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

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

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

Implications of new technologies for future food supply systems

The combination of advances in knowledge, technology, changes in consumer preference and low cost of manufacturing is accelerating the next technology revolution in crop, livestock and fish production systems. This will have major implications for how, where and by whom food will be produced in the future. This next technology revolution could benefit the producer through substantial improvements in resource use and profitability, but also the environment through reduced externalities. The consumer will ultimately benefit through more nutritious, safe and affordable food diversity, which in turn will also contribute to the acceleration of the next technology. It will create new opportunities in achieving progress towards many of the Sustainable Development Goals, but it will require early recognition of trends and impact, public research and policy guidance to avoid negative trade-offs. Unfortunately, the quantitative predictability of future impacts will remain low and uncertain, while new chocks with unexpected consequences will continue to interrupt current and future outcomes. However, there is a continuing need for improving the predictability of shocks to future food systems especially for ex-ante assessment for policy and planning

Livestock feed resources in the West African Sahel

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

Control of E. coli O157:H7 in corn silage with inoculants under anaerobic and aerobic conditions.

Previous research in our laboratory demonstrated hormones known to respond to changing day length can influence fecal shedding of E. coli O157:H7 in cattle. Continuing with this research, we examined the effect of serum prolactin concentrations on fecal shedding of E. coli O157:H7 and cellular immune response. 2?Bromo???ergocryptine methanesulfonate salt (BROMO) a dopamine agonist and sulpiride a D?2 dopamine receptor blocker were administered to decrease and increase prolactin levels, respectively. Fifteen Holstein steers experimentally infected with E. coli O157:H7 were randomly assigned to receive BROMO (0.05 mg/ kg BW), sulpiride (0.05 mg/kg BW) or control (ethanol) via s.c. injection, twice daily. Fecal samples were collected daily and shedding of E. coli O157:H7 was determined via an immunomagnetic separation technique. Blood samples were collected via jugular venipuncture for analysis of serum prolactin concentrations and circulating neutrophils were isolated from peripheral blood on d 7 and 14 and degranulation and oxidative burst (OB) assays conducted. When examined over the 14-d experimental period, BROMO decreased (P = 0.0001) the percentage of cattle shedding E. coli O157:H7 (56% vs. 25.33% for control and BROMO treatments, respectively) while sulpiride had no effect (P > 0.10). BROMO decreased (P 0.10). Oxidative burst by neutrophils for BROMO vs. control showed no significant difference on d 7, however, on d 14 OB by neutrophils tended to be higher for BROMO vs. controls (P = 0.08). Serum prolactin concentrations tended to be negatively correlated with OB (P = 0.09). No significant differences were observed for degranulation in BROMO vs. control on either d 7 or14. These results support our hypothesis that hormones influenced by day length are responsible for the seasonality of E. coli O157:H7

Tropical plant supplementation effects on the performance and parasite burden of goats

Objective Examine the effects of supplementing bahiagrass hay (BG) with potentially anthelmintic quantities of hays of perennial peanut (PEA) or sericea lespedeza (LES) or seeds of velvet bean (Mucuna pruriens L.; MUC) or papaya (PAP) on the intake and nutritive value (Experiment 1), and the performance and parasite burden (Experiment 2) of goats. Methods In Experiment 1, 38 male goats (27.4±5.7 kg body weight) were randomly assigned to each of 5 treatments: i) BG alone and BG plus; ii) PEA; iii) LES; iv) MUC; and v) PAP. Goats were fed for ad libitum consumption and adapted to the diets for 14 d followed by 7 d of measurement. The PEA, LES, MUC (50%, 50%, and 10% of the diet dry matter [DM], respectively), and PAP (forced-fed at 10 g/d) were fed at rates that would elicit anthelmintic effects. In Experiment 2, goats remained in the same treatments but were allocated to 15 pens (3 pens per treatment) from d 22 to 63. All goats were infected with parasites by grazing an infected bahiagrass pasture from 0800 to 1500 h daily and then returned to the pens. Results Dry matter intake tended to be greater in goats fed PEA and LES than those fed BG (757 and 745 vs 612 g/d, respectively). Digestibility of DM (59.5% vs 54.9%) and organic matter (60.8% vs 56.0%) were greater in goats fed MUC vs BG, respectively. In Experiment 2, feeding PAP, LES, and PEA to goats reduced nematode fecal egg counts by 72%, 52%, and 32%, reduced abomasal adult worm counts by 78%, 52%, and 42%, and decreased plasma haptoglobin concentrations by 42%, 40%, and 45% relative to feeding BG alone, respectively. Conclusion Supplementation with PEA, LES, and PAP decreased the parasite burden of goats but did not increase their performance. PAP was the most effective anthelmintic supplement