Direct-fed Microbials Research Articles

PSIX-6 Ruminal Tissue Morphology of Beef Yearling Steers Offered Finishing Diets with Direct fed Microbial Mixtures

Abstract The effects of the dietary inclusion of live bacteria mixtures on feedlot beef cattle ruminal papillae morphology were evaluated. Crossbred-Angus yearling steers (n = 192; initial BW = 409 kg ± 8 kg) were blocked by body weight (BW) and randomly assigned into 48 pens (4 steers/pen; 16 pens/treatment) following a randomized complete block design. A steam-flaked corn-based fishing diet was offered ad libitum once daily during 153 d containing the following treatments: 1) Control, in which no direct-fed microbial (DFM) was offered (lactose as carrier only); 2 and 3) Probiotic mixtures at distinct concentrations [Mixture A and B, at 2g/animal-daily (lactose used as carrier)]. Upon harvest at a federally inspected slaughter facility, epithelium samples were collected from the cranial sac of the rumen, immersed in a 70% alcohol, and preserved under refrigeration (5°C). Ruminal tissue fragments were trimmed (1cm2), in which papillae were completely counted within the fragment, followed by the removal of 12 random individual papillae for further area measurement using electronic scanning (ImageJ). Data were analyzed using the GLIMMIX procedure of SAS and pen was considered the experimental unit with the fixed effect of treatment and the random effect of block. Regardless of treatments, average papillae area in cm2 (P = 0.39; control: 0.38, DFM mixture-A: 0.40, DFM mixture-B: 0.37), papillae number within fragment (P = 0.70; control: 47, DFM mixture-A: 52, DFM mixture-B: 49), absorptive surface area in cm2/fragment cm2 (P = 0.87; control: 37, DFM mixture-A: 39, DFM mixture-B: 38), and ruminal absorptive surface area (P = 0.74; control: 97%, DFM mixture-A: 97%, DFM mixture-B: 97%) were not affected compared with control. The addition of DFM mixtures did not seem to affect ruminal papillae physical aspect, although the long-term effects of dietary inclusion of live bacteria on ruminal morphology needs to be further evaluated.

PSVIII-11 In Vitro Incubation with a Bacillus-Based Direct-fed Microbial Improves Starch Digestibility

Abstract Besides being well-recognized as a probiotic to human and livestock species, Bacillus spp. are also able to secrete a wide range of enzymes that improve carbohydrate, protein, and lipid digestibility, which in turn, will lead to greater milk yield and growth performance in dairy and beef cattle, respectively. Hence, we hypothesized that the incubation of a Bacillus-based direct-fed microbials (DFM) solution would improve in vitro starch digestibility (IVSD) in different concentrates (two barley sources, corn, sorghum, and wheat; starch content = 41.1 to 72.5% DM). Therefore, our objective was to evaluate the effects of incubating a Bacillus-based DFM on IVSD of these concentrates over a 12-h period. Concentrates were incubated, in triplicates, into the media containing (DFM) or not (CON) the DFM (Bacillus licheniformis and B. subtilis; 3.2 × 109 CFU/g; Bovacillus, Chr. Hansen A/S, Horsholm, Denmark) over a 12-h period, whereas IVSD was evaluated at 6- and 12-h post-DFM incubation. Ruminal IVSD on dried 1-mm screen ground samples was determined using procedures previously described and validated. All data were analyzed using SAS. Incubation of a Bacillus-based DFM increased mean IVSD in all samples (P ≤ 0.01) analyzed herein, with the greatest overall improvement observed in low-density barley (18.2%) and sorghum (13.6%). Treatment × hour interactions were observed in 3 out 5 concentrates (P ≤ 0.001). In general, incubation with a DFM improved 6-h IVSD (P ≤ 0.02), ranging from 6.7 (wheat) to 67.8% (low-density barley), whereas 12-h IVSD was also greater in wheat inoculated with DFM (14.9% increase vs. CON; P < 0.0001). In summary, incubation of a Bacillus-based DFM improved in vitro starch digestibility in 5 out 6 concentrate sources, with most of the improvements within 6-h. These results highlight the ability of Bacillus spp. in releasing enzymes that degrade carbohydrates, likely benefiting production parameters of livestock.

339 Growth Performance and Carcass Characteristics of Feedlot Beef Yearling Steers Offered Finishing Diets with Direct fed Microbial Mixtures

Abstract The effects of dietary inclusion of live bacteria on feedlot beef cattle growth performance and carcass characteristics were evaluated. Crossbred-Angus yearling steers (n = 192; initial BW = 409 kg ± 8 kg) were blocked by body weight (BW) and randomly assigned into 48 pens (4 steers/pen; 16 pens/treatment) following a randomized complete block design. A steam-flaked corn-based fishing diet was offered ad libitum once daily containing the following treatments: 1) Control, in which no direct fed microbial (DFM) was offered (lactose as carrier only); 2 and 3) Probiotic mixtures at distinct concentrations [Mixture A and B, at 2g/animal-daily (lactose used as carrier)]. Orts DM were quantified daily and subtracted from total dietary DM offered to calculate DM intake. Two-day consecutive unshrunk BW were recorded before feeding on d 0, 30, 60, 90, 121, and 153 (prior to shipment to a federally inspected slaughter facility). Data were analyzed using the GLIMMIX procedure of SAS and pen was considered the experimental unit, in which F-test protected pre-planned contrasts comparing control versus DFM mixture-A and control versus DFM mixture-B were used. Steers offered mixture-A increased carcass-adjusted ADG (P = 0.03) by 6.7%, gain efficiency (P < 0.01) by 6%, tended to increase carcass-adjusted final BW (P = 0.07) by 15kg and hot carcass weight (P = 0.07) by 10kg. The overall (d 0 to end) DM intake (P = 0.36) was not affected by treatment; however, a subtle (1.2%) decrease (P < 0.01) during the initial 30 days for steers offered DFM mixture-B was observed. Carcass variables (dressing percentage, 12th rib fat, longissimus muscle area, marbling, yield grade, and liver scores) were not affected (P ≥ 0.13) by treatments. Growth performance was improved with DFM mixture-A which seemed to positively affect carcass weight without inducing deleterious effects on other carcass characteristics.

353 Neonatal Holstein Calves fed a Pelleted Calf Starter Containing a Botanical Extract and Direct-fed Microbial (DFM) Alone or in Combination without or with Milk Replacer DFM

Abstract Botanical extracts (BE; Adisseo North America, Altanta, GA) are known to enhance dry matter intake (DMI) and gut health, while direct-fed microbials (DFM), such as a actobacillus acidophilus fermentation product (RC: RumaCell DF 5G; Pacer Technology, Inc., Murtaugh, ID), had shown improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance. Eighty 2- to 5-d old Holstein bull calves were blocked by body weight (BW) and randomly assigned to one of 8 treatments arranged in a 2 x 4 factorial using a randomized complete block design. Main factors were 2 milk replacers (MR) without (Control) and with RC added at 5 g/d fed with calf starter (CS) main effect of 4 experimental CS being: 1) Control: no additives; or 2) BE added at 496 mg/kg to the calf starter (CS); 3) RC added to the CS at 2.50 g/kg; and 4) BE&RC: same BE and RC rates to CS. The CS was a 25% crude protein dry matter basis with the MR being a 22:20 (CP:fat) fed 2x/day at 0630 and 1800 h along with free choice water. Weaning occurred after d 42 for the 56-d experiment. No significant (P > 0.10) MR by CS interactions were detected for BW, BW gain, CS intake, total DMI, or feed conversion parameters. The BW gain (38.0 and 39.3 kg for Control and RC, respectively) for MR main effect was similar (P > 0.10) for calves fed both MR, while CS main effect (38.7, 39.7, 39.2, and 37.2 kg for Control, BE, RC, and BE&RC, respectively) were similar (P > 0.10) among all CS. This study demonstrated little calf growth performance and health benefits when feeding an BE and/or RC alone or in combination compared with calves fed Control.

PSVIII-10 In Vitro Incubation with a Bacillus-Based Direct-fed Microbial Improves Forage Digestibility Parameters

Abstract Over the years, the use of direct-fed microbials (DFM) has been gaining attention and interest by beef cattle producers and nutritionists, due to health benefits associated with these solutions. Moreover, some bacterial strains currently fed to cattle are also capable of producing and releasing enzymes that might improve nutrient utilization in beef animals. Hence, we hypothesized that the incubation of a Bacillus-based DFM would improve in vitro dry matter (DM) and neutral detergent fiber (NDF) digestibility of ten forage sources (spinifex, buffel grass, Flinders grass, Queensland bluegrass, corn silage, lucerne hay, ryegrass, rhodes grass hay, leucaena, and Mitchell grass hay). Our objective was to evaluate the effects of incubating a Bacillus-based DFM on in vitro forage digestibility. Forage sources were incubated, in triplicate, into the media containing or not Bacillus-based DFM (Bacillus licheniformis and B. subtilis; 3.2 × 109 CFU/g; Bovacillus, Chr. Hansen A/S, Horsholm, Denmark) over a 48-h period. The DAISY-II fermentation technique was used with the buffer and nutrient solution described by Goering and Van Soest (1970). The DFM was added to the rumen fluid of treatment groups to simulate the dose of 3 g/animal per day and filter bags were used to isolate 0.5 g of ground forage samples. All data were analyzed using SAS. Inoculation of a Bacillus-based DFM increased overall mean in vitro DM digestibility in 8 out of 10 forage sources with improvements ranging from 6. 1 to 27.3% (P ≤ 0.01). Similarly, mean in vitro NDF digestibility was improved in 8 out of 10 forage types (P ≤ 0.01). In summary, incubation of a Bacillus-based DFM improved in vitro DM and NDF digestibility in forage sources of varying nutritional profile, demonstrating its feasibility to be used in forage-based beef systems.

PSVII-17 Feeding Behavior of Beef Feedlot Yearling Steers Offered Finishing Diets with Direct fed Microbial Mixtures

Abstract The effects of dietary inclusion of live bacteria mixtures on feedlot beef cattle feeding behavior were evaluated. Crossbred-Angus yearling steers (n = 192; initial BW = 409 kg ± 8 kg) were blocked by body weight (BW) and randomly assigned into 48 pens (4 steers/pen; 16 pens/treatment) following a randomized complete block design. A steam-flaked corn-based fishing diet was offered ad libitum once daily containing the following treatments: 1) Control, in which no direct fed microbial (DFM) was offered (lactose as carrier only); 2 and 3) Probiotic mixtures at distinct concentrations [Mixture A and B, at 2g/animal-daily (lactose used as carrier)]. Orts DM were quantified daily and subtracted from total dietary DM offered to calculate DM intake. Feeding behavior activities (continuous 24 h) were visually assessed (d 106 and 113) by trained personnel, where time spent on each activity was recorded every 5 min. Data were analyzed using the GLIMMIX procedures of SAS and pen was considered the experimental unit. No treatment × period interactions (P ≥ 0.21) were observed. Main feeding behavior variables consisting of time spent ruminating, chewing, eating, and drinking in minutes per day were not affected (P ≥ 0.17) by treatments, while steers in general ruminated, ate, chewed, and were more active (P ≤ 0.01) during the second behavioral assessment, regardless of treatments. Rates of intake in minutes per kg of DM, OM, fiber and digestible DM, OM, and fiber were not affected (P ≥ 0.12) by treatments; however more time spent (P < 0.01) ruminating, eating, and chewing in minutes per kg were observed on d113 compared to d106 regardless of treatments. Drinking time (min/d) and drinking rates (min/kg) were not affected (P ≥ 0.81) by period. The DFM mixtures did not negatively affect feeding behavior of yearling steers consuming steam-flaked corn-based finishing diets.

PSVIII-18 Nutrient Digestibility of Feedlot Beef Yearling Steers Offered Finishing Diets with Direct fed Microbial Mixtures

Abstract The effects of dietary inclusion of live bacteria on feedlot beef cattle apparent total tract nutrient digestibility were evaluated. Crossbred-Angus yearling steers (n = 192; initial BW = 409 kg ± 8 kg) were blocked by body weight (BW) and randomly assigned into 48 pens (4 steers/pen; 16 pens/treatment) following a randomized complete block design. A steam-flaked corn-based fishing diet was offered ad libitum once daily containing the following treatments: 1) Control, in which no direct fed microbial (DFM) was offered (lactose as carrier only); 2 and 3) Probiotic mixtures at distinct concentrations [Mixture A and B, at 2g/animal-daily (lactose used as carrier)]. Orts DM were quantified (if any) daily and subtracted from total dietary DM offered to calculate DM intake. Fecal samples were collected twice daily (0700 and 1700 h) for 5 consecutive days (d 68 to 72) from at least 3 steers per pen, while feed samples were collected daily. Samples were composited within period, dehydrated (55°C), and ground (1mm) for further analyses. Total fecal output was estimated with a dietary internal marker (288-h indigestible NDF) and used to calculate nutrient digestibility. Data were analyzed using the GLIMMIX procedure of SAS and pen was considered the experimental unit. Intakes of DM, OM, NDF, and ADF during the digestibility assessment were not affected (P ≥ 0.13) by treatments. Steers offered DFM mixture-A tended to increase digestibility of DM (P = 0.07; 79.3 vs. 77.1%), NDF (P = 0.10; 56.9 vs. 51.6%), and hemicellulose (P = 0.08; 59.4 vs. 53.9%) compared with control, while digestibility of ADF was not affected (P = 0.24) by treatment. The DFM mixture-A seemed to positively affect apparent digestibility of nutrients in steers consuming a steam-flaked corn-based finishing diet, in which improvements in the fiber fraction digestion seemed to be a meaningful contributor.

356 Neonatal Holstein Calves fed a Pelleted Calf Starter Containing a Botanical Extract and Direct fed Microbial Alone or in Combination

Abstract Botanical extracts (BE; Adisseo North America, Altanta, GA) are known to enhance dry matter intake (DMI) and gut health, while direct-fed microbials (DFM), such as a Lactobacillus acidophilus fermentation product (RC: RumaCell DF 5G; Pacer Technology, Inc., Murtaugh, ID), had shown improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance. Eighty 2- to 5-day old Holstein bull calves were blocked by body weight (BW) and randomly assigned to 1 of 4 treatments in a randomized complete block design. Treatments were: 1) Control: no additives; or 2) BE added at 496 mg/kg to the calf starter (CS); 3) RC added to the CS at 2.50 g/kg with RC added to the milk replacer (MR) at 5 g/d; and 4) BE&RC: BE and RC added to CS at same rates and added RC to MR. The CS was a 25% crude protein dry matter basis and MR was a 22:20 (CP:fat) fed 2x/d at 0630 and 1800 h along with free choice water. Weaning occurred after d 49 for the 70 d experiment. Calves fed RC demonstrated greater (P < 0.05) BW gain compared with calves fed BE&RC with calves fed Control and BE being intermediate and similar (63.9, 63.5, 65.0, and 59.7 kg for Control, BE, RC, and BE&RC, respectively). Total experiment DMI (MR+CS) was less (P < 0.05) for calves fed BE&RC than calves fed the remaining treatments (116.5, 114.2, 116.4, and 104.9 kg). Total experiment BW gain/DMI was greater (P < 0.05) for calves fed BE&RC compared with calves fed Control with calves fed BE and RC being intermediate and similar (0.55, 0.56, 0.56, and 0.57 kg/kg). This experiment demonstrated that specific BE should not be fed in combination with specific DFM.

PSVII-3 Effects of Feeding Direct-fed Microbials on Digestibility and Rumen Fermentation Characteristics of Finishing Bos Indicus Cattle

Abstract Direct feed microbials (DFM) are probiotics often fed to feedlot to cattle offered to improve rumen fermentation and/or intestinal health, thus benefiting animal health and performance. We hypothesized that DFM supplementation would improve nutrient digestibility and rumen fermentation in finishing Bos indicus cattle. On day -1, 30 rumen-cannulated Nellore bulls were blocked based on initial body weight (BW; 350 ± 35.0 kg) in 1 of 30 pens and, within each block, animals were randomly assigned to: (1) Control: corn-based diet without DFM (n = 10), (2) EFSC: CONT + 1 gram/head per day of a DFM based on Enterococcus faecium and Saccharomyces cerevisiae (Probios Precise, Chr. Hansen A/S, Horsholm, Denmark; n = 10), and (3) BLBS: CONT + 2 grams/head per day of a DFM based on Bacillus licheniformis and Bacillus subtilis (Bovacillus, Chr. Hansen A/S; n = 10). The experimental period lasted 35 days, while between days 30 to 33, total fecal collection was performed and on days 34 and 35, feces and rumen fluid were collected at 0, 3, 6, 9, 12, 15, 18, and 21 h post-feeding for ammonia, VFA, and pH determination. All data were analyzed as orthogonal contrasts using SAS: (1) DFM vs. CONT and (2) EFSC vs. BLBS. Inclusion or type of DFM did not affect either nutrient digestibility or ruminal fermentation parameters (P ≥ 0.40). In contrast, DFM supplementation, regardless of type, yielded a reduced mean ammonia concentration (14.7 vs. 15.7 mg/L; P = 0.05). Moreover, ammonia concentrations were decreased in EFSC at 3 and 6 h post-feeding vs. CONT (P ≤ 0.04), but also less for BSBL vs. CONT at 6 h (P < 0.01). In summary, DFM supplementation, regardless of type, reduced proteolysis, with no effect on other parameters of rumen fermentation in Bos indicus bulls fed a finishing diet.

The effect of supplementing CLOSTAT 500 (Bacillus subtilis PB6) to yearling steers in a commercial feedyard on health, Salmonella spp. prevalence, feedlot growth performance and carcass characteristics.

British and British × Continental crossbred beef steers, n = 2,100; 313 ± 38 kg of initial body weight (BW) were used to evaluate the effects of Bacillus subtilis PB6 supplementation to yearling steers in a commercial feedyard on health, prevalence of Salmonella spp., growth performance, and carcass characteristics. Steers were blocked by arrival date and assigned randomly to pens within the block; pens were randomly assigned to 1 of 2 dietary treatments within block. Treatments, replicated in 15 pens/treatment with 70 steers/pen, included: 1) control (CON), diets containing no supplemental direct-fed microbials; 2) CLOSTAT (CLO), diets supplemented with 0.5 g/steer/d Bacillus subtilis PB6 (CLOSTAT 500, Kemin Industries, Des Moines, IA) to provide 6.6 × 109 CFU/g of the active ingredient. Supplementing CLO decreased the overall incidence of morbidity (P = 0.03), 10.38% (CLO) vs. 13.43% (CON), decreased the percentage of steers treated once for bovine respiratory disease (BRD; P < 0.01), 9.14% (CLO) vs. 12.76% (CON), and decreased the incidence of BRD retreatment (P = 0.03) compared with CON. Mortality did not differ among treatments (P = 0.23); however, overall deads and removals tended to be less for CLO than CON (53 heads vs. 73 heads respectively, P = 0.06). Prevalence of fecal Salmonella did not differ among treatments, (P ≥ 0.35); overall fecal Salmonella counts tended to be less for CLO (1.59 log (10) CFU/g) than CON (2.04 log (10) CFU/g; P = 0.07). Salmonella concentration in subiliac lymph nodes (n =150/treatment) was not different (P = 0.62) between CON (0.22 log (10) CFU/g) or CLO (0.19 log (10) CFU/g); however, there was a 46% reduction in the overall mean prevalence of lymph node Salmonella (P = 0.46; 15.48% vs. 28.66%) for CLO and CON, respectively. With deads and removals included, final BW was heavier for CLO steers than CON, (654 kg vs. 641 kg, respectively, P = 0.05), and average daily gain (ADG; P = 0.08) and gain efficiency (G:F; P = 0.06) tended to be greater for CLO than CON. With deads and removals excluded, final BW, ADG, and G:F did not differ among treatments (P ≥ 0.30). Carcass traits were not different between treatments (P ≥ 0.15). Supplementing CLO throughout the feeding period in a commercial feedyard improved the health outcomes of yearling steers by decreasing BRD and overall treatment rates, reducing the overall abundance of Salmonella, and resulting in fewer steers removed from the study compared with CON.

An Evaluation of Nutritional and Therapeutic Factors Affecting Pre-Weaned Calf Health and Welfare, and Direct-Fed Microbials as a Potential Alternative for Promoting Performance—A Review

The priority for calf rearing has been to maintain good health and welfare in order to promote and sustain future production. However, there have been numerous reports of undesirable levels of morbidity and mortality amongst pre-weaned calves. This may be mitigated or exacerbated by nutritional management practices. Some areas of concern include colostrum feeding, utilization of waste milk, and restrictive milk feeding regimes. Antibiotics may be prescribed at lethal or sub-inhibitory doses to treat or prevent disease. However, extensive antibiotic use may disrupt the gastrointestinal microbiota and aid in expanding the antibiotic resistant gene pool. In an attempt to reduce the use of antibiotics, there is a demand to find alternative performance enhancers. Direct-fed microbials, also known as probiotics, may comply with this role. A DFM consists of live microorganisms that are biologically active and able to confer health benefits onto the host. Lactic acid bacteria have been the most frequently investigated; however, this field of research has expanded to include spore-forming bacteria and live yeast preparations. This review aims to provide a comprehensive evaluation of the nutritional management strategies that may increase a calf’s susceptibility to morbidity and mortality, the efficacy and sustainability of antibiotics as a tool for managing calf health and welfare, and the potential for DFMs as a supportive strategy for promoting calf wellbeing.

The effect of benzoic acid with or without a direct-fed microbial on the nutrient metabolism and gas emissions of growing pigs.

Twenty-four gilts (PIC 337 × 1050, PIC Genus, Hendersonville, TN) with an initial body weight (BW) of 33.09 ± 1.33 kg were used to investigate the effects of benzoic acid (BA) and a Bacillus-based direct-fed microbial (DFM) on the nutrient metabolism and manure gas emissions of growing pigs. Pigs were blocked by BW, placed into metabolism stalls, and randomly assigned to one of four dietary treatments: basal control (PC), low nitrogen (NC), PC plus 0.3% BA (PC+BA; VevoVitall, DSM Nutritional Products), and PC plus 0.3% BA and 0.025% DFM (PC+BA+DFM; PureGro, DSM Nutritional Products). Pigs were fed a common diet from day 0 to 14, and the experimental diets were fed in two phases (day 14 to 28 and day 28 to 53). The experiment consisted of four collection periods, with each period subdivided into two subperiods to collect samples for gas emissions and nutrient balance. Firstly, manure samples were collected for 72 h. Twice daily, urine and feces were weighed, and urine pH was measured. After each period, manure was subsampled and taken to the lab to measure gas emissions. Secondly, urine and feces were quantitatively collected for 96 h to allow for measurement of nutrient digestibility (ATTD) and retention. Data were analyzed as repeated measures in SAS 9.4 (SAS Inst., Cary, NC) with fixed effects of treatment, collection period, and block. Pig was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.05 < P ≤ 0.10. Pigs fed PC+BA had the greatest ADG compared to pigs fed NC (P = 0.016), with intermediate ADG for pigs fed PC or PC+BA+DFM (P ≥ 0.148). The ATTD of dry matter, gross energy, P, and N did not differ between treatments (P ≥ 0.093). However, the ATTD of Ca was reduced in pigs fed PC+BA+DFM compared to pigs fed PC+BA (P = 0.012). Pigs fed PC+BA or NC excreted less urinary N compared to PC and PC+BA+DFM (P ≤ 0.034), which contributed to greater nitrogen retention in PC+BA compared to PC (P = 0.016). Furthermore, decreased manure pH from pigs fed PC+BA or NC resulted in lower ammonia (NH3) emissions compared to pigs fed PC+BA+DFM or PC. There was no effect of dietary treatment on manure hydrogen sulfide, methane, or carbon dioxide emissions. In conclusion, supplementing 0.3% BA improved N retention and reduced manure pH and NH3 emissions, similar to feeding pigs low N, but improved the ADG of pigs when compared to feeding a low N diet.

Effects of Dietary Supplementation with Bacillus amyloliquefaciens US573 on Intestinal Morphology and Gut Microbiota of European Sea Bass.

Probiotics or direct-fed microbials (DFM) have proven strong potential for improving aquaculture sustainability. This study aims to evaluate the effects of dietary supplementation with the DFM Bacillus amyloliquefaciens US573 on growth performance, intestinal morphology, and gut microbiota (GM) of European sea bass. For this purpose, healthy fish were divided into two feeding trials in triplicate of 25 fish in each tank. The fish were fed with a control basal diet or a DFM-supplemented diet for 42days. Results showed that, while no significant effects on growth performance were observed, the length and abundance of villi were higher in the DFM-fed group. The benefic effects of DFM supplementation included also the absence of cysts formation and the increase in number of goblet cells playing essential role in immune response. Through DNA metabarcoding analysis of GM, 5 phyla and 14 major genera were identified. At day 42, the main microbiome changes in response to B. amyloliquefaciens US573 addition included the significant decrease in abundance of Actinobacteria phylum that perfectly correlates with a decrease in Nocardia genus representatives which represent serious threat in marine and freshwater fish. On the contrary, an obvious dominance of Betaproteobacteria associated with the abundance in Variovorax genus members, known for their ability to metabolize numerous substrates, was recorded. Interestingly, Firmicutes, particularly species affiliated to the genus Sporosarcina with recent promising probiotic potential, were identified as the most abundant. These results suggest that B. amyloliquefaciens US573 can be effectively recommended as health-promoting DFM in European sea bass farming.

Enterotoxigenic Escherichia coli infection of weaned pigs: Intestinal challenges and nutritional intervention to enhance disease resistance

Enterotoxigenic Escherichia coli (ETEC) infection induced post-weaning diarrhea is one of the leading causes of morbidity and mortality in newly weaned pigs and one of the significant drivers for antimicrobial use in swine production. ETEC attachment to the small intestine initiates ETEC colonization and infection. The secretion of enterotoxins further disrupts intestinal barrier function and induces intestinal inflammation in weaned pigs. ETEC infection can also aggravate the intestinal microbiota dysbiosis due to weaning stress and increase the susceptibility of weaned pigs to other enteric infectious diseases, which may result in diarrhea or sudden death. Therefore, the amount of antimicrobial drugs for medical treatment purposes in major food-producing animal species is still significant. The alternative practices that may help reduce the reliance on such antimicrobial drugs and address animal health requirements are needed. Nutritional intervention in order to enhance intestinal health and the overall performance of weaned pigs is one of the most powerful practices in the antibiotic-free production system. This review summarizes the utilization of several categories of feed additives or supplements, such as direct-fed microbials, prebiotics, phytochemicals, lysozyme, and micro minerals in newly weaned pigs. The current understanding of these candidates on intestinal health and disease resistance of pigs under ETEC infection are particularly discussed, which may inspire more research on the development of alternative practices to support food-producing animals.

Isolation of indigenous microorganisms from the liquid produced by the bioprocess of corn straw as direct fed microbials

Abstract. Tasripin DS, Yuniarti E, Mutaqin BK. 2022. Isolation of indigenous microorganisms from the liquid produced by the bioprocess of corn straw as direct fed microbials. Biodiversitas 23: 3452-3456. Digestion of ruminants is highly dependent on microbial activity of rumen. Rumen microbes are responsible for degrading food nutrients into simpler components that can be easily utilized by the body. In order to improve the rumen ecosystem, the Direct Fed Microbials (DFM) was added. The addition of DFM to feed can be in the form of a mixture of several beneficial microbes (such as from the group of bacteria, yeast, and fungi) for the body of livestock. This group of microorganisms can be obtained from the results of the bioprocess of bioprocessed materials such as corn straw. In order to obtain the right microorganisms to be used as DFM, it is necessary to isolate the results of the bioprocess. The analysis was carried out by purification of indigenous microorganisms from the bioprocess of corn straw. Microbial purification can be done by isolation of microbes on agar media such as Nutrient Agar, MRS, and PDA by incubation to obtain a single cell. The results showed that isolation of the liquid from the bioprocess of corn straw was obtained in the form of Coccus and Bacilli which included gram-positive bacteria which were found to be dominant after incubation and microbial staining.

Effects of a multi-strain Bacillus subtilis-based direct-fed microbial on immunity markers and intestinal morphology in diets fed to weanling pigs.

The objective of this experiment was to evaluate the effects of a multi-strain Bacillus subtilis-based direct-fed microbial (DFM) on nursery pig health as indicated by intestinal mucosal and blood plasma immunological markers and intestinal morphology. Eighty pigs, of equal number of barrows and gilts (initial BW: 7.0 ± 0.60 kg), weaned at 21 ± 1 d of age were randomly allotted to sixteen pens, with five pigs per pen. Two dietary treatments were implemented, a basal control (CON) and a basal control plus DFM (CDFM). Both diets were corn, soybean meal, and distillers dried grains based and were formulated to meet or exceed all nutritional requirements (NRC, 2012) and manufactured on site. Diets were fed for 42 d. On d 21 and 42 of the experiment, one pig per pen was randomly selected and euthanized, with equal number of males and females represented. Blood samples were collected prior to euthanasia for assessment of plasma concentrations of immunoglobulin A (IgA) and intestinal fatty acid binding protein. Segments of the gastrointestinal tract including duodenum, jejunum, ileum, ascending and distal colon were removed for analysis of intestinal morphology, and levels of interleukin 6, interleukin 10 (IL-10), and tumor necrosis factor alpha. Jejunal villus height was greater in the CDFM pigs as compared with CON pigs (P = 0.02) and ascending colon crypt depth tended to be greater on d 21 (P = 0.10). Compared to CON, CDFM significantly increased overall plasma IgA (P = 0.03) (0.58 vs. 0.73 0.05 mg/mL, respectively), while it tended to increase plasma IgA (P = 0.06) on d 21 (0.34 vs. 0.54 ± 0.07 mg/mL, respectively) and tended to increase overall IL-10 (P = 0.10) in the jejunum (113 vs. 195 ± 35 pg/mL, respectively). Addition of a multi-strain Bacillus subtilis-based DFM may have an early benefit to nursery pig health status, observed through specific changes in morphology and both systemic and localized immunological markers.

Environmental performance of commercial beef production systems utilizing conventional productivity-enhancing technologies.

The objective of this study was to evaluate the effects of using conventional productivity-enhancing technologies (PETs) with or without other natural PETs on the growth performance, carcass traits, and environmental impacts of feedlot cattle. A total of 768 cross-bred yearling steers (499 ± 28.6 kg; n = 384) and heifers (390 ± 34.9 kg; n = 384) were offered a barley grain-based basal diet and divided into implanted or non-implanted groups. Steers were then allocated to diets that contained either: (i) no additive (control); natural feed additives including (ii) fibrolytic enzymes (Enz), (iii) essential oil (Oleo), (iv) direct-fed microbial (DFM), (v) DFM + Enz + Oleo combination; conventional feed additives including (vi) Conv (monensin, tylosin, and beta-adrenergic agonists [βAA]); or Conv with natural feed additives including (vii) Conv + DFM + Enz; (viii) Conv + DFM + Enz + Oleo. Heifers received one of the first three dietary treatments or the following: (iv) probiotic (Citr); (v) Oleo + Citr; (vi) Melengesterol acetate (MGA) + Oleo + βAA; (vii) Conv (monensin, tylosin, βAA, and MGA); or (viii) Conv + Oleo (ConvOleo). Data were used to estimate greenhouse gas (GHG) and ammonia (NH3) emissions, as well as land and water use. Implant and Conv-treated cattle exhibited improvements in growth and carcass traits as compared to the other treatments (P < 0.05). Improvements in the performance of Conv-cattle illustrated that replacing conventional feed additives with natural feed additives would increase both the land and water required to satisfy the feed demand of steers and heifers by 7.9% and 10.5%, respectively. Further, GHG emission intensity for steers and heifers increased by 5.8% and 6.7%, and NH3 emission intensity by 4.3% and 6.7%, respectively. Eliminating the use of implants in cattle increased both land and water use by 14.6% and 19.5%, GHG emission intensity by 10.5% and 15.8%, and NH3 emission intensity by 3.4% and 11.0% for heifers and steers, respectively. These results demonstrate that the use of conventional PETs increases animal performance while reducing the environmental impacts of beef production. Restricting use would increase the environmental footprint of beef produced for both domestic and international markets.

Impact of a live bacterial-based direct-fed microbial (DFM) postpartum and weaning system on performance, mortality, and health of Najdi lambs

Abstract Among the non-nutritive additives available for lamb nutrition, direct-fed microbial (DFM) stands out for altering rumen fermentation and increasing animal productivity. This study was conducted to evaluate the effects of DFM and weaning systems on performance, mortality, and health of newborn lambs. A total of 60 newborn lambs were divided into 4 equal groups and assigned to one of 4 treatments: Control (C) without DFM and late weaning; T1, DFM and early weaning; T2, DFM and mid weaning; and T3, DFM and late weaning. Each lamb in the treated group received 3 doses of DFM (5 mL/lamb). The mortality was reduced by 80% compared to the control group. Lambs in the T2 and T3 with DFM groups had significantly (P &lt; 0.05) higher body weight (BW) and body weight gain (BWG) than lambs in the C group. Glucose, creatinine, and urea nitrogen levels of T3 lambs were significantly (P &lt; 0.05) higher in late weaning compared with the remining treatments. DFM supplementation and weaning system significantly (P &lt; 0.01) reduced serum Zn concentration. These results suggest that the addition of DFM to the diet of newborn lambs and weaning at 60 days improves the overall performance and immunity of the lambs and consequently reduces the mortality rate.

Megasphaera elsdenii and Saccharomyces Cerevisiae as direct fed microbials during an in vitro acute ruminal acidosis challenge

This study aimed to evaluate the effects of Saccharomyces cerevisiae and Megasphaera elsdenii as direct fed microbials (DFM) in beef cattle finishing diets to alleviate acute ruminal lactic acidosis in vitro. A dual-flow continuous culture system was used. Treatments were a Control, no DFM; YM1, S. cerevisiae and M. elsdenii strain 1; YM2, S. cerevisiae and M. elsdenii strain 2; and YMM, S. cerevisiae and half of the doses of M. elsdenii strain 1 and strain 2. Each DFM dose had a concentration of 1 × 108 CFU/mL. Four experimental periods lasted 11 days each. For the non-acidotic days (day 1–8), diet contained 50:50 forage to concentrate ratio. For the challenge days (day 9–11), diet contained 10:90 forage to concentrate ratio. Acute ruminal acidosis was successfully established. No differences in pH, d-, l-, or total lactate were observed among treatments. Propionic acid increased in treatments containing DFM. For N metabolism, the YMM treatment decreased protein degradation and microbial protein synthesis. No treatment effects were observed on NH3–N concentration; however, efficiency of N utilization by ruminal bacteria was greater than 80% during the challenge period and NH3–N concentration was reduced to approximately 2 mg/dL as the challenge progressed.

Influence of yeast-based pre- and probiotics in lactation and nursery diets on nursery pig performance and antimicrobial resistance of fecal Escherichia coli.

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs. yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from days 0 to 7, then concentrations were decreased by 50% from days 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P < 0.05) average daily gain (ADG) from days 0 to 24 and days 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased days 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery, there was reduced (P < 0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24; or DFM, 0.10% MicroSaf-S from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From days 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. Although feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2.