Performance and fecal flora of calves fed a Bacillus subtilis concentrate

Research Progress of Biological Feed in Beef Cattle

Biological feed is a feed product developed through bioengineering technologies such as fermentation engineering, enzyme engineering, protein engineering, and genetic engineering. It possesses functional characteristics of high nutritional value and good palatability that can improve feed utilization, replace antibiotics, enhance the health level of livestock and poultry, improve the quality of livestock products, and promote a better breeding environment. A comprehensive review is provided on the types of biological feed, their mechanism of action, fermenting strains, fermenting raw material resources, and their current status in animal production to facilitate in-depth research and development of applications.

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.

Impacts of Various Nutraceutical Milk Replacer Supplements on the Health and Performance of High-Risk Holstein Calves

The objectives of this study were to determine the impacts of supplementing various nutraceuticals in milk replacers, including a blend of probiotics, β-glucan extract, mannanoligosaccharide extract, or a non-immunoglobulin rich extract, from colostrum on the performance and health of high-risk calves and to determine carry-over effects into the immediate post-weaned period. One hundred bull calves were acquired from a local calf ranch within 24 h of birth and randomly assigned to one of five dietary treatments added to milk replacer only: (1) Control (CON), no additive; (2) Immu-PRIME (ImmPr), 1.5 g/d ImmPr first 3 d only (Sterling Technology, Brookings, SD, USA); (3) Beta glucan (BG), 1 g/d BG extract (ImmuOligo, Irvine, CA, USA); (4) Mannanoligosaccharide + Bacillus subtilis (MOS+Bs), 3 g/d CEREVIDA EXCELL-M + 4 x 109 CFU/d Bacillus subtilis (MB Nutritional Sciences, Lubbock, TX, USA); and (5) PROVIDA CALF (PRO), proprietary blend of 2 x 109 CFU/d of a Lactobacillus casei and an Enterococcus faecium + 2 x 109 CFU/d Saccharomyces cerevisiae (MB Nutritional Sciences, Lubbock, TX, USA). Calves were weaned at d 56, comingled, and treatment carry-over effects evaluated through d 84. Starter intake was measured daily and BW weekly. Peripheral blood samples were collected and analyzed for hematology and serum was analyzed for haptoglobin concentrations. Polymorphonuclear leukocyte (PMNL) function was assessed through surface L-selectin expression, phagocytic, and oxidative burst activities against Escherichia coli. Data were analyzed using Proc Mixed in SAS (SAS 9.4, Cary, NC). The BG calves consumed the most starter from d 1 to 28 and pre-weaned average daily gain was greater for both the PRO and BG when compared to the CON group. There was a tendency for BG, MOS+Bs, and PRO to have reduced serum haptoglobin throughout the study. Total leukocyte, neutrophil, and lymphocyte counts were reduced among MOS+Bs calves, whereas BG calves tended to have the greatest neutrophil:lymphocyte ratio. Oxidative burst function for PMNL was reduced among BG and PRO treatments, suggesting a decreased need for neutrophil function. Supplementing BG, MOS+Bs, and PRO all influenced the performance and health of high-risk calves, but mechanistically appear to be different.

Potential novel nutritional beverage using submerged fermentation with Bacillus subtilis WX-17 on brewers' spent grains

Food processing generates side streams that are not fully utilized and typically treated as waste materials. One of such food by-product, brewers’ spent grains (BSG) are disposed in huge quantities from the beer industry annually. Submerged fermentation of BSG using Bacillus subtilis WX-17, without supplementary components, is herein employed. The fermentation products were extracted in the liquid phase, resulting in a potential novel nutritional beverage containing Bacillus subtilis WX-17. Bacillus subtilis WX-17, was still viable after a period of 6 weeks with a final cell count of 9.86 log CFU/mL. Gas chromatography-mass spectrophotometry (GC-MS) was employed for identification of the metabolites produced from the growth of Bacillus subtilis WX-17. Seven essential amino acids and citric acid cycle (TCA) intermediates were found to have increased significantly (p < 0.05) whereas all carbohydrates decreased significantly (p < 0.05) in the beverage after submerged fermentation. Additionally, antioxidant activity quantified using DPPH radical scavenging activity, increased by 2.08-fold while total phenolic content increased from 125.7 ± 0.74 μg/mL to 446.74 ± 1.26 μg/mL. The results proved the potential of employing submerged fermentation of BSG using Bacillus subtilis WX-17 to produce a novel and highly nutritious beverage.

Effects of a blend of Saccharomyces cerevisiae-based direct-fed microbial and fermentation products in the diet of newly weaned beef steers: growth performance, whole-blood immune gene expression, serum biochemistry, and plasma metabolome1

We examined the effects of dietary supplementation of a Saccharomyces cerevisiae-based direct-fed microbial (DFM) on the growth performance, whole-blood immune gene expression, serum biochemistry, and plasma metabolome of newly weaned beef steers during a 42 d receiving period. Forty newly weaned Angus crossbred steers (7 d post-weaning; 210 ± 12 kg of BW; 180 ± 17 d of age) from a single source were stratified by BW and randomly assigned to 1 of 2 treatments: basal diet with no additive (CON; n = 20) or a basal diet top-dressed with 19 g of the DFM (PROB; n = 20). Daily DMI and weekly body weights were measured to calculate average daily gain (ADG) and feed efficiency (FE). Expression of 84 immune-related genes was analyzed on blood samples collected on days 21 and 42. Serum biochemical parameters and plasma metabolome were analyzed on days 0, 21, and 42. On day 40, fecal grab samples were collected for pH measurement. Compared with CON, dietary supplementation of PROB increased final body weight (P = 0.01) and ADG (1.42 vs. 1.23 kg; P = 0.04) over the 42 d feeding trial. There was a tendency for improved FE with PROB supplementation (P = 0.10). No treatment effect (P = 0.24) on DMI was observed. Supplementation with PROB increased (P ≤ 0.05) the concentrations of serum calcium, total protein, and albumin. Compared with CON, dietary supplementation with PROB increased (P ≤ 0.05) the expression of some immune-related genes involved in detecting pathogen-associated molecular patterns (such as TLR1, TLR2, and TLR6), T-cell differentiation (such as STAT6, ICAM1, RORC, TBX21, and CXCR3) and others such as TNF and CASP1, on day 21 and/or day 42. Conversely, IL-8 was upregulated (P = 0.01) in beef steers fed CON diet on day 21. Plasma untargeted plasma metabolome analysis revealed an increase (P ≤ 0.05) in the concentration of metabolites, 5-methylcytosine and indoleacrylic acid involved in protecting the animals against inflammation in steers fed PROB diet. There was a tendency for lower fecal pH in steers fed PROB diet (P = 0.08), a possible indication of increased hindgut fermentation. This study demonstrated that supplementation of PROB diet improved the performance, nutritional status, and health of newly weaned beef steers during a 42 d receiving period.

Growth performance, nutrient utilization, and health of dairy calves supplemented with condensed whey solubles

Our objective was to evaluate growth performance, nutrient utilization, and health of calves supplemented with condensed whey solubles (CWS). Twenty-four Holstein calves (2 d old) in hutches were used in a 12-wk randomized complete block design study. Calves were blocked by birth date and sex. Treatments were (1) control (CON) with no supplement and (2) 50 g/d of CWS. Preweaning CWS was fed with milk and postweaning CWS was top-dressed on starter pellets. Calves were fed 2.83 L of pasteurized milk 2×/d during wk 1 to 5, 1×/d in wk 6, and weaned at d 42. Calves had ad libitum access to starter pellets and water. Individual intakes of milk and starter pellets were measured daily. Fecal scores (0 = firm, 3 = watery) and respiratory scores (healthy ≤3, sick ≥5), calculated from the sum of scores for rectal temperature, cough, ocular, and nasal discharge, were recorded daily. Body weights (BW), frame growth, and jugular blood samples were taken once every week at 3 h after the morning feeding. Fecal grab samples were collected in wk 12 for analysis of apparent total-tract digestibility. Data were analyzed using MIXED procedures of SAS 9.4 (SAS Institute Inc., Cary, NC) with repeated measures. Total dry matter intake was greater in calves fed CWS compared with CON. Calves fed CWS tended to have greater BW during the postweaning period. Gain:feed, average daily gains, withers heights, and concentrations of plasma urea nitrogen were not different. Concentrations of plasma β-hydroxybutyrate were greater in calves fed CWS compared with CON. Serum glucose concentrations were greater in calves fed CON during the preweaning stage, but similar concentrations were found between treatments during the postweaning stage. Rumen pH, ammonia-N, and total volatile fatty acids were similar between treatments. The acetate:propionate ratio was greater in calves fed CWS. The apparent total-tract digestion of nutrients was similar; however, CON tended to have greater digestion of neutral detergent fiber. Fecal scores were not different, but a treatment by week interaction was observed. Supplementing CWS improved starter intake, postweaning BW, β-hydroxybutyrate, fecal scores, and maintained frame growth.

Short communication: Effects of porcine plasma or combined sodium butyrate and Bacillus subtilis on growth and health of grain-fed veal calves

The objective of this study was to evaluate the effects of incorporating 2 commonly used additives or spray-dried porcine plasma in calf milk replacer (CMR) on calf performance and health. Male Holstein calves (n = 158) transported from auction barns and local dairy farms were randomly assigned to receive 1 of 3 decoquinate-containing CMR for the first 49 d of the experiment: all milk protein and no additives (CONT); 15% of crude protein (CP) replaced with spray-dried porcine plasma, no additives (PLM); or all milk protein and an added combination of sodium butyrate (rate 1.4 kg of butyric acid/Mt) and Bacillus subtilis (1.28 million cfu/g of feed; BB). All milk replacers were formulated to contain 26% CP and 17% fat, 2.4% Lys, and 0.8% Met, and were bucket-fed at daily feeding rates of 520 g during wk 1 and 2, 650 g during wk 3, and 900 g during wk 4 and 5, in a total of 4, 5, and 6 L of solution, respectively. Calves were offered texturized calf starter (18% CP) upon arrival until wk 3 and transitioned to a corn and pellet ration with 2% straw (18.1% CP). No prophylactic administration of antibiotics occurred. All calves were gradually weaned over a 2-wk period. Calves were individually housed until weaned and then housed in groups of 5 in a mechanically ventilated facility in southwestern Ontario, Canada. Fecal scores, treatments administered (antibiotic or supportive therapy), and mortalities were recorded daily. Body weight was measured using a digital scale at arrival and at 14, 49, 56, and 78 d after arrival. No differences were found among the groups with respect to growth, feed efficiency, or incidence of diarrhea or respiratory infection treatment. Calves supplemented with BB had a greater hazard of mortality over the growing period compared with CONT. An interaction was found between the BB group and the level of total serum protein, with the BB group having a lower proportion of days with a fecal score of 3 when the calves had a higher total serum protein level. Calves fed PLM had a lower proportion of d with a fecal score of 3 relative to CONT but no difference in the proportion of d with a fecal score of 2 or higher. This study found that the addition of spray-dried plasma in CMR reduced diarrhea severity; however, supplementing BB was associated with a higher hazard of calf mortality and had a varying response on fecal score.

Effects of mannan-oligosaccharides and Lactobacillus acidophilus supplementation on growth performance, nutrient utilization and faecal characteristics in Murrah buffalo calves

A study of 120 days was undertaken to ascertain the effect of mannan-oligosaccharides (MOS) and Lactobacillus acidophilus supplementation on growth performance, nutrient utilization and faecal characteristics in Murrah buffalo calves. Twenty Murrah buffalo calves of 5-7 days old and 31 ± 2.0 kg of body weight (BW) were randomly assigned into four groups. Group I served as the control (CON) in which only basal diet (concentrate mixture and green fodder) was provided, without any supplementation. Mannan-oligosaccharides at 4 g/calf/day were supplemented as prebiotic to Group II (PRE), whereas Group III (PRO) received Lactobacillus acidophilus in the form of fermented milk as probiotic at 200 ml/calf/day having 10⁸  CFU/ml and Group IV (SYN) was supplemented with both MOS and Lactobacillus acidophilus as synbiotic at similar dose. Final BW (kg), dry matter intake, average daily gain, feed conversion efficiency and structural growth measurements were improved (p < .05) in the treatment groups compared to control. Digestibility of neutral detergent fibre was higher (p < .05) in SYN followed by PRE and PRO than control. The faecal lactobacilli and bifidobacterium population was higher (p < .05) in all the supplemented groups with a concomitant reduction in faecal coliform count as compared to control. Faecal ammonia, lactate and pH were also altered favourably (p < .05) in all the supplemented groups as compared to CON. The faecal volatile fatty acids were higher (p < .05) in PRE, PRO and SYN group than CON. The incorporation of MOS and Lactobacillus acidophilus in diet either individually or in combination as synbiotic has the potential to improve the performance and faecal characteristics in Murrah buffalo calves; however, the observed responses among the treatment groups were more evident in the synbiotic fed group compared to individual supplementation of MOS and Lactobacillus acidophilus.

Bacillus probiotics: an alternative to antibiotics for livestock production

The use of probiotics as feed supplements in animal production has increased considerably over the last decade, particularly since the ban on antibiotic growth promoters in the livestock sector. Several Bacillus sp. are attractive for use as probiotic supplements in animal feed due to their ability to produce spores. Their heat stability and ability to survive the low pH of the gastric barrier represent an advantage over other probiotic micro-organisms. This review discusses important characteristics required for selection of Bacillus probiotic strains and summarizes the beneficial effect of Bacillus-based feed additives on animal production. Although the mechanism of action of Bacillus probiotics has not been fully elucidated, they are effective in improving the growth, survival and health status of terrestrial and aquatic livestock. Bacillus strains also have utility in bioremediation and can reduce nitrogenous waste, thereby improving environmental conditions and water quality. Finally, recent innovative approaches for using Bacillus spores in various applications are discussed.

High Doses of Halotolerant Gut-Indigenous Lactobacillus plantarum Reduce Cultivable Lactobacilli in Newborn Calves without Increasing Its Species Abundance

To elucidate the ecological effect of high oral doses of halotolerant (resistant to table salt) indigenous-gut bacteria on other commensals early in life, we conducted a culture-based study to quantify the effect of intestinal Lactobacillus plantarum strain of bovine origin (with remarkable aerobic growth capabilities and inhibitory activity against Escherichia coli O157:H7 and F5) on clinical health and gut lactobacilli/coliforms in newborn calves. In a double-blind placebo-randomized trial twelve colostrum-fed calves, consecutively born at a farm, were fed L. plantarum within 12 hours from birth at low (10^7-8 CFU/day) or high concentrations (10^10-11) or placebo (q24 h, 5 d; 10 d follow-up). We developed a 2.5% NaCl-selective culture strategy to facilitate the enumeration of L. plantarum-strain-B80, and tested 384 samples (>1,152 cultures). L. plantarum-B80-like colonies were detected in a large proportion of calves (58%) even before their first 24 hours of life indicating endemic presence of the strain in the farm. In contrast to studies where human-derived Lactobacillus LGG or rhamnosus had notoriously high, but short-lived, colonization, we found that L. plantarum colonized stably with fecal shedding of 6 ± 1 log₁₀·g⁻¹ (irrespective of dose, P > 0.2). High doses significantly reduced other fecal lactic acid bacteria (e.g., lactobacilli, P < 0.01) and slightly reduced body weight gain in calves after treatment. For the first time, a halotolerant strain of L. plantarum with inhibitory activity against a human pathogen has the ability to inhibit other lactobacilli in vivo without changing its species abundance, causing transintestinal translocation, or inducing clinical disease. The future selection of probiotics based on halotolerance may expand therapeutic product applicability.

Desempenho de bezerros leiteiros recebendo probiótico contendo Bacillus subtilis e Bacillus licheniformis

RESUMO Foram utilizados 24 bezerros que receberam 4L/dia de sucedâneo, além de livre acesso a água e concentrado até a 8a semana. Os animais foram distribuídos em delineamento de blocos casualizados, em dois tratamentos: 1) Controle: sem a suplementação de probiótico; 2) Suplementação de 2g/d de Bacillus subtilis e Bacillus licheniformis via sucedâneo lácteo. Semanalmente os animais foram pesados e foram aferidas as medidas corporais; também foram realizadas colheitas de sangue para determinação de glicose, proteína total, ureia e albumina, além de hematócrito. Foram colhidas amostras de fezes semanalmente para contagem de bactérias ácido láticas e enterobactérias e determinação de pH fecal. O peso corporal, o ganho de peso médio diário e as medidas corporais não foram alteradas pela suplementação; muito embora tenham apresentado efeito significativo de idade dos animais. O escore fecal, pH fecal e consumo de concentrado diário também não foram afetados pela suplementação. No entanto, o consumo de concentrado e o pH fecal sofreram influência da idade em resposta ao crescimento natural dos bezerros. A contagem de bactérias ácido láticas foi maior em número do que a contagem de enterobactérias durante todo o período. Apenas as enterobactérias sofreram efeito da idade, enquanto as bactérias ácido láticas permaneceram variando, porém dentro de um padrão constante. Os parâmetros sanguíneos também não foram afetados pela suplementação com probiótico mas todos, com a exceção da albumina, tiveram influência da idade. A suplementação com o probiótico não apresentou benefícios no desempenho ou no metabolismo de bezerros leiteiros, também não reduziu a ocorrência de casos de diarreia.

The effects of increasing amounts of milk replacer powder added to whole milk on feed intake and performance in dairy heifers

The aim of this study was to evaluate the effects on feed intake, heifer performance, and health of increasing the total solids (TS) content of liquid feed (whole milk) by adding increasing amounts of milk replacer powder during the pre- and postweaning periods. Crossbred Holstein-Gyr heifers (n=60) were assigned to 1 of 4 treatments (n=15 per group), which consisted of different TS concentrations: 12.5, 15.0, 17.5, and 20.0% of liquid feed. Heifers received 6 L of liquid feed per day, divided into 2 equal meals (0800 and 1600h) and provided in buckets, from 5 to 55d of age. From 56 to 59d of age, the total amount of liquid feed was reduced by half, maintaining only morning feedings. Heifers were weaned at 60d and monitored until 90d of age. Water and starter were provided ad libitum during the entire experiment. Corn silage was included in the diet during the postweaning period (70d of age). Feed intake and health scores were evaluated daily. Body weight and body frame development were recorded weekly. Starting at 14d, ruminal pH was measured every other week. Laboratory analysis determined that the actual TS contents of the liquid feed were 13.5, 16.1, 18.2, and 20.4%, for the proposed 12.5, 15.0, 17.5, and 20.0% TS treatments, respectively. The osmolality of liquid feed treatments was 265 to 533mOsm/L. Intake of liquid feed was similar among treatments from 4wk of age. During the preweaning period, starter intake, fecal score, and days with diarrhea were similar among treatments. Ruminal pH at weaning averaged 6.2 and was similar among treatments. Increasing concentrations of TS in the liquid feed were associated with linear increases in average daily gain, final body weight, and growth performance, but linear decreases in feed efficiency. During the postweaning period, intake of starter, corn silage, and water were similar among treatments, as well as average daily gain and feed efficiency. Final body weight and growth performance during the postweaning period also increased linearly with concentration of TS in liquid feed. Increasing the concentration of TS in liquid feed up to 20.4% increased performance and body frame development in dairy heifers during the pre- and postweaning periods and had no effects on solid feed intake or health.

Desempenho e parâmetros sanguíneos de bezerros em sistema de desaleitamento precoce suplementados com probiótico de bactérias ruminais

RESUMO Vinte bezerros mestiços da raça Holandês x Jersey, distribuídos em blocos completos casualizados, foram utilizados para determinar o efeito do fornecimento de probiótico de bactérias ruminais sobre o desempenho e os parâmetros sanguíneos de bezerros leiteiros em sistema de desaleitamento precoce. Os animais foram submetidos ao tratamento controle ou ao fornecimento via oral de 2g de probiótico/dia durante o aleitamento. Os bezerros receberam 6 litros de sucedâneo lácteo por dia divididos em duas refeições diárias e foram desaleitados de forma gradual na 6ª semana de vida, entretanto, as variáveis foram coletadas até a 10ª semana. O consumo de concentrado inicial e o escore fecal foram registrados diariamente. Semanalmente foram realizadas pesagens e medidas corporais como, altura de cernelha, largura de garupa e perímetro torácico. Foram realizadas colheitas de sangue nas semanas, 2, 4, 6, 8 e 10, 2h após o primeiro aleitamento, para determinação de concentrações plasmáticas de glicose, proteína total, albumina, β-hidroxibutirato e cortisol. A suplementação de probiótico não afetou o consumo de concentrado, o peso, o ganho de peso, e as medidas corporais dos animais. Não houve efeito sobre o escore fecal entre os tratamentos. Os parâmetros sanguíneos não foram alterados em resposta ao fornecimento do probiótico, apenas a concentração de cortisol, que foi maior nos animais suplementados. O fornecimento de probiótico de bactérias ruminais não favorece o desempenho e o metabolismo de bezerros leiteiros em sistema de desaleitamento precoce.

Microbial competition between Bacillus subtilis and Staphylococcus aureus monitored by imaging mass spectrometry

Microbial competition exists in the general environment, such as soil or aquatic habitats, upon or within unicellular or multicellular eukaryotic life forms. The molecular actions that govern microbial competition, leading to niche establishment and microbial monopolization, remain undetermined. The emerging technology of imaging mass spectrometry (IMS) enabled the observation that there is directionality in the metabolic output of the organism Bacillus subtilis when co-cultured with Staphylococcus aureus. The directionally released antibiotic alters S. aureus virulence factor production and colonization. Therefore, IMS provides insight into the largely hidden nature of competitive microbial encounters and niche establishment, and provides a paradigm for future antibiotic discovery.

Impact of probiotic administration on the health and fecal microbiota of young calves: a meta-analysis of randomized controlled trials of lactic acid bacteria

Before weaning, dairy calves are susceptible to many pathogens which can affect their subsequent performance. The use of lactic acid bacteria (LAB) has been identified as a tool to maintain the intestinal microbial balance and to prevent the establishment of opportunistic pathogenic bacterial populations. However, a consensus has not been reached as to whether probiotics may be effective in reducing the prevalence of gastrointestinal diseases in young calves. The aim of this meta-analysis was to assess the effect of probiotics on diarrhea incidence and the intestinal microbial balance. LAB supplementation has been shown to exert a protective effect and to reduce the incidence of diarrhea (relative risk, RR=0.437, 95% confidence interval (CI) 0.251-0.761). In the subanalysis, this protective effect of the probiotics against diarrhea was observed only in trials that used whole milk (RR=0.154, 95% CI 0.079-0.301) and trials that used multistrain inocula (RR=0.415, 95% CI 0.227-0.759). Probiotics did not improve the fecal characteristics (standardized mean difference, SMD=-0.4904, 95% CI -1.011-0.035) and were unable to change the LAB:coliforms ratio (SMD=0.016, 95% CI -0.701-0.733). Probiotics showed a beneficial impact on the LAB:coliforms ratio in the subanalysis that included trials that used whole milk (SMD=0.780, 95% CI 0.141-1.418) and monostrain inocula (SMD=0.990, 95% CI 0.340-1.641). The probability of significant effects (probiotic positive effect) in a new study was >0.70 for diarrhea and fecal consistency. Whole milk feeding improved the action of the probiotic effect on the incidence of diarrhea and LAB:coliforms ratio. The probability to find significant effects in the diarrhea frequency and LAB:coliforms ratio was higher (P>0.85) if the new studies were conducted using whole milk to feed calves. This paper defines the guidelines to standardize the experimental designs of future trials. LAB can be used as growth promoters in calves instead of antibiotics to counteract the negative effects of their widespread use.

Effects of Bacillus subtilis natto on performance and immune function of preweaning calves

The effects of Bacillus subtilis natto on performance and immune function of dairy calves during the preweaning phase were investigated in this study. Twelve Holstein male calves 7 ± 1 d of age were randomly allotted to 2 treatments of 6 calves. The Bacillus subtilis natto was mixed with milk and fed directly to the calves. The calves were weaned when their starter intake reached 2% of their weight. Blood was collected and IgA, IgE, IgG, IgM, and cytokine levels in the serum of all the calves were determined. The results showed that Bacillus subtilis natto increased general performance by improving the average daily gain and feed efficiency and advanced the weaning age of the calves. No difference was observed in serum IgE, IgA, and IgM, whereas serum IgG was higher in the Bacillus subtilis natto-supplemented calves than in the control calves. Furthermore, calves fed with Bacillus subtilis natto were found to secrete more IFN-γ, but tended to produce less IL-4 than did the control calves, although serum IL-6 and IL-10 were not affected. This study demonstrated that Bacillus subtilis natto did not stimulate IgE-mediated allergic reactions, but increased serum IgG and IFN-γ levels in the probiotic-fed calves. We propose that the viable probiotic characteristics of Bacillus subtilis natto benefit calf immune function.

Evaluation of the bacterial diversity in the feces of cattle using 16S rDNA bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP)

BACKGROUND

The microbiota of an animal's intestinal tract plays important roles in the animal's overall health, productivity and well-being. There is still a scarcity of information on the microbial diversity in the gut of livestock species such as cattle. The primary reason for this lack of data relates to the expense of methods needed to generate such data. Here we have utilized a bacterial tag-encoded FLX 16s rDNA amplicon pyrosequencing (bTEFAP) approach that is able to perform diversity analyses of gastrointestinal populations. bTEFAP is relatively inexpensive in terms of both time and labor due to the implementation of a novel tag priming method and an efficient bioinformatics pipeline. We have evaluated the microbiome from the feces of 20 commercial, lactating dairy cows.

RESULTS

Ubiquitous bacteria detected from the cattle feces included Clostridium, Bacteroides, Porpyhyromonas, Ruminococcus, Alistipes, Lachnospiraceae, Prevotella, Lachnospira, Enterococcus, Oscillospira, Cytophage, Anaerotruncus, and Acidaminococcus spp. Foodborne pathogenic bacteria were detected in several of the cattle, a total of 4 cows were found to be positive for Salmonella spp (tentative enterica) and 6 cows were positive for Campylobacter spp. (tentative lanienae).

CONCLUSION

Using bTEFAP we have examined the microbiota in the feces of cattle. As these methods continue to mature we will better understand the ecology of the major populations of bacteria the lower intestinal tract. This in turn will allow for a better understanding of ways in which the intestinal microbiome contributes to animal health, productivity and wellbeing.

Calf nutrition from birth to breeding

The general principles of growth and nutrients required are no different for young calves than for any other species. Additional complexity is introduced, however, by the need to transition the young preruminant to functioning ruminant. The nutritional and digestive physiology of dairy calves as future ruminants needs to be the governing factor in designing practical feeding systems to meet nutrient requirements. Key aspects common to all systems include the composition and amount of liquid feed, water availability, and the first starter feeds offered. This article focuses on nutrition of calves before weaning and to breeding age, with primary emphasis on the preweaning and transition phases.

The use of bacterial spore formers as probiotics: Table 1

The field of probiosis has emerged as a new science with applications in farming and aqaculture as alternatives to antibiotics as well as prophylactics in humans. Probiotics are being developed commercially for both human use, primarily as novel foods or dietary supplements, and in animal feeds for the prevention of gastrointestinal infections, with extensive use in the poultry and aquaculture industries. The impending ban of antibiotics in animal feed, the current concern over the spread of antibiotic resistance genes, the failure to identify new antibiotics and the inherent problems with developing new vaccines make a compelling case for developing alternative prophylactics. Among the large number of probiotic products in use today are bacterial spore formers, mostly of the genus Bacillus. Used primarily in their spore form, these products have been shown to prevent gastrointestinal disorders and the diversity of species used and their applications are astonishing. Understanding the nature of this probiotic effect is complicated, not only because of the complexities of understanding the microbial interactions that occur within the gastrointestinal tract (GIT), but also because Bacillus species are considered allochthonous microorganisms. This review summarizes the commercial applications of Bacillus probiotics. A case will be made that many Bacillus species should not be considered allochthonous microorganisms but, instead, ones that have a bimodal life cycle of growth and sporulation in the environment as well as within the GIT. Specific mechanisms for how Bacillus species can inhibit gastrointestinal infections will be covered, including immunomodulation and the synthesis of antimicrobials. Finally, the safety and licensing issues that affect the use of Bacillus species for commercial development will be summarized, together with evidence showing the growing need to evaluate the safety of individual Bacillus strains as well as species on a case by case by basis.

Effects of Mannan Oligosaccharide or Antibiotics in Neonatal Diets on Health and Growth of Dairy Calves

Seventy-two Holstein calves were used to study the effect of feeding antibiotics or mannan oligosaccharides (MOS) in milk replacer. Calves were fed a 20% protein, 20% fat milk replacer containing antibiotics (400 g/ton neomycin + 200 g/ton oxytetracycline), MOS (4 g of Bio-Mos/d), or no additive (control) for 5 wk. Milk replacer was reconstituted to 12.5% dry matter and fed at 12% of birth weight during wk 1 and 14% of birth weight in wk 2 to 5. Fecal scores were monitored 3 times per week; body weight, heart girth, withers height, hip height, and hip width were measured at birth and weekly to 6 wk of age. Addition of MOS or antibiotics increased the probability of normal scores for fecal fluidity, scours severity, and fecal consistency as compared to control calves during the course of the study. Consumption of calf starter increased at a faster rate in calves fed MOS, and these calves consumed more calf starter after weaning (wk 6), than those fed antibiotic. No treatment differences in growth measures, total blood protein, or blood urea nitrogen were detected during the trial. Addition of MOS or antibiotics to milk replacer improved fecal scores in calves. Feed intake was improved in MOS-fed calves compared to antibiotic-fed calves, but this difference did not result in growth differences during the experimental period. The results suggest that antibiotics in milk replacers can be replaced with compounds such as mannan oligosaccharides to obtain similar calf performance.

Increase in milk yield of commercial dairy herds fed a microbial and enzyme supplement

A microbial and enzyme supplement fed at 21.2 g/d per cow to 46 Virginia dairy herds increased the milk yield of 31 herds (17 significantly) and decreased the milk yield of 15 herds (7 significantly). Effects of season were important but consistent with overall results. Herds began receiving the supplement, which contained dried fermentation products of Aspergillus oryzae, Bacillus subtilis, Lactobacillus acidophilus, and yeast culture, midway between the first and second monthly Dairy Herd Improvement tests and continued on the supplement through the 3rd mo. Entry of herds was staggered over 8 mo to reduce the influence of season. The trial involved 3417 cows with 5 test mo between 60 and 365 d in milk. Milk yield during mo 3 averaged 0.64 kg/d per cow more (+0.73 kg/d for first lactation cows and +0.56 kg/d for later lactation cows) than the mean milk yield during mo 1 and 5. Herds completing the study before summer responded similarly to all other herds, which included herds that were fed the product during summer and those that finished the study during summer. Fat and protein yields and protein percentage differed little with or without the supplement. Fat percentage decreased (0.10%). Twenty-one herds that were fed a yeast product prior to and during the study responded similarly to the 17 herds that were not fed a yeast product.

Body weight gain, feed efficiency, and fecal scores of dairy calves in response to galactosyl-lactose or antibiotics in milk replacers

Holstein bull calves (n = 96) were purchased at approximately 7 d of age and were assigned to receive 400, 450, 500, and 550 g/d of milk replacer solids during wk 1 to 4, respectively. Treatments were nonmedicated milk replacer plus dried whey, medicated milk replacer (138 mg/kg of oxytetracycline and 276 mg/kg of neomycin) plus dried whey, or nonmedicated milk replacer plus whey processed with beta-galactosidase to contain 15% galactosyl-lactose. Processed whey was added to provide 1% of dry matter as galactosyl-lactose; an equivalent amount of dried whey was added to the other treatments to provide 6.3% of dry matter daily. Intake of milk replacer and fecal scores were measured daily. No calf starter or hay was fed. Body weights were measured weekly from arrival to 26 d. Serum immunoglobulin G, measured 1 d after arrival, averaged 18.3 g/L. Intake of milk replacer plus additive during the 26-d study was 445 g/d and did not vary with treatment. Body weight and body weight gain were increased by 52 and 72 g/d in response to antibiotics and galactosyl-lactose, respectively. Severity of scours and number of days scouring tended to be reduced when calves were fed milk replacer containing galactosyl-lactose or antibiotics.

Effect of Lactobacillus acidophilus supplementation of milk replacer on preweaning performance of calves

Forty Holstein-Friesian calves were used to evaluate the effect on young calves of daily dietary supplementation with Lactobacillus acidophilus. Calves were randomly assigned at 2 d of age to one of two treatments; 1) milk replacer with no additives or 2) milk replacer supplemented with 1 ml (5 x 10(7)) of viable L. acidophilus bacteria at each of two feedings per day. Milk replacer was reconstituted to 12% DM and fed at 10% of BW/d for the duration of the 6-wk trial. A commercial starter pellet was offered for ad libitum intake from 7 d of age. Treatment had no effect on actual BW at any stage or on total BW gain; however, average daily gain during wk 2 was affected by L. acidophilus supplementation. Calves receiving L. acidophilus maintained initial BW, and the control calves lost BW until 2 wk of age, at an average rate of 112 g/d. Starter intake, total DMI, feed efficiency, and occurrence of diarrhea were unaffected by treatment. Therefore, L. acidophilus supplementation for calves fed milk replacer may be beneficial during the first 2 wk of life.