Cracked Maize Research Articles

Maximizing Laboratory Production of Aflatoxins and Fumonisins for Use in Experimental Animal Feeds.

Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 °C for 21 days had the highest AFB1 level of 12,550 ± 3397 μg/kg of substrate. The highest level of total FBs (386,533 ± 153,302 μg/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22-25 °C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials.

Dangerous liaisons of three key secondary stored-product pests in cracked maize

The current study examines the relationships of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) with Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Tenebrio molitor L. (Coleoptera: Tenebrionidae) through Gaussian and Poisson regression models on cracked maize. For this purpose, variable temperatures (25 °C, 30 °C, and 35 °C), relative humidities (RH) (55% and 75%), exposure intervals (65 days, 130 days, and 195 days), and insect combinations (the insect species alone and the combinations per 2 or 3 species that included O. surinamensis) were utilized. Poisson model was the most suitable for the response insects alive while Gaussian model for the weight loss. The increase of temperature from 25 °C to 30 °C and from 30 °C to 35 °C led to a gradual decrease of insects alive and a gradual increase of weight loss, while the enhancement of RH caused increase of both responses. At the 195 days of storage period, insects alive reduced whereas weight loss amplified. The combinations of insects that led to the highest and the lowest numbers of insects alive were O. surinamensis alone and T. molitor alone respectively. The most damaging combination was O. surinamensis-T. molitor while the least damaging was T. molitor alone. Findings of the current study enrich the existing knowledge of the relationships of three secondary stored-product insects in processed maize. The complexity of their coexistence is linked with the forecast of the contingent damage of the insect activity during the storage period.

Fusarium abutilonis and F. guadeloupense, two novel species in the Fusarium buharicum clade supported by multilocus molecular phylogenetic analyses

ABSTRACT This study was conducted to elucidate evolutionary relationships and species diversity within the Fusarium buharicum species complex (FBSC). We also evaluate the potential of these species to produce mycotoxins and other bioactive secondary metabolites. Maximum likelihood and maximum parsimony analyses of sequences from portions of four marker loci (ITS rDNA, TEF1, RPB1, and RPB2) and the combined 4495 bp data set support recognition of seven genealogically exclusive species within the FBSC. Two of the three newly discovered species are formally described as F. abutilonis and F. guadeloupense based on concordance of gene genealogies and morphological data. Fusarium abutilonis induces leaf, stem, and root lesions on several weedy Malvaceae (Abution theophrasti, Anoda cristata, Sida spinosa) and a fabaceous host (Senna obtusifolia) in North America and also was recovered from soil in New Caledonia. Fusarium abutilonis, together with its unnamed sister, Fusarium sp. ex common marsh mallow (Hibiscus moscheutos) from Washington state, and F. buharicum pathogenic to cotton and kenaf in Russia and Iran, respectively, were strongly supported as a clade of malvaceous pathogens. The four other species of the FBSC are not known to be phytopathogenic; however, F. guadeloupense was isolated from human blood in Texas and soil in Guadeloupe. The former isolate is unique because it represents the only known case of a fusarial infection disseminated hematogenously by a species lacking microconidia and the only documented fusariosis caused by a member of the FBSC. Whole genome sequence data and extracts of cracked maize kernel cultures were analyzed to assess the potential of FBSC isolates to produce mycotoxins, pigments, and phytohormones.

Developmental and reproductive biology of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) on seven commodities

This study examines the effect of semolina, cracked wheat, maize flour, cracked maize, whole oat flakes, whole barley flour and cracked barley on the developmental and reproductive biology of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). The pest completed its development at all tested commodities except semolina and cracked wheat, while females did not produce eggs on maize flour and cracked barley. The developmental time of larvae was significantly longer when O. surinamensis fed on whole oat flakes (20.3 days) and whole barley flour (19.2 days) compared with maize flour (16.6 days) or cracked maize (17.2 days). The developmental duration of larvae fed on cracked barley (18.3 days) did not differ significantly when fed on cracked maize or whole barley flour, but it was significantly longer compared to maize flour and significantly shorter compared to whole oat flakes. The tested commodities did not affect the pupal development, which ranged between 4.6 and 4.7 days. The highest fecundity was recorded when O. surinamensis fed on cracked maize (4.8 eggs/female) and whole oat flakes (0.3 eggs/female). The tested commodities also affected the risk of death of O. surinamensis and its mean survival time. The shortest survival time was recorded on cracked wheat (11.1 days) while the longest was on cracked maize and whole oat flakes (37.8 and 42.2 days, respectively). The calculation of demographic parameters was feasible only on cracked maize. The net reproductive rate, the intrinsic rate of increase, the finite rate of increase and the mean generation time were 1.48 females/female, 0.01 females/female/day, 1.01 and 37.1 days, respectively. These results may be useful for improving the knowledge on the biology of this species and its potential spread.

Suitability of Semolina, Cracked Wheat and Cracked Maize as Feeding Commodities for Tribolium castaneum (Herbst; Coleoptera: Tenebrionidae).

In the current study it was investigated the suitability of semolina, cracked wheat and cracked maize as feeding commodities for the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The pest completed its development on all tested commodities. The developmental time of larvae was lower on cracked wheat (59.6 days) and cracked maize (54.6 days) compared to semolina (72.8 days). The developmental time of pupae did not differ significantly among tested commodities, ranging from 6.2 to 6.6 days. Female and male longevities were 70.9 and 77.1 days, 92.2 and 77.9 days and 177.0 and 183.7 days, when T. castaneum was fed on semolina, cracked wheat and cracked maize, respectively. The highest fecundity (28.7 eggs/female) was recorded when T. castaneum was fed on semolina, followed by cracked wheat (2.7 eggs/female) and cracked maize (1.2 eggs/female). The prolonged adult longevity, which was observed on cracked maize, may be attributed to the absence of the cost of reproduction, due to low fecundity on this commodity. The values of the intrinsic rate of increase were 0.014 and −0.021 females/female/day when it was fed on semolina and cracked wheat, respectively, while no demographic analysis was carried out for cracked maize due to high early larval mortality and low fecundity on this commodity. The net reproductive rate and mean generation time were 6.19 females/female and 127.5 days and 0.16 females/female and 91.9 days, when it was fed on semolina and cracked wheat, respectively. Based on demographic analysis, T. castaneum population growth is favored only on semolina. We expect semolina to act as a suitable commodity for T. castaneum, while cracked wheat and cracked maize allow only its survival by acting as alternative commodities. The estimated demographic parameters of T. castaneum on the tested commodities could be used as a useful tool to predict its population outcome in storage facilities.

Fusarium xyrophilum, sp. nov., a member of the Fusarium fujikuroi species complex recovered from pseudoflowers on yellow-eyed grass (Xyris spp.) from Guyana

ABSTRACT We report on the discovery and characterization of a novel Fusarium species that produced yellow-orange pseudoflowers on Xyris spp. (yellow-eyed grass; Xyridaceae) growing in the savannas of the Pakaraima Mountains of western Guyana. The petaloid fungal structures produced on infected plants mimic host flowers in gross morphology. Molecular phylogenetic analyses of full-length RPB1 (RNA polymerase largest subunit), RPB2 (RNA polymerase second largest subunit), and TEF1 (elongation factor 1-α) DNA sequences mined from genome sequences resolved the fungus, described herein as F. xyrophilum, sp. nov., as sister to F. pseudocircinatum within the African clade of the F. fujikuroi species complex. Results of a polymerase chain reaction (PCR) assay for mating type idiomorph revealed that single-conidial isolates of F. xyrophilum had only one of the MAT idiomorphs (MAT1-1 or MAT1-2), which suggests that the fungus may have a heterothallic sexual reproductive mode. BLASTn searches of whole-genome sequence of three strains of F. xyrophilum indicated that it has the genetic potential to produce secondary metabolites, including phytohormones, pigments, and mycotoxins. However, a polyketide-derived pigment, 8-O-methylbostrycoidin, was the only metabolite detected in cracked maize kernel cultures. When grown on carnation leaf agar, F. xyrophilum is phenotypically distinct from other described Fusarium species in that it produces aseptate microconidia on erect indeterminate synnemata that are up to 2 mm tall and it does not produce multiseptate macroconidia.

The influence of phytase, pre-pellet cracked maize and dietary crude protein level on broiler performance via response surface methodology

BackgroundThe reduction of crude protein levels in diets for broiler chickens may generate economic, environmental and flock welfare and health benefits; however, performance is usually compromised. Whole grain feeding and phytase may improve the utilization of reduced crude protein diets.ResultsThe effects of pre-pellet cracked maize (0, 15% and 30%) and phytase (0, 750 and 1500 FTU/kg) in iso-energetic maize-soy diets with three levels of crude protein (22%, 19.5% and 17%) were evaluated via a Box-Behnken response surface design. Each of 13 dietary treatments were offered to 6 replicate cages (6 birds/cage) of male Ross 308 broiler chicks from 7 to 28 d post-hatch. Model prediction and response surface plots were generated from experimental data via polynomial regression in R and only significant coefficients were included and discussed in the predicted models. Weight gain, feed intake and FCR were all influenced by pre-pellet cracked maize, phytase and crude protein level, where crude protein level had the greatest influence. Consequently, the reduction from 22% to 17% dietary crude protein in non-supplemented diets reduced weight gain, feed intake, relative gizzard weight, relative gizzard content and relative pancreas weight but improved FCR. However, the inclusion of 30% cracked maize to 17% crude protein diets restored gizzard weight and 1500 FTU phytase inclusion to 17% crude protein diets increased relative gizzard contents and pancreas weights. Cracked maize and phytase inclusion in tandem to 17% crude protein diets increased weight gain, feed intake and FCR; however, this FCR was still more efficient than broilers offered the non-supplemented 22% crude protein diet. Broilers offered the pre-pellet cracked maize and phytase inclusions reduced AME in 22% crude protein diets but improved AME by 2.92 MJ (14.16 versus 11.24 MJ; P < 0.001) in diets containing 17% crude protein. Ileal N digestibility was greater in broilers offered diets with 17% crude protein than those offered the 22% crude protein diet; irrespective of phytase and pre-pellet cracked maize.ConclusionPre-pellet cracked maize and phytase inclusions will improve the performance of broilers offered reduced crude protein diets.

Productive and economic response to partial replacement of cracked maize ears with ground maize or molasses in supplements for dual-purpose cows

The aim of the study was to assess the effect of partial replacement of cracked maize ears with ground maize (GM) or sugar cane molasses (SCM) in supplements for dual purpose cows. Eighteen (18) multiparous cows (414 ± 13 kg of body weight and 106 ± 32 d in milk) were randomly assigned to the treatments. Treatments were as follows: 1) Control supplement (CS) which consisted of 87% of cracked maize ears (CME), 11% soybean meal, and 2% urea; 2) Ground maize replacing 20% of CME in CS (GMS); 3) Sugar cane molasses replacing 18% of CME in the CS (MOS). Each cow received 5 kg/d of supplement DM, whereas their calves received 1.8 kg/d DM of the CS. The experiment lasted eleven weeks, and data were recorded once at the end of every week. Data were analysed using a linear mixed model as a completely randomized design. Net profit from milk and beef due to supplements were estimated using the partial budget approach. There were no differences (P&gt;0.05) between treatments on milk composition, body conditions score, nor daily weight gain of cows and calves. However, compared to GM, CS shown greater (9.0 %, P&lt;0.05) dry matter intake and SCM shown greater milk yield (18.6 %, P&lt;0.05). Partial replacement of cracked maize ears with ground maize or sugar cane molasses, in supplements for dual purpose cows, did not affected animal productive response. However, considered the combined net profit margins (milk and calves), SCM got an average of 9 % higher profits compared of the rest of supplements.

Marasas et al. 1984 “Toxigenic Fusarium Species: Identity and Mycotoxicology” revisited

ABSTRACTThis study was conducted to determine the species identity and mycotoxin potential of 158 Fusarium strains originally archived in the South African Medical Research Council’s Mycotoxigenic Fungal Collection (MRC) that were reported to comprise 17 morphologically distinct species in the classic 1984 compilation by Marasas et al., Toxigenic Fusarium Species: Identity and Mycotoxicology. Maximum likelihood and maximum parsimony molecular phylogenetic analyses of single and multilocus DNA sequence data indicated that the strains represented 46 genealogically exclusive phylogenetically distinct species distributed among eight species complexes. Moreover, the phylogenetic data revealed that 80/158 strains were received under a name that is not accepted today (ex F. moniliforme) or classified under a different species name. In addition, gas chromatography–mass spectrometry (GC-MS) and/or high-performance liquid chromatography–mass spectrometry (HPLC-MS)-based mycotoxin analyses were conducted to determine which toxins the strains could produce in liquid and/or solid cultures. All of the trichothecene toxin–producing fusaria were nested within the F. sambucinum (FSAMSC) or F. incarnatum-equiseti (FIESC) species complexes. Consistent with this finding, GC-MS analyses detected trichothecenes in agmatine-containing broth or rice culture extracts of all 13 FSAMSC and 10/12 FIESC species tested. Species in six and seven of the eight species complexes were able to produce moniliformin and beauvericin, respectively, whereas B-type fumonisins were only detected in extracts of cracked maize kernel cultures of three species in the F. fujikuroi (FFSC) species complex.

Effects of replacing dietary maize grains with increasing levels of sugar beet pulp on rumen fermentation constituents and performance of growing buffalo calves

This study was conducted to evaluate the effects of replacing cracked maize with increasing levels of sugar beet pulp (SBP) on nutrients digestibility, blood biochemical and rumen fermentation constituents and animal performance of growing Egyptian buffalo calves. Forty male Egyptian buffalo calves (237.2±24.46kg of initial body weight, IBW) were allocated into a completely randomized design and stratified to one of four experimental diets. The basal diet was isonitrogenous (40:60 forage: concentrate) and was formulated to contain 60% of dietary DM cracked maize replaced by ascending levels of SBP (0, 333, 667, and 1000g/kg respectively). The study lasted for a period of 143days from which 21days for adaptation while the remaining 122days were used for data collection. Increasing the level of SBP resulted in a quadratic increase (P=0.017) in the average daily gain (ADG) with a linear tendency of increase (P=0.064) in dietary dry matter intake. A quadratic decrease of feed conversion ratio (FCR, P=0.005) was observed with the ascending levels of SBP. In addition, the daily intake of organic matter, neutral detergent fiber assayed with heat stable α-amylase and corrected for ash (aNDFom), acid detergent fiber corrected for ash (ADFom) were quadratically (P<0.01) improved upon increasing the dietary SBP level while the daily intake and digestibility of ether extract were declined linearly (P<0.01). Replacing SBP for maize resulted in linear increase (P<0.01) in OM, aNDFom, cellulose and hemicellulose digestibility coefficients. Ruminal pH, total short chain fatty acids, proportions of acetate (C2) and butyrate were increased linearly (P<0.05). In contrast, the proportions of propionate (C3) and isobutyrate were decreased linearly (P<0.05) upon increasing the levels of SBP. In addition, the C2:C3 ratio and total protozoa were linearly (P<0.01) increased while the ruminal NH3-N concentration was quadratically (P=0.046) increased as SBP replaced maize in the diet. Furthermore, upon increasing the dietary SBP levels, the blood urea-N, cortisol and thyroxin (T4) concentrations were quadratically elevated (P<0.01). Conversely, linear decreases in creatinine, (P=0.027) and cholesterol (P=0.001) concentrations were found. In addition, blood insulin like growth factor-1 (IGF-1) concentration increased linearly (P=0.006) as SBP level increased. Feeding cost based on BW gain was linearly reduced (P=0.043) by 25%, causing the overall profits ($/head/d) to be quadratically (P<0.01) increased. Overall, the obtained results indicate that replacing maize grains with up to 667g SBP/kg diet resulted in a highest profit by 21%, enhanced ruminal fermentation, nutrients digestibility and ADG and reduced FCR. Therefore, this study could be economically feasible for use in fattening diets of growing Egyptian buffalo calves without impairing animal performance or health.

Influence of commodity on the population growth of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae)

In this study, we compared different amylaceous commodities for their suitability for population growth of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. In this context, we conducted three different series of tests. In the first test, we compared whole grains: whole barley, peeled barley, maize, whole oats, peeled oats, peeled rice, rough rice, rye, triticale, and wheat. Only maize was found suitable for P. trunctatus to reproduce and significantly increase its population, but there were certain commodities where surviving adults were found. In the second series of tests, we evaluated the percentage of cracked maize kernels on P. truncatus population growth. In this test, we found that the numbers of alive P. truncatus adults in the vials that contained 100% cracked kernels was higher than these with lower percentages of cracked kernels (5–50%) or no cracked kernels (0%). Finally, in the third series of tests, we compared eleven different types of amylaceous commodities with maize. These commodities were: whole maize (whole kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour, and semolina. The results indicated that only whole maize and maize flour were suitable for P. truncatus population growth. Nevertheless, in some of the other commodities tested, there was a low number of adults and immatures that were able to survive 60 days after the incorporation of the parental adults. The results of the present study indicate that from the commodity range tested here, only maize was suitable for P. truncatus population growth. Nevertheless, the marginal numbers of surviving individuals in the non-maize commodities and the role of these substrates as potential “non-preferred food vehicles” that may contribute to further spread of this species should be tested in more detail.

Serological response and protection level evaluation in chickens exposed to grains coated with I2 Newcastle disease virus for effective oral vaccination of village chickens.

BackgroundConventional Newcastle disease (ND) vaccination strategies in village chicken production settings is impractical due to shortage of cold-chain, unsuitability of vaccine administration routes and demanding trained personnel and hence affected its adoption. Results from earlier works elsewhere showed that the heat stable vaccines such as NDI2 are thought to be promising for village chickens. This study investigated the suitability and efficacy of Ethiopian cereal grains as carriers for the orally administrated NDI2 vaccine in chickens.ResultsOf the 15 treatment groups, drinking water, cracked maize and parboiled barley induced significantly higher HI antibody titer than the other carrier grains and naive control. The higher mean HI titer of chickens in drinking-water, cracked maize and parboiled barley group resulted in 100 % survival rate. In general, there was an inverse relationship between chicken mortality (%) and mean HI titer. Chickens with higher HI antibody titers had better survival rate to the challenge experiment. Booster vaccination at age of day 35 and 105 induced progressively higher HI antibodies titers in all treatment groups.ConclusionsVaccine coated parboiled grains could be a good carrier followed by cracked grains while untreated vaccine carrier grains had lower serological responses and protection levels. The current finding gives insights on suitable vaccine delivery system in villages with weak health and transportation infrastructure, unreliable electricity, and minimally trained health workers without catching chickens individually.

Molasses supplementation for dual-purpose cows during the dry season in subtropical Mexico.

The effect of including 9% of molasses in supplements offered to dual purpose cows, during dry season in subtropical Mexico was determined. Forage availability in pastures during the dry season is reduced and of low quality. Molasses is a readily available source of energy that may improve forage utilization and could have a positive effect on cow's milk production and calves daily weight gain (CDWG). Twelve multiparous Brown Swiss cows (409 ± 33kg of body weight and 136 ± 73days in milk), and their calves were randomly assigned to two supplements (six cows per treatment). Control supplement (COS) consisted of cracked maize ears (CME), soybean meal and urea (14% CP), and experimental supplement in which 9% of CME was replaced by molasses (MOS). Cows received 4.5kg/cow/day dry matter (DM) of supplement. Experiment lasted 10weeks divided in five experimental periods (EP). Animal responses (milk yield, milk composition, body weight, body condition score and CDWG) were recorded at the end of every EP. A linear mixed model was used to analyse the data as a complete random design. Net profits from milk and beef due to supplements were estimated using partial budget approach. Average milk yield was 7 (kg/cow/day) with 30.6, 30.4 and 42.5 (g/kg milk) of fat, protein and lactose, respectively. Average cow weight was 422kg and CDWG was 0.8kg/day. No significant responses on animal production variables were found when 9% of MOS was included in the supplement; however, total net income increased on 4%, due to higher CDWG.

English

The study was conducted to assess the suitability of soaked parboiled cracked maize as a carrier of I-2 vaccine for oral immunization of village chickens. Chickens were vaccinated once via ocular route and orally with cracked maize at the second and fifth weeks of the experiment. Post vaccination serum was collected 4, 7, 9 and 11 weeks of the experiment and haemagglutination inhibition test was done to evaluate the antibody titer. The results show that chickens vaccinated via ocular route produce geometric mean log2 HI antibody titers of 5.71 and 5.51 at the fourth and seventh weeks of the experiment, respectively. On the other hand, the antibody titer of chickens vaccinated with coated cracked maize vaccine was 2.54 during the first vaccination; and during the booster vaccination, the titter increased to 2.92. Among the chickens vaccinated via ocular route, 90% (during the first vaccination) and 84.2% (during the booster vaccination) have titer above the protection titer of 3. Similarly, for chickens under cracked maize group, 54 and 74.8% of them were able to produce geometric mean log2 HI antibody titers ≥ 3. The current experimental study indicates that cracked maize can be good candidate carrier of I-2 vaccine virus with easy administration methods for village chickens. Keywords: Antibody, chickens, cracked maize, ocular, haemagglutination inhibition, I-2 vaccine. African Journal of Biotechnology , Vol 13(43) 4183-4187

Fusarium verticillioides and maize interaction in vitro: relationship between oxylipin cross-talk and fumonisin synthesis

Fusarium verticillioides is one of the most important fungal pathogens causing ear and stalk rot in maize. Even if frequently asymptomatic, it can produce a harmful series of compounds named fumonisins. Plant and fungal oxylipins play a crucial role in determining the outcome of the interaction between the pathogen and its host. Moreover, oxylipins are factors able to modulate the secondary metabolism in fungi. To uncover the existence of the relationship between oxylipin production and fumonisin synthesis in F. verticillioides, we analysed some molecular and physiological parameters, such as the expression of genes whose products are related to oxylipin synthesis (i.e. lipoxygenase, diol synthases and fatty acid oxidase), the oxylipin profile of both cracked maize and the pathogen by using a lipidomic approach (i.e. combining LC-TOF and LC-MS/MS approaches with a robust statistical analysis) and the synthesis of fumonisin B1. The results suggested a close relationship between the modification of the pathogen oxylipin profile with the fumonisin synthesis. Notably, a modification of the oxylipin profile of the pathogen during its growth on cracked maize can be demonstrated. The switch in oxylipin synthesis could indicate that the ‘presence’ of maize determinants (e.g. plant cell wall fragments and/or lipids) was able to promote the modification of the pathogen lifestyle, also by adapting the secondary metabolism, notably fumonisin synthesis.

&lt;i&gt;Fusarium verticillioides&lt;/i&gt; and maize interaction &lt;i&gt;in vitro&lt;/i&gt;: relationship between oxylipin cross-talk and fumonisin synthesis

Fusarium verticillioides is one of the most important fungal pathogens causing ear and stalk rot in maize. Even if frequently asymptomatic, it can produce a harmful series of compounds named fumonisins. Plant and fungal oxylipins play a crucial role in determining the outcome of the interaction between the pathogen and its host. Moreover, oxylipins are factors able to modulate the secondary metabolism in fungi. To uncover the existence of the relationship between oxylipin production and fumonisin synthesis in F. verticillioides, we analysed some molecular and physiological parameters, such as the expression of genes whose products are related to oxylipin synthesis (i.e. lipoxygenase, diol synthases and fatty acid oxidase), the oxylipin profile of both cracked maize and the pathogen by using a lipidomic approach (i.e. combining LC-TOF and LC-MS/MS approaches with a robust statistical analysis) and the synthesis of fumonisin B1. The results suggested a close relationship between the modification of the pathogen oxylipin profile with the fumonisin synthesis. Notably, a modification of the oxylipin profile of the pathogen during its growth on cracked maize can be demonstrated. The switch in oxylipin synthesis could indicate that the ‘presence’ of maize determinants (e.g. plant cell wall fragments and/or lipids) was able to promote the modification of the pathogen lifestyle, also by adapting the secondary metabolism, notably fumonisin synthesis.

Performance and Carcass Characteristics of Broilers Under Diets Supplemented with Whole Grains

This study was conducted at the Institute of Agriculture and Animal Science (IAAS), Rampur, Chitwan with the objective to study the effects of mixing starter diet with whole grains on the performance and carcass characteristics of broilers. The control group (T1) was fed only with the commercial starter and grower diets throughout the experimental period. Other treatment groups, T2, T3, and T4 received commercial starter diets supplemented with whole wheat, cracked maize and bajra pearl millet (Pennisetum glaucam) respectively from day 6. At 37 days, cumulative feed intakes (FI) were significantly lower (P&lt;0.01) for all the whole grain treated groups, the lowest FI being noted in T2 followed by T4 and T3. Cumulative body weights at 37 days were considerably poorer in the 3 whole grain treatments. Feed conversion ratio in T3 and T4 were equal to T1, at 1.70 whereas T2 FCR was 13 points higher than T1. Lower carcass yield and breast yield (P&lt;0.05) were noted in whole grain diets except T3, which had similar figures to that of control. Whole grains produced a larger gizzards (P&lt;0.01). Economic analysis favoured cracked maize and whole bajra treatments, each generating a net profit of NRs. 12.3/bird and NRs. 6.48/bird respectively. This study clearly demonstrated that these whole grains could be successfully fed to broilers in a method of diluting a starter diet. But more research is needed with higher nutrient density starter diets with some adjustments in whole grain dilution to develop an efficient method of whole grain feeding that gives at least equal weights, better FCR, and lower feed costs. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 21-28 DOI: http://dx.doi.org/10.3126/njst.v13i2.7709

Electromyographic evaluation of masseter muscle activity in horses fed (i) different types of roughage and (ii) maize after different hay allocations

The aims of this study were to monitor electromyographic (EMG) activity of masseter muscle in healthy horses fed (i) different types of roughage and (ii) maize after different hay allocations. Four horses were offered the following three diets ad libitum: hay, haylage or straw/alfalfa chaff (SAC). In a second trial, four horses were fed cracked maize (CM) and hay in three different orders: (i) CM after a 12-h overnight fast; (ii) CM immediately after restricted hay intake (0.6 kg hay/100 kg BW); or 3) CM after hay intake ad libitum. The activity of the masseter muscle was determined by EMG (IED(®) ), and the following were measured: amplitude (muscle action potential = MAP, maximum voltage) and duration of MAP (s). The intake of hay or haylage was associated with intense masseter muscle activity (MAP: hay, 10 ± 1.7 V; haylage, 11 ± 3.3 V; and duration of MAP: hay, 0.31 ± 0.04 s; haylage, 0.30 ± 0.04 s). Similar intense chewing was measured for SAC (MAP 13 ± 3.8 V), although duration of the chewing cycle was relatively short (0.22 ± 0.03 s, diet p < 0.05), which is possibly related to the shorter fibre length. CM was consumed rapidly, with less intense masseter muscle activity (MAP 6.0 ± 1.5 V). Hay intake before CM did not affect chewing force of CM, but duration of chewing cycle was significantly prolonged by feeding hay ad libitum before CM was fed. The consumption of hay, haylage or SAC was associated with intensive masseter muscle activity that was likely to stimulate salivary flow rate. In contrast to roughage, concentrates like CM are consumed rapidly with less intensive masseter muscle activity. This situation is associated with a low salivary flow that may have an adverse effect on gastric function.

The liveweight gain response of heifers to supplements of molasses or maize while grazing irrigated Leucaena leucocephala/Digitaria eriantha pastures in north-west Australia

This experiment in the Ord River Irrigation area (ORIA) of north Western Australia evaluated the liveweight gain of cattle rotationally grazing leucaena (Leucaena leucocephala cv. Cunningham)/pangola (Digitaria eriantha cv. Steudel) pastures alone, or supplemented with four levels of molasses (1.25, 2.50, 3.75, 5.00 kg molasses/head.day, as fed or fresh weight basis) or two levels of cracked maize supplementation (0.75, 1.50 kg/head.day, as fed or fresh weight basis). Seventy Bos indicus cross heifers [~12 months of age, mean initial weight 252 ± 3.8 (s.e.) kg] were allocated to the seven treatments and two replicates of each treatment (five cattle per replicate plus five additional similar heifers) with the stocking rate set at 6.25 head/ha. The experiment was conducted over 106 days of the dry season (August–November). Each replicate paddock of 0.4 ha was rotationally grazed with 10 animals with a 7-day grazing period and a 21-day regrowth period for each rotation. The mean herbage mass, residual herbage mass and herbage allowance for the experiment were 3.78 t DM/ha, 3.07 t DM/ha and 7.32 kg DM/100 kg liveweight, respectively. Pangola contributed a mean of 0.79 of the herbage mass. There was a significant quadratic response of liveweight gain to level of molasses supplement (P &lt; 0.0087) with an optimum liveweight gain of 1.08 kg/head.day at a supplement level of 2.65 kg molasses/head.day or 8.9 g/kg LW.day derived from the quadratic equation. The quadratic equation was: Liveweight gain = 0.763(±0.0644) + 0.241(±0.0658) * M – 0.046(±0.0126) * M2 (where M is level of molasses supplement kg/head.day). There was no significant response to level of maize supplement. There were no significant differences between treatments in the concentration of rumen ammonia N or volatile fatty acids or in the molar proportion of volatile fatty acids. It was concluded that molasses can be used effectively to increase the liveweight gain of cattle grazing leucaena/pangola pasture at a level of ~8.9 g/kg LW.day.

Use of cracked maize as a carrier for NDV4 vaccine in experimental vaccination of chickens

The suitability of V4 vaccine coated on cracked local grain (maize) and its husks and used for oral vaccination of chickens was assessed. Seventy-two (72) birds aged three (3) weeks and above were divided into six groups of twelve (12) birds per group. The birds were bled to determine their prevaccination HI antibody status while five different samples of cracked maize were coated with the V4 vaccine and fed to the chickens orally in each of the groups. All birds in the group including the controls were bled at 7, 14 and 21 days post vaccination to determine the presence and level of antibody response in each of the groups. Results obtained showed that prevaccination haemagglutination inhibition (HI) titre was less than two (log2) in 18% of the birds used in this experiment, however 14% of the birds had an HI titre of ≤ 4. The post vaccination antibody titre showed that birds vaccinated with vaccine coated maize gave a post vaccination HI antibody titre of between Log2(6-8). when the coated maize samples were soaked in water at room temperature and assessed after 24 hours, the treated maize parts gave >6.3 log10 EID50 and above while the untreated parts gave < 3.0 log10 EID50. The experiment showed that whole maize and husks, which were not treated, may contain agents which are virus inhibitory. Form this research the treated maize which was soaked and washed gave a higher geometric mean titre, hence tends to be good carriers of the virus (vaccine). It is therefore concluded from this work that processed cracked maize could be a good carrier of NDV4 vaccine. It is hereby recommended that only treated maize could be used as carrier for the V4 vaccine.