Maize Gluten Research Articles

Carbon balances for in vitro digestion and fermentation of potential roughages for pregnant sows

Ad libitum feeding of pregnant sows requires satiating, intake-restricting feed components to prevent sows from getting excessively fat. Because hindgut fermentation starts only after and proceeds much slower than enzymatic digestion in the small intestine, fermentation products might, as nutrients, induce a prolonged physiological satiation of sows. To simulate hindgut fermentation and determine the fermentative release of short-chain fatty acids (SCFA) in vitro, gas production tests (GPTs) were performed with different raw materials after removal of enzymatically hydrolysable compounds. Fresh feces from sows that received standard sow feed was used as inoculum. Fresh, ensiled, or dehydrated by-products of the food industry (brewers’ grains, liquid yeast feed, maize gluten feed, raw potato chips, potato steam peel, pressed potato pulp, sugar beet pulp (SBP)) and whole-plant products (grass, maize) were tested as individual products. Balances were drawn up of the in vitro flow of organic carbon (OC) to an “ileal” nutrient fraction, a “hindgut” fraction of SCFA and gas, and “fecal” remnants. The OC balances revealed large variations among raw materials in terms of their contribution to the different fractions. Potato steam peel gave the largest “ileal” nutrient fraction (77% of total OC), the lowest was observed with fresh sugar beet pulp (9% of total OC). In the GPT, SBP, and potato pulp brought about the highest “hindgut” SCFA yields (32–49% of total OC), and together with raw potato chips, the highest amounts of gas. Grass products and liquid yeast feed were slower fermented than most by-products. Moreover, whole-plant materials gave larger “fecal” OC portions than by-products, with the exception of fresh and dehydrated brewer’s grains. Together with straw, the latter were the least degradable of all raw materials tested. Among the grass products, dehydrated grass, and among the by-products, raw potato chips left the least “fecal” residues, i.e. they were nutritionally utilized to the largest extent.

The nutritive value of concentrate feedstuffs for ruminant animals: Part III. Small intestinal digestibility as measured by in vitro or mobile bag techniques

The aim of the study was to generate a database of small intestinal digestibility (SID) of different sources of concentrate ingredients commonly offered to ruminants in European countries. Test protein feeds were sunflower meal (SUN), rapeseed meal (RAP), soyabean meal (SBM) and cottonseed meal (CSM). Test energy feeds were palm kernel meal (PK), pollard (PO), barley (BA) and beet pulp (BP). Test protein+energy feeds were maize distillers grains (MDG), maize gluten feed (MGF), copra meal (CO) and malt combings (MC). The ruminal undegradable protein (RUP) portion of the test feedstuffs was obtained by ruminal incubation in four Friesian steers offered grass silage and concentrate. The RUP fraction was digested with pepsin and pancreatin enzymes (PPD) or placed into the duodenal cannula of two Friesian cows using the mobile bag technique, which were recovered in the faeces. The average in situ SID (g/kg) of CSM, RSM, SBM, SUN, BA, BP, PK, CO, MDG, MGF and MC was 834 (S.D. 61), 711 (S.D. 47), 978 (S.D. 9), 586 (S.D. 170), 427 (S.D. 80), 712 (S.D. 24), 767 (S.D. 53), 816 (S.D. 38), 860 (S.D. 73), 656 (S.D. 65) and 510 (S.D. 41), respectively. Corresponding in vitro SID values (g/kg) were 641 (S.D. 65), 620 (S.D. 45), 840 (S.D. 27), 606 (S.D. 155), 445 (S.D. 36), 601 (S.D. 17), 640 (S.D. 63), 686 (S.D. 69), 756 (S.D. 63), 634 (S.D. 84) and 504 (S.D. 16), respectively. These results show that the SID of feeds can vary substantially between different sources and indicates that different feeds should be screened for their nutritive value as a result. As the relationship between in situ ( Y) and in vitro ( X) SID is best described by the linear regression equation Y=−91.9+12.7 X ( r=0.91), indicating a close relationship between results obtained using both techniques, the in vitro PPD technique offers a quick and reliable method for SID of feeds to be screened on a regular basis.

The nutritive value of concentrate feedstuffs for ruminant animals: Part II: In situ ruminal degradability of crude protein

The objective of the study was to generate a database of in situ ruminal degradability of crude protein (CP) from different samples of a range of concentrate feedstuffs comprising protein, energy or protein+energy feeds commonly offered to ruminant animals in European countries. The in situ disappearance of CP was calculated using the in situ nylon bag technique where the test feedstuffs were subject to ruminal incubation in four Friesian steers offered grass silage and concentrate. Disappearance of CP from the test feeds from the rumen was measured at 0, 2, 4, 8, 14, 24 and 48 h. The exponential model of Ørskov and McDonald (1979) was used to measure degradation kinetics of CP. Test protein feeds were sunflower meal (SUN), rapeseed meal (RAP), soyabean meal (SBM) and cottonseed meal (CSM). Test energy feeds were palm kernel meal (PK), pollard (PO), barley (BA) and beet pulp (BP). Test protein+energy feeds were maize distillers grains (MDG), maize gluten feed (MGF), copra meal (CO) and malt combings (MC). The effective degradability of CP (EDP) in the protein feed SBM, where outflow rate ( k)=0.02 was not influenced ( P>0.05) by the sample of feed used. For the energy feeds, the EDP in PO for k=0.05 h −1, 0.06 h −1 and 0.08 h −1 and EDP in BA for k=0.08 h −1 were not significantly affected ( P>0.05) by the sample of feed used. The data has shown that for the majority of feeds examined in this study, the different samples of any one feed are not equal in nutritive value and it is necessary to screen feeds for nutritive value before using them in ration formulation systems.

The nutritive value of concentrate feedstuffs for ruminant animals: Part I: In situ ruminal degradability of dry matter and organic matter

The aim of the study was to generate a database of ruminal degradability of dry matter (DM), and organic matter (OM) of different sources of concentrate ingredients (classified as protein, energy or protein+energy feeds) commonly offered to ruminants in European countries. The ruminal disappearance of DM and OM was measured using the in situ nylon bag technique, where the test feedstuffs were subject to ruminal incubation in four Friesian steers offered grass silage and concentrate. Disappearance of DM and OM from the test feeds from the rumen was measured at 0, 2, 4, 8, 14, 24 and 48 h. The exponential model of Ørskov and McDonald (1979) was used to calculate degradation kinetics. Test protein feeds were sunflower meal (SUN), rapeseed meal (RAP), soyabean meal (SBM) and cottonseed meal (CSM). Test energy feeds were palm kernel meal (PK), pollard (PO), barley (BA) and beet pulp (BP). Test protein+energy feeds were maize distillers grains (MDG), maize gluten feed (MGF), copra meal (CO) and malt combings (MC). The effective degradability (degradability of feed, whilst considering rate of flow of feed from rumen to small intestine) of DM (EDDM) and OM (EDOM) in the protein feed SBM, where outflow rate k=0.02, was not influenced ( P>0.05) by the sample of feed used. For the feeds classified as protein+energy feeds, the EDDM in MGF and MC were not affected ( P>0.05) by the sample of feed for k=0.02. For the remainder of the concentrate feedstuffs used in this study, the sample of feed used had a pronounced effect on in situ degradability values. These data have shown that for the majority of feeds examined in this study, the different sources of any one feed are not equal in nutritive value and it is necessary to screen feeds for nutritive value before using them in ration formulation systems.

White muscle free amino acid concentrations following feeding a maize gluten dietary protein in Atlantic salmon ( Salmo salar L.)

This study aimed to investigate the effect of high maize gluten protein diets on the white muscle free amino acid (FAA) concentrations of Atlantic salmon following feeding and to examine whether these tissue free amino acids profiles highlighted any dietary deficiencies in essential amino acids (EAA). Two isocaloric and isonitrogenous diets (52% protein, 20% oil) were formulated and mixed proportionately to give a total of five feeds in which maize gluten provided 0%, 16%, 32%, 48% and 64% of the total dietary protein (diets 0MG, 16MG, 32MG, 48MG, 64MG, respectively). Triplicate groups of 19 g Atlantic salmon were fed each of the experimental diets for a period of 40 days. At the end of the growth experiment, groups of four salmon from each diet were taken at 4, 8 and 12 h after feeding for the white muscle amino acids analysis. Although fish doubled their weights during the growth period, no significant differences were observed in specific growth rates, feed conversion ratios, protein digestibility and protein growth rates among fish fed the test diets. Total free amino acid (FAA) concentrations did not change at various times after a meal and this was also true for the majority of individual FAAs (except asparagine, which increased significantly 12 h after feeding). The most notable diet-induced changes in the white muscle were an overall reduction in essential FAA concentrations (threonine and lysine) as dietary maize gluten content increased and an increase in histidine and leucine. Correlations between dietary essential amino acids patterns and white muscle protein-bound amino acids were examined. The possibility of partial replacement of fish meal maize gluten up to 50% was demonstrated.

Efficiency of feed utilization in Atlantic salmon (Salmo salar L.) fed diets with increasing substitution of fish meal with vegetable proteins

Atlantic salmon smolts were fed for 15-week diets where 28% and 55% of the fish meal, respectively, were replaced by a mixture of full-fat soybean meal and maize gluten meal in comparison with a diet where 89% of the protein came from fish meal and the remainder from full-fat soybean meal and maize gluten meal. The diets were equal in gross energy, crude protein, lipids, carbohydrates, lysine and methionine plus cystine. Apparent digestibilities of energy and protein in fish meal, full-fat soybean meal and maize gluten meal were determined as 93.5% (19.5 MJ digestible energy (DE) kg−1) and 89.3%, 69.3% (14.4 MJ DE kg−1) and 76.9%, and 78.6% (16.4 MJ DE kg−1) and 87.0%, respectively. Tested by ANOVA and orthogonal polynomials, a linear reduction that approached significance and with no significant deviation from linearity was found in growth, SGR and TGC with increasing substitution of fish meal. Substitution of fish meal caused a significant linear reduction in the condition factor, while feed consumption was not affected. The effect of substitution on feed conversion ratio (FCR=g feed g−1 growth) showed a near significant deviation from linearity, FCR being significantly higher on Diet 3 than Diet 1 and slightly lower on Diet 2 than Diet 1. Apparent protein digestibility of the test diets decreased significantly linearly with increasing substitution, while no significant effects were found on digestibility of lipids and gross energy. Carbohydrate digestibility was low with no significant differences between diets. Fish meal substitution had no significant effect on carcass content of moisture, protein, ash or energy, while content of fat was nearly significantly linearly reduced. Substitution caused a nominal insignificant linear reduction in protein accretion but had no effect on digestible protein consumption per gram of protein accretion. Protein efficiency ratio (PER=weight gain/protein consumption) decreased significantly curvilinearly and net protein value (NPV=carcass protein gain/protein consumption) significantly linearly with increasing substitution. Energy utilization for growth decreased significantly linearly with increasing substitution. There was a nominal linear reduction, which approached significance in energy accretion with increasing substitution. Substitution impaired energy utilization for energy accretion (i.e. increased MJ DE consumed/MJ accredited).

Ingredient apparent digestibility coefficients for the Australian short-finned eel (Anguilla australis australis, Richardson)

AbstractFish meal is the most widely used protein source in commercial eel foods and information on the nutritive value of more economical protein sources is needed in order to improve cost-effectiveness of diets. This investigation was conducted to determine apparent digestibility coefficients of available plant and animal meals for juvenile Australian short-finned eel (Anguilla australis australis, Richardson). The suitability of a modified Guelph-type settlement faecal collector in eel digestibility studies was assessed. Animal by-product (spray-dried meat solubles; blood meal; high fat poultry meal) and plant protein (soya bean; canola; maize gluten; lupin; field pea) meals were mixed with a reference diet and marker (0·3: 0·69: 0·01) and the resultant test diets given to the juvenile eels (3·15 (s.e. 0·42) g) at 0·05 live weight per day. The reference diet and all the test diets were well accepted by the fish. Apparent digestibility coefficients for crude protein (ADCCP) for maize gluten meal (MGM), lupin meal (LM) and blood meal (BM) were found to be 0·97, 0·96 and 0·96 respectively and they were significantly (P < 0·001) higher than that for the other ingredients. However, apparent digestibilities for dry matter (ADCDM) and energy (ADCkJ) were significantly (P < 0·0001) higher for animal by-products than for plant proteins except for maize gluten meal. This was explained by the higher content of nitrogen free extractives in the former plant proteins. There was a strong positive correlation between ADCDM and ADCkJ for all ingredients (P < 0·01). Weaker positive correlations were also found between ADCCP and ADCDM and between ADCCP and ADCkJ. Similar results obtained for warm water species using similar faecal collection techniques and over limited eel digestibility data support the suitability of the modified Guelph-type settlement collector system in digestibility studies with juvenile eels.

Amino Acid Profile of Escaped Feed Protein After Rumen Incubation and Their Intestinal Digestibility

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than >80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.

Effects of sources of protein and enzyme supplementation on protein digestibility and chyme characteristics in broilers

1. The purpose of this study was to evaluate the effects of protein source and enzyme supplementation on protein digestibility and chyme characteristics in broilers. 2. One hundred and twenty growing (13 d old) and 60 finishing (34 d old) Arbor Acre strain commercial male broilers were selected and placed into individual metabolic cages. 3. The experiment was a 5 × 2 factorial arrangement with 5 different sources of protein: casein, fish meal, soybean meal (SBM), soy protein concentrate (SPC), maize gluten meal (MGM) and two levels of protease (bromelain), 0 and 65 CDU/kg diets. 4. The diets were iso-nitrogenous and semi-purified, with Cr 2 O 3 as an indicator for determination of ileal digestibility and chyme characteristics. 5. Apparent ileal protein digestibility (AIPD) in both growing and finishing chickens was highest on the casein diet, followed by fish meal, SBM, SPC and MGM. 6. Enzyme inclusion did not improve protein digestibility, but significantly decreased the digesta pH value in the gizzard and increased pH in the ileum in the 3-week-old broilers. 7. The digesta pH values in the gizzard and duodenum were significantly lower in the SBM and fish meal groups compared with the other protein groups. The molecular weight distribution pattern of the soluble protein in the chyme of the gastrointestinal (GI) segments showed a similar trend, regardless of the enzyme inclusion or the stage of growth. 8. The molecular weight profile of soluble protein changed dynamically in the casein fed broilers from the gizzard to ileum and the low molecular weight proteins, <7 kDa, reached maximum levels at the ileum. The molecular weight profile of the soluble protein in the SBM and SPC changed between the jejunum and the ileum and in the intermediate molecular soluble protein weight (7 to 10 kDa) was significantly decreased. This indicated that the hydrolysis process began from the middle to the posterior end of the small intestine. 9. Similar profiles were also shown with fish meal protein. The pattern of distribution, however, did not show any prominent change in the GI segments of the MGM group. 10. The pepsin, trypsin and chymotrypsin protease activity in the gizzard and duodenum were highest in the casein group and lowest in the MGM group as compared with the other protein groups. 11. The rate change in the patterns of molecular weight distribution in soluble protein and the digestive enzyme activity provide indications of the partial digestibility of different protein sources. The exogenous enzyme, bromelain, did not show any beneficial effect on protein digestion.

Comparison of organic matter degradation in several feedstuffs in the rumen as determined with the nylon bag and gas production techniques

Organic matter (OM) degradation of 21 feedstuffs was investigated with rumen fluid using a rumen in situ technique and a gas production technique. Fitting the nylon bag data to an exponential model showed that there was a high variation in the rate of OM degradation ranging from 1.7% h −1 for protected solvent extracted soybean meal to 10.5% h −1 for potato pulp. The percentage fermentable OM (FOM), calculated from the nylon bag data, ranged from 26.9% for maize gluten meal to 76.4% for pea meal. Gas production was recorded with fully automated equipment using twice-diluted rumen fluid. The gas production profiles were fitted to a mono-phasic and a tri-phasic model. The aim of the study described is to investigate the possibilities to estimate in situ degradation characteristics using gas production characteristics and chemical composition. The in situ washout fraction ( W), degradable fraction ( D) and undegradable fraction ( U) could be predicted from chemical composition and gas production parameters with R 2 ranging from 0.50 to 0.72. There was a closer relationship between in situ degradation rate of OM ( k d) and the incubation period halfway to maximum gas production ( B), using the tri-phasic model ( R 2=0.58) than the mono-phasic model ( R 2=0.43). Accounting for an in situ lag-period slightly improved prediction of k d by gas production parameters ( R 2=0.47–0.62). Percentage FOM, calculated from in situ results, could be predicted from chemical composition and gas production parameters with R 2 ranging from 0.50 to 0.75. Transformation of k d (determined in situ) to its half-life value of degradation ( (ln 2/k d)×100 ) provided a slight improvement of k d prediction by chemical composition and gas production parameters, with R 2 ranging from 0.56 to 0.81. There was only a moderate relationship for OM degradation in these feedstuffs determined using an in situ and a gas production technique.

Effects of varying the energy and protein supply to dry cows on high-forage systems

A total of 57 Holstein–Friesian dairy cows were used to investigate the effect of dry period energy and protein intake on performance in the early part of the subsequent lactation, when animals were given a single diet based on low-quality grass silage. Animals were balanced for parity across four dietary treatments for the last 5 weeks of gestation. Four dietary treatments were offered in factorial arrangement of high and low energy forages offered ad libitum with or without a high protein supplement. The two forage treatments were a ryegrass silage only and a mix of the same silage and barley straw (60:40 on a dry matter basis), and the protein supplement was 0.5 kg/day high protein maize gluten meal. Dry period diet forage intake was significantly higher for silage diets than for silage and straw mix diets but was not affected by the protein supplement. At 3 weeks before calving, N balance was significantly greater on the silage diets, and was significantly increased by the protein supplement. A period of 1 week before calving, there was no difference between treatments in body weight or body condition score. After calving, there were no residual effects of dry period treatment on feed intake, although milk and protein yields were significantly higher for the first month of lactation from animals previously offered the two silage-based diets; there was no effect of protein supplement. Subclinical ketosis in the animals may have limited all animals, production capabilities, which was lower than expected for the genetic potential of the animals, due to poor early lactation diets. It is concluded that improved dry period nutrition cannot compensate for poor early lactation diets to enable cows to achieve good production levels.

Concentration and estimated flow of soluble non-ammonia nitrogen entering the omasum of dairy cows as influenced by different protein supplements

Four ruminally fistulated Finnish Ayrshire cows were used to study the effects of different protein supplements on concentration and flow of soluble non-ammonia N (SNAN)into the omasum.The treatments in a 4 × 4 Latin square design were a basal diet of grass silage and barley and the basal diet supplemented with fishmeal, soybean meal and maize gluten meal. Protein supplements significantly increased concentrations of peptide N (P=0.009)and total SNAN (P =0.03)fractions in omasal digesta.Peptide constituted the largest proportion of SNAN flow into the omasum indicating that hydrolysis of peptides to amino acids is the most limiting step in rumen proteolysis.The microbial contribution to SNAN was on an average 0.64 indicating that a large proportion of SNAN flow leaving the rumen was of microbial origin.The estimated SNAN flow per kg dry matter intake from the basal diet and protein supplemented diets indicated that approximately 49,22 and 37 g kg-1 of fishmeal,soybean meal and maize gluten meal protein, respectively, escaped from ruminal degradation as SNAN.;

Dietary protein source affects the susceptibility to lipid peroxidation of rainbow trout (Oncorhynchus mykiss) and sea bass (Dicentrarchus labrax) muscle

AbstractThis study was designed to explore the effect of protein source on muscle susceptibility to lipid peroxidation in two representative species of fish farmed for human consumption: the freshwater rainbow trout and the seawater European sea bass. Four isoproteic diets (digestible protein in the range 366 to 392 for rainbow trout and 391 to 415 g/kg for European sea bass) were formulated to contain one of the following as the main protein source: fish meal, warm water alcohol-extracted or toasted soya protein concentrates or maize gluten meal. Highest daily growth indices were always achieved using the diets based on fish meal as the main source of protein (P&lt; 0·05). Fish of both species given diets containing maize gluten and the toasted soya protein concentrate showed slowest growth. The depressant growth effect of the vegetable protein concentrates was greater in sea bass than in rainbow trout. Dietary treatment was not correlated with any significant effect on whole-body composition or intramuscular fat content except for ash concentration in European sea bass. Under conditions of forced peroxidation in vitro for 240 min, muscle specimens of trout and sea bass given diets containing fish protein as the main source of protein showed the highest peroxidation levels (P&lt; 0·05); while the lowest peroxidation values were found in fish given maize gluten-containing diets (P&lt; 0·05). In the present case, the partial substitution of fish meal with vegetable proteins in diets led to a lower susceptibility of fish flesh to peroxidation. This finding may have applications in the production of fish of improved quality and longer shelf life.

Effect of concentrate on nitrogen turnover and excretion of P, K, Na, Ca and Mg in lactating cows rotationally grazed at high altitude

The effects of concentrate on N and mineral excretion were determined in 2×12 early-lactating cows rotationally grazed at 2000 m above sea level for 77 days in two seasons A and B. Supplementation was oriented towards maintenance energy requirements to account for the extra requirements on alps. Two concentrates equally high in easily-fermentable energy (8.7 MJ NEL) but differing by 94 g/kg DM in absorbable protein (±maize gluten) were fed at three respective maintenance energy:protein levels as 1.0:0.8 (A/B), 0.5:0.4 (A) and 1.0:1.8 (B). A control group received no concentrate (A/B). Herbage and N intake was reduced in cows supplemented with approximately 4 kg of the low protein concentrate (1.0:0.8). Milk N excretion increased improving N utilisation by 52%. Excretion of urine N and its proportion of manure N decreased by 44 and 18% with this type of concentrate. Supplementing extra protein (1.0:1.8) reduced effects on N utilisation and excretion relative to controls, although herbage intake was similarly reduced as with the low-protein concentrate. Concentrate reduced the excretion of faecal Ca and Mg, and urine K. Seasonal N and P fertilisation rates from excreta were low. Supplementary feeding increased fertilisation rates per hectare of P and K whereas N only increased with additional protein.

Nutrient composition and the use of solubility to estimate rumen degradability of food proteins in cattle

AbstractThe use of protein solubility to estimate protein degradability in cattle was tested using 12 by‐products representing agricultural and distillers' food raw materials (RM). Agricultural RM included cereals (rice bran, maize gluten feed), legumes (field beans, soybean hulls) and oil‐seeds (rape meal, sunflower meal). Distillers' RM involved dark grains (DG1, DG2, DG3) and malts (MT1, MT2, MT3). Soluble proteins, as proportions of total soluble N (TSN), were extracted from RM and their undegraded residues (RU) after 18 h of in sacco rumen incubation in cattle (dg18) by using water (albumin), salt (globulin), acid (glutalin 1) and alkali (glutalin 2) in succession. RM and RU differed significantly for all soluble proteins (P &lt; 0.001). While albumin was the major protein in legume RM (0.74TSN), glutalin 1 was the major protein in legume RU (0.54TSN). Cereals were the most variable group, where maize gluten contained five times more albumin and two times more TSN in RM and three times more glutalin 1 + 2 in RU than those in rice bran. Distillers' RM contained slightly less albumin (0.53 vs 0.56TSN) but over twice as much glutalin 1 (0.29 vs 0.12TSN) as agricultural RM. Albumins were the most (0.55TSN, RM; 0.16TSN, RU) and glutalin 1 the least (0.21TSN, RM; 0.48TSN, RU) degradable proteins. There were moderate to strong correlations between protein solubility, dg18 and acid detergent‐insoluble N (ADIN). ADIN correlated satisfactorily with glutalin 1 + 2 (r = −0.55, RM and −0.70, RU), TSN (r = −0.75, RM and RU) and slowly degradable N, (SDN; r = −0.70, all). TSN in all RM related well with SDN (r = 0.65) and dUN (r = 0.72). TSN in distillers' RM correlated closely with SDN (r = 0.91) and dUN (r = 0.96). Glutalin 1 in distillers' foods correlated extremely well (r = 0.94, RM and 0.93, RU) with dUN. Globulins correlated most consistently with SDN (r = 0.82, all; r = 0.77, agricultural; r = 0.92, distillers' RM). It is possible to predict protein degradability from the presence or absence of soluble proteins in various foods. While ADIN may be more suitable to predict DUN, globulins showed more potential to predict SDN in various foods. However, it may be necessary to be selective in choosing solvents for various foods. Further studies must validate this method by using a greater range of foods before suggesting its routine use for food evaluation.© 2001 Society of Chemical Industry

Effects of type and treatment of grain and protein source on dairy cow performance

AbstractThe effects of different types of energy or protein supplementation on performance of cows given grass silage-based diets were studied. The possibility of maintaining high energy intakes by using different grain sources, barley or maize, or by the use of the physical processing of the barley was investigated. In addition, the relative quality of rapeseed meal as a protein supplement compared with alternative protein supplements was examined. In experiment 1 16 Finnish Holstein-Friesian cows were used in a cyclic change-over design experiment with eight diets and four 21- day periods. The concentrate supplements comprised a 2 ✕ 2 ✕ 2 factorial arrangement of two grain sources (barley (B) and maize (M)) given either ground (T–) or steam-rolled (T+), each supplemented with either rapeseed expeller (R) or a mixture of maize gluten and soya-bean meal (GS). Grass silage was givenad libitumand concentrates at a rate of 11·2 kg DM per day. M supplements increased milk, milk protein and lactose output (P&lt; 0·05) and decreased milk urea concentration (P&lt; 0·01) compared with B supplements. Blood β-hydroxy-butyrate (BHB) and plasma urea concentrations were higher (P&lt; 0·01) for B than M diets. R supplements increased silage intake, energy-corrected milk yield and milk protein output and concentration (P&lt; 0·05) compared with GS supplements. Steam-rolled grain decreased food intake, blood BHB (P&lt; 0·05) and plasma and milk urea concentrations (P&lt; 0·001). Steam rolling improved organic matter digestibility (grain ✕ processing interaction,P&lt; 0·05) with M but not with B supplements.In experiment 2 four Finnish Holstein-Friesian cows fitted with rumen cannula were used in a balanced complete change-over design to evaluate ground or steam-rolled barley (T– v. T+) and two protein treatments (rapeseed expeller, R or a mixture of maize gluten/soya-bean meal/sugar beet solubles, GSS). Cows were given concentrates at 11·2 kg dry matter (DM) per day and offered grass silagead libitum. There were no differences (P&gt; 0·05) in food intake, digestibility or milk production and composition between treatments. Plasma urea concentrations (P&lt; 0·01) and molar proportion of butyrate (P&lt; 0·05) in rumen fluid were decreased with R compared with GSS supplements. The results showed that replacing B with M grain resulted in minor increases in milk production. Steam rolling of grain did not influence animal performance. Among the protein supplements R increased animal performance compared with GS supplement.

Short-term dietary effects on reproductive wastage after induced ovulation and artificial insemination in primiparous lactating Sarda ewes.

Short-term effects of nutrition on conception rate (CR), ovulation rate (OR), ova and embryo losses (OEL) during the first 50 days following insemination and total reproductive wastage after ovulation (TRW), were investigated in primiparous lactating Sarda ewes after oestrous synchronisation and cervical [corrected] artificial insemination (AI). Eighty ewes grazing a green high-quality pasture were offered one of three iso-energetic supplements from day 14 before to day 2 after AI: whole maize grain (M); soyabean meal (S); maize gluten meal (G); or served as controls (C). Supplements G and S were iso-nitrogenous but provided different amounts of rumen undegradable digestible protein. The intake of herbage and digestible dry matter, measured by the n560 mg/l was associated with lower CR. Ranking by ovulation groups of CR was single<double=triple; and of TRW was double<triple<single. In conclusion, OR in primiparous lactating Sarda ewes grazing on a good quality pasture is high, and CR after AI is reduced by ova as well as embryo loss, especially following single ovulations. Short-term supplementation with a soyabean-based concentrate may help alleviate these losses.

Ileal digestibility of amino acids in maize gluten feed for pigs

1. Standardised ileal crude protein and amino acid digestibilities in protein supplements for piglets Renata Urbaityte, Rainer Mosenthin, Meike Eklund, Hans-Peter Piepho, Nadja Sauer, Meike Rademacher Archives of Animal Nutrition CrossRef

A comparison of digestibility of some concentrate feed ingredients in cattle and sheep

An experiment was carried out to compare the digestibility of five concentrate ingredients (barley, beet pulp, citrus pulp, maize gluten feed and grain screenings) in cattle or sheep, fed at ≈1.2 maintenance. Four wether sheep and four steers were fed each concentrate, which comprised ≈800 g/kg of the dietary dry matter (DM). The remaining 200 g/kg was a hay/soyabean meal mixture whose digestibility was determined simultaneously in another four sheep and cattle. Following diet introduction and adaptation, faeces were collected for a 10-day period. Across diets, there was no difference ( p >0.05) between sheep and cattle in digestibility of organic matter (OM, 0.784 and 0.78, respectively, standard error of the difference (s.e.d.), 0.0049), crude protein (0.586 and 0.577, respectively, s.e.d. 0.0192), or neutral detergent fibre (0.632 and 0.628, respectively, s.e.d. 0.0116). However, cattle digested the OM (0.749 vs. 0.724, p <0.05, s.e.d. 0.0106) of maize gluten feed better than sheep, but there were no significant differences ( p >0.05) between sheep and cattle with any of the other four feeds. These results do not support previous conclusions that sheep digest concentrates better than cattle, but they do suggest that there are differences within specific feeds.

Effects of calcium soaps and rumen undegradable protein on the milk production and composition of dairy ewes.

Forty-eight Manchega dairy ewes were used during a complete lactation in a 2 x 2 factorial design to determine the effects of supplementing diets with fat (calcium soaps of palm oil fatty acids, CSFA) and rumen undegradable protein (RUP) on milk production and composition. Factors tested were amounts of CSFA (0 or 200 g/kg) and RUP (300 or 450 g/kg crude protein) in the concentrate. RUP was altered by adding a mixture of maize gluten meal and blood meal. Lactation was divided into one nursing period (period 1, weeks 1-4), and three milking periods (periods 2-4, weeks 5-8, 9-14 and 15-21). Concentrates were given at 0.8 kg/d during periods 1 and 2, and at 0.6 kg/d in periods 3 and 4. Ewes grazed rotationally in an Italian rye-grass pasture and received a daily supplement of 0.8 kg vetch-oat hay during period 1, and 0.3 kg lucerne hay during periods 2-4. For the whole lactation, supplemental fat markedly increased milk fat content (+23%) and yield (+16%), and decreased milk protein content (-9%). The positive effect of feeding CSFA on milk fat content was more evident at the beginning of lactation; however, its negative effect on milk protein was more pronounced in late lactation. Supplementary RUP had little effect, increasing milk protein content only in period 3, when the crude protein content of pasture was lower. Milk yield and lamb growth were not affected by dietary treatments. The results indicated that CSFA can be useful for increasing the milk fat content of dairy ewes at pasture, which may help farmers to produce milk reaching the minimum requirements of fat content for the cheese industry.