70 research outputs found

    Using bacterial inoculants to control the growth of E. coli O157:H7 in maize silages under anaerobic and aerobic conditions.

    Get PDF
    The aim was to determine if bacterial inoculants could eliminate E. coli O157:H7 (ECOL) in contaminated corn silages and if inoculants transferred antibacterial activity to silages. Chopped corn forage was ensiled in triplicate after treatment with:1) distilled water (control); 2) 5 x 105 cfu/g of ECOL (EC); 3) EC and 1 x 106 cfu/g of Pediococcus pentosaceus and Propionibacterium freudenreichii (EC+BII); 4) EC and 1 x 106 cfu/g of Lactobacillus buchneri (LB; EC+LB); 5) EC and 1 x 106 cfu/g of LB and P. pentosaceus (EC+B500). Silos were opened after 3, 7, 31, and 82 d and analyzed for pH and ECOL counts as well as VFA, lactate, and aerobic stability on d 82. By d 3, all silages had pH was <4 (SE=0.33; p=1) and pH did not increase subsequently; therefore ECOL was not detected in any silage. The Kirby-Bauer disc diffusion test showed that all pure cultures of inoculants had pH-independent antibacterial activity against ECOL but inoculated silages did not, suggesting that ECOL elimination was mediated by pH reduction. Inoculation with LB resulted in less lactate (SE=0.31; p<0.05), more acetate (SE=0.35; p<0.05), and greater aerobic stability (SE=7.1; p<0.05) versus control. Day-82 silages were reinoculated with EC at silo opening (immediate) or after 144 h of exposure (delay) and ECOL were enumerated 24 h later. All immediately reinoculated silages had low pH values (<4) and no ECOL 24 h later. Control, EC, and EC+BII silages reinoculated after the delay had relatively high pH values (4.71, 5.67, and 6.03) (SE=0.74; p<0.05) and ECOL counts (2.87, 6.73, and 6.87 log cfu/g) (SE=1.4; p<0.05), whereas those treated with LB had low pH values (<4) and undetectable (EC+B500) or low ECOL counts (1.96, cfu/g; EC+LB). Inoculants did not enhance elimination of ECOL during ensiling, but L. buchneri inoculants increased stability and eliminated or inhibited ECOL in aerobically exposed silages

    Mitigation of methane and nitrous oxide emissions from animal operations: III. A review of animal management mitigation options

    Get PDF
    The goal of this review was to analyze published data on animal management practices that mitigate enteric methane (CH4) and nitrous oxide (N2O) emissions from animal operations. Increasing animal productivity can be a very effective strategy for reducing greenhouse gas (GHG) emissions per unit of livestock product. Improving the genetic potential of animals through planned cross-breeding or selection within breeds and achieving this genetic potential through proper nutrition and improvements in reproductive efficiency, animal health, and reproductive lifespan are effective approaches for improving animal productivity and reducing GHG emission intensity. In subsistence production systems, reduction of herd size would increase feed availability and productivity of individual animals and the total herd, thus lowering CH4 emission intensity. In these systems, improving the nutritive value of low-quality feeds for ruminant diets can have a considerable benefit on herd productivity while keeping the herd CH4 output constant or even decreasing it. Residual feed intake may be a tool for screening animals that are low CH4 emitters, but there is currently insufficient evidence that low residual feed intake animals have a lower CH4 yield per unit of feed intake or animal product. Reducing age at slaughter of finished cattle and the number of days that animals are on feed in the feedlot can significantly reduce GHG emissions in beef and other meat animal production systems. Improved animal health and reduced mortality and morbidity are expected to increase herd productivity and reduce GHG emission intensity in all livestock production systems. Pursuing a suite of intensive and extensive reproductive management technologies provides a significant opportunity to reduce GHG emissions. Recommended approaches will differ by region and species but should target increasing conception rates in dairy, beef, and buffalo, increasing fecundity in swine and small ruminants, and reducing embryo wastage in all species. Interactions among individual components of livestock production systems are complex but must be considered when recommending GHG mitigation practices

    Evaluation of probabilistic models for characterizing design low-flows of River Ogun, Southwest Nigeria

    Get PDF
    Information of low-flow is important for maintaining instream flow, conserving biodiversity, enhancing food production, industrial abstraction, tourism and dilution of effluents from industries and households. This study establishes suitable probabilistic models for characterizing different durations of design low-flows of Ogun River. The adequacy of fit of four probability distributions, namely Reversed Generalized Extreme Value (GEVR) distribution, Generalized Normal (GNO) distribution, Generalized Logistic (GLO) distribution and Pearson Type III (PE3) were evaluated using the Anderson-Darling (A2) goodness-of-fit statistic and the D-index diagnostic test. The study revealed that GLO is best suited for predicting the annual minimal, 3-day minima, 7-day minima, 10-day minima, 15-day minima and 30-day minima based on the A2 and D-index values. Six mathematical models derived from probability plots were established to relate the different low-flow series to their non-exceedance probability. The models could be used for characterizing low-flows and for water resources management of Ogun River Basin

    Livestock feed resources in the West African Sahel

    No full text
    Limited supply of quality feed is the most important factor limiting livestock productivity in many sub‐Saharan African (SSA) countries. Having a systematic inventory of available feed resources, identifying main challenges and potentials for improvement is the first step towards designing development strategies to improve feed quality and quantity. The objective of this study was to review the available feed resources and their quality in West African Sahel across different agro‐ecological zones and to identify the research gaps and strategies to improve feed resource availability. The West African Sahelian zone is home to 135 million people who herd 173 million head of ruminant livestock. The main feed resources for grazing ruminants are pastures and crop residues; commercially formulated feeds are increasingly being used in poultry and pig production, particularly in peri‐urban areas. Feed resources for livestock are diverse and vary markedly across agro‐ecological zones in the West African Sahel and across seasons in terms of type, quantity, and quality. Given that crop residues are among the most important feed resources, there is need to invest in promoting adoption of proven methods for improving their quality and preserving it. Given poorly developed feed markets in the Sahelian rural areas and cities, strengthening the feed value chain is critical for improving the feed resource base in West Africa. Additional critically important needs are to increase awareness about the importance of feed quality, to create quality‐based feed marketing systems, and to appreciate and enhance women's roles in feed production
    corecore