Use of a commercial probiotic supplement in meat goats

Can a blend of integrated feed additives modulate ruminal fermentation patterns and performance of growing lambs? In vitro and in vivo assessments

Two in vitro and in vivo experiments were accomplished to investigate the impacts of integrated feed additives (IFA, combination of protected fat, lysine, and methionine plus yucca extract, eucalyptus essential oil, and direct-fed microbial) on gas production (GP), ruminal fermentation and degradability parameters and lamb performance, digestibility, and nitrogen balance. In the in vitro experiment, responses of graded doses (0, 25, 50, 75, 100, and 125 g IFA/kg DM) were evaluated. In the in vivo experiment, 15 Barki male lambs (30.43 ± 0.74 kg BW ± SE) were individually allotted in complete randomized design into three treatments (five animal/treatment) as control (basal diet without additive), low dose (50 g/kg DM) and high dose (100 g/kg DM) for 120 days. In vitro results showed that both doses (100 and 125 g/kg DM) quadratically decreased (p < 0.001) GP and ammonia nitrogen (NH-3N) concentration. In vivo experiment revealed that dry matter intake was increased (p = 0.016) with low dose compared to high dose. Inclusion of high dose decreased blood serum glucose concentrations (p > 0.05) and ruminal protozoal populations (p = 0.094) compared with low dose and control diet. Both doses of IFA increased (p < 0.05) serum urea, creatinine, and triglyceride concentrations, while decreased (p < 0.001) ruminal NH3-N concentrations. These results suggested that, although IFA was effective to modify in vitro ruminal fermentation process and feed degradability, such aspects did not improve in vivo performance of growing lambs.

Recent Advances in the Use of Probiotics to Improve Meat Quality of Small Ruminants: A Review

Meat from small ruminants is considered a high quality and delicacy product in many countries. Several benefits have been perceived from probiotics as dietary supplements, such as improved carcass weight, color, tenderness, flavor, muscle fiber structure, water-holding capacity, and healthy fatty acid profile of the meat. Thus, the present review focuses on the effect of probiotics on improving the quality of meat from small ruminants. Though many benefits have been associated with the use of probiotics, the findings of all the considered articles are not always consistent, and the mechanisms behind improving meat quality are not appropriately defined. This variability of findings could be due to the use of different probiotic strains, dosage rates, number of days of experiment, nutrition, breed, age, and health status of the animals. Therefore, future research should emphasize specific strains, optimal dose and days of administration, route, and mechanisms for the specific probiotic strains to host. This review provides a comprehensive overview of the use of probiotics for small ruminants and their impact on meat quality.

Comparison of the effect of Saccharomyces cerevisiae-Megasphaera elsdenii and buffer on growth performance, digestibility, ruminal histomorphometry, and carcass characteristics of fattening lambs in high concentrate diet

This study aimed to investigate the effect of rumen pH-adjusting additives in the high-concentrated diet on functional traits, nutrient digestion, some meat parameters, and histomorphometry, and rumen histopathology. Twenty-four Arabia male lambs with 3 to 4 months old and initial body weight of 23.9 ± 3.15 kg were used in a completely randomized design with three treatments and eight replicates. The study was 77 days, including 14 days of the adaptation period and 63 days of the record taking and sampling period. The experimental treatments consisted of a control diet, control diet + sodium bicarbonate buffer, control diet + Megasphaera elsdenii, and Saccharomyces cerevisiae (bacterial-yeast). Rumen fluid was taken by stomach tube at 3 h after morning feeding to measure pH. The lambs were weighed every 3 weeks during the period, and the body weight changes, average daily gain, and total weight gain were measured, and the feed conversion ratio was calculated. At the end of the experiment, the lambs were slaughtered, and the longissimus dorsi muscle was prepared to determine the meat parameters. For histological studies, the abdominal rumen sac was sampled. There were no differences among treatments in dry matter intake (DMI), daily weight gain (ADG), and feed conversion ratio (P > 0.05). Propionate concentration was higher in the bacteria-yeast treatment than other treatments (P < 0.05). Protein digestibility was higher in control and bacteria-yeast treatments than buffer treatment (P < 0.05). The percentage of meat protein, carcass weight, and dressing percentage in bacterial-yeast treatment was higher than other treatments (P < 0.05). Rumen wall thickness in the buffer and bacterial-yeast receiving treatments was greater than the control treatment and was significant in the buffer treatment compared to the control treatment (P < 0.05). The thickness of rumen epithelial tissue in the buffer and bacterial-yeast recipient treatments was less than the control treatment (P < 0.05). Rumen papillae thickness was higher in the control treatment than other treatments (P < 0.05). Hydropic degeneration and parakeratosis were less in pH-regulating treatments than in control. The results showed that the use of Megasphaera elsdenii could be an effective way to modulate the ruminal fermentation conditions of lambs fed with high concentrate diets. In addition, to increaseing dressing percentage and meat protein, it can also reduce tissue damage and improve ruminal tissue structure.

Effect of propionate, monensin, and saccharomyces cerevisiae or their combination on production and rumen fermentation of holstein steers

This study aimed to evaluate the effects of calcium propionate (PrCa), PrCa + monensin sodium (PrCa + Mon), and PrCa + Saccharomyces cerevisiae (PrCa + Sc) on the productive performance of Holstein steers. Twenty-four Holstein steers (270.0 ± 25.85 kg) were distributed individually into four treatments of six replicates. The treatments were control (no additives), PrCa (10 g/kg), PrCa + Mon (10 g/kg + 30 mg/kg), and PrCa + Sc (10 g/kg + 12.8 × 10⁹ cfu). The steers were fed for 43 days, and afterwards, nutrient intake and digestibility as well as volatile fatty acids were determined, while the weight gained, feed efficiency, and CH₄ production were calculated. Diet of PrCa + Sc had the highest (P < 0.0001) acid detergent fiber intake and propionate acid as well as the nutrient digestibility, with lowest (P < 0.0001) rumen acetic acid, methane, and protozoa concentration versus other diets. In conclusion, dietary inclusion of PrCa + Sc (10 g/kg + 12.8 × 10⁹ cfu) improved nutrient digestibility, rumen fermentation, and reduced methane emission, thereby enhancing the possibility of ecofriendly ruminant farming.

Antimicrobial Properties of Bacillus Probiotics as Animal Growth Promoters

Antibiotic growth promoters (AGPs) suppress the growth of infectious pathogens. These pathogens negatively impact agricultural production worldwide and often cause health problems if left untreated. Here, we evaluate six Bacillus strains (BPR-11, BPR-12, BPR-13, BPR-14, BPR-16 and BPR-17), which are known for their ability to survive harsh environmental conditions, as AGP replacements in animal feed. Four of these Bacillus strains (BPR-11, BPR-14, BPR-16 and BPR-17) showed antimicrobial activity against the pathogenic strains Clostridium perfringens, Escherichia coli and Staphylococcus aureus at 25 μg/mL, with BPR-16 and BPR-17 also able to inhibit Pseudomonas aeruginosa and Salmonella enterica at 100 μg/mL. Further chemical investigation of BPR-17 led to the identification of eight metabolites, namely C16, C15, C14 and C13 surfactin C (1-4), maculosin (5), maculosine 2 (6), genistein (7) and daidzein (8). Purified compounds (1-4) were able to inhibit all the tested pathogens with MIC values ranging from 6.25 to 50 μg/mL. Maculosin (5) and maculosine 2 (6) inhibited C. perfringens, E. coli and S. aureus with an MIC of 25 μg/mL while genistein (7) and daidzein (8) showed no activity. An animal trial involving feeding BPR-11, BPR-16 and BPR-17 to a laboratory poultry model led to an increase in animal growth, and a decrease in feed conversion ratio and mortality. The presence of surfactin C analogues (3-4) in the gut following feeding with probiotics was confirmed using an LC-MS analysis. The investigation of these Bacillus probiotics, their metabolites, their impacts on animal performance indicators and their presence in the gastrointestinal system illustrates that these probiotics are effective alternatives to AGPs.

Effect of probiotic lactobacilli supplementation on growth parameters, blood profile, productive performance, and fecal microbiology in feedlot cattle

Lactic acid bacteria (LAB) selected on the basis of probiotic characteristics were administered to beef feedlot catlle and the effect on body condition/growth and nutritional-metabolic status as well as on E. coli O157:H7 fecal shedding, were investigated. A feeding trials involving 126 steers were used to evaluate the effects of Lactobacillus acidophilus CRL2074, Limosilactobacillus fermentum CRL2085 and Limosilactobacillus mucosae CRL2069 and their combinations (5 different probiotic groups and control) when 10⁷-10⁸ CFU/animal of each probiotic group were in-feed supplemented. Cattle were fed a high energy corn-based diet (16 to 88%) and samples from each animal were taken at 0, 40, 104 and 163 days. In general, animals body condition and sensorium state showed optimal muscle-skeletal development and behavioral adaption to confinement; no nasal/eye discharges and diarrheic feces were observed. The nutritional performance of the steers revealed a steady increase of biometric parameters and weight. Animals supplied with L. mucosae CRL2069 for 104 days reached the maximum mean live weight (343.2 kg), whereas the greatest weight daily gain (1.27 ± 0.16 Kg/day) was obtained when CRL2069 and its combination with L. fermentum CRL2085 (1.26 ± 0.11 kg/day) were administered during the complete fattening cycle. With several exceptions, bovine cattle blood and serum parameters showed values within referential ranges. As a preharvest strategy to reduce Escherichia coli O157:H7 in cattle feces, CRL2085 administered during 40 days decreased pathogen shedding with a reduction of 43% during the feeding period. L. fermentum CRL2085 and L. mucosae CRL2069 show promise for feedlot cattle feeding supplementation to improve metabolic-nutritional status, overall productive performance and to reduce E. coli O157:H7 shedding, thus decreasing contamination chances of meat food products.

Effect of probiotic supplementation on growth performance of Osmanabadi kids

The present experiment was conducted for 90 days to assess the effect of probiotic supplementation on performance of Osmanabadi kids at Osmanabadi goat unit of Red Kandhari Research and Instructional Farm, College of Veterinary and Animal Sciences, MAFSU, Parbhani, Maharashtra. Eighteen male or female kids of 3-6 months age were selected and randomly divided on equal weight basis into three treatment groups viz. T0 (control) with basal ration, T1 group with basal ration plus probiotics (Aspergillus oryzae and Lactobacillus), T2 group with basal ration plus probiotics (Saccharomyces cerevisiae and Lactobacillus). The averages for weekly body weight (kg) of kids in different treatment groups (T0, T1 and T2) at the end of experiment were 12.69±0.27, 13.78±0.48, 14.94±0.34 kg, respectively. The weekly body weight gain was 0.35±0.01, 0.50±0.01, 0.58±0.01 kg, respectively while the average daily gain was 50.33±1.45, 70.83±0.70, 83.33±1.65 g, respectively, for T0, T1 and T2 groups. At the end of 13th week, FCR for T2 group was significantly lower (6.14±0.01) as compared to T1 (7.14±0.04) and T0 (9.20±0.28) groups. Highly significant differences were observed for weekly body weight, weekly body weight gain, average daily gain, weekly and daily feed intake. It can be concluded that Saccharomyces cerevisiae and Lactobacillus supplemented group (T2) exhibited better performance in terms of growth and FCR as compared to Aspergillus oryzae and Lactobacillus supplemented group (T1) and control (T0).

Influence of microbial probiotics on ruminant health and nutrition: sources, mode of action and implications

Globally, ruminant production contributes immensely to the supply of the highest quality and quantity of proteins for human consumption, sustenance of livelihoods, and attainment of food security. Nevertheless, the phasing out of antibiotics in animal production has posed a myriad of challenges, including poor growth, performance and nutrient utilization, pathogen colonization, dysbiosis, and food safety issues in ruminants. Probiotics (direct-fed microbials), comprising live microbial strains that confer health and nutritional benefits to the host when administered in appropriate quantities, are emerging as a viable, safe, natural and sustainable alternative to antibiotics. Although the mechanisms of action exerted by probiotics on ruminants are not well elucidated, dietary probiotic dosage to ruminants enhances development and maturation, growth and performance, milk production and composition, nutrient digestibility, feed efficiency, pathogen reduction, and mitigation of gastrointestinal diseases. However, the beneficial response to probiotic supplementation in ruminants is not consistent, being dependent on the microbial strain selected, combination of strains, dose, time and frequency of supplementation, diet, animal breed, physiological stage, husbandry practice, and farm management. Nonetheless, several studies have recently reported beneficial effects of probiotics on ruminant performance, health and production. This review conclusively re-iterates the need for probiotics inclusion for the sustainability of ruminant production. Considering the role that ruminants play in food production and employment, global acceptance of sustainable ruminant production through supplementation with probiotics will undoubtedly ensure food security and food safety for the world. © 2021 Society of Chemical Industry.

Carryover effect of direct-fed microbial supplementation and early weaning on the growth performance and carcass characteristics of growing Najdi lambs

Growing Najdi lambs were randomly selected from lambs weaned at 30, 45, and 60 days old which were treated with 3 doses of direct-fed microbial (DFM) at 5, 10, and 15 days old to investigate the carryover effect of early weaning and DFM supplementation on their growth performance and carcass characteristics. Ten lambs from each group were transferred to individual pens for a feeding trial using the total mixed ration (Wafi). Lambs treated with DFM and weaned at 60 days old showed numerically higher body weight and average daily gains compared to other groups. Concerning the carcass and meat quality, there were significant differences between all groups in all carcass and tissue measurements, except for the back-fat and body wall thickness. In conclusion, treatment did not have any significant negative effect on body weight, feed intake, and conversion ratio compared with the control, but positively affected Zn and Cu absorption. DFM also played an important role in fat metabolism, which affects fat deposits in carcasses. The most important finding was that early weaning can be performed using DFM supplementation without any negative effect on the lambs’ performance during growth.

The Effects of Single or Combined Supplementation of Probiotics and Prebiotics on Growth Performance, Dietary Energetics, Carcass Traits, and Visceral Mass in Lambs Finished under Subtropical Climate Conditions

Simple Summary

Concern about the use of antimicrobial compounds in livestock production has promoted research of “generally recognized as safe” additive alternatives. Probiotics (living microorganisms) and prebiotics (certain type of carbohydrates derived from yeast) have been shown to alleviate the negative effects of stress and boost immunity, thereby enhancing efficiency of energy utilization. In some regions (i.e., tropical and arid zones), livestock experience adverse climatic conditions, including elevated ambient temperature and humidity, which affect their productivity. Supplementation with probiotics and prebiotics may help to alleviate these adverse effects. In the present study, supplemental probiotics or/and prebiotics improved dietary energetic efficiency in lambs finished under subtropical climatic conditions. The combination of probiotics with prebiotics reinforced this positive effect.

Abstract

The aim of this trial was to test the effects of the use of eubiotics (pro- and prebiotics) alone or in combination in the diet of lambs finished under subtropical climate conditions. For this purpose, 40 Pelibuey × Katahdin lambs (29.5 ± 4.8 kg initial live weight) were used in a 93 day growth-performance experiment. Dietary treatments consisted of a cracked corn-based finishing diet supplemented with (1) no eubiotics (control), (2) 3 g of probiotics (live Saccharomyces cerevisiae, SC), (3) 3 g of prebiotics (mannan oligosaccharide plus b-glucans, MOS), and (4) a combination of 1.5 g of SC and 1.5 g of MOS (SC+MOS). Throughout the study, the average temperature humidity index (THI) was 78.60. Compared to controls, supplementation with SC or MOS, alone did not affect average daily gain (ADG), but enhanced feed efficiency by 5.6% and 6.9% (gain-to-feed ratio, G:F) and dietary net energy by 4.6% and 5.9%, respectively. Compared to controls, SC+MOS enhanced ADG (10%), G:F (9.5%), and dietary net energy (7.2%). Lambs fed SC+MOS had also greater ADG, G:F, and dietary net energy compared to lambs fed SC alone. When compared to MOS, the combination enhanced ADG (10.4%, p = 0.04). This effect could be attributed to the increased dry matter intake (7.6%, p = 0.06), as neither G:F nor dietary energy was significantly affected. Compared with controls and SC, supplementation with MOS alone and SC+MOS increased kidney–pelvic–heart fat, while SC supplementation tended (p = 0.08) to reduce 4.1% the relative intestinal mass (as a proportion of empty body weight) when compared to controls. Treatment effects on the other carcass measures were not significant. In the present study, supplemental probiotics and/or prebiotics improved dietary energetic efficiency in lambs finished under subtropical climatic conditions. The combination of probiotics with prebiotics reinforced this positive effect.

The Recent Trend in the Use of Multistrain Probiotics in Livestock Production: An Overview

It has been established that introducing feed additives to livestock, either nutritional or non-nutritional, is beneficial in manipulating the microbial ecosystem to maintain a balance in the gut microbes and thereby improving nutrient utilization, productivity, and health status of animals. Probiotic use has gained popularity in the livestock industry, especially since antimicrobial growth promoter's use has been restricted due to the challenge of antibiotic resistance in both animals and consumers of animal products. Their usage has been linked to intestinal microbial balance and improved performance in administered animals. Even though monostrain probiotics could be beneficial, multistrain probiotics containing two or more species or strains have gained considerable attention. Combining different strains has presumably achieved several health benefits over single strains due to individual isolates' addition and positive synergistic adhesion effects on animal health and performance. However, there has been inconsistency in the effects of the probiotic complexes in literature. This review discusses multistrain probiotics, summarizes selected literature on their effects on ruminants, poultry, and swine productivity and the various modes by which they function.

Effects of Concentrate and Bypass Fat Supplementations on Growth Performance, Blood Profile, and Rearing Cost of Feedlot Buffaloes

Simple Summary

Studies have shown that providing concentrate and bypass fat as feed supplements resulted in better performance of large ruminants. However, there is limited information about the effects of these supplements on the performance of buffaloes. This study evaluates the effects of concentrate and bypass fat supplementations on the growth performance, blood metabolites, and feeding cost of Murrah cross and Swamp buffaloes. Following diet supplementation, the feed intake, body weight, and body condition score were significantly improved without any side effects on the blood metabolites of both buffalo breeds. Although the mixture of concentrate and bypass fat supplement (26:4) used in this study was found to increase the cost of feed, overall, it resulted in a greater return.

Abstract

This study investigates the effects of supplementation of the basal diet with concentrate and rumen bypass fat on the dry matter intake (DMI), growth performance, blood metabolites and hormonal changes, and the feeding cost of feedlot water buffaloes. Thirty-six healthy, three- to four-month-old male Murrah crossbred (n = 18) and Swamp (n = 18) buffaloes with a similar average initial body weight of 98.64 ± 1.93 kg were each randomly allocated into three dietary experimental groups. Buffaloes were fed with Diet A, which consisted of 100% Brachiaria decumbens, Diet B, consisting of 70% Brachiaria decumbens and 30% concentrate, and Diet C, consisting of 70% Brachiaria decumbens, 26% concentrate, and 4% rumen bypass fat for a period of 730 days. Feed intake was measured daily, while blood samples were collected for every eight months. Furthermore, body scores were noted prior to and at the end of the experimental period. The results showed that the average daily gain for buffaloes fed with Diet C was the highest. The DMI, BCS, FI, and FCR for the three groups showed significant (p < 0.05) differences, in the following order: Diet C > Diet B > Diet A. At the end of the two-year feeding trial, buffaloes fed with Diet B had significantly (p < 0.05) higher cholesterol levels than Diet A and Diet C. In addition, buffaloes fed with Diet C had significantly (p < 0.05) higher levels of serum total protein, growth hormone, and insulin-like growth factor-I hormone compared to Diet A and Diet B. On the other hand, buffaloes fed with Diet B and Diet C showed significant (p < 0.05) decrease in glucose levels. Supplemented diet improved the buffalos’ weight gain to achieve the market weight in a shorter period of time, thus, giving farmers a greater return. In conclusion, concentrate and bypass fat supplementations in the diet of water buffaloes improved the growth performance without adverse effect on the blood metabolites, which enabled better farmer profitability.

Enhancing the Utilization of Palm Leaf Hay Using Bacillus subtilis and Phanerochaete chrysosporium in the Diet of Lambs Under Desert Conditions

The efficiency of the bacterium Bacillus subtilis and white-rot fungus Phanerochaete chrysosporium on growth performance, blood metabolites, carcass characteristics, meat composition and nutrient digestibility of lambs fed crushed whole palm leaf hay was investigated for 105 d. In Experiment 1 (Growth experiment), twenty-four lambs (29.5 ± 1.25 kg) were divided into four feed-based treatments: (1) concentrate and wheat straw ad libitum (control), (2) palm leaf hay (DPL), (3) palm leaf hay supplemented with 2 g of B. subtilis and P. chrysosporium (DPL2) or (4) palm leaf hay supplemented with 4 g of B. subtilis and P. chrysosporium (DPL4). In Experiment 2 (Digestibility experiment), twelve rams, three from each treatment, were used to study nutrient digestibility using the faecal bag technique. Results of the Experiment 1 showed that the DPL4 showed greater (P=0.049) live-weight gain than the control. The diets containing palm leaf hay showed lower (P=0.001) roughage and total feed intake and higher (P=0.001) feed efficiency than the control. Increased serum total protein, globulin, urea-N, aspartate aminotransferase and alanine aminotransferase (ALT) levels were observed with the DPL4 (P˂0.05). Additionally, diets containing palm leaf hay showed higher ALT levels than the control. The DPL4 increased the hot carcass weight (P=0.006) and dressing percentage (P=0.036), and the diets supplemented with B. subtilis and P. chrysosporium decreased (P˂0.05) the tail fat and all fat levels compared with the DPL treatment. Results of the Experiment 2 showed that nutrient digestibility was lower (P˂0.05) with the DPL and DPL2 than with the control and DPL4. Compared with the control, nutrient digestibility of DPL4 was not affected. It is concluded that replacement of wheat straw with palm leaf hay did not affect the feed utilization or animal performance of the lambs; however, supplementation with B. subtilis and P. chrysosporium at 4 g/lamb daily enhanced the growth performance, and carcass characteristics without any adverse effects on blood metabolites.

Supplementation of Lactobacillus plantarum or Macleaya cordata Extract Alleviates Oxidative Damage Induced by Weaning in the Lower Gut of Young Goats

Weaning usually leads to stress in livestock, which has a negative impact on their growth and development. Research on oxidative stress and inflammation induced by weaning has not been reported in goats. Here, we focused on oxidative stress profile and inflammation status of the lower gut (jejunum, ileum, and colon) of goats. First, we illustrated the status of antioxidant activity and inflammation in the intestine of young goats on pre-(2 weeks postnatal, 2 wk^pn) or post-(11 wk^pn, weaning at day 45 postnatal)-weaned period of young goats. Malondialdehyde (MDA) was higher (p < 0.0001) in jejunum and ileum of the young goats in 11 wk^pn than that in 2 wk^pn, whereas superoxide dismutase (SOD) activity was lower (p = 0.012) in the lower gut of the young goats with 11 wk^pn than that in 2 wk^pn. Furthermore, we intended to explore the protective influence of a probiotic additive (Lactobacillus plantarum (LAC) P-8, 10 g/d) and a prebiotic additive (Sangrovit^®, Macleaya cordata (MAC) extract 3.75% w/w premix, 0.3 g/d) on intestinal oxidative stress and inflammation status of early-weaned young goats (average weights of 5.63 ± 0.30 kg, weaned on d 45 postnatal). We observed that LAC reduced MDA in jejunum and ileum (p < 0.0001), increased SOD activity in ileum (p < 0.01), and increased glutathione peroxidase (GSH-Px) activity in jejunum (p < 0.05). Similarly, MAC reduced MDA contents (p < 0.0001), increased SOD activities (p < 0.01) in both of ileum and jejunum, and increased GSH-Px activity (p < 0.05) in jejunum. However, there were no differences in feed intake, average daily gain, inflammation parameters (interleukin 2 and interleukin 6), and colon oxidative stress profile (MDA, SOD, or GSH-Px) among treatments. These results provide evidence that weaning induces oxidative damage in the lower gut of young goats, and the oxidative damage in the small intestine can be reduced by adding the addition of LAC or MAC in diets depending on the region of the lower gut.

Effects of postbiotic supplementation on growth performance, ruminal fermentation and microbial profile, blood metabolite and GHR, IGF-1 and MCT-1 gene expression in post-weaning lambs

Background

Postbiotics have been established as potential feed additive to be used in monogastric such as poultry and swine to enhance health and growth performance. However, information on the postbiotics as feed additive in ruminants is very limited. The aim of this study was to elucidate the effects of supplementation of postbiotics in newly-weaned lambs on growth performance, digestibility, rumen fermentation characteristics and microbial population, blood metabolite and expression of genes related to growth and volatile fatty acid transport across the rumen epithelium.

Results

Postbiotic supplementation increased weight gain, feed intake, nutrient intake and nutrient digestibility of the lambs. No effect on ruminal pH and total VFA, whereas butyrate and ruminal ammonia-N concentration were improved. The lambs fed with postbiotics had higher blood total protein, urea nitrogen and glucose. However, no difference was observed in blood triglycerides and cholesterol levels. Postbiotics increased the population of fibre degrading bacteria but decreased total protozoa and methanogens in rumen. Postbiotics increased the mRNA expression of hepatic IGF-1 and ruminal MCT-1.

Conclusions

The inclusion of postbiotics from L. plantarum RG14 in newly-weaned lambs improved growth performance, nutrient intake and nutrient digestibility reflected from better rumen fermentation and microbial parameters, blood metabolites and upregulation of growth and nutrient intake genes in the post-weaning lambs.

Effects of supplementation of Bacillus spp. on blood metabolites, antioxidant status, and gene expression pattern of selective cytokines in growing Barki lambs

OBJECTIVE

In this study, we investigated the potential immune-enhancing effects in addition to anti-oxidative stress properties of commercially accessible Bacillus subtilis supplementation in Barki lambs.

MATERIALS AND METHODS

Twenty apparently healthy weaned Barki lambs were used in this study and distributed randomly into two experimental groups: Negative control group, received control basal diet without any feed supplements and a supplemented group, received control basal diet supplemented with water added to commercially accessible bacilli at 1 gm/l/day for 30 consecutive days. Blood samples were collected from each lamb before starting the experiment (T0), 2 weeks (T15), and 4 weeks (T30) post-supplementation for serum biochemical analyses, total leucocytes and lymphocytes count, and real-time polymerase chain reaction assays.

RESULTS

The supplemented group showed a significant increase (p < 0.05) in the total number of leukocytes and the number of lymphocytes, lysozyme activity, reduced glutathione, total antioxidant capacity with a significantly lower malondialdehyde values at T30 and significantly higher levels (p < 0.05) of serum catalase and nitric oxide at T15 as compared with control ones. B. subtilis elicited maximal up-regulation of most of the studied genes compared with the control group.

CONCLUSION

The results herein suggest that B. subtilis could be used as useful nutritional supplements to support the immune system in healthy lambs.

Synergetic action between the rumen microbiota and bovine health

Host-rumen-microbe interactions are essential components of many physiological processes, and therefore can affect ruminant health. Classical knowledge of rumen microbiology is based on culture-dependent methodologies, which only account for 10-20% of the rumen bacterial communities. While, the advancement in DNA sequencing and bioinformatics platforms provide novel approaches to investigate the composition and dynamics of the rumen microbiota. Recent studies demonstrated that the ruminal ecosystem is highly diverse and harbors numerous microbial communities. The composition of these microbial communities are affected by various environmental factors such as nutrition and different management strategies. Disturbance in the microbial ecology of the rumen is associated with the development of various diseases. Despite the flow of recent rumen-based studies, rumen microbiota is still not fully characterized. This review provides an overview of recent efforts to characterize rumen microbiota and its potential role in rumen health and disease. Moreover, the recent effects of dietary interventions and probiotics on rumen microbiota are discussed.

The effects of Saccharomyces cerevisiae supplementation on intake, nutrient digestibility, and rumen fluid pH in Awassi female lambs

Aim:

The aim of this study was to evaluate the effect of feeding low (LO)- or high (HI)-fiber diets supplemented with Saccharomyces cerevisiae (SC) on nutrient intake, digestibility, nitrogen balance, rumen fluid pH, and serum concentrations of glucose and urea nitrogen in Awassi female lambs in a 2×2 factorial arrangement of treatments.

Materials and Methods:

Experimental diets were as follows: (1) LO-fiber diet with no SC supplementation (−LO), (2) LO-fiber diet supplemented with SC (+LO), (3) HI-fiber diet with no SC supplementation (−HI), or (4) HI-fiber diet supplemented with SC (+HI). Eight female lambs were used in a replicated 4×4 Latin square design with 15-day experimental periods (10-day adaptation period and 5-day collection period).

Results:

A fiber×SC interaction (p≤0.05) was detected for dry matter (DM) and crude protein (CP) intake among diets showing greater DM and CP intake for +LO diet compared to +HI group supplemented with SC, whereas −LO and −HI were intermediate. A fiber×SC interaction (p=0.05) was also detected for the neutral detergent fiber (NDF) intake among diets. Intake of NDF was greater for the –HI diet compared with +LO and –LO diets. Similarly, NDF intake was greater for +HI diet than –LO diet. A tendency (p=0.07) for a fiber×SC interaction was detected for acid detergent fiber (ADF) intake among diets as well. ADF intake tended to be greater for HI-fiber diets. No difference was observed in the rumen fluid pH for lambs fed with the different diets. No fiber×SC interactions were detected for the digestibility of DM, CP, NDF, and ADF among dietary treatments. Digestibility of DM was greater (72.9 g/100 g vs. 67.1 g/100 g; p=0.0002) for LO versus HI fiber. However, NDF and ADF digestibilities were greater (60.8 and 61.9 g/100 g vs. 55.8 and 52.7 g/100 g for NDF and ADF digestibility, respectively; p≤0.01) for the HI-fiber than the LO-fiber diets.

Conclusion:

Results obtained in the current study indicate that SC supplementation has a minimal effect on the performance of Awassi female lambs fed with varying fiber levels.

Growth performance, nutrients digestibility, and blood metabolites of lambs fed diets supplemented with probiotics during pre- and post-weaning period

Objective

Two experiments were conducted to evaluate the effects on growth performance, digestibility, and blood metabolites of lambs during pre- and post-weaning period of inclusion of a commercial probiotic (PRO) containing a mixture of two strains of Pediococcus, Pediococcus acidilactici (1×10⁶ colony-forming unit [cfu]/g) and Pediococcus pentosaceus (1.3×10⁶ cfu/g), with dextrose as the carrier compound compared to a diet based on concentrate mixture and wheat straw.

Methods

In exp. 1, 24 male lambs of about 15±2.6 d age and initial body weight (BW) of 5.52±0.6 kg were randomly allocated into three groups. One group received control diet without additives, and remainders received control diet supplemented with 0.5 or 1 g PRO/lamb/d. Daily feed intake and biweekly BW were recorded. In exp. 2, five lambs, (initial BW = 29.72±1.15 kg, age = 6.54±0.32 mo) were used as experimental animals in a digestion trial. They were fed the same diets as in Exp. 1.

Results

The supplementation of PRO did not result in any significant differences in milk intake, average daily gain (ADG), or total gain between treatments during the pre-weaning period. Total dry matter intake tended to be greater (p = 0.07) with addition of PRO in the post-weaning diets. During post-weaning phase, the final BW, ADG, total gain, and feed conversion ratio of the lambs receiving PRO treatments tended to be greater (p≤0.10) than the control group. Addition of PRO in post-weaning diet decreased (p≤0.01) blood urea and cholesterol concentrations. With the exception of ether extract digestibility, all nutrients digestibility were improved with inclusion PRO in the post-weaning diets.

Conclusion

Lambs that received PRO in post-weaning diet appeared to show a better performance than lambs in pre-weaning period. Addition of the probiotic in the post-weaning diet trended towards improved dry matter intake, growth performance, feed conversion ratio, and nutrients digestibility.

Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs

Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.

Use of probiotics to reduce faecal shedding of Shiga toxin-producing Escherichia coli in sheep

Shiga toxin-producing Escherichia coli (STEC) are zoonotic, foodborne pathogens of humans. Ruminants, including sheep, are the primary reservoirs of STEC and there is a need to develop intervention strategies to reduce the entry of STEC into the food chain. The initiation of the majority of bacterial, enteric infections involves colonisation of the gut mucosal surface by the pathogen. However, probiotic bacteria can serve to decrease the severity of infection via a number of mechanisms including competition for receptors and nutrients, and/or the synthesis of organic acids and bacteriocins that create an environment unfavourable for pathogen development. The aim of the current study was to determine whether the administration of a probiotic mixture to sheep experimentally infected with a non-O157 STEC strain, carrying stx1, stx2 and eae genes, was able to decrease faecal shedding of the pathogen. The probiotic mixture contained Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus lactis, Streptococcus thermophilus and Enterococcus faecium. The numbers of non-O157 STEC in faecal samples collected from sheep receiving daily doses of the probiotic mixture were significantly lower at the 3rd, 5th and 6th week post-inoculation when compared to the levels recorded in untreated animals. It was concluded that administration of the probiotic mixture reduced faecal shedding of non-O157 STEC in sheep, and holds potential as a pre-harvest intervention method to reduce transmission to humans.

Effect of Feeding Bacillus subtilis natto on Hindgut Fermentation and Microbiota of Holstein Dairy Cows

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with 0.5×10(11) cfu as DMF1 group and B. subtilis natto with 1.0×10(11) cfu as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, NH3-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal NH3-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.

Antimicrobial peptides targeting Gram-negative pathogens, produced and delivered by lactic acid bacteria

We present results of tests with recombinant Lactococcus lactis that produce and secrete heterologous antimicrobial peptides with activity against Gram-negative pathogenic Escherichia coli and Salmonella . In an initial screening, the activities of numerous candidate antimicrobial peptides, made by solid state synthesis, were assessed against several indicator pathogenic E. coli and Salmonella strains. Peptides A3APO and Alyteserin were selected as top performers based on high antimicrobial activity against the pathogens tested and on significantly lower antimicrobial activity against L. lactis . Expression cassettes containing the signal peptide of the protein Usp45 fused to the codon-optimized sequence of mature A3APO and Alyteserin were cloned under the control of a nisin-inducible promoter PnisA and transformed into L. lactis IL1403. The resulting recombinant strains were induced to express and secrete both peptides. A3APO- and Alyteserin-containing supernatants from these recombinant L. lactis inhibited the growth of pathogenic E. coli and Salmonella by up to 20-fold, while maintaining the host's viability. This system may serve as a model for the production and delivery of antimicrobial peptides by lactic acid bacteria to target Gram-negative pathogenic bacteria populations.

Effects of feeding different levels of chromium-enriched live yeast in hairy lambs fed a corn-based diet: effects on growth performance, dietary energetics, carcass traits and visceral organ mass

Forty Pelibuey × Kathdin lambs (35.5 ± 0.4 kg) were used in a 56-day feeding experiment to assess the effects of feeding different levels of chromium-enriched live yeast (Cr-YC) on growth performance, dietary energetics, carcass traits and visceral organ mass. The Cr-YC source contained 5.5 × 109 colony forming units (CFU) and 0.40 mg of Cr per gram. Treatments consisted of a dry rolled corn-based finishing diet supplemented with 0, 1, 2 or 3 g Cr-YC/lamb.day. Total daily dosages were: 5.5 × 109 CFU and 0.4 mg; 1.1 × 1010 CFU and 0.8 mg Cr, and 1.65 × 1010 CFU and 1.2 mg Cr for supplementation levels of 1, 2 or 3 g Cr-YC/lamb.day, respectively. There were no treatments effects on dry matter intake. As the level of Cr-YC supplementation increased, average daily gain, gain to feed and dietary net energy were linearly increased, and observed/expected dry matter intake was linearly decreased. Chromium-enriched live yeast supplementation increased empty bodyweight (EBW), gastrointestinal fill and full viscera weight, but did not influence organ weights as a proportion of EBW (g/kg EBW). Cr-YC level did not affect carcass length, backfat thickness, kidney, pelvic and heart fat or body wall thickness, but increased hot carcass weight and longissimus muscle area. In general, treatment effects on percentage yield of wholesale cuts (tissue weight as a percentage of cold carcass weight) were small. However, Cr-YC decreased percentage flank. Chromium-enriched yeast supplementation enhances growth rate, longissimus muscle area, and dietary energetic efficiency in finishing feedlot lambs.

Effects of breed and harvest age on feed intake, growth, carcass traits, blood metabolites, and lipogenic gene expression in Boer and Kiko goats

The objectives of this experiment were to determine the effects of 2 different breeds (BR), Boer and Kiko, and 4 post-weaning harvest ages (HA; Days 0, 29, 56, and 85) on growth, carcass traits, blood metabolites, and lipogenic gene expression. Forty-eight goat (Capra hircus) kids (BW = 23.9 ± 1.50 kg; 3 to 4 mo) were used in a 2 × 4 factorial arrangement of treatments. Goats were stratified by BW within BR and randomly assigned to 4 HA. Kids were born between March 15 and April 7 to purebred does, and were represented by at least 3 purebred sires within each BR. They were fed a grain/hay (80:20) diet once per day. At designated HA, randomly pre-assigned goats (n = 6) from each BR were transported to the Meat Science Lab at Mississippi State University, Starkville, MS, and were harvested. There were no interactions (P > 0.10) between BR and HA. Boer tended (P = 0.08) to have greater initial BW, final BW (P = 0.05), and G/F ratio (P = 0.05). Although the 80:20 grain/hay diet was reinforced by adjusting DMI, both BR had similar total DMI, Boer kept that ratio, while Kiko consumed more (P = 0.001) hay (70:30, grain/hay) and had more (P = 0.001) DMI when expressed as g/kg BW. Boer tended to have greater transportation shrink (P = 0.07), HCW (P = 0.08), and cold carcass weights (CCW; P = 0.08), with greater (P = 0.001) carcass fat. No differences (P > 0.10) were observed in carcass shrink, dressing percentage, 12th rib fat thickness, and LM area between the 2 BR. When expressed as percentage empty BW, carcass bone was similar (P = 0.25), whereas muscle percentage (P = 0.02) was greater for Kiko and fat percentage was greater (P = 0.001) for Boer. Fat as a percentage of CCW remained relatively similar (P > 0.10) for both BR for the 2nd and 3rd HA. Differences were more evident (P = 0.01) at the 4th HA. Boer reached targeted harvest weight (29 kg) at the 3rd HA, while fat deposition continued (P = 0.01) during the 4th HA. Breed had no effect (P > 0.10) on meat color (L*, a*, b*) but HA affected (P = 0.001) all color values. Boer had similar 3-hydroxyl-3-methylglutaryl-CoA synthase mRNA abundance, but was greater (P < 0.03) in acetyl CoA carboxylase compared with Kiko. There was no difference (P = 0.52) in total serum fatty acids (FA, mg/mL) between the 2 BR. As animals aged, their total serum FA increased (P < 0.05) and changed to an undesirable profile. Kiko had a greater (P = 0.02) percentage of muscle and less (P = 0.001) fat in the carcass. We concluded that different BR might need different harvest endpoints and feed input according to consumer acceptability.