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Sixty-six dairy farms (as average, 167.0 ± 106.5 milking cows and milk yield of 31.4 ± 5.1) were visited to identify different nutritional approaches adopted in dairy cows diet formulation. Forage, TMR, faecal, and milk samples from lactating herds were collected and diet composition, in vitro methane production, in vivo nutrient digestibility, faecal fermentation profile and milk yield and milk quality were characterised. A hierarchical cluster analysis was applied and six nutritional approaches in diet formulation corresponding with six different clusters (CL) were identified. The CL discriminated the farm feeding choices in the following nutritional strategies, based on high use of: (i) high moisture corn (HMC) and legume silage, (ii) compound feed, (iii) corn and soy meals, (iv) HMC and soy meal, (v) corn meal and protein compound feeds, or (vi) HMC and protein compound feed strategies, respectively for CL1 to CL6. The milk yield tended (p =.061) to differ among CL. The greatest (>1.60) feed efficiency was calculated for CL1 and 5, whereas the lowest (<1.45) for CL 2. The CL2 and 5 had the highest feed costs (i.e. 0.24 or 0.22 €/kg of milk, respectively). Interestingly, the high use of HMC or steam flaked corn resulted associated to higher farm performances. Particularly, HMC and legume silage (CL1), HCM and soy meal (CL4) and HCM and protein compound feed (CL6) nutritional strategies resulted more efficient and profitable, having the greatest feed efficiency, protein and starch degradability as well as income over feed costs. Differentiate carbohydrates in dairy cow diets seems highly convenient. Six different nutritional strategies were identified based on use of single ingredients and a great variability in both economic and feed efficiency was observed for dairy farms clustering into different groups The use of high moisture ear corn in substitution of corn meal increased dry matter intake, feed efficiency, milk yield and lactose content of milk, whereas the use of steam flaked corn reduced the faecal fermentations The in vitro methane emission potential of diets did not differ among clustered nutritional strategies [ABSTRACT FROM AUTHOR]

The aim was to identify optimized combinations of Streptomyces griseus protease concentration (CONC), incubation length (TIME), or amount of crude protein (CP) incubated in buffered enzymatic solution (CPW) to predict the in vitro rumen-undegraded feed CP (RUP) of 26 different feeds (soybean, rapeseed or sunflower meals, wheat bran, distillers dried grains with solubles, maize co-products and alfalfa hay). Different levels of CONC (0.08, 0.19, 0.44, 0.69 and 0.80 enzymatic units [U] of S. griseus protease/ml), TIME (6, 10, 18, 26 and 30 h) and CPW (69, 118, 235, 353 and 401 mg CP) were tested in agreement with a central composite design (CCD) with four replications of the central point to calculate second-order polynomial equations of main tested effects. The RUP was estimated by incubating samples in a buffered rumen fluid for 16 h or by adopting different enzymatic approaches as planned a priori in CCD. Differences between rumen and enzymatic RUP (ΔRUP) were estimated and regression terms of second-order polynomial equations for estimating ΔRUP were calculated between and within feeds. These equations were optimized using the non-linear generalized reduced gradient method with the objective set at ΔRUP equal to 0. The adoption of CCD permitted identification of optimized enzymatic combinations of CONC (0.12 U of S. griseus protease/ml), TIME (18 h) and CPW (from 233 to 458 mg CP for distillers dried grains with solubles and soft white wheat bran, respectively) to predict RUP accurately in all feed categories except for soybean meal, where optimized combinations were 0.47 U of S. griseus protease/ml, 18 h and 435 mg CP. [ABSTRACT FROM PUBLISHER]

The study was performed on forages (n = 8), nonforage fibrous feeds (n = 10), and crop residues (n = 2). Samples were characterized for in situ NDF degradability (NDFD) at 6, 12, 18, 24, 30, 36, 48, 72, 96, 120, and 240 h of ruminal incubation. Then, samples were characterized for enzymatic NDFD by adopting a multistep enzymatic method consisting of a preincubation (PreInc) phase followed by enzymatic incubation (EnzInc) steps. In the PreInc phase, samples were incubated in a NaOH solution for 0, 30, 60, or 90 min. Then, in the EnzInc phase, samples were first incubated in a buffered enzymatic solution containing hemicellulase, cellulase, and Viscozyme L enzymes. Then, samples were incubated in a xylanase-buffered enzymatic solution. These 2-step EnzInc lasted for a total of 16 (8 h for the first enzymatic step + 8 h for the second enzymatic step), 32 (16 + 16 h), or 48 h (24 + 24 h). The enzymatic NDFD coefficients were increased by increasing both PreInc and EnzInc incubation times, and no PreInc x EnzInc interaction was observed, except for ryegrass hay. On average, enzymatic NDFD increased (P < 0.05) by 0.35, 0.54, or 0.68, respectively, for 30-, 60-, or 90-min PreInc compared with 0-min PreInc. The enzymatic NDFD increased (P < 0.05), on average, by 0.11 in 32-h EnzInc or 0.16 in 48-h EnzInc with respect to 16-h EnzInc. Enzymatic NDFD were used to predict in situ NDFD coefficients by adopting single regression equations. High coefficients of regression (R2 > 0.80, P < 0.05) and low errors of prediction were measured when specific enzymatic conditions were performed to predict in situ NDFD at intermediate (from 24 to 48 h) ruminal incubation. Generally, worse regression performances were obtained when enzymatic NDFD were used to predict in situ NDFD evaluated after shorter or longer incubation times. The direct prediction of the rate of NDF degradation was not possible using enzymatic NDFD coefficients. Even if the proposed multistep enzymatic method appeared promising, further studies are required to improve enzymatic NDFD prediction ability within specific forage types or nonforage fibrous feeds. [ABSTRACT FROM AUTHOR]

The objective of this work was to reduce the predictor dimensionality and to develop a model able to forecast Clostridium tyrobutyricum contamination in corn silages. A survey on 33 dairy farms was performed, and samples from core, lateral, and apical parts of the feed-out face of corn silage bunkers were analyzed for chemical, biological (digestible and indigestible NDF), fermentative (pH, ammonia nitrogen, lactic acid, VFA, and ethanol), and microbiological (yeasts and molds) traits. Corn silage samples were analyzed for C. tyrobutyricum cell and spore counts by adoption of a molecular DNA--based method. A partial least squares (PLS) regression with a leaveone- out cross-validation method was used to reduce the dimensionality of the original predictors (n = 30) by projecting the independent variables into latent constructs. In a first step of the model development, the importance of independent variables in predicting C. tyrobutyricum contamination was assessed by plotting factor loadings of both dependent and independent variables on the first 2 components and by verifying for each predictor the variable influence on projection values adopting the Wold's criterion as well as the entity of standardized regression coefficients. Three ensiling characteristics (bunker type, presence of lateral wrap plastic film, and penetration resistance as a measurement of the ensiled mass density), a chemical trait (DM), 9 characterizations of the fermentative profile (pH, ammonia nitrogen, acetic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, ethanol, and lactic acid), and 2 microbiological traits (yeasts and molds) were retained as important terms in the PLS model. Three reduced-variable PLS (rPLS) regressions--the first based on ensiling, chemical, fermentative, and microbiological retained important variables (rPLSecfm); the second based on chemical, fermentative, and microbiological retained important traits (rPLScfm); and the last based on only chemical and fermentative retained important variables (rPLScf)--were performed. The model that best fit the C. tyrobutyricum measurements was rPLSecfm. The rPLScfm and rPLScf models had similar regression performances but higher mean square errors of prediction than rPLSecfm. However, all tested models seemed adequate to rank corn silages for low, medium, and high risks of C. tyrobutyricum contamination. To avoid the visit on farm by trained people required to measure penetration resistance, the use of the rPLScf model is suggested as a useful tool to assess the risk of C. tyrobutyricum in corn silage. [ABSTRACT FROM AUTHOR]

The role of indigestible NDF is essential in relation to OM digestibility prediction, total tract digestibility, rumen fill, passage rate, and digestion kinetics. Moreover, the truly indigestible NDF (iNDF) represents a core point in dynamic models used for diet formulations. However, despite its wide possible applications, few trials have been conducted to quantify iNDF and even fewer to investigate whether or not it is consistent among different forage sources. The objective of this study was to predict the iNDF by measuring the residual NDF after 240-h in vitro fermentation to determine the unavailable NDF (uNDF240) within and among various forage types. Finally, a mathematical approach was investigated for the estimation of the uNDF240 fraction. In all, 688 forages were analyzed in this study. This pool included 122 alfalfa hays, 282 corn silages, and 284 grass hays. Values of uNDF240 varied among different forages and within the same type (22.7% ± 4.48%, 20.1% ± 4.23%, and 11.8% ± 3.5% DM for grass hay, alfalfa hay, and corn silages, respectively). The relationship among uNDF240 and ADL was not constant and, for grass hay and corn silage, was different (P < 0.05) from the 2.4 × lignin value applied by the traditional Chandler equation. The observed uNDF240:ADL ratio was 3.22 for grass hay and 3.11 for corn silage. Relationships among chemical and biological parameters and uNDF240 were investigated via simple and multiple regression equations. The greatest correlation with a single variable was obtained by ADL and ADF when applied to the whole data set (R2 = 0.63). Greater coefficients of determination resulted from a multiple regression equation for the whole data set (R2 = 0.80) and within each forage type (R2 = 0.65, 0.77, and 0.54 for grass hay, alfalfa hay, and corn silage, respectively). In conclusion, a regression approach requires specific equations and different regression coefficients for each forage type. The direct measurement of uNDF240 represented the best approach to obtain an accurate prediction of the iNDF and to optimize its specific purpose in dynamic nutrition models. [ABSTRACT FROM AUTHOR]

Moulds belonging to Penicillium section roqueforti are common contaminants of feedstuffs and produce several mycotoxins that can cause health hazards when ingested by farm animals. Among these, PR toxin (PR), mycophenolic acid (MY) and roquefortine C (RC) have been frequently detected in forages, particularly silages. The aims of the current trials were to study the effects of the presence of pure mycotoxins on in vitro rumen fermentation parameters and to assess their stability in the rumen environment. Two successive in vitro gas production experiments were carried out: a central composite design with four replications of central point (CCD) and a completely randomized design with a fully factorial arrangement of treatments (FFD). In CCD, the effects of PR, MY and RC concentrations in diluted rumen fluid (i.e. 0·01, 0·30, 1·01, 1·71 and 2·00 μg of each mycotoxin/ml) were tested. Gas volume produced after 48 h of incubation (Vf) decreased linearly as concentrations of RC and MY in diluted rumen fluid increased, with marginal effects similar for two mycotoxins, being respectively −14·6 and −13·4 ml/g organic matter (OM) for each 1·0 μg/ml of increment in mycotoxin concentration. Similarly, total volatile fatty acid (VFA) production decreased quadratically as concentrations of RC and MY increased, with marginal effects about two times higher for MY than RC, being −4·22 and −2·62 mmol/l for each 1·0 μg/ml of increment in mycotoxin concentration. With respect to maximum Vf (i.e. 410·6 ml/g OM) and VFA (98·06 mmol/l) values estimated by the model, decreases of 13·6 and 15·2% were obtained when incubating the highest RC and MY concentrations, respectively. The PR did not interfere with rumen fermentation pattern and it was not recovered after 48 h of incubation, whereas the stabilities of MY and RC in rumen fluid were similar and on average equal to about 50%. On the basis of CCD results, a second experiment (FFD) was carried out in which only effects of MY and RC concentrations (i.e. 0, 0·67, 1·33 and 2·00 μg of each mycotoxin/ml of diluted rumen fluid) were tested. Data from FFD showed Vf decreased linearly when concentrations of MY and RC increased, with marginal effect two-folds higher for MY than for RC (−11·1 ml/g OM and −6·7 ml/g OM, respectively). Similar marginal effects of MY and RC in decreasing VFA production were recorded: −2·38 and −2·86 mmol/l for each 1·0 μg/ml of increment in mycotoxin concentration, respectively. At the highest RC and MY tested concentrations, Vf and VFA decreased by 8·7 and 10·7%, respectively, over maximum estimated values. In FFD, the average amounts of MY and RC recovered in rumen fluid after 48 h of incubation were 79·0 and 40·6%, respectively. In conclusion, the MY and RC from standards interfered with rumen microorganisms at relatively low levels and were partially stable in the rumen environment after 48 h of incubation. These findings suggested that MY and RC could interfere with digestive processes and might represent a potential risk for ruminants fed diets containing feeds contaminated by mycotoxins produced by P. roqueforti. [ABSTRACT FROM PUBLISHER]

The aim of this trial was to assess the effects of the administration of different combinations of mycotoxins in naturally contaminated maize grains on dairy heifer growth, blood measurements and puberty onset. A total of 35 Friesian female heifers were randomly allotted to three experimental groups from 18–21 to 42–45 weeks of age. During the 24-week experimental period (EP), heifers were fed the same diet, but with maize meal derived from three differently contaminated lots: very low contamination, as control (C); medium–low aflatoxin-contaminated (A); and mixed aflatoxin–fumonisin contaminated (A-F). At the end of the EP, they returned to a common diet without contaminated maize, and they were monitored for an additional period of 12 weeks (post-experimental period, PEP). BW, wither height, hip height, body length and heart girth were measured every 4 weeks from the beginning of EP to the end of PEP. At the same time, body condition score was evaluated and blood samples were taken from the jugular vein to be analysed for haematological, serum protein and metabolic profiles. Age at puberty was assessed by measuring weekly plasma progesterone levels from 40 to 52 weeks of age. Body growth measurements were processed both by ANOVA of average daily gain of EP and PEP separately, and by the analysis of growth curve parameters. Haematological, serum protein and metabolic profile were evaluated using a mixed model, taking into account the repeated measurements in time on each animal. Heifers’ growth was delayed both in A and A-F groups during EP, as evidenced by the different linear coefficients of the BW growth curve in the three groups. Differently contaminated diets did not affect the haematological profile, so that it can be concluded that these levels of mycotoxin contamination do not determine any specific effect on haematopoiesis and immunity in growing heifers. The main blood marker of mycotoxin chronic toxicity was the γ-glutamyl transferase activity level in plasma, which appeared to be altered even after the removal of mycotoxins. During EP, plasma glucose was lower in the groups fed contaminated diet compared with C. The joint actions of an altered nutritional status and a long-lasting liver damage were probably the causes of the delay in puberty attainment in A and, particularly, in the A-F group. The results from this trial evidenced that a chronic aflatoxin–fumonisin contamination in diets of dairy heifers can determine an important delay in the reproductive career of these animals. [ABSTRACT FROM PUBLISHER]

The need to improve the knowledge of fermentation processes within the digestive tract in pigs is growing, particularly for ingredients that may act as potential prebiotic sources, such as resistant starch (RS). A study (based on enzymatic digestion followed by in vitro fermentation) was conducted to investigate whether various sources of RS, obtained from eight native starches characterized by inherent heterogeneous starch chemistry and structure, can influence short-chain fatty acid (SCFA) concentrations and relative production kinetics. Total and individual SCFA productions were evaluated over time and up to 72 h of incubation. The in vitro hydrolysis of native starches allowed a classification from very high [⩾650 g/kg dry matter (DM)] to low (<50 g/kg DM) RS amount. The total SCFA production was similar between ingredients, whereas acetate and butyrate molar ratios in the SCFA profile differed (from 0.48 to 0.56 and from 0.17 to 0.25, respectively; P < 0.05). Differences in fermentation kinetic parameters for total and individual SCFA productions were observed (P < 0.05). Considering the total SCFA production after 72 h of incubation, the time at which half of the maximum production has been reached (T1/2), the maximum rate of production (Rmax) and its time of occurrence (Tmax) differed between ingredients (P < 0.05), with values ranging from 6.1 to 11.9 h, from 0.459 to 1.300 mmol/g DM incubated per hour and from 5.1 to 9.8 h, respectively. Overall, a similar trend was observed considering individual SCFA productions. In particular, T1/2 ranged from 6.4 to 12.5 h, from 5.5 to 12.5 h and from 6.7 to 11.3 h for acetate, propionate and butyrate, respectively (P < 0.05). For Rmax, differences were obtained for propionate and butyrate productions (P < 0.05), whereas no difference was recorded for acetate. In summary, our findings indicated that both quantitative and qualitative production of SCFA and related kinetics were influenced by fermentation of RS obtained from native starches characterized by heterogeneous starch characteristics. Current findings are based on an in vitro approach, and thus require further in vivo validations. [ABSTRACT FROM PUBLISHER]

A set of 180 forages (47 alfalfa hays, 26 grass hays, 52 corn silages, 35 small grain silages and 20 sorghum silages) were randomly collected from different locations of the Po Valley (Northern Italy) from 2009 to 2010. The forages were characterised for chemical composition (11 parameters), NDF digestibility (five parameters) and net energy for lactation (NEL). The latter was calculated according to the two approaches adopted by the 2001 Nutrient Research Council and based on chemical parameters either alone (NEL3x-Lig) or in combination with 48 h NDF degradability in the rumen (NEL3x-48h). Thereafter, a principal component analysis (PCA) was used to define forage populations and limit the number of variables to those useful for obtaining a rapid forage quality evaluation on the basis of the calculated NEL content of forages. The PCA identified three forage populations: corn silage, alfalfa hay and a generic population of so-called ‘grasses’, consisting of grass hays, small grain and sorghum silages. This differentiation was also confirmed by a cluster analysis. The first three principal components (PC) together explained 79.9% of the total variation. PC1 was mainly associated with protein fractions, ether extract and lignin, PC2 with ash, starch, NDF and indigestible NDF (iNDF) and PC3 with NDF digestibility. Moreover, PC2 was highly correlated to both NEL3x-Lig (r = −0.84) and NEL3x-48h (r = −0.94). Subsequently, forage-based scores (FS) were calculated by multiplying the original standardised variables of ash, starch, NDF and iNDF with the scoring factors obtained from PCA (0.112, −0.141, 0.227 and 0.170, respectively). The FS showed a high determination coefficient for both NEL3x-Lig (R2 = 0.86) and NEL3x-48h (R2 = 0.73). These results indicate that PCA enables the distinction of different forage classes and appropriate prediction of the energy value on the basis of a reduced number of parameters. With respect to the rumen in situ parameters, iNDF was found to be more powerful at discriminating forage quality compared with NDF digestibility at different rumen incubation times or rates of NDF digestion. [ABSTRACT FROM AUTHOR]

Abstract: The experiment compared reductions in the level of N fertilisation of corn crop (i.e., no N fertilisation; 0-N, or 150kg of N/ha; 150-N) with those currently adopted in the Po valley of North Italy (i.e., 300kg of N/ha; 300-N) on chemical and nutritional characteristics of grain, stalks and leaves in corn hybrids selected for whole plant silage production (i.e., FAO 700 maturity). Grain composition and starch availability for digestion was examined at three stages of maturity of the kernels (i.e., ½ milk line, ¾ milk line and black layer). One hybrid had a lower grain yield (15.2 versus 16.0–16.8tonnesDM/ha; P<0.05), while all hybrids were similar in whole plant yield. Levels of N fertilization of 150-N and 300-N resulted in similar yields of grain and whole plants, which were 17 and 33% higher, respectively (P<0.01) than 0-N plots. Hybrids were similar in chemical composition. Reduction of N fertilisation from 300-N to 0-N lowered (P<0.01) the crude protein content in grains, leaves and stalks (P<0.05 in apical part of stalks) and reduced the zein content in grains from 43 to 33g/kg DM (P<0.01). Vitreousness of grains was not influenced by N fertilisation, while the highest (P<0.01) gas production was at the short incubation time of 2h for grains with 300-N. Reduction of fertilisation levels (i.e., 150-N and 0-N versus 300-N) lowered (P<0.01) NDF degradation in the basal stalks (0.385 and 0.392 versus 0.412) and leaves (0.604 and 0.620 versus 0.622). Stage of maturity of grain did not interact with the N level of fertilization, and advanced maturity was associated with a marked increase (P<0.01) in zein content from 36 to 49g/100g CP and in grain vitreousness from 31 to 40g/100g endosperm and with a reduction of the gas production, which had the lowest values at 2 and 48h (P<0.01) of incubation. Overall, reductions in N fertilisation of corn crop slightly lowered the crude protein content and fiber degradation of different part plants. In grains, the lowest N fertilisation (i.e., 0-N) reduced the zein contents and increased rumen fermentability. [Copyright &y& Elsevier]

Abstract: This experiment determined the chemical composition, rumen degradability (aNDF in stalks and starch in kernels) and in vitro gas production of kernels from three corn hybrids treated (TT) or not treated (control, CTR) with insecticides against the European corn borer (ECB, Ostrinia nubilalis). Two whole-plant silage hybrids belonging to the FAO rating 600 and 700 maturity class (S600 and S700, respectively) and one selected for grain production (G600, FAO rating 600, Dekalb-Monsanto Agricoltura S.p.A., Lodi, Italy) were sown in two main plots (TT and CTR) of an experimental field. Two subsequent treatments of pyrethroids (25 and 1.2g/ha of cyfluthrin and deltamethrin, respectively) were applied to the TT plots. The insecticide treatment reduced the number of damaged plants (4.5 broken plants/plot versus 0.3 broken plants/plot, P<0.01) and increased the total grain yield by 11% (13.8t/ha versus 12.4t/ha), while hybrids did not differ. ECB larvae which bored into the stalk tunnels modified the chemical composition of stalks and kernels. In stalks, total sugars content (i.e. glucose, fructose, sucrose) was about twice that in TT versus CTR plants (123g/kg versus 60g/kg DM, P<0.01), while aNDF content was higher in CTR stalks (765 versus 702g/kg DM, P<0.01). DM degradability after 48h of incubation of stalks was higher in TT than in CTR, both in vitro (0.360 versus 0.298, P<0.01) and in situ (0.370 versus 0.298, P<0.05), while there were no differences in aNDF degradability. Kernels from TT plots contained less DM (615g/kg versus 651g/kg, P<0.01) and more CP (84g/kg and 78g/kg DM, P<0.05) than those from CTR plots, while in situ rumen starch disappearance and in vitro gas production were similar. Corn hybrid selected for yield of grain (G600) differed from S600 and S700 due to a higher (P<0.01) content of aNDF, ADF and lignin(sa) in the stalks, and a higher starch content (696g/kg versus 674 and 671g/kg DM, P<0.01) and CP (87g/kg versus 77 and 76g/kg DM, P<0.05) in grain. The G600 hybrid produced stalks with a lower (P<0.01) aNDF rumen degradability than the S600 and S700. On field ECB insecticide treatment improved corn grain yield, reduced broken plants and increased stalk sugars content at harvesting, but did not change the rumen degradation of either stalks or grain. [Copyright &y& Elsevier]

The extraction efficiency of aflatoxin B1 (AFB1) in cattle feed containing nine adsorbents (ADSs) was investigated using two organic/aqueous solvents composed of methanol/water (80/20 v/v; MeOH) and acetone/water (85/15 v/v; AC). Samples were obtained including a highly AFB1-contaminated (HC) and a low-level AFB1-contaminated (LC) feedstuff (15.33 and 7.57 µg kg–1, respectively), nine ADSs (four clay minerals; one yeast cell wall-based product; one activated carbon and three commercial ADS products) at two different levels of inclusion (10 and 20 g kg−1). After solvent extraction and immunoaffinity column clean-up, all samples were analysed for AFB1 by high-performance liquid chromatography (HPLC) with fluorescence detection. For each contamination level (HC and LC), the data obtained were analysed using a factorial arrangement in a completely randomized design. Means were compared with the correspondent controls using the Dunnett's test. No statistical difference was found in AFB1 levels of feedstuffs not containing ADSs when extracted with AC or MeOH, even if numerically higher values were obtained with AC. A dose-dependent effect (p < 0.01) of ADSs inclusion was observed on AFB1 recoveries that were lower when the higher ADS level (20 g kg−1) was included in the HC and LC feedstuffs. Higher AFB1 recoveries were obtained using AC compared with MeOH, both in HC (75.0% versus 12.0%, respectively) and in LC (84.0% versus 22.8%, respectively) ADSs containing feedstuffs. However, when the activated carbon and the sodium bentonite were included in feeds, lower AFB1 concentrations with respect to control values (p < 0.001 and <0.05, respectively) were obtained also using AC. The data obtained in this study indicate that routine use of the MeOH solvent for AFB1 analysis of unknown feedstuffs, can produce misleading results if they contain an ADS. [ABSTRACT FROM AUTHOR]

Iodine and selenium are essential trace elements involved in the regulation of thyroid metabolism and antioxidant status. Two experiments were undertaken on lactating cows to determine the milk concentrations of iodine and selenium, carry over (CO) in milk, the fraction in curdle portion and how milk yield affects the milk iodine and selenium concentrations and CO. Sources of elements were potassium iodide and sodium selenite. In Experiment 1, 12 cows were randomly allotted to three diet groups in a completely randomized design: control group (CTR) - total mixed ration (TMR) containing 1.71 and 0.08mg/kg dry matter (DM); Group 1 (T1) - TMR plus 23.8 and 2.2 mg; Group 2 (T2) - TMR plus 45.5 and 4.3mg, respectively, for iodine and selenium. In Experiment 2, 30 cows were allotted to three groups according to milk yield: high (H), average (A) and low (L). Within each group, cows were randomly assigned two levels of iodine and selenium: Level 1: TMR containing 1.55 and 0.15mg/kg DM; Level 2: TMR plus 47.2mg and 8.0mg, respectively, iodine and selenium. In both experiments, individual milk samples were collected and analyzed for iodine and selenium contents. In Experiment 1, Grana Padano cheese was obtained at lab scale and the iodine and selenium fractions in the curd were measured. In Experiment 1, the iodine intake increased (P<0.001) the concentration and total excretion in milk. The CO increased (P<0.05) from 16 (CTR) to 27 (T1) and 26% (T2); the sampling time was significant (P<0.05) with no interaction with treatments. Concentration of selenium in milk was increased (P<0.05) by treatment and CO decreased (P<0.01) from 26 (CTR) to 12 (T1) and 9% (T2). The iodine showed a mild enrichment factor in the curdle (about 1.7-fold), whereas selenium enriched five- to sevenfold. In Experiment 2, the level of iodine supplementation affected (P<0.05) the concentration and total excretion in milk. No effects on milk iodine concentration were related to milk yield or milk yield × treatment interaction; however, the iodine excretion in milk was major (P<0.05) in higher yielding groups. The iodine CO was affected (P<0.05) by the milk yield in supplemented groups. The selenium milk concentration and excretion were affected (P<0.01) by the milk yield, whereas the CO was affected (P<0.05) by the milk yield and selenium supplementation. Results highlight the possibility of fortification with iodine in milk and selenium in cheese through animal feeding. [ABSTRACT FROM AUTHOR]

Abstract: The objectives were to determine changes of aflatoxin M1 (AFM1) concentration and proportional excretion in milk of lactating cows when adding a commercial sequestering agent (SA) to a total mixed ration (TMR) contaminated with aflatoxin B1 (AFB1) from different feeds and how these changes were affected by different ways of adding the SA to the TMR. Two experiments were completed using eight cows each and the same TMR which had a common forage base of corn silage, alfalfa and grass hays (300, 250 and 50g/kg dry matter, respectively) to which AFB1-contaminated feeds were added. The AFB1 ingestion period was 9 days followed by a 5 day clearance period. In experiment 1, cows were randomly assigned to one of the two diets in a completely randomized design and fed a control diet made of forages plus AFB1-contaminated corn meal plus a pelleted protein/mineral/vitamin premix (Pmx) or the CC-SA diet of forages plus AFB1-contaminated corn meal with SA plus the pellet Pmx. In experiment 2, cows were randomly assigned to one of four diets in a replicated 4×4 Latin square design. Diets were CC-SA (forages plus AFB1-contaminated corn meal with SA plus a pellet Pmx), Pellet-SA (forages plus an AFB1-contaminated complete concentrate with SA as a pellet), Meal-SA (forages plus AFB1-contaminated complete concentrate with SA as a meal) and PMX-SA (forages plus AFB1-contaminated corn meal plus a pellet Pmx with SA). Milk samples were collected at days 0, 3, 5, 7, 9, 11 and 14 of each period and analyzed for AFM1 content and the proportion AFB1 excretion in milk was calculated. In experiment 1, milk AFM1 concentration and proportional excretion were reduced (47% and 44%, respectively; P<0.05) when SA was added to the diet. In experiment 2, the lowest (P<0.05) proportional AFB1 excretion (0.013) occurred in milk from cows feed the Pellet-SA diet. The PMX-SA diet obtained higher (P<0.05) AFM1 concentration in the milk (120ng/kg) when compared to other ways of SA inclusion (97, 76 and 11ng/kg, respectively for CC-SA, Pellet-SA and Meal-SA diets). [Copyright &y& Elsevier]

The purpose of this study was to optimize the conditions of a previously proposed enzymatic method used to estimate in situ undigested neutral detergent fiber (uNDF). We used a multi-step enzymatic approach, in which samples were first solubilized in NaOH solutions as a preincubation (PreInc) phase. After rinsing, samples were incubated (24 h at 39°C) in a buffered solution (pH 6) containing hemicellulase, cellulase, and Viscozyme L enzymes (Sigma-Aldrich s.r.l., Milan, Italy), followed by incubation (24 h at 39°C) in a buffered solution (pH 5) containing xylanase. Two sets of experiments were performed: a calibration trial (that tested different PreInc conditions on 9 selected forages) and a validation trial (that verified the results by testing multiple samples of 6 different forage types and a group of fibrous by-products). In the calibration trial, samples (300 mg in Ankom F57 filter bags; Ankom Technology Corp., Fairport, NY) were preincubated at 39°C in a 0.1 M NaOH solution for 90, 180, or 240 min, or in 0.2, 0.5, 1.0, or 2.0 M NaOH solution for 90 min. The results indicated that the best PreInc method, in terms of intra-laboratory repeatability and estimation of reference in situ values, was 90 min in a 0.2 M NaOH solution. Thus, we used this PreInc condition to determine enzymatic uNDF of 257 samples in the validation trial. Although the selected method generally had good accuracy in predicting in situ uNDF, inconsistencies were noted for certain forage types. Overall, when enzymatic uNDF was used to predict the in situ uNDF of all samples, the regression was satisfactory (intercept = 7.098, slope = 0.920, R2 = 0.73). The regression models developed for alfalfa hays, corn silages, and small grain silages had also acceptable regression performances and mean square error of prediction (MSEP) values, and the main sources of MSEP variation were error due to incomplete (co)variation and random error. Even when R2 values were >0.70, the MSEP value of the regression model for grass hays was 149.55, and that for nonforage fibrous feeds was 155.16. Although enzymatic uNDF partially overestimated the in situ uNDF, particularly in grass silages, the proposed procedure seems to be promising for accurately predicting in situ uNDF, because it generally had good repeatability and provided satisfactory estimates of in situ uNDF. [ABSTRACT FROM AUTHOR]

Accurate measurements of concentration and ruminal degradability of corn silage starch is necessary for formulation of diets that meet the energy requirements of dairy cows. Five corn silage hybrids ensiled for 0 (unfermented), 30, 60, 120, and 150 d were used to determine the effects of ensiling time on starch degradability of corn silage. In addition, the effects of grind size of silage samples on 7-h in vitro starch degradability and the relationship between in vitro, in situ and near-infrared reflectance spectroscopy (NIRS) starch degradability were studied. In situ disappearance of corn silage starch increased from 0 to 150 d of ensiling, primarily as a result of an increase in the washout or rapidly degraded fraction of starch, particularly during the first 60 d of ensiling. When analyzed in vitro and by NIRS, ensiling time increased corn silage starch degradability either linearly or to a greater extent during the first 2 mo of ensiling. Differences in in situ starch disappearance among corn silage hybrids were apparent during the first 2 mo of ensiling but were attenuated as silages aged. No differences among hybrids were detected using a 7-h in vitro starch digestibility approach. Results from the in vitro subexperiment indicate that 7-h in vitro starch degradability was increased by reducing grind size of corn silage from 4 to 1 mm, regardless of ensiling duration. Fine grinding corn silages samples (i.e., 1-mm sieve) allowed distinguishing low- from medium- and high-starch degradability rated hybrids. Correlations among in situ, in vitro and NIRS measurements for starch degradability were medium to high (r ≥0.57); however, agreement among methods was low (concordance correlation coefficient ≤0.15). In conclusion, ensiling time linearly increased degradation rate of corn silage resulting in greater in situ starch disappearance after 150 d of ensiling. Reductions in grind size from 4 to 1 mm resulted in greater in vitro starch degradability, regardless of ensiling duration. Strong correlation but low agreement between starch degradability methods suggest that absolute estimations of corn silage starch degradability will vary, but all methods can be used to assess the effect of ensiling time on starch degradability. [ABSTRACT FROM AUTHOR]

Zeins are corn endosperm storage proteins that encapsulate starch granules into a protein matrix, which can act as a barrier to starch accessibility and digestion. Laboratory methods to quantify zein are seldom used because they are considered arduous and timeconsuming. A recently published rapid turbidimetric method (mTM) was reinvestigated by changing the solution originally used for the zein solubilization step. In particular, the aim was to explore whether, and to what extent, the use of tert-butyl alcohol (t-BuOHmTM) in lieu of isopropyl alcohol (i-PrOH-mTM) was able to improve the quantification of zeins from dry corn, high-moisture corn, and corn silage samples. The nature of the alcohol influenced the zein extraction values, and t-BuOH-mTM gave higher zein values in corn (3.6 vs. 3.3 g/100 g of dry matter) and corn silage samples (1.2 vs. 0.9 g/100 g of dry matter) compared with i-PrOH-mTM. In contrast, similar zein extraction values were obtained for high-moisture corn (2.1 vs. 1.9 g/100 g of dry matter, respectively). Sodium dodecyl sulfate-PAGE analysis revealed no contamination by nonzein proteins with the use of tert-butyl alcohol. Overall, these findings indicated that tert-butyl alcohol has a greater ability to solubilize zein compared with isopropyl alcohol and thus the t-BuOH-mTM allowed greater extraction of zeins. Considering the growing interest of animal nutritionists in zein proteins, such results should provide useful information for routine laboratory analysis. [ABSTRACT FROM AUTHOR]

Many of the metrics used to evaluate farm performance are only partial indicators of farm operations, which are assumed to be best predictors of the whole farm efficiency. The main objective of this work was to identify aggregated multiple indexes of profitability using common partial indicators that are routinely available from individual farms to better support the short-term decision-making processes of the cattle-feeding process. Data were collected from face-to-face interviews with farmers from 90 dairy farms in Italy and used to calculate 16 partial indicators that covered almost all indicators currently used to target feeding and economic efficiency in dairy farms. These partial indicators described feed efficiency, energy utilization, feed costs, milk-to-feed price ratio, income over feed costs, income equal feed cost, money-corrected milk, and bargaining power for feed costs. Calculations of feeding costs were based on lactating cows or the whole herd, and income from milk deliveries was determined with or without considering the milk quality payment. Multivariate factor analysis was then applied to the 16 partial indicators to determine simplified and latent structures. The results indicated that 5 factors explained 70% of the variability. Each of the original partial indicator was associated with all factors in different proportions, as indicated by loading scores from the multivariate factor analysis. Based on the loading scores, we labeled these 5 factors as "economic efficiency," "energy utilization," "break-even point," "milk-to-feed price," and "bargaining power of the farm," in decreasing order of explained communality. The first 3 factors shared 83% of the total communality. Feed efficiency was similarly associated with factor 1 (53% loading) and factor 2 (66% loading). Only factor 4 was significantly affected by farm location. Milk production and herd size had significant effects on factor 1 and factor 2. Our multivariate approach eliminated the problem of multicollinearity of partial indicators, providing simple and effective descriptions of farm feeding economics. The proposed method allowed the evaluation, benchmarking, and ranking of dairy herd performance at the level of single farms and at territorial level with high opportunity to be used or replicated in other areas. [ABSTRACT FROM AUTHOR]

A linear programming model that selects the optimal cropping plan and feeds allocation for diets to minimize the whole dairy farm feed costs was developed. The model was virtually applied on 29 high-yielding Holstein-Friesian herds, confined, total mixed ration dairy farms. The average herd size was 313.2 ± 144.1 lactating cows and the average land size was 152.2 ± 92.5 ha. Farm characteristics such as herd structure, nutritional grouping strategies, feed consumption, cropping plan, intrinsic farm limitations (e.g., silage and hay storage availability, water for irrigation, manure storage) and on farm produced forage costs of production were collected from each farm for the year 2017. Actual feeding strategies, land availability, herd structure, crop production costs and yields, and milk and feed market prices for the year 2017 were used as model inputs. Through optimization, the feeding system was kept equal to the actual farm practice. The linear program formulated diets for each animal group to respect actual herd dry matter intake and fulfill actual consumption of crude protein, rumen-degradable and rumen-undegradable fractions of crude protein, net energy for lactation, neutral detergent fiber, acid detergent fiber, forage neutral detergent fiber, and nonfiber carbohydrate. Production levels and herd composition were considered to remain constant as the nutritional requirement would remain unchanged. The objective function was set to minimize the whole-farm feed costs including cash crop sales as income, and crop production costs and purchased feed costs as expenses. Optimization improved income over feed costs by reducing herd feed costs by 7.8 ± 6.4%, from baseline to optimized scenario, the improved was explained by lower feed costs per kilogram of milk produced due to a higher feed self-sufficiency and higher income from cash crop. In particular, the model suggested to maximize, starting from baseline to optimized scenario, the net energy for lactation (+8.5 ± 6.3%) and crude protein (+3.6 ± 3.1%) produced on farm, whereas total feed cost (€/100 kg of milk) was greater in the baseline (20.4 ± 2.3) than the optimized scenario (19.0 ± 1.9), resulting in a 6.7% feed cost reduction with a range between 0.49% and 21.6%. This meant €109 ± 96.9 greater net return per cow per year. The implementation of the proposed linear programming model for the optimal allocation of the nutritional resources and crops in a dairy herd has the potential to reduce feed cost of diets and improve the farm feed self-sufficiency. [ABSTRACT FROM AUTHOR]

Our objective was to model the effect of mean particle size (mPS) on in vitro rumen starch degradation (IVSD) and the kinetics of gas production for different starch-based feeds. For each feed, 2 batches of the same grains were separately processed through 2 different mills (cutter or rotor speed mills), with or without different screens to achieve a wide range of mPS (0.32 to 3.31 mm for corn meals; 0.19 to 2.81 mm for barley meals; 0.16 to 2.13 mm for wheat meals; 0.28 to 2.32 mm for oat meals; 0.21 to 2.36 mm for rye meals; 0.40 to 1.79 for sorghum meals; 0.26 to 4.71 mm for pea meals; and 0.25 to 4.53 mm for faba meals). The IVSD data and gas production kinetics, obtained by fitting to a single-pool exponential model, were analyzed using a completely randomized design, in which the main tested effect was mPS (n = 6 for all tested meals, except n = 7 for corn meals and n = 5 for sorghum meals). Rumen inocula were collected from 2 fistulated Holstein dairy cows that were fed a total mixed ration consisting of 16.2% crude protein, 28.5% starch, and 35.0% neutral detergent fiber on a dry matter basis. The IVSD, evaluated after 7 h of rumen incubation, decreased linearly with increasing mPS for corn, barley, wheat, rye, pea, and faba meals, and decreased quadratically with increasing mPS for the other meals. The y-axis intercept for 7-h IVSD was below 90% starch for corn, barley, and rye feeds and greater than 90% for the other tested feeds. The mPS adjustment factors for the rate of rumen starch degradation varied widely among the different tested feeds. We found a linear decrease in starch degradation with increasing mPS for barley, wheat, rye, and pea meals, whereas we noted a quadratic decrease in starch degradation for the other tested meals. Further, we observed a linear decrease in the rate of gas production with increasing mPS in each tested feed, except for pea meal, which had a quadratic relationship. For each 1 mm increase in mPS, the gas production was adjusted by −0.009 h−1 for corn, −0.011 h−1 for barley, −0.008 h−1 for wheat, and −0.006 h−1 for faba, whereas numerically greater adjustments were needed for oat (−0.022 h−1), rye (−0.017 h−1), and sorghum (−0.014 h−1). These mPS adjustment factors could be used to modify the starch-based feed energy values as a function of mean particle size, although in vivo validation is required. [ABSTRACT FROM AUTHOR]

Abstract: The interest in the study of the effect of endosperm vitreousness (VT) on the nutritive value of maize is increasing in pig nutrition. Therefore, an experiment was conducted to determine the effect of maize VT on starch digestion, resistant starch (RS) content, dry matter digestibility as well as on large intestine fermentation kinetics and related end products by using several in vitro techniques specifically designed for pigs. A set of 30 maize grains was selected to represent a wide range of VT (as a proportion of vitreous in total endosperm) determined by a manual dissection method. Five distinct VT classes were designed [very low (vlVT), low (lVT), medium (mVT), high (hVT) and very high (vhVT)] and identified by a specific VT value (i.e., 291, 357, 432, 611 and 830g/kg endosperm, respectively), calculated as the mean of VT values of maize samples entering the specific class. Starch digestion (expressed as predicted glycemic index) and the rate of starch digestion decreased linearly (ranging from 42.5 to 14.5 and from 0.018 to 0.006/min respectively, for vlVT and vhVT; P<0.05), whereas RS increased linearly (from 183 to 381g/kg dry matter; P<0.05) with VT classes. The total tract in vitro dry matter digestibility decreased linearly (from 0.96 to 0.75; P<0.05) with VT classes. The in vitro fermentation showed that the rate of fermentation decreased (from 0.060 to 0.044/h; P<0.05), whereas the total short chain fatty acid (SCFA) production increased (ranging from 6.29 to 7.29mmol/g dry matter incubated; P<0.05) linearly with VT classes. The molar ratio of acetate linearly increased, ranging from 0.50 to 0.55 (P<0.05) with VT classes, whereas no differences were observed for other individual SCFA. The loading plot of principal component analysis revealed significant relationships between VT and variables of interest. Results indicated that VT promoted marked effects on in vitro parameters related to starch and dry matter digestibility and fermentable kinetics for pigs. Further in vivo validations are required to validate these findings. [Copyright &y& Elsevier]

Abstract: Starch is the largest constituent in diets for pigs and its structure is considered to have a great impact on the rate of starch digestion. Despite several works showing starch is digested at varying rates in vitro, limited information exist on the characterization of single feedstuffs commonly utilized in pig nutrition through a predicted glycemic index (pGI) approach. Our objectives were: (1) to assess the variability of in vitro starch digestibility of cereal grains as a mean of screening samples by involving a pGI approach, (2) to investigate the role of heat processing and amylose level on pGI and (3) to investigate relationships among pGI, chemical variables and Englyst starch fractions. For this purpose, 137 samples of cereal grains [normal and low-amylose and heat processed (NA, LA and HP, respectively)] were evaluated using an in vitro method based on the Englyst-assay for nutritional classification of starch and a non-linear model was used to fit starch digestibility data. Starch digestion potential greatly differed among cereal grains (P<0.05). Consequently, pGI values differed (P<0.05), ranging from 15.9 for sorghum to 106.9 for HP rice. In general, higher pGI scores were recorded for HP and LA cereals than respective NA counterparts (P<0.05). Differences (P<0.05) were measured both in the rate of starch digestion (ranging from 0.017/min for NA maize to 0.182/min for HP rice) and in the starch digestible fractions. In particular, rapidly digestible starch (RDS) ranged from 119g/kg dry matter (DM) for sorghum to 704g/kg DM for HP rice, whereas resistant starch (RS) ranged from 32g/kg DM for HP barley to 275g/kg DM for sorghum. The loading plots of principal component (PC) analysis revealed significant relationships between pGI and variables of interest, showing that both chemical compositions and starch fractions could affect the pGI. In particular, the PC analysis conducted on all samples revealed that pGI was positively related with glucose and RDS (P<0.05) and negatively related to crude lipid, slowly digestible starch and RS (P<0.05) contents. The pGI approach could be a rapid, laboratory-based functional evaluation of starch value of cereal feeds entering in pig diet formulations. [Copyright &y& Elsevier]

Abstract: In an in vitro experiment, aluminosilicates (Atox® and Novasil™ Plus) and a yeast cell wall derivate (Mycosorb®) were used as sequestering agents (SAs) to verify their capacity for binding aflatoxin B1 (AFB1) in vitro. SAs were individually mixed at three different ratios with AFB1 (1:5000, 1:50,000 and 1:500,000, w/w) in water (CTR), rumen fluid from a lactating cow with a low rumen pH (LRS) or rumen fluid from a dry cow with a high rumen pH (HRS), and then used in a 3×3×3 factorial arrangement of a completely randomized design. At the 1:500,000 AF:SA ratio Atox® and Novasil™ Plus sequestered over 0.87 and 0.98 of the AFB1 in the CTR and rumen solutions (LRS and HRS), respectively. This efficacy decreased when the amount of clays was reduced, with higher values (P<0.001) for Atox® compared with Novasil™ Plus (0.50 vs. 0.28 in CTR; 0.58 vs. 0.16 in LRS and 0.44 vs. 0.27 in HRS). Mycosorb® had a lower sequestering efficacy (P<0.001) in all of tested experimental conditions, with 0.34 being the maximum value obtained in the CTR solution. In a parallel in vivo experiment, complexes between AFB1 and SAs (AF:SA) were obtained by mixing one litre of AFB1 contaminant solutions (0.845, 0.790, 0.832 and 0.911μg/mL) with 50g Atox®, 150g Mycosorb®, 50g Novasil™ Plus and 4000mL rumen fluid, respectively. The unbound AFB1 was eliminated from the AF:SA complexes after centrifugation and washing of the precipitates. The strengths of the complexes were investigated in vivo by measuring both the aflatoxin M1 (AFM1) levels and the AFB1 recovery rate (RR) in milk from cows administered through the esophagus, before the morning meal, 300mL/cow of the prepared AF:SA complex suspension for a total of 0.447, 0.360, 0.460 and 0.367μg/mL AFB1, respectively for Atox®, Mycosorb®, Novasil™ Plus and contaminated rumen fluid (R-SA). When the prepared AF:SA complexes were given to cows, differences (P<0.05) were observed for the total excreted AFM1, with amounts (ng) of 199, 870, 2394 and 1056, respectively, measured for Atox®, Mycosorb®, Novasil™ Plus and R-SA. Among the used aluminosilicates, Atox® had the lowest RR value compared with Novasil™ Plus (0.002 vs. 0.017; P<0.05), however this was not different to Mycosorb® or R-SA. Higher levels (P<0.05) of AFB1 were released from the Novasil™ Plus AF:SA complex compared with the Atox® complex. R-SA showed a sequestering activity and a low release of the sequestered AFB1 from the AF:SA complex. [Copyright &y& Elsevier]

Focuses on a study that determined the content of conjugated linoleic acid in dairy products. Materials and methods; Results and discussion.

Introduction: Feed additives represents a valid tool in animal nutrition to improve animal performance and livestock productivity under a sustainable perspective; however, there is a paucity of information about their comprehensive metabolomic and bioactive profiles., Objective: In this study, we tested the ability of an untargeted metabolomics approach to discriminate nine commercial feed additives and unique blends of botanical extracts used in both ruminant and non-ruminant nutrition, according to their phytochemical profiles and different in vitro bioactive properties., Methods: An ultra-high-performance liquid chromatography coupled with Orbitrap mass spectrometry and multivariate statistics were combined to search for potential markers, in order to better discriminate the different commercial samples., Results: Several phytochemicals were identified, namely alkaloids, phenolics, organosulfurs, and terpenoids. The polyherbal formulation Zigbir was the best source of phytochemicals, accounting for a cumulative total content of phytochemicals equal to 3.03 mg Eq./g, being particularly abundant in terpenoids, stilbenes, phenolic acids, and small-molecular-weight phenolics. Multivariate statistics allowed to group the different products in 2 bioactive subclusters. The diterpenoid andrographolide recorded the highest abundance in Zigbir and Sangrovit. The most predictive biomarkers were: piperine, isoquercitrin, 6-methylthiohexyldesulfoglucosinolate, 6-methylumbelliferone, benzoic acid, (+)-(1R,2R)-1,2-diphenylethane-1,2-diol, and piperitenone. Flavonoids were highly correlated with both in vitro antioxidant and enzyme inhibition assays., Conclusions: Our findings provide new insights into the comprehensive phytochemical composition of commercial feed additives and blend of botanical extracts used for both ruminant and non-ruminant nutrition. A great importance of polyphenols in relation to the biological activities was detected., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Parmigiano Reggiano is a hard cheese with a Protected Designation of Origin (PDO) certification that also applies to the grated product. The percentage of rind in grated Parmigiano Reggiano is regulated by the PDO production Specification and must not exceed the limit of 18% (w/w). The present study evaluates the potential of an untargeted foodomics approach to detect anomalous inclusions of rind in grated Parmigiano Reggiano cheese. In particular, a combined metabolomics and peptidomics approach was used to detect potential markers of counterfeits (rind > 18%). In the framework of realistic food integrity purposes, non-Parmigiano Reggiano grated samples and different ripening times were also considered. Untargeted metabolomics allowed detecting 347 compounds, with a prevalence of amino acids and peptide derivatives, followed by fatty acyls and other compounds (such as lactones, ketones, and aldehydes) typically related to proteolysis and lipolysis events. Overall, the unsupervised multivariate statistics showed that the ripening time plays a hierarchically higher impact than rind inclusion in determining the main differences in the chemical profiles detected. Interestingly, supervised statistics highlighted distinctive markers for ripening time and rind inclusion, with only 16 common discriminant compounds being shared between the two conditions. The best markers of rind inclusion > 18% were 2-hydroxyadenine (VIP score = 1.937; AUC value = 0.83) and the amino acid derivatives argininic acid (VIP score = 1.462; AUC value = 0.75) and 5-hydroxyindole acetaldehyde (VIP score = 1.710; AUC value = 0.86). Interestingly, the medium-chain aldehyde 4-hydroperoxy-2-nonenal was a common marker of both ripening time and anomalous rind inclusion (>18%), likely arising from the lipid oxidation processes. Finally, among potential marker peptides of rind inclusion, the alpha-S1 casein proteolytic product (F)FVAPFPEVFGK(E) could be identified., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this work, a retrospective screening based on ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS) based on Orbitrap-Q-Exactive Focus™ was used to check the occurrence of regulated and emerging mycotoxins in bulk milk samples. Milk samples were collected from dairy farms in which corn silage was the main ingredient of the feeding system. The 45 bulk milk samples were previously analyzed for a detailed untargeted metabolomic profiling and classified into five clusters according to the corn silage contamination profile, namely: (1) low levels of Aspergillus - and Penicillium -mycotoxins; (2) low levels of fumonisins and other Fusarium -mycotoxins; (3) high levels of Aspergillus -mycotoxins; (4) high levels of non-regulated Fusarium -mycotoxins; (5) high levels of fumonisins and their metabolites. Multivariate statistics based on both unsupervised and supervised analyses were used to evaluate the significant fold-change variations of the main groups of mycotoxins detected when comparing milk samples from clusters 3, 4, and 5 (high contamination levels of the corn silages) with cluster 1 and 2 (low contamination levels of the corn silages). Overall, 14 compounds showed a significant prediction ability, with antibiotic Y (VIP score = 2.579), bikaverin (VIP score = 1.975) and fumonisin B2 (VIP score = 1.846) being the best markers. The k-means clustering combined with supervised statistics showed two discriminant groups of milk samples, thus revealing a hierarchically higher impact of the whole feeding system (rather than the only corn silages) together with other factors of variability on the final mycotoxin contamination profile. Among the discriminant metabolites we found some Fusarium mycotoxins, together with the tetrapeptide tentoxin (an Alternaria toxin), the α-zearalenol (a catabolite of zearalenone), mycophenolic acid and apicidin. These preliminary findings provide new insights into the potential role of UHPLC-HRMS to evaluate the contamination profile and the safety of raw milk to produce hard cheese.

In this study, an untargeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) was used for investigating changes in chemical profiles of cow milk considering diets based on mycotoxins-contaminated corn silages. For this purpose, 45 milk samples were classified into five clusters according to the corn silage contamination profile, namely (1) low levels of Aspergillus - and Penicillium -mycotoxins; (2) low levels of fumonisins and other Fusarium -mycotoxins; (3) high levels of Aspergillus -mycotoxins; (4) high levels of non-regulated Fusarium -mycotoxins; (5) high levels of fumonisins and their metabolites, and subsequently analyzed by UHPLC-HRMS followed by a multivariate statistical analysis (both unsupervised and supervised statistical approaches). Overall, the milk metabolomic profile highlighted potential correlations between the quality of contaminated corn silages (as part of the total mixed ration) and milk composition. Metabolomics allowed to identify 628 significant milk metabolites as affected by the five levels of corn silage contamination considered, with amino acids and peptides showing the highest metabolite set enrichment (134 compounds). Additionally, 78 metabolites were selected as the best discriminant of the prediction model built, possessing a variable importance in projection score >1.2. The average Log Fold-Change variations of the discriminant metabolites provided evidence that sphingolipids, together with purine and pyrimidine-derived metabolites were the most affected chemical classes. Also, metabolomics revealed a significant accumulation of oxidized glutathione in milk samples belonging to the silage cluster contaminated by emerging Aspergillus toxins, likely involved in the oxidative imbalance. These preliminary findings provide new insights into the potential role of milk metabolomics to provide chemical indicators of mycotoxins-contaminated corn silage feeding systems.

Little is known about the effects of Fusarium mycotoxins on the fermentation potential of rumen fluid sampled from lactating dairy cows ingesting diets contaminated at regular levels of these mycotoxins (i.e., contamination levels that can normally be found on dairy farms). In the current experiment, rumen donor animals received diets contaminated with both deoxynivalenol (DON) and fumonisins (FB) with or without a mycotoxin-deactivating product. The rumen fluid donor animals were 12 lactating Holstein dairy cows that received one of 3 experimental diets in agreement with a 3 × 3 Latin square design (3 periods and 3 treatments). The 3 diets were as follows: (1) a TMR contaminated with a regular level of Fusarium mycotoxins [340.5 ± 161.0 µg of DON/kg of dry matter (DM) and 127.9 ± 43.9 µg of FB/kg of DM; control diet, CTR], (2) a TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (733.0 ± 213.6 µg of DON/kg of DM and 994.4 ± 323.2 µg of FB/kg of DM; MTX), and (3) the MTX diet (897.3 ± 230.4 µg of DON/kg of DM and 1,247.1 ± 370.2 µg of FB/kg of DM) supplemented with a mycotoxin-deactivator product (Mycofix, Biomin Holding GmbH; 35 g/animal per day; MDP). Each experimental period lasted 21 d, and rumen fluid was individually sampled from all cows on the last day of each intoxication period. Then, the 4 rumen fluids sampled from cows receiving the same experimental diets were pooled into a single rumen inoculum, which was used in the in vitro gas production test. For the gas production test, 3 different rumen inocula (i.e., CTR, MTX, and MDP) were buffered (buffer:rumen ratio of 2:1, vol/vol) and then used in 3 fermentation runs to evaluate gas production dynamics in the presence of 8 feeds (i.e., corn meal, barley meal, corn silage, sorghum silage, alfalfa hay, ryegrass hay, dry brewers barley grains, and dried distillers grains with solubles). The kinetic parameters of gas production and volatile fatty acid concentrations were evaluated at the end of fermentation. The block run (i.e., fermentation day) effect influenced all of the fermentative and kinetic parameters. Greater final volumes or rates of gas production over time were observed for MDP compared with MTX rumen inocula (i.e., 172.6 vs. 147.8 mL/g of organic matter or 0.078 vs. 0.063 h -1 , respectively). However, the increase in rate of gas production was not consistent among tested feeds, meaning that a treatment by feed interaction was observed. Volatile fatty acid concentrations were not different among treatments, except for a slight increase of acetic acid in CTR compared with MTX (i.e., 71.0 vs. 67.9 mmol/L). This study showed that Fusarium -produced mycotoxins negatively affected the kinetics of gas production in feeds, whereas the presence of the mycotoxin-deactivator product in the diets of donor animals resulted in an increase in rumen fermentation potential, thus safeguarding the rumen environment., (© 2021.)

The chemical composition of milk can be significantly affected by different factors across the dairy supply chain, including primary production practices. Among the latter, the feeding system could drive the nutritional value and technological properties of milk and dairy products. Therefore, in this work, a combined foodomics approach based on both untargeted metabolomics and metagenomics was used to shed light onto the impact of feeding systems (i.e., hay vs. a mixed ration based on hay and fresh forage) on the chemical profile of raw milk for the production of hard cheese. In particular, ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) was used to investigate the chemical profile of raw milk (n = 46) collected from dairy herds located in the Po River Valley (Italy) and considering different feeding systems. Overall, a total of 3320 molecular features were putatively annotated across samples, corresponding to 734 unique compound structures, with significant differences ( p < 0.05) between the two feeding regimens under investigation. Additionally, supervised multivariate statistics following metabolomics-based analysis allowed us to clearly discriminate raw milk samples according to the feeding systems, also extrapolating the most discriminant metabolites. Interestingly, 10 compounds were able to strongly explain the differences as imposed by the addition of forage in the cows' diet, being mainly glycerophospholipids (i.e., lysophosphatidylethanolamines, lysophosphatidylcholines, and phosphatidylcholines), followed by 5-(3',4'-Dihydroxyphenyl)-gamma-valerolactone-4'- O -glucuronide, 5a-androstan-3a,17b-diol disulfuric acid, and N-stearoyl glycine. The markers identified included both feed-derived (such as phenolic metabolites) and animal-derived compounds (such as lipids and derivatives). Finally, although characterized by a lower prediction ability, the metagenomic profile was found to be significantly correlated to some milk metabolites, with Staphylococcaceae , Pseudomonadaceae , and Dermabacteraceae establishing a higher number of significant correlations with the discriminant metabolites. Therefore, taken together, our preliminary results provide a comprehensive foodomic picture of raw milk samples from different feeding regimens, thus supporting further ad hoc studies investigating the metabolomic and metagenomic changes of milk in all processing conditions.

The feeding system represents one of the main factors driving raw milk composition, thus determining differences in nutritional value and technological properties. In this preliminary study, untargeted metabolomics with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) coupled with both unsupervised and supervised multivariate statistics was used to investigate the chemical profile of bulk milk collected from dairy cows (n = 103) following different feeding regimens, being corn silage (MS-FS, n = 51), hay (H-FS, n = 35) and a mixed ration consisted in fresh forage and hay (MR-FS, n = 17). Overall, a total of 1686 metabolites was identified by means of UHPLC-QTOF, with significant differences (p < 0.05) between the three feeding regimens under investigation. The metabolites detected mainly belonged to lipids (mainly glycerophospholipids and triglycerides), followed by oligopeptides, steroid derivatives, and secondary metabolites (such as phenolic compounds and terpenoids). Interestingly, multivariate statistics applied to the metabolomics data revealed intriguing differences in the discriminant markers detected. The markers identified included both feed-derived (such as phenolic metabolites) but also animal-derived compounds (such as fatty acids). Therefore, our results provide comprehensive insights into the metabolomics profile of different bulk milk samples, suggesting also an indirect influence of feeding regimens on its chemical signature., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The purpose of this preliminary study was to discriminate the chemical fingerprints of Protected Designation of Origin (PDO) Grana Padano cheeses from non-PDO "Grana-type" cheeses by means of an untargeted metabolomic approach based on ultra-high-pressure liquid chromatography coupled to quadrupole time-of-flight mass spectrometer (UHPLC/QTOF-MS). Hierarchical cluster analysis and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) allowed discriminating PDO vs. non-PDO cheeses. Lipids (fatty acids and their derivatives, phospholipids and monoacylglycerols), amino acids and oligopeptides, together with plant-derived compounds were the markers having the highest discrimination potential. It can be postulated that Grana Padano value chain, as strictly defined in the PDO production specification rules, can drive the biochemical processes involved in cheese making and ripening in a distinct manner, thus leaving a defined chemical signature on the final product. These preliminary findings provide the basis for further authenticity studies, aiming to protect the designation of origin of PDO Grana Padano cheese by applying a comprehensive foodomics-based approach., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Cooking by boiling dry pasta could have varying degrees of influence on nutritional and functional components. In the present study, its effect on total phenolic content and antioxidant capacity, as well as on the comprehensive profile of free and bound phenolics, was investigated in six commercial gluten-free (GF) pasta products. Overall, the heat treatment caused a significant reduction (P<0.01) of the total phenolic content as well as FRAP reducing power and ORAC radical scavenging, with significant differences among the pasta samples considered. The highest values were recorded in free phenolic fraction remaining in black rice (41mggallic acid equivalents100g -1 and 25mmolTrolox Equivalents100g -1 ) and quinoa (24mggallic acid equivalents100g -1 and 14mmolTrolox Equivalents100g -1 ) cooked GF pasta. Significant correlations (P<0.01) could be found between total phenolics and both the antioxidant capacity assays performed. UHPLC-ESI/QTOF-MS mass profiling allowed confirming the spectrophotometric results, while identifying the amount of free and bound fractions. Among phenolic classes, lignans exhibited the highest decrease during the cooking process, followed by stilbenes and flavonoids. However, phenolic acids and other phenolics showed the highest stability. Furthermore, cooking by boiling strongly lowered the bound-to-free ratio of phenolic compounds, by an averaged factor ranging from 14-folds for flavonoids to 5-folds for other classes of phenolics., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The characterization of phenolic fingerprints in common gluten-free flours is still scarce. Total phenolic and anthocyanin contents, antioxidant capacity and the entire phenolic profile were investigated for extracts from chickpea, sorghum, quinoa, black rice, lentil, amaranth, brown rice, oat and white rice flours, using soft wheat flour as a comparison. The highest phenolic content was found in black rice, followed by quinoa extracts (147.9 and 87.2mg gallic acid equivalents 100g -1 , respectively). Consistently, antioxidant capacity was highest in black rice and quinoa flours (34mmol trolox equivalents 100g -1 ), while anthocyanins were highest in black rice flour. Data showed a high correlation between phenolic content and both reducing and scavenging activities, with Pearson's coefficient of 0.90 and 0.91, respectively. Although the entire phenolic profile was diverse and differed among flours, these represent a valuable source of health-promoting compounds, mainly belonging to flavonoids, phenolic acids and lignans., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Considering that water availability for agricultural needs is being restricted, an alternative to corn in animal nutrition should be explored in the Po Valley. The present study aimed to evaluate the effects of either a partial (Trial I) or a total (Trial II) corn silage substitution with barley silage in dairy cows' diet on milk yield and composition, its coagulation properties, cheese yield and the sensorial profile of 16-month-aged Grana Padano cheese., Results: A partial or a total substitution of corn silage with barley silage had no effect on milk yield. Milk fat content in Trial I and milk urea content in both trials were higher with barley silage based diets than in corn silage based diets. No effects were observed concerning the lactodinamographic profile for milk aptitude to cheese-making, cheese yield and its organoleptic traits between feed treatments in Trials I and II. In both trials, hardness, friability and solubility scores were generally lower than reference values, whereas deformability, elasticity and stickiness scores were generally higher than reference values., Conclusion: A partial or a total substitution of corn silage with barley silage in diets for dairy cows did not induce any negative effects on animal performance, nor on milk-quality traits, cheese quality and yield. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)

The fate of phenolic compounds, along with short-chain fatty acids (SCFAs) production kinetics, was evaluated on six different commercial gluten-free (GF) pasta samples varying in ingredient compositions, focussing on the in vitro faecal fermentation after the gastrointestinal digestion. A general reduction of both total phenolics and reducing power was observed in all samples, together with a substantial change in phenolic profile over 24h of faecal fermentation, with differences among GF pasta samples. Flavonoids, hydroxycinnamics and lignans degraded over time, with a concurrent increase in low-molecular-weight phenolic acids (hydroxybenzoic acids), alkylphenols, hydroxybenzoketones and tyrosols. Interestingly, discriminant analysis also identified several alkyl derivatives of resorcinol as markers of the changes in phenolic profile during in vitro fermentation. Furthermore, degradation pathways of phenolics by intestinal microbiota have been proposed. Considering the total SCFAs and butyrate production during the in vitro fermentation, different fermentation kinetics were observed among GF pasta post-hydrolysis residues., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The objective of this work was to reduce the predictor dimensionality and to develop a model able to forecast contamination in corn silages. A survey on 33 dairy farms was performed, and samples from core, lateral, and apical parts of the feed-out face of corn silage bunkers were analyzed for chemical, biological (digestible and indigestible NDF), fermentative (pH, ammonia nitrogen, lactic acid, VFA, and ethanol), and microbiological (yeasts and molds) traits. Corn silage samples were analyzed for cell and spore counts by adoption of a molecular DNA-based method. A partial least squares (PLS) regression with a leave-one-out cross-validation method was used to reduce the dimensionality of the original predictors ( = 30) by projecting the independent variables into latent constructs. In a first step of the model development, the importance of independent variables in predicting contamination was assessed by plotting factor loadings of both dependent and independent variables on the first 2 components and by verifying for each predictor the variable influence on projection values adopting the Wold's criterion as well as the entity of standardized regression coefficients. Three ensiling characteristics (bunker type, presence of lateral wrap plastic film, and penetration resistance as a measurement of the ensiled mass density), a chemical trait (DM), 9 characterizations of the fermentative profile (pH, ammonia nitrogen, acetic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, ethanol, and lactic acid), and 2 microbiological traits (yeasts and molds) were retained as important terms in the PLS model. Three reduced-variable PLS (rPLS) regressions-the first based on ensiling, chemical, fermentative, and microbiological retained important variables (rPLSecfm); the second based on chemical, fermentative, and microbiological retained important traits (rPLScfm); and the last based on only chemical and fermentative retained important variables (rPLScf)-were performed. The model that best fit the measurements was rPLSecfm. The rPLScfm and rPLScf models had similar regression performances but higher mean square errors of prediction than rPLSecfm. However, all tested models seemed adequate to rank corn silages for low, medium, and high risks of contamination. To avoid the visit on farm by trained people required to measure penetration resistance, the use of the rPLScf model is suggested as a useful tool to assess the risk of in corn silage.

Background: To investigate corn silage fermentative quality, a principal factor analysis was carried out on a database consisting of 196 corn silages sampled from the core, lateral and apical parts of silo feed-out face and characterised by 36 variables. Eleven principal factor components (PCs) were retained and interpreted. Two PCs were related to chemical and digestibility variables; four PCs were characterised by end-products associated with clostridia, heterolactic, homolactic or aerobic fermentations; two PCs were associated with mycotoxins produced by Penicillium roqueforti or by Aspergillus fumigatus and Fusarium spp., while three PCs explained ensiling procedures adopted to store corn silages., Results: Lower (P < 0.05) yeast or mould counts and greater (P < 0.05) aerobic stability were measured in core than in peripheral samples. Excluding PCs related to ensiling procedures, other PCs were able to predict microbiological counts, aerobic stability or biogenic amine content as verified by multiple linear regression analysis. Based on these results, several corn silage quality index calculations were computed by using a summative equation approach in which different PCs as well as diverse relative weights multiplying each PCs were combined. To compute definitive index calculation, only PCs explaining clostridia, heterolactic and homolactic fermentations were used with relative weights of 30%, 50% and 20%., Conclusions: The new proposed fermentative quality index was highly correlated to parameters related to corn silage fermentative quality, such as microbiological counts, aerobic stability or biogenic amines and it properly discriminated well- and poorly preserved forages., (© 2015 Society of Chemical Industry.)

Background: A survey on 68 dairy farms was carried out to evaluate the ensiling procedures adopted to store corn silage. Samples from core, lateral and apical zones of the feed-out face of silos were analysed. A principal factor analysis (PFA) was carried out on the entire database (196 silage samples and 36 variables) and 11 principal factor components (PCs) were retained and interpreted., Results: Ensiling procedures influenced the area exposed to risk of air penetration. Cores had higher dry matter, starch and lactic acid content or lower pH, fibre, propionate and butyrate concentrations than peripheral samples (P < 0.05). The highest (P < 0.05) mycophenolic acid and roquefortina C concentrations were detected in lateral samples. Chemical and digestibility variables loaded on two PCs; four PCs were characterized by end-products associated with clostridia, heterolactic, homolactic and aerobic fermentations; two PCs were associated with mycotoxins, whereas three PCs explained ensiling procedures., Conclusion: The main quality traits of corn silages differed throughout the entire silo face. Minimization of the area exposed to risk of air penetration represents the best strategy to preserve the nutritional value and safety of corn silages. PFA allowed a clusterization of original variables into 11 PCs, appearing able to discriminate well and poorly preserved corn silages., (© 2015 Society of Chemical Industry.)

The use of rice/leguminous blend may be nutritionally convenient in gluten free product manufacturing. Gluten free spaghetti was prepared with rice flour and different concentrations of bean flour (included at levels of 0%, 20% and 40%, w/w) derived from a new developed white-seeded low phytic acid and lectin free (ws+lpa+lf) bean cultivar. Protein, ash and dietary fibre contents increased linearly (P<0.05) while total starch decreased quadratically (P<0.05) with the inclusion of ws+lpa+lf bean flour. The colour of spaghetti was influenced (P<0.05) by ws+lpa+lf bean inclusion. With respect to 0% spaghetti, the inclusion of ws+lpa+lf bean increased linearly (P<0.05) the optimal cooking time and the water absorption capacity, without affecting cooking loss and texture properties. The ws+lpa+lf bean inclusion increases quadratically (P<0.05) the resistant starch content, while decreasing quadratically (P<0.05) the in vitro glycemic index. The partial replacement of rice flour with bean flour can favourably be used in gluten free spaghetti formulation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

It was previously reported that injection of anaflatoxin B1 (AnAFB1) conjugated to keyhole limpet hemocyanin (KLH), together with Freund's adjuvant, was effective in inducing in cows a long lasting titer of anti-aflatoxin B1 (AFB1) antibodies (Abs), cross-reacting with other aflatoxins, which were able to hinder, proportionally to their titer, the secretion of aflatoxin M1 (AFM1) into the milk of cows continuously fed with AFB1. According to anti-AFB1 Ab titer, 50% of the vaccinated cows were recognized as high responder animals. In an attempt to prepare a more effective formulation for vaccination of cows, it was compared the immunogenicity, in Holstein Friesian heifers, of AnAFB1 covalently conjugated to KLH or to recombinant diphtheria toxin (CRM197) molecules, and injected together with various adjuvants. This study demonstrated that injection of AnAFB1 conjugated to KLH and mixed with complete (priming) and incomplete Freund's adjuvant (boosters), as in the previous schedule of immunization, was the most effective regimen for inducing Ab responses against AFB1, although pre-calving administration could increase the effectiveness of vaccination, resulting in 100% high responder animals. After one booster dose at the beginning of the milk production cycle, anti-AFB1 Ab titers were comparable to those recorded at the end of the immunization schedule, and proved to be effective in reducing significantly AFB1 carry over, as AFM1, from feed to milk. Pre-calving vaccination of dairy heifers with conjugated AnAFB1, adjuvated with complete and incomplete Freund's adjuvant, may represent the most effective tool for preventing the public health hazard constituted by milk and cheese contaminated with aflatoxins.

The link between diet and health has been recognized since the Grecian period; as Hippocrates said, "Let food be your medicine and medicine be your food". Although the primary goals of diet are meeting nutritional requirements and providing energy, there is increasing awareness that a correct and balanced diet may prevent the insurgence of diet-related pathologies and/or improve well-being and life expectancy, also reflecting on the ageing process. Research on the interaction among nutrients, gut microbiota and host metabolism is presently unravelling the molecular mechanisms underlying the positive and negative effects of traditional diets on health and ageing, providing useful information for the design of innovative foods targeting specific needs and segments of the population. The food supply chain plays a key role in ensuring quality and safety through both comprehensive quality management and inspection systems and a focused innovation process mainly devoted to the creation of functional foods. However, innovation and scientific development pose a problem of information asymmetry towards final consumers; thus, regulatory aspects and private and public communication strategies must be efficiently developed.

Background: The effect of a water-saving irrigation regime on yield, chemical composition, rumen in situ dry matter disappearance (DMD) and neutral detergent fiber disappearance (NDFD), along with 7 h in vitro starch degradability (7 h IVSD), in maize hybrids selected for whole-plant silage making was investigated. A plot experiment was conducted in a continental climate location and four commercial maize hybrids (FAO class 700) were used in a completely randomized design with a factorial arrangement of irrigation treatments (fully irrigated (FI) and water-saving regime (WS)) and four replicates/treatment. The total amount of irrigation water was 494 mm in FI plots and 367 mm in WS plots, the latter achieved by skipping irrigations at vegetative growth stage, silking and blistering., Results: Whole-plant yield, chemical composition, DMD, NDFD and 7 h IVSD slightly differed among hybrids and were not influenced by irrigation treatments. Plant dry matter content was lower in FI than WS plots (320 vs. 341 g kg⁻¹) , respectively; P < 0.05). Differences among hybrids were recorded for starch and acid detergent fiber contents (P < 0.05)., Conclusions: The lack of differences on yield and nutritive value in tested maize hybrids grown under different water supply suggests the water-saving regime could be suitable for an optimal use of available water in maize management., (© 2013 Society of Chemical Industry.)