Influence of market stress and protein level on feeder pig hematologic and blood chemical values

One hundred twenty crossbred feeder pigs were used in 2 trials to determine the effects of food and water deprivation at the auction market and the effects of protein levels of receiving diet on blood chemical values. Food- and water-deprived animals had significantly higher packed-cell volume, colloid osmotic pressure, and cortisol values than did nondeprived animals. Total osmolality and plasma triiodothyronine values were significantly lower in deprived animals. Measurable effects of food and water deprivation were no longer apparent by 14 days after arrival at the research facility. Plasma colloid osmotic pressure had a positive linear relationship with increasing dietary protein level and was statistically different among levels of protein fed. Gilts had higher plasma triiodothyronine values than did barrows. Differential WBC ratios were not different between groups. Measurable differences for treatments (food and water deprivation vs food and water access; and level of protein in the receiving diet) were no longer apparent 84 days after pigs had arrived at the finishing unit.     

Comparison of market hog characteristics of pigs selected by feeder pig frame size or current USDA feeder pig grade standards

Two feeder pig grading systems were tested. Forty-five barrows were selected using current USDA Feeder Pig Grade Standards (U.S. No. 1, No. 2 and No. 3). Additionally, 45 barrows were selected using three frame sizes (large, medium and small). Pigs were slaughtered at 100, 113.5 of 127 kg live weight. Trimmed four lean cuts were separated into soft tissue, skin and bone. The skinless belly and soft tissue from the four lean cuts were ground separately and analyzed chemically. Data from each grading system were analyzed separately in a 3 X 3 factorial plan. Pigs selected using current USDA grade standards differed (P less than .05) for last rib backfat, 10th rib fat depth, longissimus muscle area, percentage of trimmed four lean cuts and USDA carcass grade. In the frame size system, pigs with large frame size had less last rib backfat, less 10th rib fat depth, longer carcasses, higher percentage of four lean cuts and superior USDA carcass grades than pigs with small frame size did (P less than .05). The Bradley and Schumann test of sensitivity showed that selection by frame size was more sensitive than current USDA grade standards for discriminating feeder pig foreleg length, body depth and ham width. In addition, selection by frame size was more sensitive than current USDA grade standards for discriminating carcass length and carcass radius length. No increase in sensitivity (P greater than .10) was noted for carcass composition or growth traits over the current USDA Feeder Pig Grade Standards.     

Health and performance of commingled feeder pigs as affected by lincomycin and carbadox

Purchased feeder pigs from 12 farms were commingled and divided into three treatment groups of carbadox, lincomycin and controls. Health and performance evaluations included serology, bacterial isolations, fecal examinations and post-mortem examinations at slaughter, weight gain, and feed efficiency.Serological tests for influenza, Aujeszky's disease and Mycoplasma hyopneumoniae were negative throughout the study. Bordetella bronchiseptica was isolated from 14% of the pigs on arrival and from 42% of the pigs 30 days after commingling. No Salmonella spp. were isolated from fecal swabs on arrival; Salmonella typhimurium was isolated from 2.5% of the pigs on Day 30, but no Salmonella was isolated on Day 90. Fecal examination on arrival revealed that 12.5% were infected with gastrointestinal parasites (5.0% Trichuris suis, 5.0% Ascaris suum and 2.5% Strongyloides ransomi).During the 30-day treatment period immediately following purchase and commingling, carbadox and lincomycin improved growth rate by 7.6% and 10.2%, respectively. The treatments also improved feed efficiency, by 9.9% and 5.7%, respectively, and uniformity of growth. Growth rate and feed efficiency were not affected by treatment from Days 30 to 90 following removal of the feed additives from the diet.Growth rate varied greatly, depending on the farm of origin. Although the reasons for the differences in performance were not well established, results suggested that transmission of B. bronchiseptica between pigs resulted in decreased growth rate following infection. Carbadox was significantly more effective than lincomycin in preventing transmission of B. bronchiseptica between commingled pigs.Post-mortem examination at slaughter revealed turbinate atrophy in 5.8% of the noses and pneumonia in 18% of the lungs. One liver exhibited evidence of ascarid larval migration. Treatments produced no significant effect (P>0.05) on post-mortem examination results.     

Methane emission by growing pigs and adult sows as influenced by fermentation

The fermentation of carbohydrates in pigs' digestive system, especially in the lower gut results predominantly in short chain fatty acids, gasses as CO₂, H₂ and CH₄. Methane (CH₄) is especially interesting as it contributes to the greenhouse gas emission and thus also to the global warming. CH₄ production and its relation to fermentation in growing pigs (74 diets) as well as adult sows (36 diets), were investigated in diets varying greatly in chemical composition. All diets were assayed in digestibility and energy balance experiments in respiration chambers. Growing pigs fed diets varying in total fibre content (2.8–40%) had a CH₄ production equivalent to 0.1 to 1.3% of digested energy (DE). Non-lactating sows fed at maintenance had a CH₄ production equivalent to 0.4 to 3.3 % of DE. Intensively fed lactating sows had the lowest CH₄ production (about 0.6% of DE). In general, the production of methane depended on fibre origin, however high variation was found between animals.     

Digestibility and feeding value of pearl millet as influenced by the brown-midrib, low-lignin trait

Our objectives were to determine the intake and digestibility of pearl millet as influenced by the brown-midrib (BMR), low-lignin trait and to determine the relative acceptability of BMR pearl millet in relation to its normal counterpart. Two field replicates of brown-midrib pearl millet and its normal counterpart were harvested as hay at the boot to heading stage twice during the growing season (2 genotypes x 2 cuttings x 2 field replicates). Twenty-four wethers had ad libitum access to a total forage diet (pearl millet forage), water and trace mineralized salt. The experimental period was 21 d (14 d for adjustment and 7 d for sample collection). Lignin was 23% lower (P less than or equal to .01) and in vitro DM digestibility (IVDMD) was 4% higher (P less than or equal to .01) in BMR vs normal genotype forages. Wethers preferred first-cutting millet to second-cutting millet, as evidenced by 62% higher (P less than or equal to .01) DMI for first-cutting forages. Dry matter intake of second-cutting forages was higher (P less than or equal to .10) for BMR pearl millet forage than for normal pearl millet (2.0 vs 1.5% of BW), but first-cutting forages were similar in DMI (2.9% of BW). In an acceptability trial of pearl millet regrowth (4 wk), grazing lambs with access to both genotypes displayed a marked preference (P less than .01) for the BMR genotype, spending an average of 2.6 min on plots containing the brown-midrib pearl millet for every minute spent on the normal genotype.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of group size and feeder type on growth performance and feeding patterns in finishing pigs

The effects of four group sizes (2, 4, 8, and 12 pigs per pen) and two single-space feeder types (conventional and electronic feed intake recording equipment [FIRE]) on feed intake, growth performance, and feeding patterns were determined in 208 crossbred finishing pigs (equal numbers of barrows and gilts) between 84.4 (SD = 0.81) to 112.8 (SD = 1.08) kg BW over a 4-wk period. Pigs were given ad libitum access to a corn-soybean meal-based diet (15.9% CP; 0.79% lysine; 3,328 kcal ME/kg). The floor space allowance was 0.9 m2/pig for all treatments. Growth rates were not different for the two feeder types; however, feed intake was lower and gain:feed ratio higher for pigs on the FIRE feeders (P < 0.01). Feed intake, growth rate, and gain:feed ratio were not different (P > 0.05) among the group sizes. Number of feeder visits per day decreased and feed intake per visit, feeder occupation time per visit, feed consumption rate, and percentage of time the feeder was occupied increased with group size (P < 0.05). Feed intake per visit had the strongest correlation with daily feed intake (r = 0.54; P < 0.01) and was negatively correlated with gain:feed ratio (r = -0.38; P < 0.01). However, the correlations between growth performance and other feeding pattern traits were relatively weak (r < or = 0.30). As group size increased, diurnal variation in number of feeder visits and feed consumed per hour decreased. There was no difference in time spent sitting and standing between the two feeder types. The proportion of time spent eating was generally lower for the larger groups on both feeders. The proportion of time spent lying was similar across group sizes for pigs on the conventional feeders but was greater for pigs in the larger groups on the FIRE feeders. This study suggests that finishing pigs can maintain feed intake and growth rate by changing feeding behavior as group size increases from 2 to 12.     

Effect of group size and feeder type on growth performance and feeding patterns in growing pigs

The effects of four group sizes (2, 4, 8, and 12 pigs per pen) and two single-space feeder types (conventional and electronic feed intake recording equipment [FIRE]) on feed intake, growth performance, and feeding patterns were determined in growing pigs over a 4-wk period. A total of 416 hybrid pigs (barrows and gilts) were grown from 26.5 (SD = 1.6) to 47.8 (SD = 2.7) kg BW and given ad libitum access to a corn-soybean meal-based diet (17.4% CP; 0.9% lysine; 3,298 kcal ME/kg). The floor space allowance was 0.9 m2/pig for all treatments. Pigs using the electronic feeders had similar growth rates but lower feed intakes (P < 0.01) and higher gain:feed ratios (P < 0.01) compared to those using the conventional feeders. Barrows compared to gilts had higher growth rates (P < 0.05), numerically higher (P > 0.05) ADFI, and similar feed efficiency and feeding pattern. Feed intakes and growth rates were lowest (P < 0.05) for groups of 12 pigs but gain:feed ratio was not affected by group size. Daily feeder occupation time per pig was lower (P < 0.01) for groups of 12 than for groups of 2 or 4 pigs, and feed consumption rate was higher (P < 0.01) for groups of 12 than for groups of 4 pigs. The proportion of time spent eating was lower (P < 0.01) and the proportion of time spent standing was higher (P < 0.01) for pigs in groups of 12 compared to groups of 2. Correlations between ADG and ADFI and feed intake per visit were 0.29 and 0.30, respectively (P < 0.01), between ADG and ADFI and feed consumption rate were 0.27 and 0.31, respectively (P < 0.01), and between ADFI and feeder occupation time per day were 0.33 (P < 0.01). This study suggests that, in growing pigs given access to a single feeder, changes in feeding behavior with increasing group size were not sufficient to maintain feed intake and growth rate.     

Leptin mRNA expression and serum leptin concentrations as influenced by age, weight, and estradiol in pigs

Two experiments (EXP) were conducted to determine the roles of age, weight and estradiol (E) treatment on serum leptin concentrations and leptin gene expression. In EXP I, jugular blood samples were collected from gilts at 42 to 49 (n = 8), 105 to 112 (n = 8) and 140 to 154 (n = 8) d of age. Serum leptin concentrations increased (P < 0.05) with age and averaged 0.66, 2.7, and 3.0 ng/ml (pooled SE 0.21) for the 42- to 49-, 105- to 112-, and 140- to 154-d-old gilts, respectively. In EXP II, RNase protection assays were used to assess leptin mRNA in adipose tissue of ovariectomized gilts at 90 (n = 12), 150 (n = 11) or 210 (n = 12) d of age. Six pigs from each age group received estradiol (E) osmotic pump implants and the remaining animals received vehicle control implants (C; Day 0). On Day 7, back fat and blood samples were collected. Estradiol treatment resulted in greater (P < 0.05) serum E levels in E (9 +/- 1 pg/ml) than C (3 +/- 1 pg/ml) pigs. Serum leptin concentrations were not affected by age, nor E treatment. Leptin mRNA expression was not increased by age in C pigs nor by F in 90- and 150-d-old pigs. However, by 210 d of age, leptin mRNA expression was 2.5-fold greater (P < 0.01) in E-treated pigs compared to C animals. Serum insulin concentrations were similar between treatments for 210-d-old pigs. However, insulin concentrations were greater (P < 0.05) in E than C pigs at 90 d and greater in C than E animals at 150 d. Plasma glucose and serum insulin-like growth factor-I concentrations were not influenced by treatment. These results demonstrate that serum leptin concentrations increased with age and E-induced leptin mRNA expression is age- and weight-dependent.     

Effect of group size and feeding regimen on nutrient digestibility studies with weanling pigs

An experiment was conducted to determine the effects of feeding regimen and group size on nutrient (N, Lipid, Ca, P) balance measurements with weanling swine. Treatments imposed were 1) one pig pair-fed to 90% of treatment 3, 2) three pigs pair-fed to 90% of treatment 3 and 3) three pigs with ad libitum access to their diet. A total of 28 barrows weaned at 21 d of age (initial BW 5.9 kg) were allotted by weight and litter in a randomized complete block design with repeated measurements over time to the three treatments in four replicates. The pigs were placed in .6-m x 1.13-m stainless steel metabolism crates and fed the same experimental diet for an initial 4-d adjustment period. This was followed by a 5-d collection of urine and feces with a 2-d interval between collection periods each week of a 4-wk postweaning period. When feed was restricted, N intake, urine N, fecal N and retained N were similar whether pigs were fed as singles or in groups of three. Individually fed pigs had a higher urinary Ca but lower urinary P compared with those fed in groups of three. Lipid and P retention values were similar for individual and group-penned, restricted-fed animals. Pigs provided ad libitum access to feed had greater weight gains and nutrient intakes, excretions (urine, fecal) and retentions (P less than .01) than pigs that were limit-fed. Similar responses among treatments occurred each week of the 4-wk trial. These results suggest that effective weekly balance data can be collected each week sequentially with 21-d weanling pigs penned in groups and allowed to consume feed ad libitum, a situation more similar to natural nursery conditions.     

Plasma thyroid hormones, growth and carcass measurements of genetically obese and lean pigs as influenced by thyroprotein supplementation

A 2 X 2 factorial arrangement with two genotypes of pigs (genetically obese and lean) and two dietary treatments (basal, a 16% protein corn-soybean meal standard grower diet, and basal +220 ppm thyroprotein as iodinated casein) was used. The 28 gilts were housed individually and fed ad libitum from 121 d of age until slaughtered at 99 kg body weight. Compared with lean pigs, genetically obese pigs had significantly lower average daily gain and gain/feed, greater backfat thickness, smaller loin eye area, shorter carcass length and lower circulating plasma triiodothyronine (T3) concentration. However, both total plasma and free thyroxine (T4) concentrations were similar comparing obese and lean pigs. Supplementation with thyroprotein increased circulating plasma concentration of both total and free T4 and produced interactions with genotype in affecting daily gain and gain/feed of pigs. Thyroprotein reduced both daily gain and gain/feed in obese pigs, but increased daily gain and gain/feed in lean pigs. It is suggested, similar to the case with obese mice, that heat production of our genetically obese pigs may be more sensitive to thyroprotein administration compared with similar treatment of lean animals.     

Endocrine,blood metabolite,and meat quality changes in goats as influenced by short-term,preslaughter stress

The purpose of this study was to determine the effects of short-term, preslaughter stress on physiological responses and meat quality in goats of different age groups. The goats (n = 28) were classified into young (6 to 12 mo of age) and old (24 to 30 mo of age) groups, feed deprived overnight, and slaughtered at three different times (replicates). On each slaughter day, goats were either subjected to a 2-h transportation stressor (TS) or remained unstressed in holding pens (NS) before slaughter. Blood samples were collected via jugular venipuncture from TS and NS goats at 2, 1, and 0 h before slaughter. Muscle glycogen and pH were measured on samples from longissimus muscle (LM) collected at 15 min and 24 h postmortem, and instrumental measures of meat color were obtained on the LM after a 24-h chilling period at 4 degrees C. The TS goats had higher plasma cortisol (P < 0.01) and glucose (P < 0.05) concentrations than NS goats. The rates of increase in plasma cortisol, glucose, and nonesterified fatty acid concentrations were greater in TS than in NS goats (stressor treatment x blood sampling time, P < 0.01). Muscle glycogen concentrations were greater (P < 0.05) in NS than in TS goats and higher (P < 0.01) in old vs. young goats; however, pH measured at 15 min and 24 h postmortem was not (P > 0.05) influenced by stressor treatment. Water-holding capacity of meat was not (P > 0.05) influenced by stressor treatment. Older goats had lower (P < 0.01) L* values and greater (P < 0.01) a* and chroma values than the younger goats. The a* and chroma values of loin cuts from young goat carcasses were lower in the TS than NS treatment groups, but this effect was absent in the old goat carcasses (stressor treatment x age, P < 0.05). Cooking loss percentages and shear force values for loin chops aged for 7 d were not (P < 0.05) affected by stressor treatment; however, old goats produced tougher (P < 0.01) loin chops than young goats. These results indicate that short-term preslaughter transport can cause noticeable changes in stress responses and muscle metabolism in goats.     

Systemic cytokine profile in feeder pigs suffering from natural postweaning multisystemic wasting syndrome (PMWS) as determined by semiquantitative RT-PCR and flow cytometric intracellular cytokine detection

Postweaning multisystemic wasting syndrome (PMWS) is an economically important disease in pigs caused by porcine circovirus type 2 (PCV2). Development of this disease is presumably associated with an impairment of the immune system. We, therefore, investigated the systemic expression of relevant cytokines (IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, TNF-alpha, IFN-gamma) and IL-2Ralpha at mRNA (semiquantitative RT-PCR) and at protein level (flow cytometric intracellular cytokine detection after short-time stimulation of peripheral blood mononuclear cells) in 10 feeder pigs aged 14 weeks suffering from natural PMWS and in 10 clinically healthy pen-mates. Hematological examination revealed a significant (p < 0.001) relative lymphopenia in the diseased animals when compared to reference pigs. IL-1alpha and IL-10 mRNA levels were notably increased in the affected pigs, whereas IL-2 and IL-2Ralpha (CD25) mRNA levels tended to be down-regulated. IL-8, TNF-alpha and IFN-gamma mRNA expressions appeared to be slightly increased. Intracellular cytokine levels as measured by flow cytometry revealed an increase of IL-1beta, IL-2, and IL-6, whereas IL-12 and TNF-alpha expressions were not affected. IFN-gamma was slightly decreased in the diseased animals. In conclusion, despite the assumption, that the cellular immune response to PMWS as a virus-induced disease should be characterized by either a Th1 driven cytokine profile or a cytokine profile indicative of T cell immunosuppression, our results did not support that hypothesis. Nevertheless, data from intracellular cytokine detection suggest an even increased percentage of the remaining lymphocytes capable to produce IL-2 upon in vitro stimulation, which is in contrast to the slightly diminished IL-2 mRNA levels reflecting the in vivo situation at least at the mRNA level.     

Serum pyruvate kinase and its relation to stress susceptibility in pigs

SUMMARY: Four blood tests, complementary to the halothane test, have been screened for their capacity to discriminate between homozygous and heterozygous stress resistant and stress susceptible pigs: TBARS in plasma, lipid peroxides from erythrocytes and plasma creatine and pyruvate kinase activity. Blood samples were collected from homozygous (NN) and heterozygous (Nn) stress resistant and homozygous stress susceptible (nn) pigs, while subjected to the halothane test. Serum creatine kinase and pyruvate kinase tests were retained for a more elaborated study. Pyruvate kinase appears to be a more reliable indicator of stress susceptibility than the well-known creatine kinase. However both parameters display a considerable standard deviation. Consecutive assays show the pyruvate kinase activity to be dependent on age (weight), which accounts for part of the variation; other sources of variation are the conditions of the exeriment and the way the imposed stress is perceived by the animal. During this experiment a rapid and accurate DNA-test for HAL-genotype detection has been developed (Fujii et al. 1991; Otsu et al. 1991; Coppieters et al. 1992). In spite of this, the pyruvate kinase parameter is a much more discriminating and remarkable indicator for stress susceptibility than the, in previous years, widely used creatine kinase test. ZUSAMMENFASSUNG: Serum Pyruvat Kinase und seine Relation mit Streβanf?lligkeit bei Schweinen Vier Blutteste, komplement?r dem HAL-Test, wurden in einem Screening-Verfahren untersucht um homozygote und heterozygote stre?resistente und stre?anf?llige Schweine zu differenzieren: TBARS in Plasma, Lipid Peroxyde von Erythrocyten und Plasma Kreatine und Pyruvat Kinase Aktivit?t. W?hrend des Halothantestes wurde Blut entnommen von homozygoten (NN) und heterozygoten (Nn) stre?resistenten und homozygoten stre?anf?lligen Schweinen (nn). Mit Serum Kreatine Kinase und Pyruvat Kinase Aktivit?t Tests wurden eine umfassende überprüfung durchgeführt. Letztere zeigt sich als ein zuverl?ssiger Indikator der Stre?anf?lligkeit als die wohl bekanntere Kreatine Kinase. Mehrmalige Analysen zeigen, da? Pyruvat Kinase Aktivit?t vom Alter (Gewicht) abh?ngig ist, was teilweise die Variabilit?t verursacht; andere Quellen der Variabilit?t sind die experimentellen Umst?nde und die Weise, wie der auferlegte Stre? durch das Tier erfahren wird. W?hrend der Durchführung dieses Experimentes wurde ein schneller und akkurater DNA-Test für HAL-Genotyp Detektion entwickelt (Fujii et al. 1991; Otsu et al. 1991; Coppieters et al. 1992). Im Vergleich mit dem, in vorgehenden Jahren, h?ufig angewendeten Kreatine Kinase Test, ist der Pyruvat Kinase Parameter trotzdem ein bemerkenswerter und diskriminierender Indikator für Stre?anf?lligkeit.     

2005年6-11月养猪市场回顾与展望

由于养猪遇到了价格猛跌的行情．特别是10月初期，生产者感到惊慌．渴望了解当前情况和以后的养猪形势。我们尽可能分析当前情况和预测未来趋势。     

Digestibility of phosphorus in growing pigs as influenced by source and concentration of dietary phosphorus and collection site

The current study examined the influence of source and concentration of dietary phosphorus (P) on the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of P in growing pigs. Eighteen cannulated barrows (25 ± 5 kg) were allotted to a triplicate 6 × 3 incomplete Latin square design with six diets and three periods. The diets comprised of soybean meal (SBM) or distillers' dried grain with solubles ( DDGS) as sole sources of dietary P, and three concentrations of P (2.0, 2.5 or 3.0 g/kg) in a 2 × 3 factorial arrangement. The AID and ATTD of P were not different (p = 0.37) in all diets. Apparent digestibility of P was affected (p < 0.01) by source and concentration of P. There was no interaction between source and concentration of dietary P on the apparent digestibility of P. Determined by regression analysis, the true ileal digestibility of P was 58.3% or 57.6%, and true total tract digestibility of P was 56.0% or 62.6%, for SBM or DDGS, respectively. The regression-derived ileal endogenous P loss (EPL) was 0.61 or 0.13 g/kg DM intake, and total tract EPL was 0.53 or 0.35 g/kg DM intake, for SBM or DDGS, respectively. In conclusion, the study demonstrated that both the source and concentration of dietary P affect the digestibility of P in growing pigs.     

Muscle glycogen stores and meat quality as affected by strategic finishing feeding of slaughter pigs

The aim of the present study was to investigate whether muscle glycogen stores in slaughter pigs could be decreased through strategic finishing feeding before slaughter. Moreover, preliminary meat quality traits were measured to see whether such a regulation of muscle glycogen stores affected ultimate pH, color, and tenderness in the meat. The strategic finishing feeding was carried out the last 3 wk prior to slaughter. Seven experimental groups with eight animals per group were fed diets low in digestible carbohydrates. A control group with four animals was fed a traditional grower-finishing diet. The muscle glycogen stores were reduced in longissimus muscle (LM) 11 to 26% at the time of slaughter in pigs that were fed the experimental diets compared with the control group. Meat quality measured as ultimate pH and color on LM muscle in half the pigs 24 h postmortem showed that ultimate pH in LM was not affected by the reduction in glycogen stores in the muscles from pigs fed any of the experimental diets. However, the meat from pigs fed the experimental diets was darker than the meat from pigs that were fed the control diet with two of the experimental diets, resulting in significantly lower L* values. Activities of key enzymes in the glycolytic pathway, glycogen phoshorylase a and b, phosphofructokinase, and the fatty acid oxidative pathway, beta-hydrozyacyl-CoA-dehydrogenase, were not affected by the strategic feeding. In contrast, the activity of the proteolytic enzyme calpain as well as its inhibitor calpastatin was influenced by the strategic feeding. Lower activity of mu-calpain and greater activity of calpastatin in the muscle samples from the strategically fed pigs indicate a lesser muscle protein degradation in the muscles compared with muscles of control animals. The present study showed that the muscle glycogen stores in slaughter pigs can be reduced at the time of slaughter through strategic finishing feeding with diets low in digestible carbohydrate without compromising growth rate.     

Acute aflatoxicosis in feeder pigs, resulting from improper storage of corn

Aflatoxicosis was diagnosed in 600 feeder pigs, of which 400 died, 150 were destroyed, and 50 were marketed. The pigs were exposed to 2,500 to 3,500 micrograms of aflatoxins/kg of feed. Drought-stressed damaged corn infected with Aspergillus flavus was stored under ambient conditions in a glass-lined silo, and this storage environment provided conditions that favored rapid fungal growth and mycotoxin production.