Total Mixed Ration Samples Research Articles

Particle size distribution of total mixed rations fed to Italian Mediterranean buffaloes measured by the PSPS: impact on milk quality and digestibility

Buffalo breeding in Italy is becoming increasingly economically attractive, with milk production in the Lazio region growing by 15% since 2004. However, the optimal physical characteristics of total mixed rations (TMR) have not been thoroughly investigated. This lack of research suggests the need for greater attention to the physical characteristics of diet, which, combined with its chemical properties, may negatively impact milk yield (MY) and milk quality (MQ), as seen in dairy cows. Therefore, the objective of this study was to assess the effect of diet composition, with a particular focus on the physical component, on MY and MQ, and apparent digestibility (AD) of dairy buffaloes. The study was conducted on 10 dairy buffalo farms in Amaseno valley (Italy). Monthly samples of TMR, faeces, and bulk milk were collected over a 12-month period, alongside interviews with farmers to gather information on MY and diet composition. The results revealed a high variability in the physical-chemical composition of diets across farms, attributable to differences in feeding management practices. Both chemical and physical component were found to be associated with MY, MQ and AD changes. A ration poor in roughage and rich in concentrate negatively affected MQ showing lower milk fat, and higher somatic cells count and milk urea, while a greater presence of coarse particles and high fibre were associated with lower MY. Nevertheless, coarse particles and aNDF were positively associated with milk clotting parameters and aNDF digestibility. Our study emphasised the high importance of fibre for improving MQ of dairy buffaloes.

Impact of varying levels of pasture allowance on the nutritional quality and functionality of milk throughout lactation

The objective of this study was to examine the impact of increasing proportions of grazed pasture in the diet on the composition, quality, and functionality of bovine milk across a full lactation. Fifty-four spring-calving cows were randomly assigned to 1 of 3 groups (n = 18), blocked on the basis of mean calving date (February 15, 2020 ± 0.8 d), pre-experimental daily milk yield (24.70 ± 3.70 kg), milk solids yield (2.30 ± 0.27 kg), lactation number (3.10 ± 0.13), and economic breeding index (182 ± 19). Raw milk samples were obtained weekly from each group between March and November 2020. Group 1 (GRS) consumed perennial ryegrass and was supplemented with 5% concentrates (dry matter basis); group 2 was maintained indoors and consumed a total mixed ration (TMR) diet consisting of maize silage, grass silage, and concentrates; and group 3 consumed a partial mixed ration diet (PMR), rotating between perennial ryegrass during the day and indoor TMR feeding at night. Raw milk samples consisted of a pooled morning and evening milking and were analyzed for gross composition, free amino acids, fatty acid composition, heat coagulation time, color, fat globule size, and pH. The TMR milks had a significantly higher total solids, lactose, protein, and whey protein as a proportion of protein content compared with both GRS and PMR milks. The GRS milks demonstrated a significantly lower somatic cell count (SCC), but a significantly higher pH and b*-value than both TMR and PMR milks. The PMR milks exhibited significantly lower total solids and fat content, but also demonstrated significantly higher SCC and total free amino acid content compared with GRS and TMR. Partial least squares discriminant analysis of fatty acid profiles displayed a distinct separation between GRS and TMR samples, while PMR displayed an overlap between both GRS and TMR groupings. Variable importance in projection analysis identified conjugated linoleic acid cis-9,trans-11, C18:2n-6 cis, C18:3n-3, C11:0, and C18:2n-6 trans as the largest contributors to the variation between the diets. Milk fats derived from GRS diets exhibited the highest proportion of unsaturated fats and higher unsaturation, health-promoting, and desaturase indices. The lowest proportions of saturated fats and the lowest atherogenic index were also exhibited by GRS-derived milk fats. This work highlights the positive influence of grass-fed milk for human consumption through its more nutritionally beneficial fatty acid profile, despite the highest milk solid percentages derived from TMR feeding systems. Furthermore, this study demonstrates the proportional response of previously highlighted biomarkers of pasture feeding to the proportion of pasture in the cow's diet.

Establishment of Flavonoid Fingerprint of TMR Diet and Optimization Factor Analysis Strategy and In Vitro Fermentation Parameters Based on Spectrum–Effect Relationship

Nutricines, the nutritionally active substances in feed, play a vital role in enhancing immune function, antioxidant activity, and feed efficiency in dairy cows. Identifying nutricines in total mixed ration (TMR) provides insights into feed quality and their impact on dairy cow health. However, due to the structural diversity of nutricines, data mining using multivariate variable models faces challenges in exploring their relationships. To address this, this study established a hierarchical clustering and optimization factor strategy for 13 common flavonoid peaks detected using apparent data and HPLC-DAD. The establishment of the flavonoid fingerprint of TMR diet in dairy cows detected 13 common peaks, five of which were found using standard products: p-coumaric acid, sinapic acid, tricin, and diosmetin. In vitro fermentation results using different TMR samples in substrate fermentation indicated that the dry matter disappearance rate, NH3-N, acetate, propionate, butyrate, isovalerate, and valerate changes varied significantly (p < 0.05). In spectrum–activity relationship studies, P2, P6, P8, P9, P10, and P11 were all considered possible factors causing this effect. In the analysis of optimization factor strategy, the peak spectrum model of four fermentation parameters, i.e., pH, dry matter digestibility, NH3-N, and acetate, was constructed after optimization (p < 0.05), and the data model is listed in the main text. In structure–activity relationship studies, ferulic acid, isoferulic acid, methyl sinapic acid, methyl 4-hydroxycinnamate, and p-hydroxybenzalacetone may serve as candidate references for compound 10 and may play an important role in affecting the digestibility of dry matter in in vitro fermentation. These findings highlight the role of flavonoids in TMR feed as key factors in maintaining dairy cow health and differentiating nutritional value. This study proposes a novel method for future TMR diet formulation and quality evaluation, with potential implications for improving dairy cow health and performance. Further research is needed to validate these findings and elucidate the mechanisms underlying nutricine effects on dairy cow nutrition and health.

Contrasting Fecal Methanogenic and Bacterial Profiles of Organic Dairy Cows Located in Northwest Washington Receiving Either a Mixed Diet of Pasture and TMR or Solely TMR.

Simple SummaryMethane is a by-product of the microbial fermentation process from a group of archaea known as methanogens. Ruminants harbor methanogens as a component of their normal gastrointestinal microbiota. In this study, we assessed the fecal microbiome of organic dairy cows across different time points receiving a mixed diet of pasture and TMR or TMR only. Our aim was to compare the archaea and bacterial fecal microbial structure, diversity and their interactions across diets. Cluster analysis based on the cows’ fecal microbial community identified four clusters. We found little difference in the relative abundance of methanogens across clusters. However, there was evidence of differences in diversity between pasture associated communities and those associated with TMR only. The cluster associated with cows receiving high-quality pasture and TMR, had higher diversity and a less robust co-occurrence network than those in TMR only or lower-quality pasture communities. The overall good pasture and TMR quality, combined with the organic allowance for feeding high levels of TMR, might have contributed to the lack of differences in the fecal archaeal community. The development of novel strategies that are independent of pasture management could have a greater impact in helping to reduce enteric CH4 emissions on organic dairies.Currently, little is known regarding fecal microbial populations and their associations with methanogenic archaea in pasture-based dairy cattle. In this study, we assessed the fecal microbiome of organic dairy cows across different time points receiving a mixed diet of pasture and total mixed ration (TMR) or TMR only. We hypothesized that the fecal methanogenic community, as well as co-occurrence patterns with bacteria, change across diets. To test these hypotheses, we analyzed TMR and pasture samples, as well as the V3-V4 region of 16S rRNA of fecal samples collected over the course of a one-year study period from 209 cows located on an organic dairy in Northwest Washington. The inherent variability in pasture quality, quantity, availability, and animal preference can lead to diverse dietary intakes. Therefore, we conducted a k-means clustering analysis to identify samples from cows that were associated with either a pasture-based diet or a solely TMR diet. A total of 4 clusters were identified. Clusters 1 and 3 were mainly associated with samples primarily collected from cows with access to pasture of varying quality and TMR, cluster 2 was formed by samples from cows receiving only TMR, and cluster 4 was a mix of samples from cows receiving high-quality pasture and TMR or TMR only. Interestingly, we found little difference in the relative abundance of methanogens between the community clusters. There was evidence of differences in diversity between pasture associated bacterial communities and those associated with TMR. Cluster 4 had higher diversity and a less robust co-occurrence network based on Spearman correlations than communities representing TMR only or lower-quality pasture samples. These findings indicate that varied bacterial communities are correlated with the metabolic characteristics of different diets. The overall good pasture and TMR quality in this study, combined with the organic allowance for feeding high levels of TMR even during the grazing season, might have contributed to the lack of differences in the fecal archaeal community from samples associated with a mixed pasture and TMR diet, and a TMR only diet. Mitigation strategies to decrease methane emissions such as increasing concentrate to forage ratio, decreasing pasture maturity and adopting grazing systems targeting high quality pasture have been shown to be efficient for pasture-based systems. However, the allowance for organic dairy producers to provide up to an average of 70% of a ruminant’s dry matter demand from dry matter fed (e.g., TMR), suggests that reducing enteric methane emissions may require the development of novel dietary strategies independent of pasture management.

Analyses of the relationship between the concentrations of essential trace elements in total mixed ration and faeces samples from Holstein Friesian dairy cows and the estimation of faeces reference values

Undersupply and oversupply of dairy cows with essential trace elements should be avoided from the point of view of animal health and environmental pollution. The aim of the study was to proof the results faecal analyzes on the nutritional supply situation with essential trace elements in comparison to measurements from total mixed ration (TMR) analyses. Concentrations of iron (Fe), copper (Cu), zinc (Zn), Mangan (Mn), selenium (Se), cobalt (Co), molybdenum (Mo) were measured as representative multicentric random sample in 574 TMR, 600 pooled faecal and blood samples from dairy cows. Trace elements, Fe in 0 %, Se 18 %, Zn 43 %, Cu 52 %, Co 53 % and Mn 59 %, were within the target range. Undersupply was found in 0 to 8 % and an oversupply in 39 to 100 % of the TMR samples. The tolerance limit for Fe was exceeded in 11 % and for Mo in 13 %. The results indicate the need for optimized ration design. The trace element concentrations in the faecal samples varied over a wide range. Results of pooled faecal samples (n=10 per pool) corresponded closely with the mean values calculated from the individual samples (r2 > 0,9). Correlation between element concentrations in the TMR and faecal samples for Fe (r=0,687), Cu (r=0,675), Zn (r=0,635), Mn (r=0,656), Se (r=0,573), Co (r=0,795), and Mo (r=0,708) were highly significant. No correlations were detected between the element concentrations in the TMR and in the blood samples. The regression analyzes showed a highly significant linear adjustment of the measured value distribution around the regression lines over the entire value range including the zero point. Reference values were calculated for the faecal concentrations of Cu, Zn, Mn, Se and Co. Tolerance reference limits in the TMR were calculated for the faecal concentrations of Fe and Mo. The trace element concentrations in the TMR samples reflect the nutritional supply situation. Knowledge of the nutritional supply situation of the herd is of great importance for the stock management of dairy cow. Fecal sample analyzes can be used as an alternative to TMR examinations to assess the nutritional supply situation.

351 Mycotoxin Trends in US Total Mixed Rations and Corn Silage

Abstract Mycotoxins are secondary fungal metabolites identified in a variety of feed ingredients and may affect animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in 2022 US total mixed ration (TMR) and 2021 corn silage samples. Corn silage samples harvested in 2021 and submitted through March 2022 and TMR samples submitted between January through March 2022 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin A. Detailed information for each sample was provided including, state of origin and whether or not clinical signs of mycotoxicosis was observed on-farm. Parameters of the main toxins found for corn silage and TMR samples were analyzed for effect of clinical concern (yes/no) and harvest year on contamination levels using LSMeans statement with Tukey's adjustment in the GLIMMIX procedure (SAS 9.4, Cary, NC). Main effects of mean contamination by harvest year are presented in Table 1, since no interactions were significant (P > 0.05). To date, 20 TMR samples from seven states have been submitted for analysis in 2022. Preliminary results show detectable amounts of B-Trich in 95% of TMR samples, with ZEN and FUM detected less frequently in 55 and 10%, respectively. Mean contamination concentrations (parts per billion, ppb) are presented on dry matter basis and were greater in 2022 compared with 2021 for B-Trich and ZEN (P < 0.05) and similar for FUM (P = 0.022). Preliminary results for 72 corn silage samples show detectable quantities of B-Trich in 90% of samples with ZEN and FUM detected less frequently in 67 and 24%, respectively. Mean contamination levels are greater than the last two years and approaching those observed in the challenging 2018 crop for B-Trich, FUM, and ZEN.

Effect of Antioxidant Supplementation on Milk Yield and Quality in Italian Mediterranean Lactating Buffaloes.

Simple SummaryBuffalo milk has good dairy properties that allow its transformation into excellent cheeses, in particular mozzarella. What greatly influences the quality of buffalo milk, and its properties is the diet administered; for this reason, we wanted to test whether a supplement of antioxidants (SOD, Zn, and Se) in the diet of lactating buffaloes could affect the quantity and quality of their milk. The experiment was carried out on sixty-six lactating buffaloes on a farm in central Italy. Individual milk samples were collected every four weeks at morning and evening milking. The results obtained showed that treatment had no effect on feed intake, feeding behaviour, and feed efficiency and improved milk yield and milk clotting properties (MCP).Buffaloes are raised mainly to obtain milk that is nutritionally very rich. The technological characteristics of buffalo milk are optimal for processing into cheese, and it is mainly used to produce mozzarella cheese. Under stressful conditions, buffaloes, like other animals, produce milk qualitatively poorly. The stressors that can affect the quality of production are, in addition to other factors, deficiencies in nutrients such as vitamins, antioxidants, and minerals. In this study, we evaluated the effect of antioxidant supplementation on the quality of buffalo milk. Sixty-six buffaloes were enrolled and subdivided into two balanced groups of 33 each. The ZnSe group received 0.2 kg/head/day of Bufalo Plus® containing antioxidants and barley meal, CaCO3 and MgCO3 mix; the control group was supplemented with 0.2 kg/head/day of barley meal, CaCO3 and MgCO3 mix. The two groups were fed ad libitum with a total mixed ration (TMR). The amount of diet distributed was recorded daily, and the residue in the trough manger was recorded three times per week. TMR samples were taken every two weeks for each group. Daily milk yield was recorded twice a week. Milk samples were collected every four weeks and analysed for chemical and technological properties. Furthermore, milk total antioxidant capacity was determined. The results obtained showed that the antioxidant supplement had no effect on feed intake, feeding behaviour, and feed efficiency. The treatment positively influenced milk production while it did not affect the chemical characteristics of the milk. In addition, the supplement of antioxidants improved the milk clotting properties (MCP). The supplement did not affect the antioxidant activity of the milk.

Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part I—Herd description and performance characteristics

Our objective was to describe management and herd characteristics of the transition period on freestall dairy herds in the northeastern United States using an on-farm survey and prospective cohort design. Enrolled herds (n = 72) had a median of 900 milking cows (range: 345-2,900) and a rolling herd average of 12,674 kg (standard deviation ± 1,220 kg), and 87.2% (n = 82/94) of fresh pens were milked at least 3×/d. The prevalence of herds with ≥15% of sampled cows with elevated concentrations of nonesterified fatty acids prepartum (≥0.27 mmol/L, 2-14 d before parturition) and postpartum [primiparous: ≥0.60 mmol/L, multiparous: ≥0.70 mmol/L, 3-14 d in milk (DIM)], β-hydroxybutyrate postpartum (≥1.2 mmol/L, 3-14 DIM), and haptoglobin postpartum (≥1 g/L, 0-12 DIM) was 51%, 51%, 51%, and 57%, respectively. In most herds, cows were moved to a calving pen when showing signs of labor (73.6%; n = 53/72) instead of 0 to 3 d before expected calving (26.4%, n = 19/72). Cows remained in the calving or maternity pen for a median (range) time of 2 (0-24) h after parturition before moving to the next pen. Primiparous cows remained in the first pen moved to after parturition for a longer period than multiparous cows [median (range) days: 12 (1.5-25) vs. 6 (1.5-22)]. Approximately 20% of herds had routine vaccinations administered in the maternity or calving pen, first pen after parturition, or both. Almost all herds (n = 69/72) performed fresh cow health checks; however, only 53% (n = 38/72) locked up all fresh cows daily. More herds housed primiparous and multiparous cows in separate pens during the far-off dry (65.3%; n = 47/72) and high-lactation (81.9%; n = 59/72) periods compared with the close-up dry (31.9%; n = 23/72) and fresh periods (27.8%; n = 20/72). At least half of the pens observed during the far-off dry, close-up dry, and fresh periods had a stocking density <100%. Approximately one-third of pens observed during the far-off dry period had feed pushed up ≤4×/d compared with approximately 15 to 20% of pens observed during the close-up dry, fresh, and high-lactation periods. More than half of the total mixed ration samples acquired from the far-off and close-up dry period visits had greater than the recommended proportion of particles in the 19-mm screen of the Penn State Particle Separator. The results of this observational study illustrated the range of management practices used in freestall herds in this region and lay the groundwork for future hypothesis-driven studies using this sampled population.

The Financial Indicators of TMR Monitoring on Dairy Farms in Hungary, as Part of Quality Assurance Tools

The TMR (total mixed ration) technology is one of the most sufficient feeding methods on the dairy farms. From a quality assurance and technological point of view, regular TMR testing is of paramount importance to reduce the risk and extent of milk production losses and animal health problems. The goal was to find out how popular the TMR monitoring in Hungary is, and find out, how much it may cost for a dairy farm in a year. In the course of our investigations, we assessed the economic indicators of TMR samples received by the NIR Forage Laboratory of Livestock Performance Testing Ltd. between 2013 and 2021, especially the distribution and size of costs per farm and per cow. Our aim was to be able to draw conclusions about the application rates, the total and relative costs of TMR analyses according to the farm size. The proportion of farms requesting TMR examinations was higher for farms with a larger number of animals (501-1000 cows inspected). Within the category, the highest TMR sample submission rate was found for the farms with 501-600 and 801-1000 cows inspected. The average monthly total TMR laboratory cost per site was extremely low in the period of 2013-2021 (HUF 3,000-10,000 /month/farm) compared to the risk and potential loss. The relative TMR cost of farms with more than 701 cows inspected was rather low (HUF 6-9 / inspected cow / month) in terms of screening for technological errors, risk of loss and quality assurance. This indicates that there is great potential for quality assurance in TMR studies at sites and that this potential is not currently being exploited.

Prevalence of Mycotoxins and Endotoxins in Total Mixed Rations and Different Types of Ensiled Forages for Dairy Cows in Lithuania

In this study, 119 samples of total mixed rations and different types of ensiled forage (maize and grass silage, and haylage) collected in 2019–2020 from dairy farms in Lithuania were analyzed to evaluate the quantitative occurrence of mycotoxins and endotoxins. Samples were analyzed using high-performance liquid chromatography (HPLC) with a fluorescent (FLD) and an ultraviolet detector (UV) of mycotoxins and a detection assay based on the ELISA technology for endotoxins. The study included toxins regulated within the European Union (aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON) and T-2 toxin) and nonregulated toxins (endotoxins). Mycotoxin analysis showed that 49.58% of the samples out of 119 were positive for AFB1, 52.11% for ZEA and DON, 55.47% for T-2 toxin and 84.04% for endotoxins. In the contaminated samples, the highest mean values of AFB1 and T-2 toxin were determined in the grass silage samples, while ZEA and DON–were determined in the maize silage samples. Maize silage samples had the highest ZEA and DON concentrations, exceeding the EU maximum permissible concentration limits. In the haylage samples, AFB1 mycotoxin exceeded the maximum concentration limits. The highest mean value of endotoxins was determined in the total mixed rations samples. This is the first study to provide information about the concentrations of mycotoxins and endotoxins in total mixed rations and different types of ensiled forages for dairy cows in Lithuania.

Changes in Carbohydrate Composition in Fermented Total Mixed Ration and Its Effects on in vitro Methane Production and Microbiome.

The purpose of this experiment was to investigate the changes of carbohydrate composition in fermented total mixed diet and its effects on rumen fermentation, methane production, and rumen microbiome in vitro. The concentrate-to-forage ratio of the total mixed ration (TMR) was 4:6, and TMR was ensiled with lactic acid bacteria and fibrolytic enzymes. The results showed that different TMRs had different carbohydrate compositions and subfractions, fermentation characteristics, and bacterial community diversity. After fermentation, the fermented total mixed ration (FTMR) group had lower contents of neutral detergent fiber, acid detergent fiber, starch, non-fibrous carbohydrates, and carbohydrates. In addition, lactic acid content and relative abundance of Lactobacillus in the FTMR group were higher. Compared with the TMR group, the in vitro ammonia nitrogen and total volatile fatty acid concentrations and the molar proportion of propionate and butyrate were increased in the FTMR group. However, the ruminal pH, molar proportion of acetate, and methane production were significantly decreased in the FTMR group. Notably, we found that the relative abundance of ruminal bacteria was higher in FTMR than in TMR samples, including Prevotella, Coprococcus, and Oscillospira. At the same time, we found that the diversity of methanogens in the FTMR group was lower than that in the TMR group. The relative abundance of Methanobrevibacter significantly decreased, while the relative abundances of Methanoplanus and vadinCA11 increased. The relative abundances of Entodinium and Pichia significantly decreased in the FTMR group compared with the TMR group. These results suggest that FTMR can be used as an environmentally cleaner technology in animal farming due to its ability to improve ruminal fermentation, modulate the rumen microbiome, and reduce methane emissions.

70 Occurrence of Mycotoxins in 2020 US Corn Silage and Dairy Total Mixed Rations

Abstract Mycotoxins are fungal metabolites which have been identified in many feed ingredients and ruminants have an increased risk of exposure due to the complex nature of their diets. Despite varying degrees of natural detoxification in the rumen, cattle health, productivity, and reproduction can be compromised by mycotoxins. This study investigated mycotoxin occurrence and contamination levels in 2020 U.S. corn silage and dairy total mixed ration (TMR) samples. Samples were screened via LC-MS/MS for six major mycotoxin groups including: aflatoxins, type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A. Information was collected with each submission including state of origin and whether or not clinical health or performance concerns were present. Contamination levels were analyzed using the GLIMMIX procedure (SAS 9.4, Cary, NC) to investigate the interaction of clinical concern (yes/no) and harvest year. No interaction was statistically significant for each of the toxin groups, so main effects of harvest year are presented in Table 1. Type B trichothecenes have been identified most frequently in 2020 corn silage. Although not often detected, A-Trich occurrence has increased ten percentage points from 2019 crop year. Among 236 TMR samples analyzed, B-Trich have been detected in a high percentage of samples. Mean contamination levels (parts per billion, ppb) are presented on a dry matter basis and within each data set were similar in 2020 compared to 2019 for respective toxin groups. Preliminary survey results indicate B-Trich occur frequently in both U.S. corn silage and TMR samples. Despite less frequent detection, other mycotoxin groups do occur including ZEN, FUM, and A-Trich, so the potential risk from toxin interactions due to co-contamination should be considered.

Handheld NIRS for forage evaluation

Handheld near infrared reflectance (NIR) instruments are now available for non-scientist operators for on-farm evaluation of forages. There are a variety of instruments with different detector technologies and greatly different NIR scanning ranges. However, there is little public data or independent evaluation of their relative effectiveness in the field. Our objective was to evaluate several hand-held NIR instruments for precision and accuracy of currently available calibrations for dry matter (DM) compared to a state-of-the-art electronic moisture meter, and to evaluate forage nutritive value calibrations available on one instrument. The AuroraNir, NIR4, and SCiO handheld NIR instruments were evaluated, along with the HST-1 electronic impedance moisture probe. Over 600 haylage, corn silage and total mixed ration samples were collected in 2019 and 2020 from 19 dairy farms in NY and WI. After scanning, two subsamples of each sample were dried to determine oven DM. Samples from three of the 19 farms were measured 10 times each, with remixing between measurements, to evaluate precision. The Aurora and NIR4 instruments, with a similar NIR scanning range, were similar in precision for estimating oven DM, while the SCiO and HST-1 instruments were less precise. Using currently available calibrations, accuracy of DM estimations was in the order of AuroraNIR > NIR4 ≫ SCiO > HST-1, although current calibrations were not sufficiently robust for a range of mixed haylage, corn silage and TMR samples from NY and WI. Calibrations for the AuroraNir did not produce consistently accurate results for nutritive value determinations, particularly when dealing with mixed species haylage.

Diets for Dairy Cows with Different Proportions of Crude Protein Originating from Red Clover Silage versus Soybean Meal: Ruminal Degradation and Intestinal Digestibility of Amino Acids.

Simple SummaryThe purpose was to assess the effect of exchanging crude protein of soybean meal with red clover silage (RCS) in total mixed rations (TMR) on ruminal degradation and intestinal digestibility (ID) of essential amino acids (EAA). Increasing proportions of RCS in the TMR increased the ruminal degradation and reduced the ID of EAA. The ruminal degradation of EAA of the TMR followed that of CP, but the ID of EAA differed from that of CP at higher levels of RCS in the diet. In conclusion, increasing proportions of RCS in TMR reduced the extent of EAA flow into the small intestine, reduced the ID of EAA, and consequently the intestinal absorbable EAA.The purpose was to assess the effect of exchanging crude protein (CP) of soybean meal (SBM) with red clover silage (RCS) in total mixed rations (TMR) on ruminal degradation and intestinal digestibility (ID) of essential amino acids (EAA). Four TMR and their individual feed components were studied. The TMR were composed of forage and concentrates (75:25), with proportions of RCS in TMR of 0.15, 0.30, 0.45, and 0.60 on a dry matter basis, resulting in diet groups RCS15, RCS30, RCS45, and RCS60, respectively. The ruminal degradation of EAA was determined using the nylon bag technique. For this, samples of TMR and their individual feed components were ruminally incubated for 16 h. The feed residues of TMR obtained after 16 h of incubation were used for the determination of ID of EAA using the mobile-bag technique. Increasing RCS and reducing SBM proportions linearly increased (p < 0.01) the in situ ruminal degradation of individual EAA from 75.5% to 83.5%. The degradation of EAA followed the trend of CP degradation among TMR, except for Cys that was lower (p < 0.05) than that of CP in RCS60 (79.7% vs. 86.3%). The degradation of EAA in individual feed ingredients not always corresponded to the degradation of CP and was feed dependent. Increasing the proportions of RCS in the TMR linearly reduced (p < 0.001) the ID of EAA (except for Ile) from 78.2% to 67.3%. However, the ID of EAA did not always reflect the ID of CP, and in general, the differences between the ID of CP and EAA increased as RCS increased in the TMR. The ID values of most of the EAA were similar (p > 0.05) to ID of CP in RCS15 and RCS30, while they mostly differed (p < 0.05) in RCS45 and RCS60, and being higher for EAA than CP (except for Cys that was lower than CP, p < 0.05). Similar trends were observed for intestinal absorbable AA, resulting in higher values (p < 0.05) of intestinal absorbable for all EAA than of CP in diet RCS60. In conclusion, increasing levels of RCS in TMR reduced the extent of EAA flow into the small intestine, the ID of EAA, and consequently the intestinal absorbable EAA. Therefore, accurate determination of metabolizable AA must be considered for optimal diet formulation when including high proportions of RCS in diets of high-producing dairy cows.

209 Appropriation of feedlot rations’ nutrient levels of imported cattle in central region of Turkey

Abstract An experiment was conducted to determine the nutrient contents of concentrated feed and Total Mixed Ration (TMR) samples taken from 6 feedlot farms in Kirikkale province and their compensation of bulls’ requirements. In the province, 6 farms active in the feedlot business were identified, and their manufactured feed and TMR samples were taken at 15-day intervals, starting from cattle received either from Europe or South America. For all periods, in each sample, crude fat (EE), crude protein (CP), crude ash (CA), crude cellulose (CS), dry matter (DM), acid detergent fiber (ADF) and neutral detergent fiber (NDF) levels were determined based on Association of Official Analytical Chemists (AOAC) methods. Metabolizable Energy levels of Total Mixed Rations (TMR) and concentrate part of feeds were calculated based on Turkish Standard Institute (TSE) method. The determined values were evaluated according to animal numbers (herd size) in feedlot and fattening periods. It was determined whether the size of the feedlot farm has an effect on TMR preparation and the nutrients in TMR are matching with the beef cattle requirements during the fattening period. Data was analyzed by using one-way ANOVA and means were separated by using LSD. Results showed that CP levels of the TMRs were significantly higher than the requirements listed in Nutrient Requirements of Beef Cattle published by National Research Council (NRC) in both cattle receiving fattening periods (0–45 days and 45–90 days) (P &amp;lt; 0,05). Additionally, cattle feeders fed their cattle with similar protein levels independent from the size of feedlot (P &amp;gt; 0,05), unexpectedly. Although it was compared with requirements, energy levels were similar in all feedlots (P &amp;gt; 0,05). All determined nutrients levels of concentrate parts of TMRs in large and small herds were similar (P &amp;gt; 0,05). In conclusion, considering that this situation absolutely increases cost of fattening and may cause metabolic diseases.

Testing selectivity of bacterial and fungal culture media compared to original silage samples using next generation sequencing

Plate counts using selective culture media is still the most frequently used method for the enumeration of the different microbial groups that colonize silage, including lactic acid bacteria, yeasts and molds. Since different culture media have specific composition, they may allow the growth of specific populations. To date, no study has used next generation sequencing technology to compare the selective capacity of these different culture media although this approach could provide comprehensive insight into the relevance of using one culture medium over another. Sequencing of the 16S rDNA and ITS amplicon were performed to compare the selectivity of different culture media used in silage microbiology. Corn silage, grass-alfalfa silage and total mixed ration extracts were plated on five selective media for lactic acid bacteria, incubated under aerobic and anaerobic conditions, and on eight selective media for yeast and molds to compare their selectivity. Ensiling provided a pre-selection environment for specific microorganisms over forage and reduced the number of observed OTUs: only 12 OTUs of bacteria were observed in corn silage sampled in the center of a bunker silo, while the mean number of OTUs identified in samples taken closer to the side of the silo, influenced by higher oxygen and humidity level, increased to 79. Still, MRS and Rogosa plates had less than 12 different OTUs in the center and 24 at the side, mainly Lactobacillaceae, Acetobacteraceae, and Leuconostocaceae. Incubating the plates under anaerobic conditions was selective against Acetobacteraceae. MRS supplemented with acetic acid increased selectivity of lactic acid bacteria. When plated on culture media specific for yeast and molds, from 17 to 68 different OTUs were observed in corn silage. Mixed grass-alfalfa silage and total mixed ration samples usually had more observed OTUs and the diversity profile of the corresponding culture media was similar to that of the original samples. For yeasts and molds, Dichloran Rose Bengal Chloramphenicol Agar revealed a diversity profile close to the that of the corn silage.

Sodium butyrate and monensin supplementation to postweaning heifer diets: Effects on growth performance, nutrient digestibility, and health

The objective of this study was to evaluate growth and performance of postweaning heifers supplemented with monensin (MON), sodium butyrate (SB), or the combination of MON and SB (MSB) compared with heifers not receiving these feed additives. Forty Holstein heifers [mean age 84.2 ± 1.2 d; body weight (BW) 99.8 ± 10.8 kg (mean ± SD)] were housed in a freestall barn, blocked by birth date, and randomly assigned to 1 of 4 treatments in a randomized complete block design. Treatments were (1) 100 g of soybean meal carrier (control; CON); (2) 0.75 g of SB/kg of BW + carrier (SB); (3) 1 mg of MON/kg of BW + carrier (MON); (4) 1 mg of MON/kg of BW + 0.75 g of SB/kg of BW (MSB). Data were analyzed using single degree of freedom contrasts evaluating CON versus additives (ADD), SB versus MON, and SB and MON versus MSB. Treatments were hand-mixed daily. Feed and orts were measured daily and frozen at -20°C. Orts samples were subsampled for dry matter (DM) determination, and total mixed ration samples were taken weekly and composited monthly for DM and nutrient analysis. Initial BW, heart and paunch girths, body length, blood samples, and fecal coccidia counts were measured before the start and weekly during the 12-wk trial. Blood samples were analyzed for glucose, plasma urea nitrogen (PUN), and ketone concentrations. Apparent total-tract nutrient digestibility was determined from d 21 to 27 and from d 63 to 69 using acid detergent insoluble ash as a marker. Daily dry matter intake (DMI) and metabolizable energy intake were increased in ADD compared with CON, and average BW, final BW, and heart girth tended to increase. Whereas MSB tended to be greater than SB and MON for heart girth, feed efficiency was greater with MON compared with SB. Compared with CON, ADD decreased coccidia counts. No effect of treatment on PUN was detected. Monensin and SB tended to have greater plasma glucose than MSB did. Average blood ketone concentrations were greater with ADD versus CON, in SB versus MON, and in MSB versus SB and MON. During the wk-3 digestibility phase, DMI tended to be greater in heifers fed SB versus MON, as well as in heifers fed MSB versus SB and MON. Digestibility of nutrients were similar, except that starch digestibility was increased in heifers fed MSB versus SB and MON. During the wk-9 digestibility phase, DMI and digestibility of nutrients were similar, except NDF, which tended to be greater in CON than in ADD. Overall, ADD resulted in positive growth and reduced coccidia compared with CON.

Fusarium mycotoxins in total mixed rations for dairy cows.

Mycotoxins produced by certain fungal species of the Fusarium genus are frequently found as contaminants in cereals and feedstuffs. Fumonisins (FBs), deoxynivalenol (DON) and zearalenone (ZEN) are of special concern relative to animal health and productivity. The aim of this work was to analyse the levels of Fusarium mycotoxin contamination in samples of total mixed rations (TMRs) for dairy cows. To accomplish this analysis, an HPLC-MS/MS multi-mycotoxin method was developed and validated. The relation between the formulation of TMR samples and the presence of mycotoxins was also studied. From February 2016 to January 2018, a total of 193 TMR samples for dairy cows collected from farms located in different areas of Spain were analysed for the presence of FBs, ZEN, DON and their metabolites. In total, 112 samples (58%) were contaminated with at least one mycotoxin, and 38 samples (20%) presented more than one mycotoxin. FBs were the mycotoxins most frequently found (34% positive samples). DON was detected in 17% of samples, and ZEN was detected in 16% of samples. Among the metabolites analysed, only deoxynivalenol-3-glucoside (DON-3-Glc) and 15-acetyldeoxynivalenol (15-ADON) were detected. The levels of all the Fusarium mycotoxins studied were always below the values recommended by the European Commission for feedstuffs. The wide variety of ingredients used in the formulation of the analysed samples made it difficult to reach definite conclusions, although it seemed that some cereal silages and concentrates such as cereals or compound feed used as ingredients of the TMR may be related to the presence of mycotoxins.

Effects of ensiling time on corn silage neutral detergent fiber degradability and relationship between laboratory fiber analyses and in vivo digestibility

Accurate analysis of degradability of silage neutral detergent fiber (NDF) is important for diet formulation and to predict lactational performance of dairy cows. In this study, 5 corn silage hybrids ensiled for 0 (unfermented), 30, 60, 120, and 150 d were used to determine the effects of ensiling time on silage neutral detergent fiber degradability (NDFD) and to assess the relationships between near-infrared reflectance spectroscopy (NIR) NDF-related analyses and in situ NDFD variables. In addition, the relationships between dietary concentration of indigestible NDF, 288-h incubation (iNDF288), or undegraded NDF, 240-h incubation (uNDF240), and in vivo total-tract apparent organic matter and NDF digestibility were studied in total mixed ration samples from 16 experiments with lactating dairy cows. Ensiling time had no effect on silage NDF concentration; however, the ratio of acid detergent fiber ÷ NDF increased, and estimated hemicellulose concentration decreased quadratically with ensiling time. Also, concentration of NDF-bound protein decreased, and that of lignin increased linearly with ensiling time. These changes in silage fiber composition resulted in a linear decrease in in situ effective degradability of silage NDF with increasing ensiling time. The indigestible fraction of NDF and concentration of structural carbohydrates were not affected by ensiling time. Correlations of in situ NDFD variables with laboratory NIR NDFD analyses were weak to moderate. The relationship of corn silage uNDF240 with lignin concentration or 30-h NDFD (all NIR analyses) was remarkably good (R2 = 0.73 and 0.88, respectively). The relationship between in situ iNDF288 concentration (but not uNDF240) and in vivo total-tract apparent digestibility of dietary organic matter and NDF was good (R2 = 0.72 and 0.80, respectively). In conclusion, in situ degradability of silage NDF linearly decreased from 0 to 150 d ensiling time, primarily caused by a decrease in concentrations of hemicellulose and NDF-bound protein. In situ NDF degradability measurements and common laboratory NIR NDF-related analyses were generally poorly correlated. We found a good relationship between in vivo NDF digestibility and dietary concentration of iNDF288 determined in situ, but the relationship with uNDF240 was poor.

A study on the optimal fermentation conditions for mixed by-products in livestock feed production

Increase in global prices of grains further adds to difficulties in feeding livestock. Total Mixed Ration (TMR) formulated with food and agricultural by-products is considered as alternative animal feeds. However, it has associated problems particularly but not limited to decomposition due to high moisture content in most of them. To solve this problem, fermentation technology was brought up on TMRs. However, the fermentation condition may vary depending on the composition of the TMRs. This study set out to identify and determine a fermentation condition which can be applied regardless of the TMR composition. The Taguchi method L9 (34) orthogonal array was adopted in this research. The study considered 3 levels of 4 controllable factors (temperature, moisture content, bulk density, and fermentation period) and 2 uncontrollable factors (compositions and ratio of TMR samples). Quality score was calculated using the silage quality assessment method by analyzing pH and organic acid content (lactic acid, acetic acid, and butyric acid). Fermentation 40 L volume chamber (ϕ 300 × 400 H) was built and three TMR samples were fermented for the validation test. Results indicated that animal feed formulated with by-products had the highest quality score at a fermentation temperature of 20 °C, moisture content of 50%, a bulk density of 0.6 kg/m3, at 96-h fermentation period. This fermentation condition delivers the silage quality score of over 82 regardless of the composition of the materials used in formulating the feed.