Full-fat Corn Germ Research Articles

Full-fat corn germ improves the performance and milk fat yield of Girolando cows fed sugarcane bagasse and cactus cladodes as forage sources.

We investigated the effects of replacing ground corn with full-fat corn germ (FFCG) on milk production, milk composition, and nutrient use in cows fed sugarcane bagasse and cactus cladodes. Ten multiparous Girolando cows (average body weight 500 ± 66kg, 90 ± 15 days in milk) were distributed in a replicated 5 × 5 Latin Square and assigned to five dietary treatments containing 0%, 25%, 50%, 75%, or 100% of full-fat corn germ in substitution to ground corn. Full-fat corn germ increased fat-corrected milk yield by 2.2kg/day and the synthesis of fat, lactose, and total solids in milk by 94.4, 60.0, and 201.10g/day, respectively (p < 0.05). Cows fed corn germ quadratically increased (p < 0.05) dry matter intake by 1.01kg/day, with the intake of crude protein and total digestible nutrients following the same pattern. Conversely, the substitution of corn for full-fat corn germ linearly reduced (p < 0.05) the total non-fiber carbohydrate intake from 5.79 to 4.40kg/d. Except for ether extract and non-fiber carbohydrates, full-fat corn germ did not alter (p > 0.05) nutrient digestibility. Cows fed corn germ excreted less (p < 0.05) urea-N in milk and urine N. These results demonstrate that full-fat corn germ can partially replace ground corn to enhance the milk production efficiency of crossbred cows fed cactus cladodes and sugarcane bagasse. Furthermore, including sugarcane bagasse in FFCG-supplemented diets prevents milk fat depression in cows fed cactus cladodes.

Full-fat corn germ in diets for dairy cows as an alternative to ground corn.

The experiments reported in this research paper address the effects of replacing ground corn (GC) with full-fat corn germ (FFCG) on nutrient intake and digestibility, nitrogen utilization efficiency, performance, and predicted methane production in dairy cows fed cactus cladodes and sugarcane. We hypothesized that the inclusion of FFCG in the diet would not alter the performance of lactating cows but would reduce the predicted methane production in vivo. Ten multiparous Holstein cows at 90 ± 10 d of lactation and yielding 24.2 ± 3.5 kg milk/d were assigned to dietary treatments consisting of different levels of replacement of GC by FFCG (0; 25; 50; 75 and 100% of diet dry matter) in a replicated 5 × 5 Latin square design with 21-d periods. Methane production was predicted using an automated gas in vitro production system. Except for ether extract intake, which increased, the intake of all nutrients decreased linearly with the replacement of GC by FFCG. The digestibility of dry matter, organic matter and neutral detergent fiber reduced, whereas the digestibility of ether extract increased linearly with FFCG. There were no changes in the digestibility of crude protein. The nitrogen intake and daily excretion in urine and feces decreased, while nitrogen use efficiency increased linearly. There was no significant effect of diets on nitrogen balance or microbial protein synthesis and efficiency. The yield of protein, lactose and total solids in milk showed a quadratic behavior. On the other hand, milk fat yield and energy-corrected milk yield decreased linearly with the replacement of GC by FFCG. No effect on pH or ammonia nitrogen was observed. The production of methane (CH4, g/kg DM) and total CH4 (g/d), and CH4 intensity decreased linearly with the replacement of GC by FFCG. In conclusion, FFCG has been shown to be an effective source of fat to reduce methane production in dairy cows, partially supporting our initial hypothesis. However, as it decreases milk fat production, it is not recommended to replace more than 50% of GC by FFCG for lactating cows fed cactus cladodes and sugarcane.

Nutritional Quality of Milk Fat from Cows Fed Full-Fat Corn Germ in Diets Containing Cactus Opuntia and Sugarcane Bagasse as Forage Sources

We evaluated the performance, milk composition, and milk fatty acid profile of cows fed diets composed of cactus cladodes (Opuntia stricta [Haw.] Haw), sugarcane bagasse and increasing levels of full-fat corn germ (FFCG). We hypothesized that ground corn can be effectively replaced by FFCG when cactus cladodes and sugarcane bagasse are used as forage sources. The cows were randomly distributed into two 5 × 5 Latin Squares and fed five diets in which ground corn was progressively replaced with full-fat corn germ (FFCG; 0%, 25%, 50%, 75%, or 100% of substitution). Adding FFCG to the diet increased milk production and milk fat content and reduced milk protein content. Overall, FFCG reduced the proportion of saturated FAs and increased mono- and polyunsaturated FAs in milk, including CLA isomers. In addition, activity indices of stearoyl-CoA desaturase were reduced by increasing levels of FFCG. We conclude that the substitution of corn for FFCG in diets based on cactus cladodes and sugarcane bagasse positively modifies the FA profile of milk and could add commercial value to milk products (e.g., CLA-enriched milk). In addition, the milk fat response indicates that the basal diet was favorable to the rumen environment, preventing the trans-10 shift commonly associated with milk fat depression.

Replacing corn with full-fat corn germ in a basal diet containing cactus (Opuntia stricta) cladodes and sugarcane as forage sources induces milk fat depression associated with the trans-10 shift in dairy cows

Recent evidence indicates that associating cactus Opuntia cladodes with plant oils represents a promising strategy to increase the nutritional value of milk fat. This study aimed to investigate the effects of full-fat corn germ (FFCG), as an alternative to plant oils, on production variables, blood metabolites, and milk fatty acid (FA) composition of dairy cows fed a basal diet containing cactus (Opuntia stricta) cladodes and sugarcane as forages. Ten multiparous Holstein cows with 90 ± 10 d of lactation and yielding 24.2 ± 3.5 kg milk/d were assigned to dietary treatments consisting of 0, 4 (low level; LL), 8 (moderate level; ML), 12 (high level; HL), and 16% (very high level; VHL) of FFCG (DM basis) in a replicated 5 × 5 Latin square design with 21-d periods. DM intake decreased linearly from 18.9 to 16.4 kg/d, whereas a quadratic response was observed for milk yield, which increased 1.7 kg/d from control to ML, and decreased to a similar extent as FFCG further increased in the diet, resulting in a quadratic increase in gross feed efficiency (GFE). Milk protein and lactose contents were unaltered, but milk fat content gradually dropped from 3.49% to 2.23%, which was accompanied by a progressive decrease in milk fat yield and fat-corrected milk yield. Serum cholesterol levels markedly increased from 756 to 1480 mg/L, but other blood metabolites were unaltered. Except for trans-16:1 isomers, proportions of short and medium-chain FA in milk fat decreased in a linear or quadratic fashion as FFCG increased in the diet, whereas the opposite was observed for 18:0 and of 18:1/18:2 isomers, including those with conjugated double bonds. In particular, a trans-11 to trans-10 shift occurred with moderate to higher FFCG levels, resulting in a quadratic change in trans-11 18:1 and cis-9, trans-11 CLA, and a linear increase in trans-10 18:1, trans-10, cis-12 CLA and trans-9, cis-11 CLA. The n-6:n-3 ratio in milk nearly doubled with increasing FFCG, mostly due to a pronounced increase in 18:2 n-6. Proportions of odd-linear and branched-chain FA in milk fat decreased in a quadratic and linear fashion, respectively, with increasing FFCG. These results indicate that FFCG can be an effective source of PUFA for increasing rumen outflow of biohydrogenation intermediates in cows fed cactus Opuntia cladodes as a partial substitute for sugarcane. The marked milk fat depression induced by FFCG suggests that the basal diet was unable to maintain a healthy rumen environment.

Performance of broilers fed digestible amino acids based diets obtained from cecectomized roosters and broilers

This experiment was carried out to evaluate the performance of broilers fed ration formulated based on digestible amino acids obtained with cecectomized roosters and broilers at different ages. A total of 300 Ag Ross 508 broiler chicks aging one to 21 days was distributed into 30 experimental units of ten broilers each (five birds of each sex) in six batteries of galvanized steel. All diets were based on corn, soybean meal and full-fat corn germ meal, considering the values of diges tible amino acids obtained from 45-week-old roosters and broilers of 21 and 42 days of age. Two rearing phases were adopted, a pre-starter phase (one to seven days) and a starter phase (eight to 21 days). The following performance variables were evaluated: average weight, weight gain, feed intake, feed:gain relation and mortality. Birds were distributed according to a completely randomized design with three forms of determination of digestible amino acids content and ten repetitions of ten birds. The use of digestible amino acids based diets determined for broiler chicks at 21 days of age resulted in better performance of bro ilers in starter phase. The digestible amino acid values of each ingredient can vary according to the age of the birds during the determination procedure.

Digestibilidade dos aminoácidos do milho, farelo de soja e gérmen integral de milho em galos e frangos de corte cecectomizados

Este experimento foi conduzido para avaliar a digestibilidade dos aminoácidos do milho, farelo de soja e gérmen integral de milho em galos e frangos de corte cecectomizados. Foram utilizados 16 galos Lohmann-LSL com 45 semanas de idade, 40 frangos de corte machos AgRoss 508, sendo 20 com 21 dias de idade e outros 20 com 42 dias de idade, todos cecectomizados. Adotou-se delineamento inteiramente casualizado com três categorias animais (galos; frangos aos 21 dias; e frangos aos 42 dias de idade) para cada alimento avaliado e cada ave considerada uma unidade experimental. O ensaio durou 84 horas: nas 36 horas iniciais, as aves foram submetidas a jejum e nas 48 horas subsequentes, à ingestão forçada dos alimentos, feita com sonda esofágica introduzida diretamente no inglúvio das aves. As excretas produzidas foram colhidas duas vezes ao dia nas 48 horas subseqüentes. Os valores de aminoácidos digestíveis verdadeiros determinados para o milho e gérmen integral de milho determinados com frangos submetidos ao procedimento experimental aos 21 dias de idade foram inferiores aos do grupo controle (galos). Contudo, os mesmos resultados não foram observados para o farelo de soja. O aproveitamento de aminoácidos foi maior nos frangos submetidos ao procedimento experimental aos 42 dias de idade em comparação aos do grupo controle (galos adultos), independentemente do alimento avaliado. O teor de aminoácidos digestíveis verdadeiros totais obtidos foi de 7,24; 6,25 e 7,33% para o milho, 9,66; 9,14 e 9,91% para o gérmen integral de milho e 41,82; 41,78 e 42,02% para o farelo de soja, valores determinados com galos, frangos aos 21 e aos 42 dias de idade, respectivamente. Observou-se que, com o amadurecimento do trato digestório, aumenta o aproveitamento proteico em aves que consomem milho e gérmen integral de milho.

Desempenho de frangos de corte consumindo rações contendo sorgo e gérmen integral de milho

Avaliou-se a substituição do sorgo pelo gérmen integral de milho em rações para frangos de corte. Foram conduzidos dois experimentos, em delineamento inteiramente casualizado com quatro níveis de substituição do sorgo pelo gérmen integral de milho (0; 33,3; 66,7 e 100%) como concentrado energético em rações com ingredientes de origem vegetal (experimento 1) ou de origem animal (experimento 2), cada um com quatro repetições. Avaliaram-se o desempenho (ganho de peso, consumo de ração e conversão alimentar) e o rendimento de carcaça e de cortes, em peso absoluto, em porcentagem do peso vivo e em porcentagem do peso da carcaça depenada e eviscerada. No experimento 1, os níveis de substituição tiveram efeito quadrático no peso final e no ganho de peso, que foram melhores nos níveis de 21,03 a 21,68% de substituição do sorgo pelo gérmen integral de milho. No experimento 2, verificou-se efeito quadrático para ganho de peso e conversão alimentar, que foram melhores nos níveis de 35,02 e 15,75% de substituição do sorgo pelo gérmen integral de milho. A substituição do sorgo pelo gérmen integral de milho não afetou os rendimentos de carcaça e dos cortes obtidos no experimento 1. No experimento 2, houve efeito quadrático para os pesos de carcaça, peito e asas. Em rações com ingredientes de origem vegetal, o sorgo pode ser substituído pelo gérmen integral de milho em níveis de 21,03 a 21,68% e, em rações com ingredientes de origem animal, de 15,75 a 35,02%.

Comparison of full-fat corn germ, whole cottonseed, and tallow as fat sources for lactating dairy cattle

Twenty-four multiparous Holstein cows (124 ± 39 d in milk; 682 ± 72kg of body weight) were used in 6 simultaneous 4 × 4 Latin squares to evaluate full-fat corn germ as a fat source for lactating dairy cows. Experimental diets were a control (containing 28% ground corn, 23% alfalfa hay, 19% wet corn gluten feed, and 10% corn silage, dry matter basis), and 3 diets with either whole cottonseed (WCS), tallow (TAL), or full-fat corn germ (FFCG) added to provide 1.6% supplemental fat. Cows were fed twice daily for ad libitum intake. Dry matter intake, milk yield, and energy-corrected milk did not differ among diets. Efficiency of milk production (energy-corrected milk/dry matter intake) was greater for cows fed WCS than for cows fed the control, TAL, or FFCG. Milk fat percentage from cows fed FFCG was less than that of cows fed WCS or the control, but was similar to that of cows fed TAL. Milk protein percentage was less for cows fed FFCG than for those fed the control. Total saturated fatty acids were less in milk from cows fed fat sources, and cows fed WCS and TAL had greater saturated fatty acids in milk than did cows fed FFCG. Unsaturated fatty acids were greater in milk from cows fed FFCG than in milk from cows fed the control, WCS, or TAL. The cis-9, trans-11 conjugated linoleic acid content was greater in milk from cows fed WCS, TAL, and FFCG than from cows fed the control, and it was greater in milk from cows fed FFCG than in milk from cows fed WCS or TAL. These results indicate that FFCG can be used effectively as a fat source in diets for lactating dairy cattle.

Effects of supplemental fat source on nutrient digestion and ruminal fermentation in steers1

Five Holstein steers (235 kg of BW) fitted with ruminal, duodenal, and ileal cannulas were used in a 5 x 5 Latin square design experiment to determine the effects of supplemental fat source on site and extent of nutrient digestion and ruminal fermentation. Treatments were diets based on steam-flaked corn containing no supplemental fat (control) or 4% (DM basis) supplemental fat as tallow, dried full-fat corn germ (corn germ), corn oil, or flax oil. Fat supplementation decreased (P < 0.08) ruminal starch digestion but increased (P < 0.03) small intestinal starch digestion as a percentage of intake. Feeding corn germ decreased (P < 0.09) ruminal starch digestion and increased (P < 0.03) large intestinal starch digestion compared with steers fed corn oil. Large intestinal starch digestion was less (P < 0.04), and ruminal NDF digestion was greater (P < 0.09) for steers fed tallow compared with steers fed other fat sources. Small intestinal (P < 0.08) and total tract NDF digestibilities were greater (P < 0.02) for steers fed corn germ than for those fed corn oil. Feeding tallow increased total ruminal VFA (P < 0.03) and NH(3) (P < 0.07) concentrations compared with steers fed the other fat sources. Feeding corn germ led to a greater (P < 0.02) rate of ruminal liquid outflow compared with corn oil. A diet x hour interaction (P < 0.04) occurred for ruminal pH, with steers fed corn oil having the greatest ruminal pH 18 h after feeding, without differences at other time points. Fat supplementation increased (P < 0.09) ruminal concentrations of Fusobacterium necrophorum. Duodenal flow of C18:3n-3 was greater (P < 0.01) for steers fed flax oil compared with those fed corn oil. Feeding corn germ led to less (P < 0.01) ruminal biohydrogenation of fatty acids compared with corn oil. Steers fed tallow had greater small intestinal digestibility of C14:0 (P < 0.02) and C16:1 (P < 0.04) than steers fed the other fat sources. Fat supplementation decreased (P < 0.06) small intestinal digestibility of C18:0. Feeding corn germ decreased (P < 0.10) small intestinal digestibility of C18:1 compared with corn oil. It appears that source of supplemental fat can affect the site and extent of fatty acid and nutrient digestion in steers fed diets based on steam-flaked corn.

Effects of dried full-fat corn germ and vitamin E on growth performance and carcass characteristics of finishing cattle1

Two experiments were conducted to evaluate dried full-fat corn germ (GERM) as a supplemental fat source in cattle finishing diets. In Exp. 1, 24 pens totaling 358 crossbred beef steers with an initial BW of 319 kg were allowed ad libitum access to diets containing dry-rolled corn, 35% wet corn gluten feed, and 0, 5, 10, or 15% GERM on a DM basis. Increasing GERM decreased (linear; P < 0.02) DMI and increased (quadratic; P < 0.02) ADG. Steers fed 10% GERM had the greatest ADG (quadratic; P < 0.02) and G:F (quadratic; P < 0.05). The addition of GERM increased (linear; P < 0.05) fat thickness, KPH, and the percentage of USDA Yield Grade 4 carcasses (quadratic; P < 0.03), with steers fed 15% GERM having the greatest percentage of USDA Yield Grade 4 carcasses. In Exp. 2, 48 pens totaling 888 crossbred beef heifers with an initial BW of 380 kg were allowed ad libitum access to diets containing steam-flaked corn, 35% wet corn gluten feed, and either no added fat (control), 4% tallow (TALLOW), or 10 or 15% GERM on a DM basis, with or without 224 IU of added vitamin E/kg of diet DM. No fat x vitamin E (P > or = 0.08) interactions were detected. Fat addition, regardless of source, decreased (P < 0.01) DMI, marbling score, and the number of carcasses grading USDA Choice. Among heifers fed finishing diets containing TALLOW or 10% GERM, supplemental fat source did not affect DMI (P = 0.76), ADG (P = 0.54), G:F (P = 0.62), or carcass characteristics (P > or = 0.06). Increasing GERM decreased DMI (linear; P < 0.01) and ADG (quadratic; P < 0.02), with ADG by heifers fed 10% GERM slightly greater than those fed control but least for heifers fed 15% GERM. Increasing GERM improved (quadratic; P < 0.03) G:F of heifers, with heifers fed 10% GERM having the greatest G:F. Increasing GERM decreased HCW (linear; P < 0.02), marbling score (linear; P < 0.01), and the percentage of carcasses grading USDA Choice (linear; P < 0.01). The addition of vitamin E increased (P < 0.04) the percentage of carcasses grading USDA Select and decreased (P < 0.01) the percentage of carcasses grading USDA Standard. These data suggest that GERM can serve as a supplemental fat source in cattle finishing diets, and that the effect of vitamin E did not depend on source or concentration of supplemental fat.

Effect of full-fat corn germ and Vitamin E on finishing performance and carcass characteristics of beef heifers (2003)

Eight hundred eighty-eight crossbred beef heifers weighing 837 lb were used in a 105- day finishing study to evaluate full-fat corn germ as a lipid source and added vitamin E in finishing diets containing steam-flaked corn. Treatments were arranged in a 2 x 4 factorial and consisted of finishing diets formulated to provide no added fat (Control), 4% tallow (Tallow), or 10% or 15% full fat corn germ on a dry matter basis (10%FFG and 15%FFG, respectively) with or without 2000 IU of additional vitamin E per heifer daily. No fat x vitamin E interaction was detected. Fat addition decreased (P<0.01) dry matter intake and tended (P<0.09) to improve gain efficiency, but marbling score and the number of carcasses grading USDA Choice were decreased by fat additions (P<0.01). Tallow and 10%FFG yielded similar finishing performance and carcass characteristics. Increasing full fat corn germ led to linear decreases (P<0.05) in dry matter intake, average daily gain, final body weight, and hot carcass weight, as well as marbling score and the number of carcasses grading USDA Choice. Gain efficiency was increased by addition of full fat corn germ at 10% of the diet, but not at 15% of the diet. Addition of full fat corn germ to the diet tended (linear, P<0.06) to decrease the incidence of liver abscesses. Addition of vitamin E did not affect finishing performance (P>0.12). This study suggests that full fat corn germ can serve as a supplemental lipid source for finishing cattle. Responses to 10% full fat corn germ were similar to those obtained when an equal amount of fat from tallow was incorporated into the diet.

Comparison of dried full-fat corn germ and tallow in finishing feedlot diets for heifers (2003)

A trial was conducted using 588 finishing beef heifers (705 lb initially) to compare tallow and dried full-fat corn germ as supplemental energy sources. Pens of 20 to 50 heifers were fed finishing diets containing 1) tallow or 2) corn germ. The tallow diet contained (dry basis) 46% steam-flaked corn, 35% wet corn gluten feed, 3% alfalfa hay, 1.5% soybean meal, and 4% tallow. The corn germ diet contained 41% steam-flaked corn, 35% wet corn gluten feed, 3% alfalfa hay, and 10% corn germ. Diets provided 300 mg monensin, 90 mg tylosin, and 0.5 mg MGA per heifer daily and were fed ad libitum once daily for 110 days. Gains of 2.99 lb/day for tallow and 2.95 lb/day for corn germ were not different (P>0.30), but dry matter intake tended to be greater for cattle fed corn germ than for those fed tallow (P=0.10; 16.7 vs 16.4 lb/day, respectively). Consequently, cattle fed germ were 3.4% less efficient than cattle fed tallow (P 0.40) between treatments. Cattle fed corn germ had more carcasses grading prime (P=0.03), more carcasses grading average choice or higher (P<0.05), and tended to have more marbling (P=0.08) than cattle fed tallow. Incidence of liver abscesses was higher (P<0.02) for cattle fed corn germ than for those fed tallow (4.8% vs 1.8%, respectively). These results indicate that corn germ is a suitable substitute for tallow in finishing rations. Introduction

Comparative value of full-fat corn germ, whole cottonseed and tallow as energy sources for lactating dairy cows (2002)

We used 24 multiparous Holstein cows in 4 x 4 Latin square design to evaluate full-fat corn germ as a replacement for whole cottonseed and tallow in total mixed diets for lactating dairy cows. Experimental diets on a dry matter basis were: 1) control 3.5% fat; 2) whole cottonseed 5.1% fat; 3) tallow 5.1% fat; 4) full-fat corn germ 5.1% fat. Diets were fed as total mixed rations typical of that fed on commercial dairy operations. Cottonseed meal and cottonseed hulls were included in the control, tallow, and full-fat corn germ diets to balance for fiber and protein fractions equal to those in the whole cottonseed diet. Dry matter intake, milk production, and energy corrected milk did not differ among the diets. Milk from cows fed full-fat corn germ contained less fat than milk from cows fed whole cottonseed but was similar to that of milk from cows fed control or tallow diets. Milk protein percentage was lower for cows fed full-fat corn germ than those fed control, but similar to cows fed whole cottonseed or tallow. Percentage milk lactose did not differ among dietary treatments. Cows fed WCS produced more pounds of milk fat than cows fed full-fat corn germ or tallow, but protein and lactose yield did not differ among the diets. Cows fed whole cottonseed produced milk more efficiently than cows fed control, tallow, or full-fat corn germ. Unexpectedly, efficiency of energy corrected milk production was not improved by tallow and tallow did not depress dry matter intake. Somatic cell count did not differ among experimental diets. Urea nitrogen concentration was lower in milk from cows fed full-fat corn germ and tallow than those fed whole cottonseed. All diets led to gains in body weight. The handling and storage characteristics of full-fat corn germ enhances its desirability as a feedstuff for dairy cattle. Full-fat corn germ supported milk production as well as whole cottonseed but not milk fat percentage or fat yield at the level fed in our diets. Additional studies need to be conducted to determine the most advantageous amount to feed full-fat corn germ and clarify the mechanisms by which it depresses milk fat production.; Dairy Day, 2002, Kansas State University, Manhattan, KS, 2002;

Performance and carcass characteristics of finishing steers fed dried, full-fat corn germ (2002)

Three hundred and fifty-eight crossbred beef steers (average initial weight 701 lb) were fed finishing diets containing 0, 5, 10, or 15% full-fat corn germ to evaluate effects on growth performance and carcass characteristics. Steers were placed into dirt-surfaced feedlot pens (12 to 16 head each) in December 2000 with a total of six pens per diet. Average daily gains during the 155-day finishing period were 2.83, 2.99, 3.01 and 2.93 lb/day for cattle fed 0, 5, 10, and 15% corn germ, respectively. Dry matter intakes decreased linearly (P<0.05) with increasing concentrations of full-fat corn germ in the diet. Relative to cattle fed no corn germ, efficiencies were improved by 8, 11, and 9% for cattle fed 5, 10, or 15% germ, respectively. Feeding corn germ also reduced the incidence of liver abscesses (P<0.05) compared to cattle fed the control diet. Dried, full-fat corn germ can be used successfully in cattle finishing diets to increase energy density and animal performance.

Aspergillus flavus infection and aflatoxin production in corn: influence of trace elements.

Distribution of trace element levels in corn germ fractions from kernels naturally infected with Aspergillus flavus and from kernels free of the fungus demonstrated an association between the presence of A. flavus and higher levels of metals. A. flavus production of aflatoxin on various autoclaved corn media showed that ground, whole corn was an excellent substrate; similar high levels of toxin were observed on full-fat corn germ but endosperm and defatted corn germ supported reduced yields. The influence of trace elements and their availability in defatted corn germ to A. flavus-mediated aflatoxin biosynthesis were measured. Enrichment of the substrate with 5 to 10 mug of manganese, copper, cadmium, or chromium per g of germ increased toxin yields. Addition of lead or zinc (50 to 250 mug/g) also enhanced toxin accumulation. Aflatoxin elaboration was reduced by the addition of 25 mug of cadmium per g or 500 mug of copper per g of germ.

Aspergillus flavus Infection and Aflatoxin Production in Corn: Influence of Trace Elements

Distribution of trace element levels in corn germ fractions from kernels naturally infected with Aspergillus flavus and from kernels free of the fungus demonstrated an association between the presence of A. flavus and higher levels of metals. A. flavus production of aflatoxin on various autoclaved corn media showed that ground, whole corn was an excellent substrate; similar high levels of toxin were observed on full-fat corn germ but endosperm and defatted corn germ supported reduced yields. The influence of trace elements and their availability in defatted corn germ to A. flavus-mediated aflatoxin biosynthesis were measured. Enrichment of the substrate with 5 to 10 mug of manganese, copper, cadmium, or chromium per g of germ increased toxin yields. Addition of lead or zinc (50 to 250 mug/g) also enhanced toxin accumulation. Aflatoxin elaboration was reduced by the addition of 25 mug of cadmium per g or 500 mug of copper per g of germ.