Maize Gluten Feed Research Articles

Degradation of Anti-Nutritional Factors in Maize Gluten Feed by Fermentation with Bacillus subtilis: A Focused Study on Optimizing Fermentation Conditions

Degradation of Anti-Nutritional Factors in Maize Gluten Feed by Fermentation with Bacillus subtilis: A Focused Study on Optimizing Fermentation Conditions

Ensiling sugar beets: Effect of mixer feed used for co-ensiling on fermentation products and losses when ensiled in vacuum bags

Co-ensiling beets with other feeds allows for year-round feeding of beets and reduces the risk of dry matter (DM) loss as effluent from the silage. This study aimed to evaluate the effect of co-ensiling high DM beets with maize and grass/clover silage, grass seed straw, fresh beet pulp, and high DM concentrates (dried beet pulp, wheat distillers’ grain solubles; DDGS, wheat bran, rapeseed meal, sunflower meal, soybean hulls, and maize gluten feed) on gaseous weight loss (GWL), loss of effluents, and silage quality. Beets from harvest year 2021 were used to produce two sets of silages in laboratory silos, resulting in a total of 2 pure beet silages and 12 mixed beets silages. GWL was measured by weighing the laboratory silos until 181 days of ensiling. Fermentation was terminated by freezing after 30, 92, and 181 days of ensiling where loss of effluent was also measured. Total GWL was highest in the two pure beet silages (mean ± SEM; 282 ± 5.47 and 250 ± 7.94 g/kg DM, respectively), and differed among the mixed silages depending on mixer feed. Effluent was only observed in the pure beet silage in Set 1. Silage DM content at 181 days of ensiling was lowest for the two pure beet silages (180 ± 10.9 and 165 ± 5.95 g/kg). For all silages, pH was below 4.25 by 30 days of ensiling. Ethanol concentrations at 181 days of ensiling were highest in the two pure beet silages (345 ± 11.5 and 287 ± 11.8 g/kg DM). L-lactate content of pure beet silages was 38.4 ± 1.85 and 31.1 ± 1.21 g/kg DM at 181 days of ensiling. In Set 1, L-lactate content was lower in beets ensiled with maize silage, grass seed straw, dried beet pulp, or DDGS compared to pure beet silage. In Set 2, L-lactate content was higher in beets ensiled with maize gluten feed compared to pure beet silage. Silage concentration of NH3 varied depending on mixer feed. The NH3 content at 181 days of ensiling was 0.817 ± 0.626 and 2.05 ± 0.601 g/kg DM for pure beet silages and was highest in beets ensiled with grass/clover silage in both silage sets (16.4 ± 0.63 and 17.6 ± 0.60 g/kg DM). Co-ensiling beets with forages, high DM concentrates, and protein-rich feeds included in this study lowered fermentation weight loss, eliminated the loss of effluent, and resulted in silages of good fermentation quality.

Intake, Growth and Carcass Traits of Steers Offered Grass Silage and Concentrates Based on Contrasting Cereal Grain Types Supplemented with Field Beans, Peas or Maize By-Products.

The study objective was to determine intake and performance of beef cattle individually offered perennial ryegrass-dominant grass silage ad libitum supplemented with 4 kg dry matter daily of, rolled barley or maize meal-based concentrate rations containing supplements of flaked field beans, flaked peas, maize dried distillers grains (MDD) or maize gluten feed (MGF) for 110 days (Experiment 1), rolled barley or rolled oats with or without supplements of flaked field beans or flaked peas for 146 days (Experiment 2), and to quantify the nitrogen balance of diets similar to those offered in Experiment 2 (Experiment 3). The protein supplements were formulated to have similar crude protein concentrations. Cereal type or protein source did not affect intake, growth, feed efficiency and carcass traits in Experiment 1 or 2. Inclusion of a legume protein supplement with barley or oats had no effect on intake or growth performance (Experiment 2), whereas their exclusion decreased nitrogen intake, plasma urea concentrations and urinary and total nitrogen excretion (Experiment 3). The feeding value of barley was similar to oats and maize meal, and flaked beans and peas were similar to MGF and MDD, as supplements to grass silage. Excluding protein ingredients from a cereal-based concentrate did not affect animal performance and reduced nitrogen excretion.

Determination of standardised ileal digestibility of amino acids in high-fibre feedstuffs and additivity of apparent and standardised ileal amino acids digestibility of diets containing mixtures of maize, sorghum, and soybean meal

ABSTRACT 1. Two experiments were conducted to determine the coefficients of standardised ileal amino acid digestibility for selected high-fibre feedstuffs (Expt.1) and to assess the additivity of coefficients of apparent (cAIAAD) and standardised (cSIAAD) ileal amino acid digestibility for diets containing combinations of sorghum, maize and soybean meal. 2. In Expt. 1, broiler chickens (324) were allocated to 54 metabolism cages (nine diets with six replicates). In Expt. 2, broiler chickens (315) were allocated to 63 metabolism cages (seven diets with nine replicates). The diets in Expt. 1 were a nitrogen-free diet plus eight semi-purified diets in which soybean meal (SBM), low-protein SBM (LPSBM), soybean hull, wheat bran, maize bran, rice bran, dried sugarbeet pulp or maize gluten feed were the only sources of protein in the respective diets. In Expt. 2, the seven diets were a nitrogen-free diet, and six semi-purified diets consisting of individual feedstuffs (SBM, maize, or sorghum) or combinations (maize and SBM; sorghum and SBM; or maize, sorghum, and SBM) as the only sources of protein. 3. In both experiments, all the broiler chickens received the same maize-SBM diet formulated to meet nutrient requirements according to the breeder’s recommendations from d 0 to 16. Allocated experimental diets were provided on d 16, and ileal digesta were collected on d 21. 4. In Expt. 1, SBM and LPSBM had greater (P < 0.01) cSIAAD for indispensable and dispensable amino acids than the other feedstuffs. The rice bran had greater (P<0.01) cSIAAD values than wheat bran and maize bran, except for Leu, Cys, and Pro. 5. In Expt. 2, predicted cAIAAD values for maize-SBM and maize-sorghum-SBM were generally lower (P<0.01) than actual values. The actual and predicted cSIAAD values for maize-SBM, sorghum-SBM and maize-sorghum-SBM combinations were not significantly different. 6. It was concluded that the standardised amino acid digestibility of sorghum, when combined with other feedstuffs, was additive and that approximately three-quarters of total amino acids in the assayed high-fibre feedstuffs, except for dried sugarbeet pulp and maize gluten feed, were digestible.

Potential of raw and fermented maize gluten feed in bread making: Assess of dough rheological properties and bread quality

Maize gluten feed (MGF) is a secondary product of maize processing with rich dietary fiber content, which remains underexploited as an ingredient by the food industry. In this study, the impact of MGF and fermented MGF (FMGF) incorporation on dough properties and bread quality was investigated. The results indicated that both MGF and FMGF demonstrated beneficial effects on the water absorption, dough development time, setback value while exerting a negative impact on the dough stability time. A significant decrease in L value (extensibility) and W value (deformation energy), and a significant increase in P value (elasticity) were observed with MGF or FMGF incorporation in the dough. For fermentation properties, the maximum height of dough and the volume of the gas retained in dough during fermentation decreased with the substitution level increased. The bread incorporated MGF or FMGF decreased the specific volume, deepened the color, led to lower porosity, increased the crumb hardness and chewiness. MGF and FMGF bread showed a slight depreciation in quality with the substitution level below 10 g/100 g. Compared with MGF, FMGF displayed advantages in bread properties at below 10 g/100 g substitution level, indicating that fermentation is a promising technology for improving the processing properties of MGF.

Characterization and proposal of potential use in foods of coproducts from waxy maize wet milling

Abstract The aim of this study was to characterize the corn gluten feed and corn gluten meal originated from waxy maize wet milling industry, in relation to its microbiological risk and physical, chemical and functional properties. The wet residues showed microbiological standards for human consumption. Maize gluten meal was characterized by having high protein content (32 g 100 g-1), lipids (16 g 100 g-1) and carbohydrates (45 g 100 g -1), whereas the maize gluten feed contains high content of dietary fiber (44 g 100 g -1). The maize gluten feed and maize gluten meal have high potential for application as food ingredient. The high dietary fiber, suggests its use as a promising ingredient to increase the availability of fibers, thereby increasing attractiveness and nutritional quality of food. Furthermore, the use of this coproduct of waxy starch may be an alternative to traditional fibers used in the production of bakery products already before with claimed functional and health properties.

Effects of correcting for microbial contamination and the use of sodium sulphite in neutral detergent fibre analyses on the ruminal fibre degradability of several feeds

SUMMARYSodium sulphite is used in an optional way to remove insoluble proteins from neutral detergent fibre (NDF) residue. To determine whether the recovery of both NDF and insoluble nitrogen (N) in NDF solution (NDIN) are altered by its use, both parameters were measured in a set of 12 feeds, including cereal grains: maize (MG), rye (RG) and wheat (WG); cereal co-products: maize gluten feed (MGF), distilled dried grains from barley (DDGB) and wheat (DDGW) and wheat bran (WB); protein concentrates: rapeseed meal (RSM) and expeller palm kernel (EPK); dehydrated sugar beet pulp (DBP) and oat (OH) and ryegrass (RGH) hays. Associated effects on thein situeffective degradability (ED) of both NDF and NDIN were also studied in DDGW, WB, RSM, EPK, DBP, OH and RGH. Also, ED of acid detergent fibre (ADF) and its N (ADIN) were studied in hays. Errors due to microbial contamination in the rumen on the ED of NDF, ADF, NDIN and ADIN were also established in these last seven samples using15N infusion methods. Three rumen and duodenum cannulated wethers were used in the study. The sulphite use in NDF solution led to reductions (DDGB, DDGW, RSM and OH) and increases (RG, WG, WB and DBP) of the NDIN proportion, as well as the contribution of crude protein to NDF. These variations were associated with irregular effects on NDF residues and on ED of both NDIN and NDF. As a consequence, sulphite use does not assure the reduction of the insoluble protein contamination and it may even increase it. This methodology may also alter the degradability estimates of NDIN or NDF. Mean ruminal microbial contamination in NDF was 7·0, 10·8, 13·3, 5·4, 12·0, 35·3 and 20·0 g/kg in WB, DDGW, RSM, EPK, DBP, OH and RGH, respectively. The associated contents of microbial N in NDIN were: 59·3, 29·9, 26·2, 19·8, 37·3, 441 and 150 g/kg, respectively. Microbial contamination in ADF and ADIN (g/kg) was 3·6 and 94·5 in OH and 1·7 and 41·2 in RGH. Not correcting this contamination led to consistent undervaluations of ED of NDIN and NDF in all tested feeds, although errors only reached significance for NDIN in hays and DBP. Microbial-corrected ED of NDIN was 0·685, 0·826, 0·481, 0·389, 0·166, 0·718 and 0·425 in WB, DDGW, RSM, EPK, DBP, OH and RGH, respectively, whereas values for ADIN were 0·504 (OH) and 0·469 (RGH).

Effects of protein sources on concentrations of hydrogen sulphide in the rumen headspace gas of dairy cows

Two Latin square design experiments investigated the relationship between hydrogen sulphide concentration in the rumen headspace gas of dairy cows and the early stages of protein degradation in the rumen. In Expt 1, three protein sources differing in rumen N (nitrogen) degradability (maize gluten feed (MGF); sunflower meal (SFM); and soyabean meal (SBM)) were used, whereas in Expt 2 four different batches of the same feed (MGF) differing in colour (CIE L*, a*, b* (CIELAB) scale) were used. After allowing the concentration of hydrogen sulphide in rumen gas to decline close to zero, a fixed amount of protein sources was offered to cows and the concentrations of hydrogen sulphide were recorded in rumen headspace gas at 30-min intervals. In Expt 1, the concentration of hydrogen sulphide showed considerable variation between protein sources, with MGF having the highest concentration followed by SFM and SBM resulting in very low concentrations. The N wash losses (zero time measurements with nylon bags) ranked the feeds in the same way, from MGF (highest; 61%) to SBM (lowest; 26%). There were marked differences in the degradation of cystine and methionine between protein sources, although the degradation of cystine was always higher than for methionine. MGF (Expt 2) led to increased concentrations of hydrogen sulphide, with peak concentrations achieved between 1 and 2 h after feeding. The concentrations of hydrogen sulphide were higher for MGF1, intermediate for MGF2 and lower for MGF3 and MGF4, agreeing with colour scale. Differences in the early stages of dietary sulphur degradation corresponded with differences in hydrogen sulphide concentrations in rumen gas. The results suggest that hydrogen sulphide concentrations in the rumen headspace gas could be useful to evaluate nutritional parameters not measured by the in sacco technique, contributing to a better understanding of the response of dairy cows to different protein supplements.

Natural occurrence of mycotoxins and their masked forms in food and feed products

A total of 174 cereal-based food products, 67 compound feeds and 19 feed raw materials were analysed for the occurrence of deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, zearalenone, α-zearalenol, β-zearalenol, and their respective masked forms, including deoxynivalenol-3-glucoside, zearalenone-4-glucoside, α-zearalenol-4-glucoside, β-zearalenol-4-glucoside and zearalenone-4-sulfate. Fibre-enriched bread, bran-enriched bread, cornflakes, popcorn and oatmeal were collected in Belgian supermarkets from April 2010 to October 2011. All food samples analysed were contaminated with an average of 2 to 6 mycotoxins, including 1 to 3 masked forms. Feed raw materials that were used in the analysed compound feeds were collected by the manufacturer. Feed raw materials included were beet pulp, sunflower seed meal, soy bean, soy peel, oats, barley, maize germs, maize gluten feed, maize, wheat gluten feed, wheat bran pellets, wheat bran and wheat. Beet pulp, sunflower seed meal, soy bean and soy peel were hardly contaminated. The feed raw materials that were mostly infected with deoxynivalenol, zearalenone and derivatives were maize and its by-products. Also, the glucosylated and sulfated forms occurred in substantial amounts. As well, wheat and its by-products were contaminated with α-zearalenol (wheat gluten feed and wheat bran) and zearalenone (wheat). The contamination pattern and level of feed raw materials were reflected in the corresponding compound feeds.

Digestibility and metabolizable energy of maize gluten feed for dogs as measured by two different techniques

Maize gluten feed (MGF) is a co-product of wet milling of maize, and is composed of structures that remain after most starch, gluten and germ has been extracted from the grain. Although currently used in dog foods, its digestibility and energy values have not been documented. Two techniques were used to determine nutrient digestibility of MGF for dog foods. Both techniques used extruded diets fed to Beagle dogs, with six replicates per diet. The first study used a difference method in which 300 g/kg of a reference diet was replaced by MGF. Based on the difference method, the coefficient of total tract apparent digestibility (CTTAD) of MGF was 0.53 for dry matter (DM), 0.69 for crude protein (CP), 0.74 for fat, 0.99 for starch, and 0.55 for gross energy (GE). The calculated metabolizable energy (ME) of MGF was 7.99 MJ/kg (as-fed). The second study used a regression method and included a basal diet and a basal diet with 70, 140 and 210 g MGF/kg of diet (as a substitute for maize starch). Maize gluten feed inclusion resulted in a linear reduction of CTTAD of DM ( R 2 = 0.99; P<0.001), CP ( R 2 = 0.95; P=0.002), fat ( R 2 = 0.87; P=0.009), starch ( R 2 = 0.81; P<0.001), and GE ( R 2 = 0.99; P<0.001). Faecal production increased linearly from 56 g to 107 g/dog/d ( R 2 = 0.99; P<0.001), with a linear reduction of faecal DM ( R 2 = 0.99; P<0.001) and a linear increase in faecal lactic acid concentration (P<0.02). Both urine ( R 2 = 0.77; P=0.029) and faeces ( R 2 = 0.92; P=0.019) showed a linear reduction in pH. Results of ingredient CTTAD obtained by the regression and difference methods were close (6% or less of variation) for CP, fat, and starch, and also for ME content (1.4% higher for the difference method), but the two methods disagreed on calculated CTTAD of DM and organic matter. The high dietary fiber content of MGF (382 g/kg) may explain the low digestibility of this ingredient. Maize gluten feed could be a useful ingredient for formulations designed to have low energy or reduce the urine pH of dogs.

The effect of the method of dietary oil addition to pelleted diets on performance and nutrient digestibility in finishing pigs

The primary aim of this study was to investigate the effect of method of vegetable oil blend application, either sprayed onto (SP) or incorporated within (IN) pelleted diets, on the performance and coefficient of total tract apparent digestibility (CTTAD) of dietary components in finishing pigs. A secondary aim was to evaluate the source of energy, i.e. starch vs oil on pig performance and the CTTAD. Diets were formulated from either by-products (maize gluten, maize gluten feed, pollards and rapeseed) or cereals (barley and wheat) to which vegetable oil was added (g/kg) in two different ways: 40 (IN) or 30 (SP) + 10 (IN). Two studies were conducted. In study 1, 48 Large White × Landrace pigs (average weight 50.4 kg, SD 3.5 kg) on a research herd were used to determine CTTAD of dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), lipid, energy and phosphorus and digestible energy (DE) content. In study 2, 960 Landrace × Large White pigs on a commercial herd, housed in groups of 20 from 14 to 24 weeks of age, were used to assess production performance and carcass characteristics. Oil addition (40IN and 10IN + 30SP) increased the CTTAD of lipid and phosphorus (both P<0.001) and decreased phosphorus excretion ( P<0.01) in both by-product-based and wheat/barley-based diets. The total amount of nitrogen excreted also decreased ( P<0.05) when oil was added to the wheat/barley-based diets but not the by-product-based diets. The CTTAD, except for lipid CTTAD, and pig performance were similar whether oil was added by 40IN or 10IN + 30 SP. Lipid CTTAD of by-product-based diets increased ( P<0.001) when oil was added by 10IN + 30SP compared with 40IN. The addition of oil (40IN and 10IN + 30SP) to by-product-based and wheat/barley-based diets improved the DE content of the diets on a DM basis by on average 0.6 and 0.85 MJ/kg DM, respectively in study 1 ( P<0.001) and FCR by on average 0.18 and 0.19 kg/kg, respectively in study 2 ( P<0.001). Pigs offered wheat/barley-based diets had higher DM CTTAD ( P<0.001) in study 1 and higher growth rates ( P<0.001), finish weights ( P<0.01) and carcass weights ( P<0.001) in study 2 compared with by-product-based diets. The excretion of nitrogen from wheat/barley-based diets was lower ( P<0.001) than from by-product-based diets. In conclusion, the performance of pigs was better when they were offered wheat/barley-based diets. Oil addition improved FCR with both wheat/barley-based and by-product-based diets but the method of oil application had no significant effect on pig performance or the CTTAD of the diet.

Comparison of in situ nutrient disappearance of alternative maize milling by-product feeds in lactating dairy cows

Two maize milling by-products (maize gluten feed; MGF and maize by-product feed; MBPF) were compared with shelled maize (SM) and soyabean meal (SBM) for their in situ nutrient disappearance. In situ experiments were conducted in two rumen fistulated Holstein cows to evaluate dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and starch disappearance of the products. Zero-hour washout (in situ Fraction A) of DM was higher for MBPF (56.9%) than SM (45.0%). The disappearing rate (kd) of DM was higher for MGF (0.054/h) than for SM (0.046/h). Fraction A for CP was higher for MBPF (69.6%) than MGF (55.9%) and lower for SBM (7.8%). Similarly, ruminal CP disappearance was higher for MBPF (83.4%) and MGF (80.1%) than SBM (52.1%). Neither NDF disappearance rate nor ruminal NDF disappearance was different between MGF and MBPF. The disappearance rate of starch was higher for MGF (0.203/h) and MBPF (0.116/h) than for SM (0.051/h). Similarly, ruminal starch disappearance was higher for MGF (82.7%) than for SM (54.2%). Results indicate that the tested maize by-product feeds had greater ruminal CP disappearance when compared to SBM. Both MGF and MBPF may be useful feedstuffs in lactating dairy cows ration due to their higher ruminal starch disappearances. South African Journal of Animal Science Vol. 36(1) 2006: 7-12

In situstudy of the relevance of bacterial adherence to feed particles for the contamination and accuracy of rumen degradability estimates for feeds of vegetable origin

An in situ study was conducted on four rumen-cannulated wethers to determine (using (15)N infusion techniques) the microbial contamination (mg bacterial DM or crude protein (CP)/100 mg DM or CP) and the associated error on the effective degradability of fourteen feeds: barley and maize grains, soyabean and sunflower meals, full-fat soyabean, maize gluten feed, soyabean hulls, brewers dried grains, sugarbeet pulp, wheat bran, lucerne and vetch-oat hays, and barley and lentil straws. The DM or CP contamination in residues (M) fitted to single exponential or sigmoid curves. A general model (M=m (1-e(-ft) ) (j)) was proposed to match this fit. Asymptotic values (m) varied from 2.84% to 13.3% and from 2.85% to 80.9% for DM and CP, respectively. Uncorrected results underestimated the effective degradability of both DM (P<0.05) and CP (P<0.01). For CP, this underestimation varied from 0.59 % to 13.1%, with a higher but unascertainable error for barley straw. Excluding maize grain, the microbial contamination of both DM and CP, and the associated underestimation of the effective degradability of CP, were positively related to the cellulose content of the feed. The error in the effective degradability of CP was also negatively related to the CP content and its apparent effective degradability (R(2) 0.867). This equation allows easier and more accurate estimates of effective degradability, needed to improve protein-rationing systems.

Inter-laboratory variation of in vitro cumulative gas production profiles of feeds using manual and automated methods

A study was conducted to estimate variation among laboratories and between manual and automated techniques of measuring pressure on the resulting gas production profiles (GPP). Eight feeds (molassed sugarbeet feed, grass silage, maize silage, soyabean hulls, maize gluten feed, whole crop wheat silage, wheat, glucose) were milled to pass a 1 mm screen and sent to three laboratories (ADAS Nutritional Sciences Research Unit, UK; Institute of Grassland and Environmental Research (IGER), UK; Wageningen University, The Netherlands). Each laboratory measured GPP over 144 h using standardised procedures with manual pressure transducers (MPT) and automated pressure systems (APS). The APS at ADAS used a pressure transducer and bottles in a shaking water bath, while the APS at Wageningen and IGER used a pressure sensor and bottles held in a stationary rack. Apparent dry matter degradability (ADDM) was estimated at the end of the incubation. GPP were fitted to a modified Michaelis–Menten model assuming a single phase of gas production, and GPP were described in terms of the asymptotic volume of gas produced ( A), the time to half A ( B), the time of maximum gas production rate ( t RM gas ) and maximum gas production rate ( R M gas ). There were effects ( P<0.001) of substrate on all parameters. However, MPT produced more ( P<0.001) gas, but with longer ( P<0.001) B and t RM gas ( P<0.05) and lower ( P<0.001) R M gas compared to APS. There was no difference between apparatus in ADDM estimates. Interactions occurred between substrate and apparatus, substrate and laboratory, and laboratory and apparatus. However, when mean values for MPT were regressed from the individual laboratories, relationships were good (i.e., adjusted R 2 = 0.827 or higher). Good relationships were also observed with APS, although they were weaker than for MPT (i.e., adjusted R 2 = 0.723 or higher). The relationships between mean MPT and mean APS data were also good (i.e., adjusted R 2 = 0.844 or higher). Data suggest that, although laboratory and method of measuring pressure are sources of variation in GPP estimation, it should be possible using appropriate mathematical models to standardise data among laboratories so that data from one laboratory could be extrapolated to others. This would allow development of a database of GPP data from many diverse feeds.

Effects of a specific blend of essential oil compounds on dry matter and crude protein degradability in heifers fed diets with different forage to concentrate ratios

Two 4×4 Latin square experiments, with four growing heifers (398±7.1 kg BW in experiment 1 and 272±6.6 kg BW in experiment 2) and four periods, were used to study effects of a specific blend of essential oil compounds (EOB, CRINA ® RUMINANTS) on in situ ruminal degradability of dry matter (DM) and crude protein (CP) of six feeds. Treatments were assigned in a 2×2 factorial design, with the main factors being type of diet and addition of EOB. In experiment 1, treatments were a high concentrate diet (HC) that consisted of 7 kg per day of concentrate with barley straw offered ad libitum, and a low concentrate diet (LC) consisting of 1 kg of the same concentrate and alfalfa hay offered likewise, with (700 mg per day) or without addition of EOB. Each experimental period consisted of a 10-day adaptation period and 7 days for incubations of soybean meal, maize gluten feed, lupin seeds, green peas, sunflower meal and fish meal. In heifers fed the HC diet, DM and CP degradation of protein supplements were lower versus the LC diet. Use of EOB in the HC diet reduced CP degradation of lupin seeds, green peas and sunflower meal. In experiment 2, treatments were a 68:32 (DM) forage to concentrate ratio diet (HF) or a 40:60 forage to concentrate ratio diet (MF), with (700 mg per day) or without addition of EOB. Diets were offered as a total mixed ration. Each experimental period consisted of a 28-day adaptation period and 7 days for incubations of soybean meal, maize gluten feed, lupin seeds, green peas, sunflower meal and alfalfa hay. In heifers fed the MF diet, CP degradation of soybean meal and sunflower meal was lower versus the HF diet. Use of EOB in the HF diet tended to reduce CP degradation of soybean meal. In the HF diet, the effect of EOB on soluble and potentially degradable protein fractions was only observed after 28 days of adaptation of rumen microflora.

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.

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