH supplementation, indicating the efficacy of this concentration in promoting the overall wellbeing of T. ovatus. Remarkably, the employment of processing methodologies, notably enzymatic hydrolysis, has not only facilitated the manifestation but also potentially augmented the inherent beneficial attributes traditionally ascribed to EPM. Furthermore, this refinement process has enabled a reduction in the inclusion rate of EPM within feed formulations, thereby enhancing cost-effectiveness. Consequently, Enteromorpha-derived products emerge as highly promising candidates for aquatic feed additives, with the potential to mitigate the economic burdens imposed by red tide management strategies. Their utilization represents a strategic approach towards sustainable aquaculture practices.

Unlocking the potential: Cinnamomum cassia (L.) D. Don aqueous extracts as natural defenders against MSRV in largemouth bass aquaculture

Aquatic viral diseases pose significant threats to aquaculture, necessitating the exploration of effective preventive measures. In this study, we evaluated the antiviral potential of Cinnamomum cassia (L.) D. Don (CCD) aqueous extracts against Micropterus salmoides rhabdovirus (MSRV) in largemouth bass aquaculture. Initially, twelve plant extracts were screened for antiviral activity against MSRV, revealing that CCD extracts at 100 mg/L concentration significantly inhibited MSRV proliferation in vitro. Further dose-response analysis revealed a concentration-dependent antiviral effect of CCD extracts, with higher concentrations demonstrating increased efficacy against MSRV. Subsequent investigations focused on the protective effects of CCD extracts on MSRV-infected cells. At a concentration of 63 mg/L, CCD extracts significantly reduced MSRV titers, preventing the onset of cytopathic effects (CPE) in cells. Fluorescence and transmission electron microscopy further illustrated the protective effects of CCD extracts on cellular morphology. MSRV-infected cells treated with CCD exhibited preserved cell morphology akin to normal cells, contrasting with the typical apoptotic features observed in untreated infected cells. Additionally, dietary supplementation of CCD extracts in largemouth bass demonstrated notable benefits. Fish fed with CCD extracts exhibited increased survival rates when infected with MSRV, with a 26 % higher survival rate compared to the virus-only group. Furthermore, CCD supplementation enhanced the expression of interferon-gamma (IFNγ), indicating improved immune responses in largemouth bass. Moreover, immersion of CCD extracts in water showed partial inhibition of horizontal MSRV transmission, effectively reducing viral spread and mitigating disease risks in fish populations. These findings highlight the potential of CCD aqueous extracts as feed additives for combating MSRV in aquaculture, showcasing their promising application prospects in disease prevention and control strategies.

Mycotoxins in Fish Production and Impact on Fish Health

The aim of this review is to provide an assessment of mycotoxin contamination in fish feed. Focusing on major mycotoxins including aflatoxins, fumonisins, ochratoxins, trichothecenes, and zearalenone, the paper explores their diverse impacts on fish health, from growth inhibition to immunosuppression. It meticulously examines the sources of mycotoxin contamination in fish feed, addressing raw ingredients, storage conditions, and feed manufacturing processes. The review emphasizes the critical role of adherence to Good Agricultural Practices (GAP) and Good Manufacturing Practices (GMP) in preventing mycotoxin risks. Additionally, the paper elucidates mitigation strategies, encompassing the use of mycotoxin-binding feed additives, feed formulation optimization, and technological advancements for early detection. This comprehensive overview serves as a valuable resource for aquaculture practitioners, researchers, and policymakers aiming to enhance the safety and sustainability of fish production amidst mycotoxin challenges.

Feed additives supplementation: a potential strategy to ameliorate heat stress in sheep

Abstract Given a significant climate-flexible and socio-economic role in developing nations, environmental heat stress imposes a major financial impact on sheep production systems globally endangering their production, reproduction, and growth. In this regard, the adverse effects of heat stress on sheep production systems have to be addressed through adoption of effective heat alleviation measures like animal management, nutritional management and genetic interventions of which the nutritional interventions seems to be the most cost effective way to alleviate heat stress. Nutritional manipulation for heat stress alleviation in sheep involves the use of antioxidant supplements (Vitamin B; Vitamin E and Selenium; Selenium; Zinc sulphate and folic acid; Vitamin C, Vitamin E, Selenium and Zinc; Naringin; Opuntia ficus-indica f. inermis; Açai oil and Brown seaweed like Ascophyllum nodosum and Sargassum latifolium). Further, electrolyte supplements (Dietary Electrolyte Balance (DEB); Sodium bicarbonate and potassium bicarbonate; Sodium hydroxide) have a beneficial effect on thermal responses, respiratory activities, gas exchange parameters, rumen fermentation, blood buffering capacity and acid-base balance. The mineral mixture supplements (Mineral blocks; Mineral mixture and antioxidants; Chromium; Zinc) play a crucial role in increasing the efficiency of antioxidant defence system, immunity-related parameters, production, reproduction, feed digestibility and insulin sensitivity. Probiotic supplements (Lactobacillus acidophilus, Saccharomyces cervisiae, Propionibacterium freudenreichii, Lactobacillus casei, Enterococcus faecium, Lactobacillus lactis, Bacillus subtilis, Propionibacterium freudenreichii, Pediococcus cerevisiae, Megaspha eraelsdenii, Bacillus licheniformis, Aspergillus oryzae, Schizochytrium limacinum, Trichoderma reesei and Saccharomyces cerevisiae) improve lactational performance, dietary energy utilization and productivity. The probiotics (live Saccharomyces cerevisiae) and prebiotics (mannan oligosaccharide plus b-glucans) used in heat stress alleviation improve dietary energy utilisation. Furthermore, the vital role of herbal supplements (Rosemary, Cinnamon, Turmeric, Clove, Naringin, Chestnut tannins, Giloy stem powder, Curcumin, Rocket oil (watercress oil), Flaxseed, Cornus, Oregano, Thyme, Chamomile flowers, Moringa oleifera, Betaine) has been highlighted to promote feed intake, antioxidant status, growth performance, feed utilization, reproductive performance and immune response. Effective adoption of nutritional strategies can thus ensure sustainable sheep production in this changing climate scenario.