Effects of selenium enrichment on fermentation characteristics, selenium content and microbial community of alfalfa silage.

BACKGROUND: Selenium is essential for livestock and human health. The traditional way of adding selenium to livestock diets has limitations, and there is a growing trend to provide livestock with a safe and efficient source of selenium through selenium-enriched pasture. Therefore, this study was conducted to investigate the effects of selenium enrichment on fermentation characteristics, selenium content, selenium morphology, microbial community and in vitro digestion of silage alfalfa by using unenriched (CK) and selenium-enriched (Se) alfalfa as raw material for silage. RESULTS: In this study, selenium enrichment significantly increased crude protein, soluble carbohydrate, total selenium, and organic selenium contents of alfalfa silage fresh and post-silage samples, and it significantly decreased neutral detergent fiber and acid detergent fiber contents (p < 0.05). Selenium enrichment altered the form of selenium in plants, mainly in the form of SeMet and SeMeCys, which were significantly higher than that of CK (p < 0.05). Selenium enrichment could significantly increase the lactic acid content, reduce the pH value, change the diversity of bacterial community, promote the growth of beneficial bacteria such as Lactiplantibacillus and inhibit the growth of harmful bacteria such as Pantoea, so as to improve the fermentation quality of silage. The in vitro digestibility of dry matter (IVDMD), in vitro digestibility of acid detergent fibers (IVADFD) and in vitro digestibility of acid detergent fibers (IVNDFD) of silage after selenium enrichment were significantly higher than those of CK (p < 0.05). CONCLUSION: This study showed that the presence of selenium could regulate the structure of the alfalfa silage bacterial community and improve alfalfa silage fermentation quality. Selenium enrichment measures can change the morphology of selenium in alfalfa silage products, thus promoting the conversion of organic selenium.

Feed intake in housed dairy cows: validation of a three-dimensional camera-based feed intake measurement system.

Measuring feed intake accurately is crucial to determine feed efficiency and for genetic selection. A system using three-dimensional (3D) cameras and deep learning algorithms can measure the volume of feed intake in dairy cows, but for now, the system has not been validated for feed intake expressed as weight of feed. The aim of this study was to validate the weight of feed intake predicted from the 3D cameras with the actual measured weight. It was hypothesised that diet-specific coefficients are necessary for predicting changes in weight, that the relationship between weight and volume is curvilinear throughout the day, and that manually pushing the feed affects this relationship. Twenty-four lactating Danish Holstein cows were used in a cross-over design with four dietary treatments, 2 × 2 factorial arranged with either grass-clover silage or maize silage as silage factor, and barley or dried beet pulp as concentrate factor. Cows were adapted to the diets for 11 d, and for 3 d to tie-stall housing before camera measurements. Six cameras were used for recording, each mounted over an individual feeding platform equipped with a weight scale. When building the predictive models, four cameras were used for training, and the remaining two for testing the prediction of the models. The most accurate predictions were found for the average feed intake over a period when using the starting density of the feed pile, which resulted in the lowest errors, 6% when expressed as RMSE and 5% expressed as mean absolute error. A model including curvilinear effects of feed volume and the impact of manual feed pushing was used on a dataset including daily time points. When cross-validating, the inclusion of a curvilinear effect and a feed push effect did not improve the accuracy of the model for neither the feed pile nor the feed removed by the cow between consecutive time points. In conclusion, measuring daily feed intake from this 3D camera system in the present experimental setup could be accomplished with an acceptable error (below 8%), but the system should be improved for individual meal intake measurements if these measures were to be implemented.

Effects of refused melon fruit in Canarana grass ensilage on intake, digestibility, serum biochemistry, performance, carcass characteristics and meat attributes of feedlot lambs.

Ensilage of refused fruit with forage is a viable approach to increase resource use in ruminant feed. The objective of this study was to investigate the impact of ensiling refused melon fruit (RMF) with Canarana grass on the intake, apparent digestibility, serum biochemistry, performance, carcass traits, and meat attributes of feedlot lambs. Four distinct silage treatment types were prepared by ensiling RMF at 0 g/kg (control), 70 g/kg, 140 g/kg, and 210 g/kg (as fed) with Canarana grass. Twenty-eight male Santa Inês lambs (7 lambs per treatment), initially weighing 22.3 ± 1.0 kg at 120 days of age, were distributed in a completely randomized design and confined for a total of 96 days, including a 23-day adaptation period and 73 experimental days in a feedlot. The lambs received the treatment-silage in diets as a complete mixture with a roughage: concentrate ratio of 30:70. The inclusion of RMF in Canarana grass ensilage decreased (P < 0.05) the lambs' intake of dry matter, crude protein and metabolisable energy. The inclusion of RMF in ensilage had a quadratic effect (P < 0.05) on the digestibility of non-fibrous carbohydrates. The serum total protein and cholesterol levels decreased (P < 0.05) with the inclusion of RMF in the ensilage, but we observed no effect on the final weight and average daily gain of the lambs. The feed efficiency increased (P < 0.05) by including RMF in the Canarana grass ensilage. The RMF in the ensilage did not influence cold carcass weight and yield. The fat content of the meat decreased (P < 0.05) with the inclusion of RMF in the ensilage. It is recommended the inclusion of up to 210 g/kg of RMF in Canarana grass ensilage to increase feed efficiency and avoid impacts on the performance and carcass attributes of confined lambs.

Co-ensiled rice straw with whole sugar beet and its effect on the performance of lactating cows.

This study investigated the effect of co-ensiled rice straw (RS) with whole sugar beet (SB) on lactating cows' performance. Ensiled rice straw (ERS) as control (CGS) was incorporated with immersed corn grains (CG) for 24 h, while the 2nd and 3rd ensiled RS (LSB and HSB) contained SB substituted of 50 and 100% of CG on an energy basis (total digestible nutrients, TDN), respectively. In the experimental diets, D1, D2, and D3, which include CGS, LSB, and HSB provided ad-libitum, respectively, while a concentrated feed mixture (2% of body weight) was offered. The population of lactic acid bacteria was slightly higher with fed HSB, relative to LSB and CGS. The OM, CP, EE, NFC, and TCH contents of CGS were slightly higher than LSB and HSB, while the opposite happened with the aNDFom, and ADFom contents. The digestibility of DM, OM, aNDFom, and ADFom of the D3 group was higher (P < 0.05) than in D1 and D2. The D3 recorded the highest values (P < 0.05) of silage consumption, and palatability. Milk production, fat-corrected milk (FCM), and energy-corrected milk (ECM) were (P < 0.05) higher for cows fed D3 compared with D1 and D2. Fat, protein, lactose, and total solids were trending on the same track. The feed conversion ratio (FCR) of cows fed diet D3 was better than cows fed D1 diet. The level of glucose in the blood increased (P < 0.05) significantly with feeding on HSB than LSB, which was significantly (P < 0.05) higher compared to CGS. In conclusion, co-ensiling of RS with the whole SB plant consider a good method to improve its nutritional value.

Improvements in fermentation and nutritive quality of elephant grass [Cenchrus purpureus (Schumach.) Morrone] silages: a review.

Elephant grass [Pennisetum purpureum Schumach. syn. Cenchrus purpureus (Schumach.) Morrone], also known as Napier grass and King grass, includes varieties Taiwán, Gigante, Merkerón, Maralfalfa, and others. The grass achieves high biomass production in tropical-subtropical, temperate, and arid areas. The high-water concentration of elephant grass suggests that ensiling could offer an alternative way to preserve the nutritional quality of the grass during storage, however, some considerations should be addressed because of the particularities of the grass. Ensiling elephant grass may produce adequate fermentation but could suffer effluent losses and subsequent losses of nutrients due to leaching. To improve fermentation and nutrient characteristics of elephant grass silages, several studies were conducted with the inclusion of additives. Lactic acid bacteria inocula have reduced pH and increased crude protein content of elephant grass silage, but aerobic stability of silages could be affected by the bacterial inoculation. There is limited information, however, on the potential of different silage inoculants to reduce growth of spoilage microorganisms during the aerobic phase of silage prepared with elephant grass. Exogenous fibrolytic enzymes also may improve elephant grass silage quality by enhancing microbial fiber-degradation with subsequent increase in lactic acid and its associated pH reduction. Another study approach to improve fermentation and nutritional quality of elephant grass silages involved the addition of different feeds at ensiling, including conventional feeds such corn, wheat, rice bran, and molasses or alternative feeds such as different dehydrated by-products obtained from the food industries of juice and jelly. In the manuscript, the presented scientific information shows the great potential of the different manipulations to improve the quality of elephant grass silages and with possible enhance of the economic profit and sustainability of livestock farming in the tropical areas.

Assessing genotypes of buffel grass (Cenchrus ciliaris) as an alternative to maize silage for sheep nutrition.

Nutritive value of five Cenchrus ciliaris (buffel grass) genotypes (IG96-50, IG96-96, IG96-358, IG96-401 and IG96-403) weredetermined. Their sugar contents (>70 mg/g of dry matter) and ensiling potential were evaluated using in vitro batch culture and in vivo studies. Research indicated significant differences (P < 0.05) in the dry matter, organic matter, ether extract, neutral detergent fiber, acid detergent fiber, cellulose and lignin contents of the C. ciliaris genotypes tested. Genotypes also differed (P < 0.05) in total carbohydrates, structural carbohydrates, non-structural carbohydrates and protein fractions. Genotype IG96-96 had the lowest total digestible nutrients, digestible energy and metabolizable energy contents (377.2 g/kg, 6.95 and 5.71 MJ/kg of dry matter, respectively), and net energy values for lactation, maintenance and growth. After 45 days of ensiling, C. ciliaris silages differed (P < 0.05) in dry matter, pH, and lactic acid contents, and their values ranged between 255-339, 4.06-5.17 g/kg of dry matter and 10.8-28.0 g/kg of dry matter, respectively. Maize silage had higher (P < 0.05) Organic Matter (919.5g/kg of dry matter), ether extract (20.4g/kg of dry matter) and hemi-cellulose (272.3 g/kg of dry matter) than IG96-401 and IG96-96 silages. The total carbohydrates and non-structural carbohydrates of maize silage were higher (P < 0.05), while structural carbohydrates were comparable (P < 0.05) with C. ciliaris silages. Sheep on maize silage had (P < 0.05) higher metabolizable energy, lower crude protein, and digestible crude protein intake (g/kg of dry matter) than those on C. ciliaris silage diets. Nitrogen intake and urinary-N excretion were higher (P < 0.05) on genotype IG96-96 silage diet. Overall, this study suggested that certain C. ciliaris genotypes, notably IG96-401 and IG96-96, exhibited nutritive values comparable to maize silage in sheep studies, offering a promising avenue for future exploration as potential alternatives in diversified and sustainable livestock nutrition programs.

Effects of replacing corn silage and soybean meal with an increasing percentage of fresh herbage on dairy cow nitrogen use efficiency and flows.

To improve sustainability, dairy farms can reduce protein-rich concentrate in the cows' diet providing fresh herbage produced on-farm. This study aimed to quantify effects of increasing the percentage of fresh herbage (0%, 25%, 50%, and 75%, on a dry matter [DM] basis) in a partial mixed ration-based diet on cow N use efficiency and excretion. The study was performed with five lactating cows, in a 4 × 4 Latin square design for four 3 week periods. Individual DM intake, milk yield, feces and urine excretions, and their N concentrations were measured daily. Dietary crude protein concentrations varied little among treatments (127 to 134 g/kg DM). DM intake and milk yield decreased linearly by 5.2 and 3.7 kg/day, respectively, while N use efficiency increased by 4.1 percentage points from 0% to 75% DM of fresh herbage in the diet. Urinary N was not influenced by the treatments, while fecal N decreased as the percentage of fresh herbage increased. This study highlights that replacing partial mixed ration with an increasing percentage of fresh herbage with slight changes in dietary N concentration increases N use efficiency and the percentage of urinary N in excreted N.

Impact of diversified grazing systems on milk production, nutrient use and enteric methane emissions in dual-purpose cows.

This study evaluated three continuous grazing systems: Brachiaria Brizantha, Clitoria ternatea and naturalized pastures, complemented with commercial concentrate and C. ternatea silage on milk yield, nutrient use and enteric methane (CH4) emissions. Nine multiparous cows of local Zebu breeds, with an average weight of 448 ± 87 kg, were used. The chemical composition of the food was determined. Live weight, milk production, and quality were assessed. Furthermore, serum urea, urea nitrogen, creatinine and glucose in blood were monitored, and nitrogen use efficiency were calculated. Enteric methane (CH4) emissions were estimated using Tier-2 methodology. A 3 × 3 latin square experimental design was applied. The grazing systems of B. brizantha and C. ternatea had the greater live weights of 465.8 and 453.3 kg/cow, although the latter is similar to naturalized pasture. Milk production and quality were not affected by grazing system, with the exception of the non-fat solids, where the C. ternatea system was lower (102.2 g/kg) than the other grazing systems. The crude protein and N intake, and N excretion in feces and urine were lower in naturalized pasture systems (1139.0 g/day). N outputs in milk was high in the C. ternatea system (56.3 g/cow/day). The naturalized pastures systems showed the better feed use efficiency (25.7%) compared to others. Serum urea and blood urea nitrogen were greater in B. brizantha followed by C. ternatea. Enteric CH4 emissions were indifferent among grazing systems when expressed as a percentage of greenhouse gases (7.1%). In conclusion, the grazing C. ternatea supplemented with commercial concentrate and C. ternatea silage maintains milk production and quality, reduced cow/day emissions (by 2.5%) and lowered energy losses as methane.

Predicting ruminal degradability and chemical composition of corn silage using near-infrared spectroscopy and multivariate regression.

The aim of this study was to develop and validate regression models to predict the chemical composition and ruminal degradation parameters of corn silage by near-infrared spectroscopy (NIR). Ninety-four samples were used to develop and validate the models to predict corn silage composition. A subset of 23 samples was used to develop and validate models to predict ruminal degradation parameters of corn silage. Wet chemistry methods were used to determine the composition values and ruminal degradation parameters of the corn silage samples. The dried and ground samples had their NIR spectra scanned using a poliSPECNIR 900-1700 model NIR sprectrophotometer (ITPhotonics S.r.l, Breganze, IT.). The models were developed using regression by partial least squares (PLS), and the ordered predictor selection (OPS) method was used. In general, the regression models obtained to predict the corn silage composition (P>0.05), except the model for organic matter (OM), adequately estimated the studied properties. It was not possible to develop prediction models for the potentially degradable fraction in the rumen of OM and crude protein and the degradation rate of OM. The regression models that could be obtained to predict the ruminal degradation parameters showed correlation coefficient of calibration between 0.530 and 0.985. The regression models developed to predict CS composition accurately estimated the CS composition, except the model for OM. The NIR has potential to be used by nutritionists as a rapid prediction tool for ruminal degradation parameters in the field.

Reducing transmission of high-risk antibiotic resistance genes in whole-crop corn silage through lactic acid bacteria inoculation and increasing ensiling temperature.

The microbial hosts of antibiotic resistance genes (ARGs) found epiphytically on plant materials could grow and flourish during silage fermentation. This study employed metagenomic analysis and elucidated the occurrence and transmission mechanisms of ARGs and their microbial hosts in whole-crop corn silage inoculated with homofermentative strain Lactiplantibacillus plantarum or heterofermentative strain Lentilactobacillus buchneri ensiled under different temperature (20 and 30 °C). The results revealed that the corn silage was dominated by Lactobacillus, Leuconostoc, Lentilactobacillus, and Latilactobacillus. Both the ensiling temperature and inoculation had greatly modified the silage microbiota. However, regardless of the ensiling temperature, L. buchneri had significantly higher ARGs, while it only exhibited significantly higher mobile genetic elements (MGEs) in low temperature treatments. The microbial community of the corn silage hosted highly diverse form of ARGs, which were primarily MacB, RanA, bcrA, msbA, TetA (58), and TetT and mainly corresponded to macrolides and tetracyclines drug classes. Plasmids were identified as the most abundant MGEs with significant correlation with some high-risk ARGs (tetM, TolC, mdtH, and NorA), and their abundances have been reduced by ensiling process. Furthermore, higher temperature and L. buchneri reduced abundances of high-risk ARGs by modifying their hosts and reduced their transmission in the silage. Therefore, ensiling, L. buchneri inoculation and higher storage temperature could improve the biosafety of corn silage.

Feed characteristics of dried corn grain and corn grain silage produced in Japan compared with imported corn grain.

We compared the in situ dry matter degradability (ISDMD) and crude protein degradability (ISCPD) of high-moisture corn grain silage and dried corn grains produced in Japan (JHC and JDC, respectively) with corn grains imported from the United States (USC), Brazil (BRC), and South Africa (SAC). The ISDMD values of USC, BAC, and SAC were between those of JHC and JDC, but ISDMD did not differ significantly between USC and SAC. In contrast, ISDMD was lower for BAC than USC and SAC. Overall, our results indicate that ISDMD and ISCPD in the rumen differ between corn grains sources (domestic compared with imported and between production locations), primarily due to differences between the corn varieties represented. In particular, the ISDMD and ISCPD of JHC were greater than those of JDC, and this difference in degradability needs to be considered when using high-moisture corn grain silage as a substitute for dried corn grain as a feed for dairy cattle.

Effects of dietary forage neutral detergent fiber and rumen degradable starch ratios on chewing activity, ruminal fermentation, ruminal microbes and nutrient digestibility of Hu sheep fed a pelleted total mixed ration.

Pelleted total mixed ration (P-TMR) feeding, which has become a common practice in providing nutrition for fattening sheep, requires careful consideration of the balance between forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) to maintain proper rumen functions. The present study aimed to investigate the effects of the dietary FNDF/RDS ratio (FRR) on chewing activity, ruminal fermentation, ruminal microbes, and nutrient digestibility in Hu sheep fed a P-TMR diet. This study utilized eight ruminally cannulated male Hu sheep, following a 4 × 4 Latin square design with 31 d each period. Diets consisted of four FRR levels: 1.0 (high FNDF/RDS ratio, HFRR), 0.8 (middle high FNDF/RDS ratio, MHFRR), 0.6 (middle low FNDF/RDS ratio, MLFRR), and 0.4 (low FNDF/RDS ratio, LFRR). Reducing the dietary FRR levels resulted in a linear decrease in ruminal minimum pH and mean pH, while linearly increasing the duration and area of pH below 5.8 and 5.6, as well as the acidosis index. Sheep in the HFRR and MHFRR groups did not experience subacute ruminal acidosis (SARA), whereas sheep in another two groups did. The concentration of total volatile fatty acid and the molar ratios of propionate and valerate, as well as the concentrate of lactate in the rumen linearly increased with reducing dietary FRR, while the molar ratio of acetate and acetate to propionate ratio linearly decreased. The degradability of NDF and ADF for alfalfa hay has a quadratic response with reducing the dietary FRR. The apparent digestibility of dry matter, organic matter, neutral detergent fiber, and acid detergent fiber linearly decreased when the dietary FRR was reduced. In addition, reducing the dietary FRR caused a linear decrease in OTUs, Chao1, and Ace index of ruminal microflora. Reducing FRR in the diet increased the percentage of reads assigned as Firmicutes, but it decreased the percentage of reads assigned as Bacteroidetes in the rumen. At genus level, the percentage of reads assigned as Prevotella, Ruminococcus, Succinivibrio, and Butyrivibrio linearly decreased when the dietary FRR was reduced. The results of this study demonstrate that the dietary FRR of 0.8 is crucial in preventing the onset of SARA and promotes an enhanced richness of ruminal microbes and also improves fiber digestibility, which is a recommended dietary FRR reference when formulating P-TMR diets for sheep.

Forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) are key components of carbohydrates in the diet for ruminants, which would reflect saliva secretion and the acid production potential of feed. However, appropriate FNDF to RDS ratios (FRR) applicable to ruminants under the condition of pelleted total mixed ration (P-TMR) feeding have not been reported. In this study, we investigated the effects of the dietary FRR on chewing activity, ruminal fermentation, ruminal microbial communities, and nutrient digestibility of Hu sheep under P-TMR feeding. The results indicate that reducing dietary FRR levels would induce acidosis in sheep, which negatively affected fiber utilization and ruminal bacterial communities. The FRR of 0.8 was a recommended dietary FRR when formulating a P-TMR diet for fattening sheep, as indicated by decreased ruminal acidosis risk and increased richness of ruminal microbes in the rumen as well as nutrient digestibility.

Gene expression of free fatty acids-sensing G protein-coupled receptors in beef cattle.

Many physiological functions are regulated by free fatty acids (FFA). Recently, the discovery of FFA-specific G protein-coupled receptors (FFARs) has added to the complexity of their actions at the cellular level. The study of FFAR in cattle is still in its earliest stages focusing mainly on dairy cows. In this study, we set out to map the expression of genes encoding FFARs in 6 tissues of beef cattle. We also investigated the potential effect of dietary forage nature on FFAR gene expression. To this end, 16 purebred Charolais bulls were fed a grass silage ration or a maize silage ration (n = 8/group) with a forage/concentrate ratio close to 60:40 for 196 d. The animals were then slaughtered at 485 ±â€…42 d and liver, spleen, ileum, rectum, perirenal adipose tissue (PRAT), and Longissimus Thoracis muscle were collected. FFAR gene expression was determined by real-time quantitative PCR. Our results showed that of the five FFARs investigated, FFAR1, FFAR2, FFAR3, and GPR84 are expressed (Ct < 30) in all six tissues, whereas FFAR4 was only expressed (Ct < 30) in PRAT, ileum, and rectum. In addition, our results showed that the nature of the forage, i.e., grass silage or maize silage, had no effect on the relative abundance of FFAR in any of the tissues studied (P value > 0.05). Taken together, these results open new perspectives for studying the physiological role of these receptors in beef cattle, particularly in nutrient partitioning during growth.

Free fatty acids (FFA) are key modulators of bovine physiology. Recently, it has been discovered that some G protein-coupled receptors, termed free fatty acid receptors (FFARs), may help mediate the action of FFA at the cellular level. In humans and rodents, a growing body of evidence has shown that i) FFARs are expressed in a wide range of tissues and ii) FFARs are involved in the regulation of major FFA-dependent physiological processes (inflammation, feed intake, insulin release, etc.). In cattle, information on FFAR expression and function in tissues are scarce and mainly concern dairy cows. In this study, we showed that FFARs are expressed in 6 different tissues of beef cattle: adipose tissue, muscle tissue, ileum, rectum, liver, and spleen. We also showed that the nature of forage fed to the animals (i.e., grass silage vs. maize silage) has no effect on FFARs gene expression.

Harvest Timing of Standing Corn Using Near-Infrared Reflectance Spectroscopy.

Harvesting corn at the proper maturity is important for managing its nutritive value as livestock feed. Standing whole-plant moisture content is commonly utilized as a surrogate for corn maturity. However, sampling whole plants is time consuming and requires equipment not commonly found on farms. This study evaluated three methods of estimating standing moisture content. The most convenient and accurate approach involved predicting ear moisture using handheld near-infrared reflectance spectrometers and applying a previously established relationship to estimate whole-plant moisture from the ear moisture. The ear moisture model was developed using a partial least squares regression model in the 2021 growing season utilizing reference data from 610 corn plants. Ear moisture contents ranged from 26 to 80 %w.b., corresponding to a whole-plant moisture range of 55 to 81 %w.b. The model was evaluated with a validation dataset of 330 plants collected in a subsequent growing year. The model could predict whole-plant moisture in 2022 plants with a standard error of prediction of 2.7 and an R2P of 0.88. Additionally, the transfer of calibrations between three spectrometers was evaluated. This revealed significant spectrometer-to-spectrometer differences that could be mitigated by including more than one spectrometer in the calibration dataset. While this result shows promise for the method, further work should be conducted to establish calibration stability in a larger geographical region.

Nutritional factors affecting camel (Camelus dromedarius) milk composition.

Saharan population in Algeria still depending on bovine milk, which suffers from serious constraints undermining its sustainability. Camelus dromedarius milk has experienced growing demand following the emerging market requirements for livestock production and dairy farming over the past decade. The present work aimed at analysing the effect of nutritional regime on milk quality. The differences in pH, Acidity D°, Ash and Fats were significant. The pH was negatively influenced by the intensification conditions such as the much higher use of concentrates. The major constituents of milk were strongly and positively correlated with barley, wheat bran, TN/Kg.DM (Total Nitrogen/ Kg. Dry Matter), Kg.DM, Concentrates and daily watering. The results showed that a good energy-protein balance around 73 g PDI/UFL (Protein Digestible in the Intestine/Energetic Forage Unit for milk production) was beneficial for a better milk protein ratio. The use of corn, soybeans, palm dates and VM-premix (Vitamin Mineral) supplementation were also favourable to the synthesis of fats. Crude fiber and cell walls were better valued in the synthesis of fats with the availability of concentrates and the increasing of TN /Kg.DM and VM-premix rate in dietary regime. The vitamin C content elevate following high ratio of UFL /Kg.DM and PDI/UFL. For thus, the influence of nutritional status can lead to major improvements that need also more advanced and detailed studies.

Novel oxidising feed additives reduce in vitro methane emissions using the rumen simulation technique.

Enteric methane (CH4) produced by ruminant livestock is a potent greenhouse gas and represents significant energy loss for the animal. The novel application of oxidising compounds as antimethanogenic agents with future potential to be included in ruminant feeds, was assessed across two separate experiments in this study. Low concentrations of oxidising agents, namely urea hydrogen peroxide (UHP) with and without potassium iodide (KI), and magnesium peroxide (MgO2), were investigated for their effects on CH4 production, total gas production (TGP), volatile fatty acid (VFA) profiles, and nutrient disappearance in vitro using the rumen simulation technique. In both experiments, the in vitro diet consisted of 50:50 grass silage:concentrate on a dry matter basis. Treatment concentrations were based on the amount of oxygen delivered and expressed in terms of fold concentration. In Experiment 1, four treatments were tested (Control, 1× UHP + KI, 1× UHP, and 0.5× UHP + KI), and six treatments were assessed in Experiment 2 (Control, 0.5× UHP + KI, 0.5× UHP, 0.25× UHP + KI, 0.25× UHP, and 0.12× MgO2). All treatments in this study had a reducing effect on CH4 parameters. A dose-dependent reduction of TGP and CH4 parameters was observed, where treatments delivering higher levels of oxygen resulted in greater CH4 suppression. 1× UHP + KI reduced TGP by 28 % (p = 0.611), CH4% by 64 % (p = 0.075) and CH4 mmol/g digestible organic matter by 71 % (p = 0.037). 0.12× MgO2 reduced CH4 volume by 25 % (p > 0.05) without affecting any other parameters. Acetate-to-propionate ratios were reduced by treatments in both experiments (p < 0.01). Molar proportions of acetate and butyrate were reduced, while propionate and valerate were increased in UHP treatments. High concentrations of UHP affected the degradation of neutral detergent fibre in the forage substrate. Future in vitro work should investigate alternative slow-release oxygen sources aimed at prolonging CH4 suppression.

Full-fat corn germ improves the performance and milk fat yield of Girolando cows fed sugarcane bagasse and cactus cladodes as forage sources.

We investigated the effects of replacing ground corn with full-fat corn germ (FFCG) on milk production, milk composition, and nutrient use in cows fed sugarcane bagasse and cactus cladodes. Ten multiparous Girolando cows (average body weight 500 ± 66 kg, 90 ± 15 days in milk) were distributed in a replicated 5 × 5 Latin Square and assigned to five dietary treatments containing 0%, 25%, 50%, 75%, or 100% of full-fat corn germ in substitution to ground corn. Full-fat corn germ increased fat-corrected milk yield by 2.2 kg/day and the synthesis of fat, lactose, and total solids in milk by 94.4, 60.0, and 201.10 g/day, respectively (p < 0.05). Cows fed corn germ quadratically increased (p < 0.05) dry matter intake by 1.01 kg/day, with the intake of crude protein and total digestible nutrients following the same pattern. Conversely, the substitution of corn for full-fat corn germ linearly reduced (p < 0.05) the total non-fiber carbohydrate intake from 5.79 to 4.40 kg/d. Except for ether extract and non-fiber carbohydrates, full-fat corn germ did not alter (p > 0.05) nutrient digestibility. Cows fed corn germ excreted less (p < 0.05) urea-N in milk and urine N. These results demonstrate that full-fat corn germ can partially replace ground corn to enhance the milk production efficiency of crossbred cows fed cactus cladodes and sugarcane bagasse. Furthermore, including sugarcane bagasse in FFCG-supplemented diets prevents milk fat depression in cows fed cactus cladodes.

Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers.

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ±â€…29.4 kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2 mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2 mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2 wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2 mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2 wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05 kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980 kg) and shrunk final BW (P < 0.01, 350 vs. 366 kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05 kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2 mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

Produced by the fungus Claviceps purpurea, ergot alkaloids (EA) are toxic to beef cattle when consumed and can lead to reduction in feed intake and growth performance, vasoconstriction of the blood vessels, hyperthermia, damage to extremities (ears, tails, and hooves) and in severe cases, death. Grain is often cleaned to meet quality standards, and the resulting screenings are often utilized for feeding livestock and can have high concentrations of EA. The application of heat during pelleting of EA contaminated grain has been suggested to reduce its toxicity. Backgrounding and finishing beef cattle feeding experiments were conducted to assess the effect of continuously or intermittently feeding EA contaminated grain (2 mg/kg of diet DM) either as a pellet or as mash on growth performance, health, and animal welfare. Feeding EA grain continuously or intermittently either as a mash or pellet drastically reduced growth performance of steers, with no difference between treatments.

Bioaugmented ensiling of sweet sorghum with Pichia anomala and cellulase and improved enzymatic hydrolysis of silage via ball milling.

Sweet sorghum, as a seasonal energy crop, is rich in cellulose and hemicellulose that can be converted into biofuels. This work aims at investigating the effects of synergistic regulation of Pichia anomala and cellulase on ensiling quality and microbial community of sweet sorghum silages as a storage and pretreatment method. Furthermore, the combined pretreatment effects of ensiling and ball milling on sweet sorghum were evaluated by microstructure change and enzymatic hydrolysis. Based on membership function analysis, the combination of P. anomala and cellulase (PA + CE) significantly improved the silage quality by preserving organic components and promoting fermentation characteristics. The bioaugmented ensiling with PA + CE restructured the bacterial community by facilitating Lactobacillus and inhibiting undesired microorganisms by killer activity of P. anomala. The combined bioaugmented ensiling pretreatment with ball milling significantly increased the enzymatic hydrolysis efficiency (EHE) to 71%, accompanied by the increased specific surface area and decreased pore size/crystallinity of sweet sorghum. Moreover, the EHE after combined pretreatment was increased by 1.37 times compared with raw material. Hence, the combined pretreatment was demonstrated as a novel strategy to effectively enhance enzymatic hydrolysis of sweet sorghum.

Enrichment of milk antioxidant activity by dietary supplementation of red clover isoflavone in cows and its improvement on mice intestinal health.

Red clover (Trifolium pratense) isoflavone was supplemented to dairy cows, and antioxidant capacity of milk was assessed. Treated cows increased the activities of antioxidant enzymes, reduced production of oxidation products, and enhanced the concentrations of vitamin E and vitamin C. Moreover, milk fatty acid profile was positive influenced by 8 g/kg red clover isoflavone, with changes in the lower saturated and higher unsaturated fatty acids. We further demonstrated the efficacy of antioxidant capacity of milk in mice, found that milk from cows feeding red clover isoflavone increased the expressions of antioxidant enzymes, and alleviated lipopolysaccharide (LPS)-stimulated tissue damage of duodenum and jejunum, which was related to upregulated metabolism pathways of carbohydrate, lipid, and amino acid, as well as downregulated inflammatory related pathways. Together, dietary supplementation of red clover isoflavone is an effective way to improve milk antioxidant capacity, providing a natural strategy for developing functional foods.