Steam Flaking Research Articles

Effects of the degree of steam flaking of corn and concentration of dietary wet distillers grains on energy metabolism of feedlot cattle*

Effects of the degree of steam flaking of corn and concentration of dietary wet distillers grains on energy metabolism of feedlot cattle*

INFLUENCE OF LIVE WEIGHT ON STARCH AND N DIGESTION OF CORN-BASED (DRY-ROLLED OR STEAM-FLAKED) FINISHING DIETS FOR HOLSTEIN STEERS

<p><strong>Background</strong>. A possible effect of live weight on digestion capacity and starch and nitrogen utilization in cattle has been suggested, however, to our knowledge, this effect has not been evaluated by direct testing. This becomes especially relevant when finishing diets are used, which are characterized by their high percentages of starch and nitrogen <strong>Objective: </strong>To study the possible effect of live weight (BW) on digestion and utilization of two treatments corn, dry rolled (DR) and steam-flaked (SF). <strong>Results</strong>. Microbial N and microbial efficiency were not affected by the live weight by corn processing interaction. PV decreased linearly (P<0.01) rumen starch digestion in response to dry-rolled corn, whereas with steamed corn, PV had an opposite effect by linearly (P<0.01) increasing rumen starch digestion. <strong>Implications.</strong> Attention should not be paid to the live weight of the animals when choosing the type of grain processing. <strong>Conclusions. </strong>It is concluded that live weight does not have a significant effect on the digestion of corn starch, but there is a quadratic effect on the nitrogen efficiency; however, the direction of this effect (increase or decrease in digestion as PV increases) depends on the type of grain processing.</p>

Effects of corn grain processing and protein source on calf performance, rumen fermentation, and blood metabolites

The objective of this study was to investigate the effects of the interaction between corn grain processing and protein source on feed intake, growth performance, rumen fermentation, and blood metabolites of dairy calves. Seventy-two 3-day-old Holstein calves with an initial weight of 39.1 ± 3.24 kg were randomly assigned (n = 12 calves (6 male and 6 female) per treatment) to a 2 × 3 factorial arrangement of treatments with the factors of physical form of the corn grain [coarsely ground (CG) and steam-flaked (SF)] and protein type [canola meal (CAN), canola meal + soybean meal (CASY), and soybean meal (SOY)] were assigned. The study showed a significant correlation between corn grain processing method and protein source on calf performance, including starter feed intake, total dry matter intake (DMI), body weight, average daily gain (ADG), and feed efficiency (FE). The CG-CAN and SF-SOY treatments resulted in the highest feed intake and DMI in the post-weaning and total period, respectively. Interestingly, corn processing did not affect feed intake, ADG, and FE, but the highest ADG was observed at SF-SOY and CG-CAN. In addition, the interaction between corn processing method and protein source improved FE in calves fed CG-CAN and SF-SOY during the preweaning period and throughout the period. Although skeletal growth parameters were unchanged, calves fed SOY and CASY had greater body length and withers height than calves fed CAN during the preweaning period. Rumen fermentation parameters were also not affected by the treatments, except that calves fed CAN had a higher molar proportion of acetate than calves fed SOY and CASY. Corn grain processing and protein source did not affect glucose, blood urea nitrogen (BUN), or β-hydroxybutyrate (BHB) concentrations, except for the highest blood glucose level observed in the CAN treatment and the highest BUN level observed in the preweaned calves fed SOY. However, a two-way interaction was observed for BHB concentration, suggesting that ground corn grain resulted in higher BHB concentration during the preweaning and postweaning periods than steam-flaked corn. In summary, it is recommended to incorporate canola meal with ground corn or soybean meal with steam-flaked corn in calf starters to enhance calf growth.

Degradability of Vicia ervilia Grain Using In Situ and CNCPS Methods, and Model-Based Analysis of Its Ruminal Degradation

Using nylon bag techniques, Cornell net carbohydrates and protein systems (CNCPS), and scanning electron microscopy, the authors examined the digestibility and structure of Vicia ervilia (ervil, bitter vetch) after steam flaking, roasting, and microwave processing. During the in situ technique, the samples were incubated at 0, 2, 4, 6, 8, 12, 16, 24, 36, and 48 h. For the description of the ruminal DM (dry matter) and CP (crude protein) degradation kinetics of treated and untreated Vicia ervilia, different models were selected as the best fit for the dry matter (DM) and crude protein (CP) degradation parameters of steam flaked samples. The results showed that both the steam flaking and microwave treatment samples contained high levels of non-protein nitrogen and buffer soluble protein, respectively. In comparison with steam flaking and microwave treatment, roasting decreased and increased the buffer soluble protein and neutral detergent insoluble protein, respectively. The control treatments showed the highest levels of neutral detergent soluble protein and the lowest levels of acid detergent soluble protein. Moreover, steam flaking and roasting decreased and increased the amount of acid detergent insoluble protein, respectively. When using dry heat (microwave and roasting), the acid detergent soluble and insoluble protein fractions were increased. As a result of this experiment, the nitrogen fractions were altered using heat processing. Hence, protein fermented feed and ruminal fermentation conditions can be expressed using these results.

The Incidence of Swine Dysentery in Pigs Can Be Reduced by Feeding Diets That Limit the Amount of Fermentable Substrate Entering the Large Intestine

Two experiments were conducted to test the hypothesis that feeding diets which limit the amount of fermentable substrate entering the large intestine would protect pigs against experimental infection with Serpulina hyodysenteriae, the causative agent of swine dysentery. Experiment 1 examined the effect of grain processing (hammer milling vs. steam flaking) and grain type (barley, groats, corn, sorghum and wheat) on indices of fermentation in the large intestine and the incidence of swine dysentery. Experiment 2 examined the role of five diets, steam-flaked corn, steam-flaked sorghum, hammer-milled wheat, extruded wheat and cooked white rice, on these same measures. All diets contained an animal protein supplement and no antibiotics. Pigs fed diets based on steam-flaked corn and steam-flaked sorghum had a lower incidence of disease (11–33%) than pigs fed diets based on other grains (75–100%). Pigs fed the diet based on cooked white rice were fully protected against swine dysentery. Both the soluble non-starch polysaccharide (NSP) concentration and the total NSP concentration of the diets explained a significant proportion of the variation in swine dysentery (R2 = 0.56, P = 0.016, and R2 = 0.71, P = 0.002, respectively), such that pigs eating diets containing <1.0 g/100 g soluble NSP showed reduced disease. However, pigs fed corn, sorghum and steam-flaked sorghum (Experiment 2), which contained only 0.4–0.5 g/100 g soluble NSP, still had a high incidence of disease (>50%). This was attributable to a higher level of resistant starch present in these grains. These data provide evidence that the expression of swine dysentery is associated with an increased concentration of fermentable substrate entering the large intestine.

Physicochemical Changes of Heat-Treated Corn Grain Used in Ruminant Nutrition.

Simple SummaryWhole grain with an intact pericarp is highly resistant to digestion by ruminants and external processing is required. Cereal grain is processed using different combinations of heat, moisture, time, and mechanical action. As a result of processing, starch becomes more available to both ruminal microbial and pancreatic enzymes. In animal science literature, there is a lack of data regarding the physicochemical properties of starchy materials prior to and after the application of processing treatments, as well as the connection to biological responses of animals in nutritional studies. Therefore, the aim of the present study was to quantitatively represent physicochemical properties of raw and heat-treated corn starch using an in vitro methodology that is commonly used by food scientists. The heat treatments examined were pelleting, steam flaking, micronization, and extrusion of corn. The obtained results indicated significant differences in gelatinization, hydration, and pasting properties of corn starch depending on the heat treatment applied. Future research should aim for the determination of rumen starch degradation traits and possible correlations with the present results.Cereal grain is processed using different combinations of heat, moisture, time, and mechanical action in order to improve its digestibility. The objective of the present research was to quantitatively represent the physicochemical properties of raw and processed starch using an in vitro methodology, as well as to describe the changes that occurred after heat treatment, such as pelleting, steam flaking, micronization, and extrusion of corn. Based on the obtained results, pelleting, steam flaking, and micronization can be considered as mild heat treatment methods, whereas extrusion proved to be a severe heat treatment method. Analysis of functional and pasting properties implied a possible interaction between the degraded components in the steam-flaked sample, as well as in the micronized sample, through to a lesser extent. Additionally, the occurrence of dextrins was noted after extrusion. The obtained results indicate the existence of significant differences in the physicochemical properties of corn starch depending on the heat treatment applied, which could possibly affect rumen starch degradation traits.

Starch Properties, Nutrients Profiles, In Vitro Ruminal Fermentation and Molecular Structure of Corn Processed in Different Ways

Processing will improve the digestion of corn by ruminant animals. The objectives of this study were to investigate the effects of processing methods (grinding, G; steam flaking, SF; extrusion, E) on the starch properties, nutrient profiles, in vitro ruminal fermentation and molecular structure of corn. Compared with G, SF and E increased (p &lt; 0.05) the starch content, starch gelatinization, ruminal gas production (GP, 0.5–32 h), propionic acid, starch degradability (SD), the area and height of carbohydrate peaks, and decreased (p &lt; 0.05) starch crystallinity, content of crude protein, neutral detergent fiber and acid detergent fiber, ruminal NH3-N, the area and height of amide I and II, α-helix, and β-sheet. The total VFA (24 h, 48 h) tended to be increased by SF and E (p &lt; 0.10). The carbohydrate peak area and height were positively (p &lt; 0.05) correlated with GP (1–24 h) and SD. The protein molecular absorption intensity was negatively correlated with SD (p &lt; 0.05). The change in starch properties, GP (1–24 h) and molecular structure caused by E was greater than SF (p &lt; 0.05). These results indicated that the higher starch gelatinization and lower starch crystallinity of E corn, induced by the high temperature and pressure, enabled more fermentation and digestion in the artificial rumen. The carbohydrate and protein molecular structures were correlated with the nutritional characteristics of corn.

PSIX-7 Differences in rumen degradability according to the degree of corn gelatinization

Abstract This study was conducted to evaluate the difference in ruminal degradability by the degree of gelatinization of corn grain. The treatments were Control (whole corn grain), T1 (70% gelatinized corn grain steam flake), and T2 (30% gelatinized corn grain steam flake). Corn grain steam flaked for T1 was produced by a pressurized steam chamber for a longer time than T2. For this reason, the thickness of T1 and T2 was 1.5 and 2.5mm on average, respectively. Two Holstein cows (BW.405±15.4kg, 26.5±12 months) fitted with ruminal cannula were fed 4 kg of tall fescue and 3 kg of a formulated concentrate mix. Immediately after morning feeding, the nylon bags containing the sample from all treatments were incubated in the ruminal ventral sac for 0, 2, 4, 8, 12, 18, 24, 36, and 48h. At 0h of incubation, the DM degradability of T1 (16.70%) was higher (P&amp;lt; 0.05) than Control (9.74%) and T2 (12.00%). The degradability of both Control and T2 slightly increased from 4 (23.08 and 27.57%) to 18h (36.65 and 35.52%), exponentially increased from 18 to 48h. On the other hand, the degradability for T1 exponentially increased from 2 (28.74%) to 18h (77.31%), only slightly increased thereafter. The final degradability (48h) of Control, T1, and T2 were 78.07, 89.20, and 84.86%, respectively (P&amp;lt; 0.05). The fraction a of DM degradability for T1 (24.29%) was higher than Control (2.26%) and T2 (6.26%) (P&amp;lt; 0.05). The effective degradability (ED) of T1 (75.31%) was higher (P&amp;lt; 0.05) than Control (57.42%) and T2 (60.86%). Therefore, this study demonstrated that 70% gelatinized corn grain steam flake showed a higher rate of ruminal degradability than other treatments. Thus, it is necessary to determine how these differences affect ruminant productivity through additional feeding experiments.

Effect of different processing conditions on essential minerals and heavy metal composition of sorghum grain

A study was conducted in order to access the effect of different processing conditions on the mineral status of the grain sorghum. Whole sorghum grain was (a) cooked in excess water, (b) fermented under submerged condition, (c) steamed after fermentation, and (d) fermented, steamed, and flaked. The mineral content of the samples was determined through a microwave plasma atomic absorption spectroscope. During cooking, essential minerals like K, Fe, and Mn decreased, while Mg, Ca, and Na contents increased; while most non-essential minerals decreased, except Ti. During fermentation Ca, Mg, and Na content increased, while heavy metals like As, Pb, Ti, and Ba decreased significantly (p < .05). Essential minerals like Fe and non-essential minerals like Cr, Ni, and Al were found to be contaminated from the machine parts during processing steps like steaming and flaking. At the same time, essential minerals like K, Ca, and Mn were lost during the flaking process. Practical applications This work provides information on how simple processing conditions like fermentation can improve the status of the essential mineral in sorghum, at the same time reducing the heavy metal presence in the sample. This study also provides an insight into where the possible metal contamination can occur during the production of fermented products and steam flaking of cereal grains like sorghum. This information will help control the metal contamination, reduction of heavy metal contamination as well as a guide for formulating the HACCP.

Effects of the degree of steam flaking and dietary concentration of wet distillers grains on growth performance and carcass characteristics of feedlot cattle

The objective was to determine the effects of degree of steam flaking of corn (SFC) on performance of finishing cattle fed diets containing wet distillers grains with solubles (WDGS). Crossbred steers (n = 214: initial BW = 357 ± 26.0 kg) and heifers (n = 121: initial BW = 323 ± 30.9 kg) were randomly assigned to 54 pens and 6 diets containing 0, 15, or 30% WDGS and corn steam flaked to either 321 or 270 g/L bulk density (25 or 21 lb/bu, respectively) in a 2 × 3 factorial arrangement. There were no interactions between WDGS concentration and SFC bulk density for growth performance ( P > 0.48), and growth performance was not influenced by the degree of steam flaking of corn ( P > 0.29). Dry matter intake ( P < 0.15) and ADG ( P < 0.06) tended to respond quadratically to dietary WDGS. Gain efficiency tended ( P = 0.15) to decrease linearly as dietary WDGS concentration increased. Carcass characteristics were not affected by SFC density but hot carcass weight ( P < 0.12), DP ( P < 0.01), and YG ( P < 0.14) were affected by WDGS concentration. Decreasing bulk density of SFC tended ( P < 0.11) to increase the frequency of liver abscesses. Results suggest optimal performance is achieved in SFC-based finishing diets when WDGS is fed at 15% of DM and that increasing the degree of steam flaking of corn to less than 321 g/L does not improve cattle performance in diets containing WDGS.

408 WS Distinguished Service Talk: Effects of steam flaking on the carbon-footprint of finishing beef cattle

Abstract Grain processing has been used for many decades to improve the digestibility of feed grains fed to finishing beef cattle and to improve animal performance. The most common methods currently used by feedyards in the U.S. are dry rolling (DRC) and steam flaking (SFC). However, the environmental effects of gain processing have not been rigorously studied. This manuscript presents a comparative estimate of the carbon footprint of steam flaking corn in beef cattle finishing diets with and without wet distiller’s grains with solubles (WDGS). Estimates were based on results of published literature and the Intergovernmental Panel on Climate Change. Although SFC required more natural gas and electricity for processing than DRC, feeding SFC decreased the total carbon-footprint by 9 to 13 % per steer. This was primarily due to 30% lower enteric methane production, 13% lower manure nitrous oxide emissions, and 8% lower feed production requirement than when DRC was fed. The carbon-footprints were slightly greater when the diet contained 20% WDGS than when it contained 0% WDGS.

218 Impact of diet and quality grade on tenderness of beef steaks

Abstract Research was conducted to evaluate the effects of feeding different types of processed corn, with or without distiller grains with solubles, and differing quality grade on tenderness of beef steaks. Steers (n=240) were finished on Dry Rolled Corn (DRC), DRC + 30% Dried Distillers Grains with Solubles (DDGS), Steam Flaked Corn (SFC), or SFC + 30% DDGS. Cattle were fed 10 per pen. Only pens with upper 2/3 Choice and Select-grade carcasses were sampled, with a goal of two (and a minimum of one) of each grade per pen. Three pens per treatment met the selection criterion and 36 carcasses were chosen (21 upper 2/3 Choice and 15 Select). Pen was considered the experimental unit. Both strip loins were collected from each carcass, halved, and aged for 2, 9, 16, or 23 d. After aging, steaks were placed under retail display for 7 d. Warner-Bratzler shear force (WBSF), slice shear force (SSF), sarcomere length, sarcoplasmic calcium, and troponin-T (Tn-T) degradation were determined. Minimal to no impacts on sarcomere length and calcium were found (P &amp;gt;0.05). For both WBSF and SSF, Choice steaks were more tender than Select. Significantly more Tn-T was degraded at 23 d of aging compared to 2 d of aging. Beef steaks from cattle fed DRC were more tender than SFC, regardless of the presence or absence of DDGS. For 2 d aged samples, Tn-T degradation was higher when cattle were fed DDGS compared to no DDGS. Overall, these data suggest that steaks from cattle fed DRC are more tender than steaks from cattle fed SFC and Choice-grade steaks are more tender than Select-grade steaks.

Corn processing and crude protein content in calf starter: Effects on growth performance, ruminal fermentation, and blood metabolites

This study aimed to investigate the effects of feeding dairy calves starter diets containing corn grain processed by different methods (ground versus steam-flaked; GRC vs. SFC) and either 18% or 21% crude protein (CP) contents (dry matter basis) on growth performance, digestibility, ruminal fermentation, urinary purine derivatives, and blood metabolites of dairy calves. Holstein dairy calves (39.3 ± 1.9 kg of body weight, n = 12 calves per treatment, 6 males and 6 females) were randomly distributed to experimental diets in a 2 × 2 factorial arrangement of treatments. The 4 dietary treatments were (1) starter diet containing GRC and 18% dietary CP (GRC-18CP; geometric mean particle size, GMPS = 0.73 mm); (2) GRC and 21% dietary CP (GRC-21CP; GMPS = 0.71 mm); (3) SFC and 18% dietary CP (SFC-18CP; GMPS = 2.21 mm); and (4) SFC and 21% dietary CP (SFC-21CP; GMPS = 2.16 mm). Calves were weaned on d 63 and remained in the study until d 83 of age. The starter feed intake did not differ among treatments; however, average daily gain and feed efficiency (FE) were improved and final body weight was higher for SFC diets compared with GRC diets. The organic matter and nonfiber carbohydrate digestibilities were greater for calves fed the SFC diets than for those fed the GRC diets. The ruminal total volatile fatty acid concentrations and the molar proportions of propionate and butyrate were greater, and the molar proportion of acetate and NH3-N concentrations were lower, for calves fed the SFC diets than for those fed the GRC diets. The excretion of allantoin and total purine derivatives, and subsequently microbial protein synthesis, were greater for calves fed the SFC diets than the GRC diets. The total urinary nitrogen excretion and its proportion of N intake were lower for calves fed the SFC diets than the GRC diets. The blood concentrations of insulin (pre- and postweaning), glucose (postweaning), and β-hydroxybutyrate (preweaning) were greater and blood urea nitrogen (preweaning) was lower for calves fed the SFC diets than the GRC diets. The protein content of the concentrate did not affect feed intake, growth performance, or ruminal fermentation of the calves. The neutral detergent fiber digestibility was greater for calves fed the 21% CP diets than the 18% CP diets. No interaction between main effects was observed regarding the starter intake, average daily gain, body weight, FE, ruminal fermentation, and nutrient digestibility of calves. The interaction between corn grain processing and starter protein content was significant for withers and hip heights with the greatest values found for SFC-21CP treatment. Our results show that steam flaking of corn improved the organic matter and nonfiber carbohydrate digestibilities, weight gain, FE, and ruminal microbial protein synthesis, and reduced urinary nitrogen excretion compared with grinding corn. Regardless of the marginal benefit derived from feeding the diet containing SFC and 21% CP in the height of calves, lower starter protein content (18% CP) may be used efficiently when calves are fed the SFC diets.

Reproductive Responses, Metabolic Disorder, Ruminal Fermentation Characteristics, and Milk Production of Postpartum Holstein Cows Fed Steam Flaked of Corn and Barley Grains

This study evaluated the effects of steam flaked of corn and barley grains on the reproductive response, ruminal fermentation characteristics, metabolic disorder, and milk production of postpartum Holstein cows. A total of 40 postpartum Holstein dairy cows were divided into 4 groups (n=10) and fed 1) ground grains (control), 2) steam flacked corn+milled barley, 3) steam flacked barely+milled corn, and 4) steam flaked corn and barley. The animals were treated for 0-30, 30-60, 60-90, and 90-120 days post-calving. Milk yield and compositions, total conception rate, endometritis, pyometra, ruminal fermentation characteristics, ketosis, and acidosis were assessed. This study was conducted in a completely randomized design. The results showed that dietary inclusion of steam flaked grains improved milk yield and compositions during the experimental period compared to the control group (p<0.05), except for cows treated for 0-30d days post-calving. Cows fed steam flaked grains showed a lower occurrence of reproduction and metabolic disorders compared to the control group (p<0.01). Cows fed a combination of steam flaked grains showed better pregnancy rates in the first 100 days and open days of postpartum cows compared to cows in control and a single form of steam flaked barley or corn (p<0.05). Total VFA, acetate, propionate, butyrate, and valerate were higher in cows fed steam flaked compared to the control group (p<0.05). Feeding steam flaked grains is advised for improving reproductive performance, milk variables, and rumen fermentation profiles in dairy cows.

Effect of different corn processing methods on starch gelatinization, granule structure alternation, rumen kinetic dynamics and starch digestion

In this study, the effect of four corn processing methods including grinding (G), dry-rolling (DR), steam-flaking (SF) and super-conditioning (SC), on corn starch parameters viz. gelatinization, granule structure alternation, rumen kinetic dynamics and the extent and site of starch digestion were compared. In addition, physical properties, chemical composition, gas production (GP), pH, ammonia nitrogen (NH3-N) and volatile fatty acids (VFAs) of batch culture after 24 h were determined. The apparent density of the SC corn resembled that of the G corn (0.758 vs 0.837 kg/L); however, its geometric mean of particle size (3.39 mm) was greater than that of the G corn (1.56 mm) and smaller than that of the SF corn (5.43 mm). In addition, dry matter (DM), ether extract (EE) and neutral detergent fiber (aNDF) were not significantly affected (P > 0.01) by the processing method. The starch content of the SC and SF corns were greater (P < 0.01) than that of the DR and G corns. GP after 6, 12 and 24-h incubation and GP rate were greater (P < 0.01) in the SC corn; nevertheless, GP at 48-h incubation was the same in SC and SF corns (P> 0.01). The pH and NH3-N of batch culture after 24-h were significantly lower (P < 0.01) in the SC corn than in the other processing methods. The SF corn increased (P < 0.01) acetate and acetate to propionate ratio, but decreased (P < 0.01) propionate while the SC corn reduced (P < 0.01) acetate and acetate to propionate ratio, but raised propionate (P < 0.01). The time required for 25 % and 75 % fermentation of substrate was significantly reduced by the SC corn (P < 0.01). The highest starch gelatinization (P < 0.01) was obtained from SC, followed by SF corn. The rapidly soluble fraction (a) for DM, starch and CP was greater (P < 0.01) in the SC corn than in other processing methods; however, the slowly degradable fraction (b) for DM and starch was lower (P < 0.001) in the SC corn than in other methods. Although the effective rumen degradability of DM (ERDDM) remained unchanged (P> 0.01), the effective rumen degradability of starch (ERDS) and the effective rumen degradability of protein (ERDCP) were found to be greater in the SC corn than in other processing methods (P < 0.01). Ruminal and total tract digestibility of starch increased (P < 0.01) in the SC corn, but intestinal DM (P = 0.002) and starch (P < 0.01) digestibility of the SC corn diminished. The ruminal CP digestibility was lower (P = 0.06) in the SF corn than in the SC corn; however, SC and SF corns showed greater intestinal (P = 0.005) and total tract (P = 0.021) CP digestibility. The results indicated more starch gelatinization in the SC process in terms of higher exposure of particles to conditioning and homogenization, which enabled the alteration of starch granules and the protein matrix in the endosperm of corn. Furthermore, the SC process could influence the rumen kinetic dynamics, the extent and site of starch digestion as well as the efficiency of using starch under in vitro and in situ conditions.

Performance and feeding behavior of dairy cows fed high-concentrate diets containing steam-flaked or ground corn varying in particle size

Steam-flaked corn (SFC) and ground corn (GC) of different particle sizes were evaluated for their effects on dry matter intake (DMI), milk yield and components, chewing activity, ration sorting, ruminal fermentation, and digestibility in lactating dairy cows. Eight multiparous Holstein cows in mid-lactation (46.6 ± 3.5 kg/d milk production and 101 ± 10 d in milk) were used in a double 4 × 4 Latin square design with 21-d periods. Cows were fed diets (dry matter basis) containing 36.2% forage (alfalfa hay and corn silage), 37.4% corn grain, and 26.4% other ingredients. The corn grain was ground (coarse: 1.08 mm; medium: 0.84 mm; and fine: 0.73 mm) or steam-flaked (SFC; density = 0.40 kg/L). The dry matter proportion retained on an 8-mm sieve was greater for the SFC diet than for the GC diets. There were no treatment effects on DMI, milk yield, fat-corrected milk, energy-corrected milk, fat or lactose yield, protein or lactose content, or milk urea nitrogen concentration. However, digestibility of dry matter and organic matter were greater for fine GC and SFC than the other diets. In addition, cows fed SFC had lower total-tract starch digestibility than cows fed GC diets. Cows fed SFC tended to have lower propionate proportion (22.8 vs. 27.1 mM) and total volatile fatty acid concentration (88.6 vs. 99.8 mM) in ruminal fluid than those fed GC diets. Acetate and butyrate concentration, acetate to propionate ratio, and ruminal concentration of ammonia-nitrogen were not affected by treatments. Ruminal pH (6.46 vs. 6.01) as well as milk fat content (2.75 vs. 2.59%) and efficiencies (fat-corrected milk/DMI and energy-corrected milk/DMI) were greater for SFC than GC, regardless of its particle size. Milk fat content tended to increase linearly with increasing particle size of GC. Eating activity (min/d) tended to be less for SFC compared with GC, but rumination activity (min/d) and total chewing activity (min/d) were not affected by processing or particle size. The results of study indicate that, compared with GC, steam flaking of corn with 400 g/L density increased milk fat content and efficiency of high-producing dairy cows without any negative effect on milk yield. For GC, milk fat content tended to linearly increase and starch digestibility decreased linearly with increasing particle size.

Different processing effects on nutritive value of barely grains by gas production method.

The purpose of this study was to investigate the effects of warm and cold physical as well as chemical processing methods on the nutritive value of barley grains by gas production technique. The processing methods included milling, steam flaking, extruding and soaking up the grain in water containing 1.00% citric acid, 1.00% propionic acid and 0.01 M sulfuric acid. Two-hundred mg of milling samples were incubated in special 100 mL glasses and the amount of gas produced at different hr was measured. The data were analyzed in a completely randomized design. The results showed that different treatments did not have a significant effect on chemical composition of barley seeds. Other methods of processing compared to the grinding method, significantly reduced the total amount of produced gas. In the 72 hr incubation period, the lowest amount of gas production was in the extruded (245.6 mL per g dry matter) treatment. However, there was no significant difference between the two methods of extruding and flaking. The highest percentage of digestible organic matter was associated with propionic acid (64.90%), while the steam cracking method (58.74%) was the least. Among the processing methods, the highest amounts of methane production, total protozoa population and volatile fatty acid concentration were related to the grinding method and the least amount of extrusion treatment was observed during 24 hr of incubation. Different experimental treatments had a significant effect on ammonia nitrogen condensation and the highest level was observed in milling. According to our results, processing methods such as extrusion and flaking may improve the grain nutritive value.

Variance of Zein Protein and Starch Granule Morphology between Corn and Steam Flaked Products Determined Starch Ruminal Degradability Through Altering Starch Hydrolyzing Bacteria Attachment.

Simple SummaryPreviously, we found that starch ruminal degradation kinetics between raw and steam flaked corn were significantly different, but the mechanism is still ambiguous. Currently, we have demonstrated that γ-zein protein, encapsulating the starch granules into the hydrophobic starch–protein matrix, and starch granule characteristics were dramatically different between raw and steam flaked corns. Along with the totally different abundance and procedures of starch hydrolyzing bacteria attached to the two grain types, we concluded that γ-zein protein content and starch granule morphology of corn grain determined starch ruminal degradation kinetics through altering the abundance and procedure of starch hydrolyzing bacteria attached to corn grain in rumen. The current study investigated differences of γ-zein protein contents and starch granule characteristics between raw and steam flaked corns and their influences on ruminal starch hydrolyzing bacteria (SHB) attached to corn grain. Two types of raw (Corn1 and Corn2) and their steam-flaked products (SFCorn1 and SFCorn2) were applied to explore physiochemical structures and SHB attachment. SDS-PAGE was conducted to detect γ-zein protein patterns, scanning electron microscope, and small angle X-ray scattering were performed to obtain starch granule morphology, while crystallinity, DQ starch, and DAPI staining were applied to quantify SHB. The steam flaking process destroyed γ-zein proteins and gelatinized starch granules. The median particle size of Corn1 and Corn2 starch granules increased from 17.8 and 18.0 μm to 30.8 and 26.0 μm, but crystallinity decreased from 22.0 and 25.0% to 9.9 and 16.9%, respectively. The percentage of SHB attached to Corn1 residues decreased (p = 0.01) after 4 h incubation, but SHB attached to SFCorn1 residues increased (p = 0.03) after 12 h incubation. Thus, the differences of γ-zein proteins and starch granule physiochemical structures between raw and steam flaked corn played an important role in improving the rate and extent of starch ruminal degradation through altering the process of SHB attached to corn.

97 Impact of diet on shelf life of beef steaks

Abstract This research was conducted to evaluate the effects of feeding different types of processed corn, with or without distiller grains, on shelf life of beef steaks. Steers (n = 240) were finished on Dry Rolled Corn (DRC), DRC + 30% Dried Distillers Grains (DDGS), Steam Flaked Corn (SFC), or SFC + 30% DDGS. Cattle were fed 10 per pen. Only pens with upper 2/3 Choice and Select-grade carcasses were sampled, with a goal of two (and a minimum of one) of each grade per pen. Three pens per treatment met the selection criterion and 36 carcasses were chosen (21 upper 2/3 Choice and 15 Select). Pen was considered the experimental unit. Both strip loins were collected from each carcass, halved, and aged for 2, 9, 16, or 23 d. After aging, steaks were placed under retail display for 7 d. Discoloration and objective color (L*, a*, and b*) were determined daily and lipid oxidation (thiobarbituric acid reactive substances; TBARS) was measured after 0 and 7 d of retail display. Fatty acid profile of the lean was obtained. Minimal to no impacts of grade on color and lipid oxidation were found (P &gt; 0.05). Steaks from cattle fed DRC were statistically or numerically lowest for discoloration and C18:2 (linoleic acid) and highest for redness compared to the other treatments (P &lt; 0.05). Conversely, steaks from cattle fed SFC+DDGS had the most C18:2 and the worst (least desirable) values for discoloration and redness toward the end of retail display (P &lt; 0.05). Steaks from cattle fed DRC had the lowest TBARS values, while steaks from cattle fed SFC+DDGS had the highest TBARS values (P &lt; 0.05). These data suggest that steaks from cattle fed SFC+DDGS oxidize, discolor, and lose redness more quickly under retail display than steaks from cattle fed DRC, likely due to changes in fatty acid content.

Dietary protein level and corn processing method: Intake, digestibility, and feeding behavior of lactating dairy cows✰

The effects of corn processing and dietary protein level and their interaction on intake, digestibility, and feeding behavior in dairy cow was examined using eight multiparous Holstein dairy cows in mid-lactation (105 ± 9 days in milk and 47.2 ± 3 kg/day milk production at the start of the experiment) that were placed in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments. Experimental diets contained either finely ground corn (FGC) or steam-flaked corn (SFC) based on either low protein (LP, 14.8%) or high protein (HP, 16.2%) content. Diets contained 40% forage (corn silage and alfalfa hay) and 40% corn grain. Dry matter intake did not differ between HP and LP diets. In contrast, cows fed LP had greater total tract digestibility compared with that for HP-fed cows. Cows fed LP had greater chewing time and lower chewing rate (g of DM/min) compared to those for cows fed HP. Cows receiving SFC had a lower intake of nutrients and tended to have greater ADF and starch digestibility than cows fed FGC. There was an interaction between corn processing and level of protein with respect to the apparent total tract digestibility with cows fed FGC with HP resulted in the lowest digestibility. Steam-flaked corn had lower density and greater moisture and mean particle size than the FGC. In comparison with FGC, SFC did not pass through the 8-mm sieve and caused significant increase in physical effectiveness factor (pef) and physically effective fiber (peNDF) in SFC diets compared to that for FGC diets. Cows fed SFC sorted against longer particles (P = 0.04) to a greater extent than cows fed FGC. Dietary protein level had no detectable effect on sorting index. Chewing time did not differ for cows fed SFC or FGC; however, cows fed SFC had lower chewing and rumination rate (g of DM/min). Chewing time per kg of DM and CP were greater and per kg of peNDF were lower in cows fed SFC rather than cows fed FGC. Results indicated that corn processing and dietary protein level may interact to affect nutrient digestibility, but did not affect the feeding and chewing behavior of lactating cows under our experimental conditions. Results also showed that dietary peNDF content and chewing activity can be effectively manipulated by steam flaking of corn, and cows fed SFC had greater peNDF and energy intake despite lower DMI.