Nutritional Value Of Grain Research Articles

Laboratory procedure to determine protein digestibility of heat-treated feedstuffs for dairy cattle

A three-step in vitro procedure was developed by Calsamiglia and Stern [J. Anim. Sci. 73 (1995) 1459] to estimate intestinal protein digestion after 16 h incubation in the rumen. The objective of our work was to modify this procedure to give an accurate estimation of N digestibility without the use of surgically modified animals by replacing the rumen incubation step by an in vitro protease enzyme incubation, and the use of small nylon bags for samples instead of the time-consuming filtration step. The results were compared with those from mobile nylon bag studies or ADIN determinations. In addition, the effect of heat treatment of grains and soybean on protein digestibility was investigated. Briefly, samples were weighed into small nylon bags, sealed, and a maximum of 30 bags were placed in a 2.4 l bottle containing borate–phosphate buffer at 39 °C. After 1 h, protease solution (protease type xiv, Streptomyces griseus) was added. After 4 h, the bags were removed and rinsed thoroughly. Half of the bags were dried at 50–55 °C for 48 h and the dry weight was recorded. The rest of the bags were incubated for 1 h in pepsin solution, then NaOH and pancreatin solutions were added and the bags were incubated for 24 h at 39 °C. Bags were rinsed thoroughly and dried at 50–55 °C for 48 h. The dry weight of the bags was recorded and the bag residue and the original feeds were analyzed for N. Samples were barley, oats, wheat and soybeans, heat-treated for various times, and were obtained from other trials for which mobile bag digestibility values were determined with or without 16 h rumen incubation. Mobile bag digestibility values without rumen incubation ranged from 77 to 97%. Regression analysis of the relationship of N digestibility (mobile bag) and N digestibility (in vitro) for all grain samples resulted in a highly significant relationship ( r 2=0.95, P<0.0001). When soybean samples were included in the analysis, the r 2 was only 0.02. Residual trypsin inhibitor activity of some of the samples interfered with mobile bag digestibility (no rumen incubation), while there was no interference of trypsin inhibitor with the in vitro digestibility determinations, demonstrating a benefit of the proposed method. There was also no interference for mobile bag digestibility when the samples were first incubated in the rumen for 16 h. This in vitro procedure closely simulated the physiological conditions in the animal allowing a prediction of intestinal N digestibility without the use of surgically modified animals. The method was sensitive to heat damage of the samples and could be used to rapidly evaluate the nutritional value of grain and soybean feedstuffs for ruminants.

Chemical and physical characteristics of grains related to variability in energy and amino acid availability in poultry

Grains such as wheat and barley, combined with legumes and oilseed meals, provide not only the bulk of essential nutrients for commercial poultry production and reproduction, but are also the prime source of anti-nutritive components, which are likely to have significant bearing on how effectively all dietary components are utilised by poultry. Sources of variation in the physical and chemical characteristics of grains used in poultry diets include variety, seasonal effects, and growth sites, crop treatment and grain fumigants, and post-harvest storage conditions and period of storage. The available energy and protein contents of grains fed to poultry, which best represent nutritive value, are extremely wide and in consequence there is an urgent need to develop rapid and objective tests for the assessment of nutritive value prior to including grains in poultry diets. Variation in the available energy and protein content of grains can be attributed to a wide range of anti-nutritive factors such as non-starch polysaccharides (NSP), enzyme activity, tannins, alkyl resorcinols, protease inhibitors, α-amylase inhibitors, phytohaemagglutinins, alkaloids, saponins, and lathyrogens. The relative importance of such factors will also differ according to the type of grain in question. However, NSP seem to be the predominant factor in Australia over the past few years given the volume of published literature on this topic. This argument is strongly supported by the fact that NSP-degrading enzymes are routinely used in monogastric diets with great success throughout the world. Numerous attempts over a long period have failed to provide unequivocal evidence that nutritive value in grains for poultry can be predicted with sufficient accuracy and precision by simple, low-cost physico-chemical measurements used singly or in combination. Nevertheless, it is highly desirable to continue to explore these simple measurements in the expectation that useful statistical relationships with more complex measurements will emerge, or that simple measurements can be used to fine-tune prediction equations based on more powerful techniques such as near infrared spectrophotometry. Finally, the nutritive value of grains for poultry will be determined not only by the chemical and physical properties of grains but also by the way that these interact with the processes of ingestion, digestion, absorption, and metabolism in birds. For this reason it is imperative that plant and animal scientists join forces to improve the nutritive value of plant material as feed for animals for the benefit of grain growers and producers of livestock.

Specific beta glucanases as tools for polysaccharide structure determination.

A number of interesting beta-glucanases with a variety of substrate specificities have recently been described. These enzymes are ideal tools for elucidating the structure of the wide array of glucose polymers found in nature. Since many of the enzymes can be easily produced in substantial quantities by cloning and 'overexpression' techniques, they are available for other purposes as well. For example, they may substantially increase the nutritional value of grain and other plant materials.

Nitrogen Fertilizer Affects Amino Acid Composition and Quality of Spring Barley Grain

High N rates used to raise yields and the grain protein concentration (GPC) of cereal crops may lower the nutritional value of the grain by reducing the proportion of essential amino acids in the grain protein. Since spring barley (Hordeum vulgare L.) is an important feed grain for monogastric animals in eastern Canada, a 2‐yr field experiment was conducted to determine N fertilization effects on the amino acid composition of the grain protein. Two cultivars, Leger (adapted feed type) and Argyle (unadapted malting type) were grown with four fertilizer treatments. The four fertilizer treatments were 0 or 100 kg N ha−1 applied as ammonium nitrate at seeding, or with 100 kg N ha−1 at seeding plus 50 kg N ha−1 applied at awn emergence as broadcast ammonium nitrate (not included in 1988) or foliar‐applied urea. Amino acid analyses were conducted by ion exchange chromatography. Nitrogen treatments increased protein per grain in both years, but increased GPC in 1988 only. In 1987, N treatments decreased the proportion of lysine in the grain protein but did not affect other amino acids. In 1988, increased N rates reduced the proportion of aspartic acid, threonine, glycine, lysine, and arginine but increased the proportion of glutamic acid and proline in grain protein. Higher N rates reduced the proportion of cyst(e)ine in grain protein in Leger only. Cultivar differences in amino acid composition were inconsistent between years. Higher rates of N fertilizer increased protein per grain and GPC but lowered the nutritional value of barley grain.

Genetic engineering of grain and pasture legumes for improved nutritive value.

This review describes work aimed at the improvement of the nutritive value of grain and forage legumes using gene transfer techniques. Two traits which are amenable to manipulation by genetic engineering have been identified. These are plant protein quality and lignin content. In order to increase the quality of protein provided by the legume grains peas and lupins, we are attempting to introduce into these species chimeric genes encoding a sunflower seed protein rich in the sulphur-containing amino acids methionine and cysteine. These genes are designed to be expressed only in developing seeds of transgenic host plants. Chimeric genes incorporating a similar protein-coding region, but different transcriptional controls, are being introduced into the forage legumes lucerne and subterranean clover. In this case the genes are highly expressed in the leaves of transformed plants, and modifications have been made to the sunflower seed protein-coding sequences in order to increase the stability of the resultant protein in leaf tissue. Another approach to increasing plant nutritive value is represented by attempts to reduce the content of indigestible lignin in lucerne.

Feeding value of raw or heated grain amaranth germplasm

Four growth experiments were conducted with weanling male rats to determine the nutritional value of grain from four cultivars of Amaranthus species ( Amaranthus cruentus ‘477913’ and Amaranthus hypochondriacus ‘1023’, ‘K343’ and ‘R158’). Feed was offered ad libitum to individually caged animals for 12–14 days. Amaranth was ground and given raw, dry-heated (2 h at 100°C), moist-heated (10 min in boiling water) or soaked (16 h in water) as the sole source of protein and energy. Rats fed on raw, dry-heated or soaked amaranth gained weight for the first 6 days, then lost weight; rats fed on moist-heated amaranth gained weight at a rate equal to that of rats fed on a maize and soya-bean meal diet containing 16% protein. When rats were fed on raw or moist-heated ‘R158’ or black seed separated from ‘K343’, body weight gain with moist-heated amaranth was equal to that produced by the maize-soya bean meal diet, confirming the high nutritive value of moist-heated amaranth (including the black seeds separated from ‘K343’). This occurred despite the higher cell wall content of black seeds of ‘K343’ (27%) than of the unseparated ‘K343’ cultivar (12%). The overall results show that cultivars and lines of A. hypochondriacus and A. cruentus have a growth-inhibiting factor (or factors) labile to moist heat.

Mycotoxins in cereal grain. Part IV. Inactivation of ochratoxin A and other mycotoxins during ammoniation.

Addition of ammonia to final concentration 2% inactivates ochratoxin A, aflatoxin, citrinin, penicillic acid and partially zearalenon at temperature 20-50 degrees C. Detoxification of contaminated cereal grain (wheat, corn or barley) can be performed on a farm using ammoniation without special investment during 4 to 6 weeks. Ammoniation changes nutritional value of grain as feed in a small extent.

The comparative nutritive value for weaner sheep of stubble and grain of pea, vetch and lupin crops

Weaner Merino wethers were used in three experiments to compare the nutritive value of lupin, pea and vetch grains and stubbles. In the first experiment, grain was offered either as the sole ration at 250 g day-1 or as a supplement of 0, 250 or 750 g day-1 to wheat chaff which was offered ad libitum. The grains were pea, vetch, lupin, barley and a 311 mixture of barley and lupin. The mixed grain was not offered as the sole ration, nor was barley offered as a supplement at more than 250 g day-1. There were only small differences in the nutritive value of the grains. The sheep ate less chaff when offered lupin or barley plus lupin grain than when offered pea or vetch grain. However, because the digestibility of the diets was higher with lupins, digestible organic matter intakes were similar within a level of feeding for the three legume grains. Substitution of barley for 75% of the lupins resulted in a lower intake of digestible organic matter than occurred with 100% lupins. In the second and third experiments the three legume grains were offered at 160 and 500 g day-1 respectively, in combinations with chaff of lupin, pea or vetch stubble offered ad libitum. Some differences in the value of the chaffs were found, but the grains had similar nutritive values when offered with any particular chaff. There were significant linear regressions between digestible organic matter intakes and liveweight gain, which were similar for the three experiments, with no differences between type of grain or type of chaff.

The amino acid composition of barley grain protein during development and germination

SUMMARYThe amino acid composition of barley grain was studied during the maturation of the grain and during germination of the mature grain. Samples of the variety Proctor, grown at two nitrogen levels in each of the years 1969 and 1970, were analysed together with one sample of Sultan grown in 1970. It was found that during maturation the proportions of glutamic acid and proline increased and that the levels of these amino acids were highest in those samples with the highest total protein content. During ripening the proportions of lysine, alanine, aspartic acid, threonine and glycine decreased. On germination the proportions of glutamic acid and proline rapidly decreased whilst aspartic acid, lysine, alanine and glycine increased.The nutritive value of ripe barley grain is limited by its low lysine content. Whilst the germination process increases the level of lysine it is suggested that this does not increase the nutritional value of the grain due to the low level of cystine in the germinated grain.

Amino Acid Content of Corn Produced With Different Fertilizer Treatments

During the last decade a considerable amount of interest has been shown relative to the effect of fertilization upon the nutritional value of the crop produced. Markely et al. (1959) suggested that as little as 25 pounds of nitrogen per acre increased the crude protein content of grass hays. Wagnon et al. (1958) previously found that the addition of sulfur to range pastures had increased deer gains. Later Breniman et al. (1961) found that the addition of either manure or nitrogenous fertilizers greatly increased the nitrate and nitrite contents of corn forage and corn silage.There is little information available on the effect of fertilization on nutritive value of grains. Gunthardt and McGinnis (1957) studied the effect of nitrogen fertilization on whole wheat and found that the total protein level was increased and that the ratio of amino acids was relatively unchanged. There was, however, a significant increase in the…

Effect of Physical and Chemical Treatment of Grams on Growth of and Feed Utilization by the Chick: 1. The Effect of Water and Acid Treatments of Corn, Wheat, Barley and Expanded or Germinated Grains on Chick Performance

DURING the past ten years numerous studies have been conducted at several experiment stations and other laboratories to improve the nutritive value of poultry feedstuffs. It has been found that the nutritive value of barley corn, and wheat can be improved by either a simple water-treatment (Fry et al., 1957, 1958; Lepkovsky and Furuta, 1960) or by supplementation with enzymes. (Jensen et al., 1957). Similar observations were reported by Arscott (1958), Wharton et al. (1958), Willingham et al. (1959) and Jensen (1960). The nutritive value of poultry feedstuffs may be improved by physical treatments. Allred et al. (1956) and Arscott et al. (1957) reported increased growth in chicks fed high-efficiency corn-type rations either in pelleted or reground pellet form. The nutritive value of grains may also be improved during the milling process as a result of the starch granules being mechanically damaged (Jones, 1940).In view of the growth responses…

Nutritive Value of Grains, Amino Acids and Proteins in Sorghum Grain

Nutritive Value of Grains, Amino Acids and Proteins in Sorghum Grain