An application of linear regression technique for predicting bulgur yield and quality of wheat cultivars.

Grains of 26 Turkish wheat cultivars and advanced breeding lines were used in this study. Simple correlations between a number of quality parameters to predict bulgur yield and bulgur cooking quality were determined. Highly significant correlations between bulgur yield and each of the thousand-kernel weight and the sum of the grain over 2.8 + 2.5 mm sieves were obtained for both durum and bread wheat samples (p < 0.01). The regression equations showed that the models involving two variables (the thousand-kernel weight and the thickness of the grain for durum wheat samples; the thousand-kernel weight and the length of the grain for bread wheat samples) resulted in the highest R2 values. For an assessment of the influence of all factors on bulgur cooking properties (total organic matter: TOM and colorimetric test values), simple and multiple regression analyses were used to find equations that predict best the relationship between various quality parameters and bulgur cooking properties. The models involving two variables; the vitreousness and the dry gluten contents for the durum wheat samples and SDS sedimentation test value and wheat protein content for the bread wheat samples resulted in the highest R2 for the TOM value.

Commercial milling of suni bug (Eurygaster spp.) damaged wheat.

In some wheat growing countries, considerable quantities of commercial wheat are rendered unusable in standard milling because of pre-harvest damage of the grain by protease-injecting insects. The possibility of mitigating the detrimental effects of bug damage by eliminating the mill streams of lower quality from straight run flour was investigated. The changes in the amount of damaged kernels by cleaning and washing prior to milling were also examined. Dry cleaning decreased the level of insect damage from 26.4% to 23.0%. A further improvement to 12.8% was obtained by removing the light-density bug-damaged kernels by washing. There were substantial differences among the mill streams of the commercial mill as evaluated by the standard and modified sedimentation tests and standard alveograph test. The best streams were those from the first, second, third and fourth reductions.

Protein and lysine content, grain yield, and other technological traits in durum wheat under Mediterranean conditions.

A major problem for durum wheat production in the Mediterranean region is yield fluctuation. This fluctuation is a result of year-to-year variation in precipitation and heat stress during grain growth, which is typical of the Mediterranean climate. Both yield stability and good quality are needed in adapted durum wheat ideotypes. Ten durum wheat cultivars differing in drought resistance were grown during 1998, under both rainfed and irrigated conditions, at three sites in southern Spain. The main traits studied were protein and lysine content, grain yield, test weight, SDS sedimentation, semolina color, and grain vitreousness. Results show a high influence of site on all traits. Only test weight (TW), SDS sedimentation, grain vitreousness, and protein per kernel appeared to be determined also by cultivar effect. Vitreousness was positively correlated with TW (r = 0.48**) and semolina color (r = 0.46**). An inverse relationship was found between grain yield and protein content. Regression of cultivar mean values of protein content and grain yield showed a negative correlation (r = -0.72***), probably due to dilution of protein by non-nitrogen compounds and reduced starch accumulation in the grain under drought conditions. Lysine content was negatively associated with protein content (r = -0.86***), indicating the difficulty of a simultaneous breeding for both characteristics.

Effects of variety, the 1B/1R translocation and xylanase supplementation on nutritive value of wheat for broilers.

1. Three consecutive studies were done with 12 wheat samples (4 per study), each of different variety (6 containing the 1B/1R rye translocation) to examine the effects of wheat variety, presence of 1B/1R and interactions with xylanase addition (Avizyme 1310). The wheat varieties covered a wide range of in vitro viscosity (6.3 to 19.8 cps). In each study 64 male, Ross broilers were individually caged and given the diets ad libitum from d 7 to 28. Bird performance, viscosity of ileal contents and diet metabolisability (AME) were measured. 2. The diets contained (g/kg): wheat 790, casein 134, dicalcium phosphate 21.4, potassium bicarbonate 10.8, sodium bicarbonate 7.5, soya oil 10, arginine 5, minerals etc. 21.3. 3. Within each study there were large differences in dry matter (DM) intake between varieties but the variety effect was significant (P<0.01) only in study 2. Liveweight gain (LWG) differences mirrored DM intake, being significant (P<0.01) in study 2. Mean gain:food was unaffected by variety in any study. 4. Calculated wheat AME (MJ/kg DM) ranged from 13.4 to 14.4 in study 2 (P<0.05), the values for studies 1 and 3 lying within this range. 5. Across all 3 studies, in vivo viscosity (proximal ileum) ranged from 5.0 to 37.6 in the absence of enzyme and from 3.9 to 12.1 with enzyme addition; in studies 1 and 2 variety differences were significant (P<0.05). 6. Enzyme addition had no effect on DM intake or LWG but gain:food tended to be improved (NS), metabolisability of energy (ME:GE) was increased (P<0.01) by 2.2% and calculated wheat AME by 4% while in vivo viscosity was reduced (P<0.001). 7. There were no significant differences in DM intake, LWG, gain:food, ME:GE or calculated wheat AME concentration associated with the presence of the 1B/1R translocation and no interactions between enzyme and 1B/1R. 8. There were poor relationships between either gain:food or wheat AME concentration and in vitro or in vivo viscosity. There was no significant relationship between AME concentration and either specific weight or thousand grain weight. 9. It was concluded that (a) variety differences tended to be small (b) there was no negative impact of the 1B/1R rye translocation with the diet formulation used (c) in vitro viscosity failed to predict satisfactorily any aspect of performance with the high wheat/low fat diet formulation used.

The relationship between high-molecular-weight glutenin subunit composition and the quality of Japanese hexaploid wheat lines.

To reveal the high-molecular-weight (1-1MW) glutenin subunit composition, the seed storage proteins of 40 Japanese wheat (Triticum aestivum) lines were fractionated by sodium dodecyl sulfate- polyacrylamide gel electrophoresis to determine their HMW glutenin subunit composition. These were identified by comparison of subunit mobility with that previously found in hexaploid wheat. Twelve different, major glutenin HMW subunits were identified. Each line contained three to five subunits, and 11 different glutenin subunit patterns were observed for 11 alleles in Japanese lines. The Glu-1 quality scores were not particularly high for most of the Japanese wheats in the southern part of Japan (Kyushu district). However, the Glu-1 quality scores of several wheat lines in the Hokkaido area (north Japan) were high. South Japanese wheat lines showed specialty allelic variation in the glutenin HMW 145 kfla subunit, different from those in non-Japanese hexaploid wheats.

[The high-molecular glutenins of the soft winter wheats from European countries and their relationship to the glutenin composition of the ancient and modern wheat varieties of Ukraine]. / Vysokomolekuliarnye gliutenitsy miagkikh ozimykh pshenits evropeiskikh stran i ikh sviaz' s sostavom gliuteninov starodavnikh i sovremennykh sortov pshenitsy Ukrainy.

The sources of high-quality components of HMW glutenines determining grain quality, as initial material for breeding in the conditions of Ukraine were revealed on the base of analysis of 75 literature sources data about composition of high-molecular weight (HMW) glutenin and pedigrees of 598 European wheats from 12 countries, bred in 1923-1997, including, 449 cultivars from West and 149 East Europe. Origin of these components was observed in varieties of Great Britain, France and Germany from ancient Ukrainian wheat Red Fife and it derivative spring wheats of Canada--Marquis, Garnet, Regent, Saunders, Selkirk and of USA--spring wheat Thatcher and winter wheats--Kanred and Oro--as directly as via cultivars of European countries and Australia; in wheats of East European countries from winter wheats Myronivs'ka 808 and Bezostaya 1 (derivative of Ukrainian cultivars Ukrainka and Krymka) and their descendants; in wheats of Austria and Italy--from the both genetical sources.

Wheat bran diet reduces tumor incidence in a rat model of colon cancer independent of effects on distal luminal butyrate concentrations.

To investigate the effects of dietary fibers in colonic luminal physiology and their role in the prevention of colon cancer, a study was conducted using two diet groups and two treatment groups in a 2 x 2 factorial design. The two diets differed only in the type of dietary fiber, wheat bran and oat bran, and the two treatments were injection with the colon-specific carcinogen azoxymethane, or saline, as a control. There were 34 rats in the carcinogen-injected groups and 11 saline-injected rats per diet group. The goal of the study was to determine if a moderate consumption (6 g/100 g diet) of wheat bran or oat bran would alter the development of colonic tumors in this rat model of colon cancer, and if the differences in tumor incidence were correlated to luminal butyrate concentrations, luminal pH or fecal bulk. Short-chain fatty acid concentrations (SCFA) were measured in feces during the first half of the study (the promotion phase of tumor development) and again at the end of the study. Rats consuming oat bran had greater body weights (P < 0. 002), produced much larger concentrations of all SCFA, including butyrate, in both the proximal and distal colon (P < 0.0001), had more acidic luminal pH values (P < 0.0001), but also had significantly more development of colon tumors (P < 0.03). Alternatively, rats consuming wheat bran produced more typical molar ratios of the SCFA (65:10:20), had a relatively greater concentration of butyrate than propionate, and produced a larger volume (P < 0.05) and more bulky stool than the rats fed oat bran. The results of this study support other evidence that an acidic luminal pH is not protective in and of itself, and that diets containing wheat bran are protective against colon cancer development. In addition, these data show that large luminal butyrate concentrations in the distal colon alone, as were present in the rats consuming oat bran diets, are not protective of tumor development.

Preference for flavored wheat straw by lambs conditioned with intraruminal infusions of acetate and propionate.

We hypothesized that volatile fatty acids in rumen fluid are feedback signals that can condition food preferences or aversions in sheep. Three predictions were tested based on this hypothesis: 1) low doses of sodium propionate or sodium acetate condition preferences, but high doses condition aversions (Exp. 1 and 2); 2) preferences are not caused by osmotic load (Exp. 3 and 4); and 3) low doses of mixtures of acetate:propionate condition preferences (Exp. 4). In Exp. 1, 2, and 4, lambs were divided into four groups (10 lambs/group), and lambs in Exp. 3 were divided into two groups (five lambs/group). In all experiments, alfalfa pellets were the basal diet. On even days, half of the lambs were offered chopped wheat straw containing a distinctive flavor, whereas the other half received straw with a different flavor. During straw ingestion, different groups of lambs received intraruminal infusions of different concentrations (4, 8, or 12% of the daily DE received) of sodium propionate (Exp. 1), sodium acetate (Exp. 2), NaCl at osmotic loads equivalent to those when propionate supplied 4% of the daily DE received (Exp. 3), or different proportions of sodium acetate:sodium propionate (55:45 or 75:25% of the DE of the infusion [4% of the daily DE received]), or equimolar amounts of NaCl (Exp. 4). On odd days, the flavors were switched, and no infusions were administered. After 8 d of conditioning, lambs were offered a choice of wheat straw with the two distinctive flavors. Lambs preferred the flavor paired with the lowest doses of propionate (P = .07) and acetate (P = .08) but avoided the highest doses (P < .001). Excesses of VFA may condition aversions due to increases in rumen fluid osmolality and(or) excessive rates of supply of energy or sodium to the rumen. Lambs also preferred flavored straw associated with combinations of acetate and propionate (P < .001), especially at the highest concentration of propionate (P = .10). Lambs avoided NaCl in Exp. 3 (P < .001) and did not form preferences for NaCl in Exp. 4 (P > .05). Thus, osmolalities were not responsible for flavor preferences. In conclusion, our results support the hypothesis that food preferences and aversions reside along a continuum that depends on the amount of VFA infused.

Escape protein supplementation of steers fed grass silage-based diets.

Beef steers (Trials 1 and 2, 280 +/- 2 kg; Trial 3, 330 +/- 2 kg) were fed diets of 67.5% wheat (Trial 1) or oat silage (Trials 2 and 3), 20.5% barley, and 12% supplement in randomized complete block design growth trials. Dietary treatments were graded levels of supplemental escape protein (EP) from corn gluten meal (Trial 1, 0 to 213 g/d escape protein) or animal by-products (1:1:1 DM mixture of blood, feather, and meat and bone meals, 0 to 223 or 0 to 317 g/d of escape protein in Trials 2 and 3, respectively) to titrate amounts needed to maximize steer live weight gain. As supplemental EP from corn gluten meal increased, steer live weight gain increased linearly (P < .001) and feed-to-gain decreased linearly (P < .001). Supplementation with 135 g/d of corn gluten meal EP (335 g/d of corn gluten meal) increased average daily gain from .76 to .91 kg/d. As supplemental EP from animal by-products increased, steer live weight gain increased quadratically (P < .05) and feed-to-gain decreased linearly (P < .01). Supplementation with 223 or 317 g/d of animal by-product EP increased live weight gain by .27 kg/d. Supplemental escape protein was needed to increase live weight gain of steers consuming ensiled forage diets due to low EP contents of silages (7, 3, and 23% of CP in Trials 1, 2, and 3, respectively) and barley (15, 27, and 22% of CP in Trials 1, 2, and 3, respectively) and limited microbial protein synthesis.

Apparent and true metabolizable energy values of feedstuffs for ducks.

Two experiments were conducted, each with 24 White Pekin ducks, to determine the AME and TME content of five feedstuffs for ducks. In each experiment, fasting losses were obtained from six ducks and six ducks were used for each feedstuff. Each experiment lasted 102 h with an initial 48-h period and a 54-h excreta collection period. During the first 48-h period, all birds were tube-fed dextrose (30 g/100 mL of water) at 8 and 32 h after feed was withdrawn. Thirty grams of each feedstuff were tube-fed (30 g/100 mL of water) at 48 and 54 h after feed was withdrawn. The birds from which fasting losses were obtained were intubated with 30 g dextrose (30 g/100 mL of water) at 48 and 54 h after feed was withdrawn. Excreta were collected during the last 54 h into bags screwed onto lids sutured around the vent of each bird. In the first experiment, the feedstuffs evaluated were corn, dehulled oats, and wheat. The fasting energy and nitrogen losses per bird in the 54-h collection period were 12.1 kcal and 0.29 g, respectively. The AMEn values for the birds fed corn, dehulled oats, and wheat were 3.10, 3.48, and 3.14 kcal/g, respectively. The TMEn values for the respective feedstuffs were 3.27, 3.64, and 3.30 kcal/g. In the second experiment, the feedstuffs evaluated were corn, parboiled rice, and rye. The fasting energy and nitrogen losses per bird in the 54-h collection period were 18.9 kcal and 1.09 g, respectively. The AMEn values for the birds fed corn, parboiled rice, and rye were 3.24, 3.45, and 2.69 kcal/g, respectively. The TMEn values for the respective feedstuffs were 3.40, 3.61, and 2.85 kcal/g. The data provide new information on AMEn and TMEn values of corn, wheat, parboiled rice, dehulled oats, and rye for ducks.

Wheat middlings in high-concentrate diets: feedlot performance, carcass characteristics, nutrient digestibilities, passage rates, and ruminal metabolism in finishing steers.

We conducted two experiments to determine the feeding value and effects on diet digestibilities, passage rates, and ruminal metabolism of wheat middlings (WM) fed as a replacement for either the concentrate or roughage components of finishing diets of steers. In Exp. 1, 120 medium-framed steers were blocked by weight and randomly allocated to one of six treatments of high-concentrate diets: control (0%); 5, 10, or 15% pelleted WM replacing dry-rolled corn (DRC); and 5 or 10% pelleted WM replacing chopped alfalfa hay (ALF) components of the diet. Increasing WM replacement of DRC increased DMI (P < .01) and feed:gain ratio (FG; P < .05) linearly. A 9.2% increase in daily DMI and 10.1% increase in FG were observed at 15% of WM. Daily gain and final weight of the steers were not influenced by WM replacement of DRC. The WM replacement of ALF decreased (P < .01) daily DMI linearly, but it had no effect on ADG, final weight, or FG. In Exp. 2, six medium-framed steers, fitted with ruminal cannulas, were used in a 6 x 6 Latin square design with the same treatments as described in Exp. 1. Dry matter, OM, and starch digestibilities decreased (P < .01) by increasing replacement of DRC with WM, and replacing ALF increased DM and OM digestibilities linearly (P < .01). Wheat middlings could replace only up to 5% of DRC without reducing feed conversion efficiency and diet digestibilities, but complete (100%) or partial (50%) replacement of ALF increased digestibilities of DRC finishing diets.

Preference of sheep and goats for extracts from high-grain concentrate.

Appetite stimulants were extracted and partially isolated from high-grain concentrate. The stimulants were fed daily and were palatable to sheep and goats used in the experiments. The stimulative effects were tested by comparing the intake of two types of hay: with or without the extracts. Diethylether and n-pentane extracts of the concentrate stimulated feeding in sheep (P < .01 and P < .05, respectively). However, methanol extracts had no significant stimulative effect on selective feeding in sheep. Goats also preferentially fed on hay sprayed with the diethyl ether extracts (P < .01). The diethyl ether extracts were divided into acid, neutral, and basic fractions. Sheep and goats had a marked preference for the acid fraction only (P < .01 and P < .05, respectively). These results suggest that specific chemicals to increase palatability of hay are present in high-grain concentrate and that the chemical are nonpolar, acidic substances.

Effect of feeding blends of Fusarium mycotoxin-contaminated grains containing deoxynivalenol and fusaric acid on growth and feed consumption of immature swine.

Experiments were conducted to determine the effect of feeding diets containing combinations of the Fusarium metabolites deoxynivalenol (DON) and fusaric acid (FA) to starter swine. In all experiments, pigs of approximately 8.2 kg initial weight were fed diets containing blends of mycotoxin-contaminated corn, wheat, and barley for 21 d with growth and feed consumption determined weekly. In the first experiment, diets were determined to contain 0 microgram DON/g + 58.9 micrograms FA/g (control), 4.4 micrograms DON/g + 57.1 micrograms FA/g, 6.0 micrograms DON/g + 48.6 micrograms FA/g, and 7.5 micrograms DON/g + 57.4 micrograms FA/g. The feeding of all diets containing DON caused significant linear depressions in growth and feed intake after only 1 wk. Lower concentrations of DON and FA were fed in the second experiment with diets containing 0 microgram DON/g + 16.3 micrograms FA/g (control), .5 microgram DON/g + 14.3 micrograms FA/g, 1.1 micrograms DON/g + 14.1 micrograms FA/g, and 1.9 micrograms DON/g + 13.6 micrograms FA/g. There was a significant linear reduction in feed intake after 1 wk with increasing levels of dietary DON. Weight gains declined significantly only after 3 wk. Increasing amounts of FA combined with relatively constant amounts of DON were fed in the third experiment. By analysis, diets contained .5 micrograms DON/g + 2.9 micrograms FA/g (control), 2.2 micrograms DON/g + 12.2 micrograms FA/g, 2.5 micrograms DON/g + 15.6 micrograms FA/g, and 2.4 micrograms DON/g + 15.9 micrograms FA/g. In the 1st wk, the feeding of increasing amounts of fusaric acid combined with a relatively constant amount of DON caused a significant linear depression in weight gain. We concluded that a toxicological synergism exists between DON and FA when fed to immature swine and that FA concentrations in feeds should be determined whenever DON analysis is conducted.

Effect of forage:concentrate ratio on digestion and reproduction in primiparous beef heifers.

We evaluated the effects of high- (HF) and moderate- (MF) forage diets on digestive and reproductive characteristics in beef heifers. Thirty primiparous beef heifers were allotted by weight and backfat thickness to receive either 80:20 (HF) or 50: 50 (MF) forage:concentrate ratio diets from parturition to at least 90 d postpartum. Alfalfa hay and wheat straw were the forage sources and barley was the concentrate source. Equal daily amounts of ME were provided to all heifers by restricting intake of the MF diet. Digestibility of DM was greater (P < .001) for MF compared with HF diets, whereas NDF digestibility was not different. Dry matter and NDF digested daily was lower (P < .001) for MF than for HF diets. Ruminal fluid pH was lower (P < .05) for MF diets; however, the acetate:propionate ratio was not different. Serum insulin concentrations were greater for MF diets for all hours (P < .001) and weeks (P < .05) of sampling. Changes in weight, backfat thickness, and body condition score at 90 d postpartum were not different between treatments. Calf gain to 30 d, however, was greater (P < .10) for the MF than for the HF treatment (25.5 vs 20.7 kg). Maximum size of the ovulatory follicle was greater (P < .10) for cows receiving the HF diet than for cows receiving the MF diet. However, other aspects of ovarian follicular growth and wave dynamics and the intervals from parturition to first and second ovulation, first estrus, first service, and conception were not different between treatments. Shifts in energy supply from forage to concentrate had minimal effect on digestion and reproduction in first-calf beef heifers in this study.

Effects of supplemental energy source and amount on forage intake and performance by steers and intake and diet digestibility by sheep.

Two levels of concentrate supplements containing different types of carbohydrates (corn-soybean meal, CSBM; wheat middlings, WM; and soybean hulls, SBH) were evaluated for effects on forage intake and performance in growing steers and total diet digestibility in sheep. In Exp. 1, 63 crossbred yearling cattle (298 and 377 kg initial BW for yr 1 and 2, respectively) were given ad libitum access to chopped bermudagrass (Cynodon dactylon [L.]) hay with no supplementation (CONTROL) or with 25 or 50% of projected total TDN intake from CSBM, WM, or SBH. In Exp. 2, digestibilities of organic matter (OMD) and neutral detergent fiber (NDFD) were determined with sheep fed levels of hay and concentrates similar to those used in the growth trials. Hay intake was 1.99% of BW for steers fed hay alone and averaged 1.93% of BW in steers fed supplements at the low level. At the high level of concentrate supplementation, hay intake was depressed (P < .001) to a similar extent (1.63% of BW) in steers supplemented with CSBM, WM, or SBH. AT the low concentrate level, shrunk ADG was similar (.63 kg/d) among supplements, but at the high concentrate level steers fed SBH had higher (P = .06) shrunk ADG (.95 kg/d) than steers fed CSBM (.76 kg/d). Body condition score (BCS) increased more (P = .06) for CSBM- and SBH- than for WM-supplemented steers. Total tract OMD was lower (P < .001) in sheep fed WM (54.8% for low and 56.9% for high supplementation levels) than in sheep fed CSBM (57.4 and 62.6%) or SBH (57.2 and 62.5%). Total tract NDFD was higher (P < .001) for the SBH (58.9% for low and 63.3% for high levels) diets than for CSBM (54.6 and 51.0%) or WM (54.6 and 51.8%) diets. Supplements containing highly digestible fiber (SBH) produced less negative associative effects than high-starch supplements (CSBM) when fed with bermudagrass hay at the high level (.8 to 1% of BW), but no differences were found at the low feeding level (.4 to .5% of BW).

Effects on nutrient digestion of wheat processing and methods of tallow addition to the diets of lactating dairy cows.

Five multiparous Holstein cows in midlactation that were fitted with ruminal and duodenal cannulas were used in a 3 x 5 incomplete Latin square. The objective of this study was to examine the effects on nutrient digestion of wheat processing and method of tallow addition to the diets of lactating dairy cows. Diets consisted of 45% forage and 55% concentrate, and each diet contained 20% wheat and 2% tallow (as-fed basis). Treatments were dry-rolled wheat with tallow added to the concentrate, steam-rolled wheat with tallow added to the concentrate, and steam-rolled wheat with tallow added first to the wheat. The dry matter intake; digestion of starch, fiber, and fatty acids; ammonia N concentration; and molar proportions of volatile fatty acids in ruminal fluid were not affected by treatments. The apparent digestibility in the total tract of organic matter and nitrogenous compounds was significantly higher for the steam-rolled treatment with tallow added first to the wheat. Mean ruminal fluid pH was similar across treatments; however, cows fed the diet containing steam-rolled wheat with tallow added first to the wheat had the smallest pH change from 0 to 2 h postfeeding. Milk yield did not differ, regardless of cow diet. Method of tallow addition had marked effects on the apparent digestibility of organic matter and N in the total tract of lactating dairy cows.

Feeding and excreta collection techniques in metabolizable energy assays for ducks.

Feeding and excreta collection techniques, lasting 102 h, for the determination of ME in feed ingredients for ducks are described. Eight and 32 h after feed withdrawal, all ducks received 30 g of dextrose in 100 g of water by orogastric administration. By orogastric administration, ducks received 30 g of test ingredients or dextrose (for ducks used in estimation of endogenous losses of energy and nitrogen) in 100 g of water at 48 and 54 h after feed withdrawal. The collection of excreta involved suturing a threaded plastic retainer ring to the vent and screwing a Whirl-Pak plastic bag, mounted on the top portion of a Playtex baby nurser set plastic bottle cut off 3 cm below the threads, to the retainer ring. Excreta were collected by replacing the Whirl-Pak bags at 54, 60, 72, 84, 96, and 102 h after feed withdrawal. In each of two experiments, ducks with an average weight of 3.7 kg were assigned to treatments. In Experiment 1, four ducks were assigned to each of three test ingredients (corn, dehulled oats, and wheat) and four ducks were assigned to be deprived of feed for estimation of endogenous losses of nitrogen and energy. In Experiment 2, six ducks were assigned to each of two test ingredients (corn and sorghum) and six ducks were assigned to be deprived of feed. Ducks lost an average of 537 g (Experiment 1) and 462 g (Experiment 2) during the 102-h experimental period and all the lost weight was regained within 7 d of return to full feed. Losses of nitrogen (milligrams per duck per 54 h) were 292 (Experiment 1) and 461 (Experiment 2) and energy (kilocalories per duck per 54 h) were 12.12 and 22.26 in feed-deprived group. The determined AMEn and TMEn for corn were 3.245 and 3.407, and 3.210 and 3.517 kcal/g for Experiments 1 and 2, respectively. For dehulled oats, wheat, and sorghum, the determined AMEn and TMEn were 3.464 and 3.625, 3.150 and 3.312, and 3.363 and 3.670 kcal/g, respectively.

The influence of different cereal grains on iron absorption from infant cereal foods.

Iron absorption from various cereal grains was evaluated in the present study to identify possible preferences for the preparation of infant weaning foods. In six separate studies, four radioiron absorption tests were performed in each of 57 volunteer subjects by using a sequential double-isotopic method. Serum ferritin concentration was used to adjust for the effect of differences in the iron status of subjects participating in separate studies. Identical commercial processing and test meal composition were used to evaluate iron absorption from 50 g cooked cereal prepared from rice, wheat, maize, oats, millet, and sweet or bitter quinoa. In an initial evaluation of cereals fortified with 2.5 mg Fe as FeSO4, geometric mean absorption values were uniformly < 1% for all cereals and were not significantly different. In subsequent studies, percentage iron absorption was enhanced by either eliminating the fortifying iron or adding 50 mg ascorbic acid to the test meal. The effect was similar for most of the cereals tested with a composite mean increase in absorption of 37% when fortifying iron was removed and 270% when ascorbic acid was added. There was a strong inverse correlation between iron absorption and the phytate content of different cereals. Except for a modestly lower absorption of iron from quinoa and a remarkably higher absorption from one lot of maize, we conclude that the type of cereal grain has little influence on iron bioavailability of infant cereals. On the other hand, modification in the milling and processing methods for cereal grains that reduce their content of phytic acid is likely to improve iron availability significantly.

Replacement of alfalfa neutral detergent fiber with a combination of nonforage fiber sources.

Sixteen Holstein cows in midlactation were used in a 4 x 4 Latin square design to determine the effect of replacing alfalfa neutral detergent fiber (NDF), with NDF from a combination of whole linted cottonseed, dried distillers grains, and wheat middlings. The four diets were a basal control diet that was low in forage and fiber [(5.9 g of corn silage NDF and 6.1 g of alfalfa NDF/100 g of dry matter (DM)], a normal forage diet (low forage plus 10 g of additional alfalfa NDF/100 g of DM), and two low forage diets with either 5 or 10 g of NDF from the nonforage fiber sources added per 100 g of DM. Milk yield, milk protein yield, and milk protein percentage were higher, and milk fat percentage and fat yield were lower, for cows fed the low forage diets than for those fed the alfalfa control diet that was higher in fiber. Among the low forage diets, dry matter intake, milk fat percentage, and fat yield all increased linearly as NDF content increased. The ratio of acetate to propionate in the rumen and rumination times were greater for the normal forage control diet than for the high nonforage fiber diet. Added NDF from these nonforage fiber sources increased milk fat percentage and yield, but this increase was less than the NDF from alfalfa and less than predicted. In agreement with results of similar previous trials, milk protein yield and percentage were increased when alfalfa NDF was replaced with fiber from nonforage fiber sources.