Total Mixed Ration Research Articles

Effects of Different Starch Sources Used at High Levels in Cattle on Ruminal Fermentation Properties and Some Blood Parameters

In this study, it was aimed to determine the effects of different starch sources on ruminal fermentation and in situ digestibility characteristics and some blood parameters in cows. In the study, three different total mixed rations (TMR) with similar energy, protein and starch contents were prepared and these TMR’s formed the groups of the ex-periment. The main starch sources of the TMR’s were from the barley, wheat, and corn grains, respectively. The study was carried out as two consecutive trails using 3 non-lactating Holstein female cattle with rumen cannulate within a 3 × 3 Latin square trial design. These TMRs were fed at ad libitum and then nutrient intakes, ruminal fermentation (pH, acetic, propionic, butyric, and lactic acids), some serum (urea, glucose, total protein, albumin, triglyceride) and blood gas parameters (pH, pCO2, pO2, HCO3-, Na+, K+, Ca++, Cl-, anion gap, lactate) were determined. Also, in situ dry matter and starch degradability were carried out in these animals. Nutrient intakes of cows fed different TMRs were similar (P>0.05), except neutral detergent fiber (NDF) intake (P<0.05). Both ruminal fermentation, serum and blood gas pa-rameters did not change among treatment groups (P>0.05). As a result, it was determined that there were no serious changes in the ruminal fluid, serum, and blood gas parameter values of the subjects due to the content difference of the trial TMR’s. On the other hand, it was determined that in situ dry matter (DM) and starch degradability of barley and wheat were significantly different among cereal grains, ruminal DM and starch degradability of corn followed a slower, stable, and gradual increase.

Evaluating the impact of 3-nitroxypropanol supplementation on enteric methane emissions in pregnant non-lactating dairy cows offered grass silage

Although 3-nitroxypropanol (3-NOP; Bovaer10®) has been proven to reduce enteric methane (CH4) by ∼30% in indoor systems of dairying when the additive is mixed throughout a total mixed ration (TMR), there has been limited research to date on the CH4 abatement potential of 3-NOP when mixed within a perennial ryegrass silage only based diet and fed to pregnant nonlactating dairy cows. To investigate the effect of 3-NOP supplementation on enteric CH4 emissions of pregnant nonlactating dairy cows, an 6-week study was undertaken in which treatment cows were supplemented with 3-NOP mixed within grass silage, while control cows were offered grass silage without additive supplementation. Enteric CH4, hydrogen (H2) and carbon dioxide (CO2) were measured using a GreenFeed machine. Body weight (BW), body condition score (BCS), dry matter intake (DMI) and calf birthweight were monitored to determine the effect of 3-NOP supplementation on productivity. The measured dietary concentration of 3-NOP was 63 (range 53.2 - 77.1) mg / kg DM. There was no effect of 3-NOP supplementation on any of the production parameters. Cows supplemented with 3-NOP produced 22% less enteric CH4 per day and CH4 per kg DMI, respectively (P < 0.001) than cows offered the control diet. Cows supplemented with 3-NOP also produced 4.4 fold more H2 and H2 per kg DMI, respectively (P < 0.001) relative to the control. Supplementing pregnant nonlactating dairy cows with 3-NOP during the winter housing period effectively reduced enteric CH4 emissions without detriment to productivity.

Dairy cow performance and nutrient utilisation when offered high or low digestibility grass silages at two levels of total diet crude protein

The hypothesis of this study was that grass silage digestibility would influence the response of dairy cows offered diets differing in crude protein (CP) content. Thirty-two mid-lactation Holstein dairy cows were used in a 2 period (21-d adaption phase, 7-d measurement phase), partially balanced change-over experiment. Four treatments were organized in a 2 × 2 factorial arrangement, comprising 2 grass silages differing in digestible organic matter in the dry matter (D-value; 748 and 668 g/kg DM, High-D and Low-D, respectively) and 2 total diet CP levels (target 145 g/kg DM and 175 g/kg DM, High CP and Low CP, respectively). The latter were achieved using 2 iso-energetic concentrates which differed in CP level (173 and 228 g/kg DM). Silages and concentrates were mixed and offered as a total mixed ration in a 50:50 DM ratio. At the end of the feeding study, nutrient utilization was measured using 4 cows per treatment. Except for milk urea nitrogen there were no interactions between silage digestibility and total diet CP for cow performance and nutrient utilization. The High-D silage improved cow performance and increased nitrogen-use-efficiency (NUE). Reducing total diet CP also increased NUE, but there were negative impacts on cow performance. While there were benefits of offering grass silage with a high digestibility, responses to total diet CP were similar at both levels of silage digestibility.

Postbiotics from Saccharomyces cerevisiae fermentation stabilize microbiota in rumen liquid digesta during grain-based subacute ruminal acidosis (SARA) in lactating dairy cows

BackgroundSubacute ruminal acidosis (SARA) is a common metabolic disorder of high yielding dairy cows, and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation. This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products (SCFP) on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges. A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition. Treatment groups included a Control diet or diets supplemented with postbiotics (SCFPa, 14 g/d Original XPC; SCFPb-1X, 19 g/d NutriTek; SCFPb-2X, 38 g/d NutriTek, Diamond V, Cedar Rapids, IA, USA). Grain-based SARA challenges were conducted during week 5 (SARA1) and week 8 (SARA2) after parturition by replacing 20% DM of the base total mixed ration (TMR) with pellets containing 50% ground barley and 50% ground wheat. Total DNA from rumen liquid samples was subjected to V3–V4 16S rRNA gene amplicon sequencing. Characteristics of rumen microbiota were compared among treatments and SARA stages.ResultsBoth SARA challenges reduced the diversity and richness of rumen liquid microbiota, altered the overall composition (β-diversity), and its predicted functionality including carbohydrates and amino acids metabolic pathways. The SARA challenges also reduced the number of significant associations among different taxa, number of hub taxa and their composition in the microbial co-occurrence networks. Supplementation with SCFP postbiotics, in particular SCFPb-2X, enhanced the robustness of the rumen microbiota. The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges. The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria, including members of Ruminococcaceae and Lachnospiraceae, and also increased the numbers of hub taxa during non-SARA and SARA stages. Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration, and α- and β-diversity metrics in rumen liquid digesta.ConclusionsInduction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows. Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.

Influence of dietary supplementation of guanidinoacetic acid on growth performance and blood chemistry profile of growing steers

Guanidinoacetic acid (GAA, Cas no. 352-97-6) is a feed additive that positively influences the energy and protein metabolism of animals, so it has the potential to improve the productivity of animals without affecting their health. The objective of the present study was to evaluate the influence of dietary supplementation with GAA on growth performance and blood chemistry profile of growing steers for 60 d. Forty growing crossbred male steers (Bos taurus × Bos indicus; 146.0 ± 0.5 kg body weight (BW)) were randomly divided into two experimental groups (n = 20): the first, consisted of a total mixed ration (TMR) without; and the second, substituted the 0.1 % of the TMR with GAA. Dietary supplementation of GAA decreased (P < 0.0001) dry matter intake (DMI) by 12.8 % compared to the steers that were fed the TMR without GAA. Although these changes did not influence (P = 0.4180) BW and average daily gain (ADG), they improved (P < 0.0490) feed conversion efficiency (FCE) by decreasing DMI per kilogram of ADG by 10.4 %. Furthermore, the inclusion of GAA in the TMR reduced (P < 0.0050) triglycerides by 23.2 % and increased the urea nitrogen (BUN) in the steers by 22.4 % (P < 0.0002). However, sampling time influenced (P ≤ 0.0042) all blood chemistry parameters except calcium, and the interaction between GAA supplementation and time did not significantly influence (P ≥ 0.0750) any parameter. In conclusion, dietary supplementation of 1 g GAA kg−1 of TMR, decreased the DMI and improved FCE without negative effects on blood chemistry profiles.

Orange (Citrus sinensis) essential oil inclusion in high-energy diets for feedlot lambs: productivity, eating behavior, carcass characteristics, rumen morphometry, and fatty acid profile of the meat

This study evaluated the effect of different orange essential oil (OEO) inclusion rates on live weight gain, eating behavior, carcass characteristics, morphology of the ruminal epithelium, and fatty acid profile in the meat of feedlot lambs. Forty uncastrated Dorper × Santa Inês ram lambs with an initial average body weight of 21.8 ± 4.7 kg and average age of 86 ± 15 days were allocated to one of five dietary treatments in a randomized complete block design. Dietary treatments consisted of a 90:10 concentrate-to-forage ratio total mixed ration supplemented as follows: 1. non-additive supplementation (Control), and 2. additive supplementation with 100, 500, and 1000 mg OEO/kg diet DM (OEO100, OEO500, and OEO1000) or with 25 mg sodium monensin/kg diet DM (MON). The feeding lasted 84 d. Supplementation with OEO increased linearly dry matter intake (DMI), growth rate and feed efficiency (FE). Because of the linear increases in growth rate and the efficiency of energy utilization of the diet, lambs receiving OEO exhibited a greater (increasing linear effect) hot carcass weight (HCW), Longissimus muscle area (LMA), subcutaneous fat thickness (SFT), and body wall thickness (BWT) than lambs fed with Control. Lambs fed MON had lower DMI, growth rate and FE than Control and OEO. Compared to Control and OEO supplemented, lambs that received MON showed lower HCW, LMA, SFT, and BWT. Lambs fed with MON had lower oocyst counts than lambs fed with all other treatments. Lambs fed with MON spent more time eating and ruminating, with higher chewing rates than lambs fed all other diets. Rumen morphometry was unaffected by dietary treatment. The OEO supplementation increased the sum of monounsaturated fatty acids, improved the human health promotion index (HP index), and reduced the thrombogenicity index in the meat relative to lambs fed the MON treatment. Under the conditions in which the experiment was conducted, the inclusion of up to 1000 g/kg diet DM in high-energy finishing diets promotes DMI and improved growth performance and FE. Improvements in the carcass (HCW, LMA, and BTF) with OEO supplementation were mainly due to improvements in growth rate rather than effects on gain composition. Based on growth performance and carcass characteristics, OEO was a superior feed additive to sodium monensin. The OEO supplementation has a discreet effect on the fatty acid profile of the meat, but it is sufficient to improve the HP index. These findings highlight its potential as an effective additive for enhancing lamb productivity.

Improving Total Mixed Ration Silage: Effects of Lactic Acid Bacteria Inoculants and Antimicrobial Additives on Fermentation Quality and Aerobic Stability

This work aimed to assess microbial inoculants (Lactiplantibacillus plantarum and Lentilactobacillus buchneri), chemical additives (natamycin and hexanoic acid), and their combination on fermentation characteristics and aerobic stability in total mixed ration (TMR) silage. The TMR consisted of 30% water bamboo shell (WBS), 10% alfalfa, 20% rice straw, and 40% concentrate. There were six treatments as follows: (1) deionized water (control, CON). (2) lactic acid bacteria (Lactiplantibacillus plantarum + Lentilactobacillus buchneri; LPB, 1 × 106 cfu/g FW). (3) natamycin (NT, 0.02 g/kg FW). (4) hexanoic acid (HA, 0.02 g/kg FW). (5) lactic acid bacteria + natamycin (SLNT, 0.02 g/kg FW). (6) lactic acid bacteria + hexanoic acid (SLHA, 0.02 g/kg FW). After fermentation, laboratory silos (10 L) were opened to assess fermentation quality, followed by a 6-day aerobic stability test. The results showed that all silages were well fermented with high lactic acid (LA) content, low ammonia nitrogen (NH3-N), and negligible butyric acid (BA) levels. Among all silages, SLNT silage exhibited the greatest LA, acetic acid (AA) levels, LAB counts, and the lowest pH and NH3-N. For aerobic stability, all additives significantly (p &lt; 0.05) enhanced aerobic stability, delayed (p &lt; 0.05) the decrease in LA and water-soluble carbohydrates (WSC) and the increase in pH, and significantly (p &lt; 0.05) minimized yeast proliferation. The SLNT silage showed the best aerobic stability, with SLHA, NT, HA, and LPB following. In conclusion, SLNT is recommended as the optimal additive in improving the fermentation quality and aerobic stability of TMR silage, with SLHA, NT, HA, and LPB following.

Effects of yeast culture on growth performance, immune function, antioxidant capacity and hormonal profile in Mongolian ram lambs.

As effective growth-promoters and immune-modulators, yeast fermented products have shown positive effects in ruminants. To explore the mechanisms of yeast culture promoting growth and regulating immunity, this study investigated the effects of yeast culture, and β-glucan as one of its main active ingredients, on the growth performance, immune function, antioxidant capacity and hormonal profile in Mongolian ram lambs. One hundred and five Mongolian ram lambs were randomly assigned to 3 groups, with 35 replicates in each group. The dietary treatments were: total mixed ration (TMR) as the control group, TMR supplemented with 50-70 g/kg yeast culture (YC) or 75 mg/kg β-glucan. The test period was 137 days. All the sheep were weighed and 6 serum samples were collected in each group on days 0, 30, 60, 90 and 130, respectively. The results showed that both YC and β-glucan could promote the growth performance with increased average daily gain and decreased feed to weight gain ratio. Moreover, these two feed additives facilitated the immune function by selectively increasing the serum levels of lysozyme, IgG, IgM, INF-γ, TNF-α and some interleukins (IL-1β, IL-2, IL-6 and IL-8); ameliorated the antioxidant capacity with higher total antioxidant capacity and enzyme activities of catalase and glutathione peroxidase; altered the metabolism-associated hormone levels with higher growth hormone and thyroid hormone T3 but lower cortisol and insulin. In conclusion, both YC and β-glucan could improve the growth performance, immune function and antioxidant capacity, and regulate the serum levels of metabolism-associated hormones, thus exerting effects of promoting growth and improving immune function. Therefore, YC could be considered as a suitable potential alternative strategy to antibiotics and be used as an animal feed additive. This article provides a theoretical basis for the clinical application of such yeast fermented preparations in mutton sheep husbandry.

Plasma proteomic analysis reveals key pathways associated with divergent residual body weight gain phenotype in beef steers.

We utilized plasma proteomics profiling to explore metabolic pathways and key proteins associated with divergent residual body weight gain (RADG) phenotype in crossbred (Angus × Hereford) beef steers. A group of 108 crossbred growing beef steers (average BW = 282.87 ± 30 kg; age = 253 ± 28 days) were fed a high-forage total mixed ration for 49 days in five dry lot pens (20-22 beef steers per pen), each equipped with two GrowSafe8000 intake nodes to determine their RADG phenotype. After RADG identification, blood samples were collected from the beef steers with the highest RADG (most efficient; n = 15; 0.76 kg/d) and lowest RADG (least efficient; n = 15; -0.65 kg/d). Plasma proteomics analysis was conducted on all plasma samples using a nano LC-MS/MS platform. Proteins with FC ≥ 1.2 and false-discovery rate-adjusted p-values (FDR) ≤ 0.05 were considered significantly differentially abundant. The analysis identified 435 proteins, with 59 differentially abundant proteins (DAPs) between positive and negative-RADG beef steers. Plasma abundance of 38 proteins, such as macrophage stimulating 1 and peptidase D was upregulated (FC ≥ 1.2, FDR ≤ 0.05) in positive-RADG beef steers, while 21 proteins, including fibronectin and ALB protein were greater (FC < 1.2, FDR ≤ 0.05) in negative-RADG beef steers. The results of the Gene Ontology (GO) analysis of all the DAPs showed enrichment of pathways such as metabolic processes, biological regulation, and catalytic activity in positive-RADG beef steers. Results of the EuKaryotic Orthologous Groups (KOG) analysis revealed increased abundance of DAPs involved in energy production and conversion, amino acid transport and metabolism, and lipid transport and metabolism in positive-RADG beef steers. The results of this study revealed key metabolic pathways and proteins associated with divergent RADG phenotype in beef cattle which give more insight into the biological basis of feed efficiency in crossbred beef cattle.

Rumen metagenome reveals the mechanism of mitigation methane emissions by unsaturated fatty acid while maintaining the performance of dairy cows

Dietary fat content can reduce the methane production of dairy cows; however, the relevance fatty acid (FA) composition has towards this inhibitory effect is debatable. Furthermore, in-depth studies elucidating the effects of unsaturated fatty acids (UFA) on rumen function and the mechanism of reducing methane (CH4) production are lacking. This study exposed 10 Holstein cows with the same parity, similar milk yield to two total mixed rations: low unsaturated FA (LUFA) and high unsaturated FA (HUFA) with similar fat content. The LUFA group mainly added fat powder (C16:0 > 90%), and the HUFA group mainly replaced fat powder with extruded flaxseed. The experiment lasted 26 d, the last 5 d of which, gas exchange in respiratory chambers was conducted to measure gas emissions. We found that an increase in the UFA in diet did not affect milk production (P > 0.05) and could align the profile of milk FAs more closely with modern human nutritional requirements. Furthermore, we found that increasing the UFA content in the diet lead to a decrease in the abundance of Methanobrevibacter in the rumen (|linear discriminant analysis [LDA] score| > 2 and P < 0.05), which resulted in a decrease in the relative abundance of multiple enzymes (EC:1.2.7.12, EC:2.3.1.101, EC:3.5.4.27, EC:1.5.98.1, EC:1.5.98.2, EC:6.2.1.1, EC:2.1.1.86 and EC:2.8.4.1) during methanogenesis (P < 0.05). Compared with the LUFA group, the pathway of CH4 metabolism was inhibited in the HUFA group (|LDA| > 2 and P < 0.05), which ultimately decreased CH4 production (P < 0.05). Our results illustrated the mechanism involving decreased CH4 production when fed a UFA diet in dairy cows. We believe that our study provides new evidence to explore CH4 emission reduction measures for dairy cows.

Development and application of a novel extraction protocol for the monitoring of microplastic contamination in widely consumed ruminant feeds

Plastics and, in particular, microplastics (MPs) (< 5 mm) are emerging environmental pollutants responsible for interconnected risks to environmental, human, and animal health. The livestock sector is highly affected by these contaminants, with 50–60 % of the foreign bodies found in slaughtered domestic cattle being recognized as plastic-based materials. Additionally, microplastics were recently detected inside ruminant bodies and in their feces. MPs presence in ruminants could be explained by the intensive usage of plastic materials on farms, in particular to store feeds (i.e. to cover horizontal silos and to wrap hay bales). Although feed could be one of the main sources of plastics, especially of microplastics, a specific protocol to detect them in ruminant feeds is not actually present. Hence, the aim of this study was to optimize a specific protocol for the extraction, quantification, and identification of five microplastic polymers (high-density polyethylene, low-density polyethylene, polyamide fibers/particles, polyethylene terephthalate and polystyrene) from feeds typically used in ruminant diets (corn silage, hay, high protein feedstuff and total mixed ration). Several combinations of Fenton reactions and KOH digestion were tested. The final extraction protocol involved a KOH digestion (60 °C for 24 h), followed by two/three cycles of Fenton reactions. The extraction recoveries were of 100 % for high-density, low-density polyethylene, polyamide particles, and polystyrene and higher than 85 % for polyethylene terephthalate and polyamide fibers. Finally, the optimized protocol was successfully applied in the extraction of microplastics from real feed samples. All the feeds contained microplastics, particularly polyethylene, thus confirming the exposure of ruminants to MPs.

Nutritional Value and Technological Parameters of Milk From Organic and Conventional Farms in Poland

Abstract The aim of the study was to assess the nutritional value and technological parameters of milk produced in organic and conventional farming systems, taking into account the breeds of cow, feeding system, and season of production in Poland. A total of 413 milk samples were analysed, of which 220 were from Simmental cows raised on organic farms and 193 were from conventional farms, including 64 from Polish Black-and-White cows fed in a traditional system, as well as 65 from Simmental cows and 64 from Holstein-Friesian cows fed in a TMR (Total Mixed Ration) system. The milk was analysed for content of fat, protein, lactose, and urea; somatic cell count; suitability for processing (active and titratable acidity, casein content, protein-to-fat ratio, heat stability, and rennet coagulation); and content of biologically active substances (whey proteins, fatty acids, and macro- and microelements). Simmental cows from organic farms had the lowest daily milk yield, with the lowest concentrations of basic nutrients. However, it was a richer source of α-lactalbumin, lactoferrin and lysozyme and had the highest content of PUFA s. It also had a favourable protein-to-fat ratio and the shortest rennet clotting time, but it contained less Ca, Mg and Zn than milk from farms using a TMR system. The season of production had a greater influence on the composition, nutritional value and technological parameters of milk from farms using traditional feeding, including organic farms, compared to those using a TMR diet. Milk from organic farms obtained in the summer season contained more dry matter, including total protein, β-lactoglobulin, α-lactalbumin, lactoferrin, and lysozyme. It was also characterised by a more preferable fatty acid profile, i.e. lower content of SFA and higher of UFA, including MUFA and PUFA . In turn, milk from the winter season contained more fat and showed better heat stability. At farms using traditional feeding regimens, both organic and conventional, the production period had a more significant impact on the differentiation of the content of mineral components in milk (mainly macroelements).

Metabolic adaptation to lactation of dairy cows in two contrasting facilities involving partial confinement plus grazing or total confinement

Context The increasing intensification of pasture-based systems has subjected the cows to different productive environments, which could affect physiological responses and, consequently, their productive performance. Aims The aim was to determine the effect of contrasting housing facilities (outdoor soil-bedded vs compost-bedded pack barn) used in partial confinement in pasture-based systems, on the metabolic adaptation during early lactation and its impact on productive and reproductive performance of autumn- and spring-calving dairy cows, having as a positive control a zero-grazing confined system in compost barn. Methods Multiparous Holstein dairy cows that calved in autumn (n = 36) and spring (n = 48) were distributed in the following three treatments from calving to 90 days in milk (DIM): outdoor soil-bedded–grazing (OD-GRZ), compost barn–grazing (CB-GRZ), compost barn–total mixed ration (CB-TMR). Milk production, total milksolids (TMS), body condition score, non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), cholesterol, insulin, insulin-like growth factor-1 (IGF-1), and the proportion of cows with corpus luteum were determined in repeated measurements. Key results In both calving seasons, milk production and TMS yields did not differ between OD-GRZ and CB-GRZ, but were greater in CB-TMR (P &lt; 0.0001). In autumn, NEFA and BHB were not affected by treatments, but cholesterol increased faster in CB-TMR (P = 0.0500). In spring, NEFA and cholesterol concentrations were not affected by treatment, but BHB remained greater in OD-GRZ until 90 DIM than in the other treatments. IGF-1 and insulin did not differ between treatments in autumn, but in spring, IGF-1 was greater in CB-TMR (P &lt; 0.0001). The proportion of cows with corpus luteum was not different between pasture-based treatments, but both were greater than CB-TMR up to 40 DIM in autumn (P = 0.0489) and during the entire study in spring CB-TMR (P = 0.0285). Conclusions Although no differences were found among housing facilities in partial confinement, except that in spring OD-GRZ cows had greater BHB concentrations, confined cows prioritised milk production instead of reproductive function, despite presenting better energy indicators than did pasture-based cows. Implications Outdoor housing combined with grazing can increase the risk of greater BHB concentrations, indicative of subclinical ketosis, under heat-stress conditions, when compared with indoor housing. Confined cows increased milk production but had a delay in the resumption of ovarian cyclicity, even having a better energy status than pasture-based cows.

Total mixed ration silages based on elephant grass with the addition of agro-industrial byproducts

The present study aimed to evaluate the fermentative profile and losses in total mixed ration silages based on elephant grass (Pennisetum purpureum Schum.) with the addition of agro-industrial byproducts. The experiment was conducted at Campus II, CCA/UFPB, Areia – PB, in a completely randomized design with six repetitions per treatment, totaling 30 experimental units. The agro-industrial byproducts used were pineapple residues, passion fruit peel, sisal mucilage, refinazil, corn bran, soybean meal, and cottonseed cake. Elephant grass constituted the basal forage of the diet. The treatments were as follows: T1: elephant grass + cottonseed cake + refinazil; T2: elephant grass + cottonseed cake + refinazil + pineapple residues; T3: elephant grass + cottonseed cake + refinazil + passion fruit peel; T4: elephant grass + cottonseed cake + refinazil + sisal mucilage; T5: elephant grass + corn bran + soybean meal. The silos remained closed for 68 days. The data were subjected to analysis of variance and Tukey's test, with a 5% significance level. The dry matter content of the silages varied from 32 to 44%. Regarding pH, treatments T2, T4, and T5 presented values above 4.5, while the others remained within the ideal range. No significant differences were observed between treatments regarding lactic acid bacteria (LAB) at the opening of the silages. The elephant grass silages including cottonseed cake and refinazil (T1 and T2) showed promise, with moderate losses and satisfactory presence of lactic acid bacteria. On the other hand, treatments that included passion fruit peel (T3) and sisal mucilage (T4) presented unfavorable conditions, with higher losses and significant presence of mold-forming microorganisms. Notably, the treatment with corn bran and soybean meal (T5) demonstrated adequate fermentation, with a significant increase in lactic acid bacteria, suggesting it to be a viable option for the production of elephant grass silage.

Occurrence of mycotoxins in total mixed ration of dairy farms in Portugal and carry-over to milk

This study aims to explore the presence of mycotoxins in total mixed rations (TMR) employed for feeding dairy cattle and their potential carry-over to milk. A total of 87 TRM samples were collected in farms from the north of Portugal from 2019 to 2022. A method based on a QuEChERS extraction followed by UHPLC-MS/MS detection was employed for sample analysis. The method was in-house validated in terms of matrix effect, linearity, sensitivity, accuracy and precision. The most frequently detected regulated toxins were fumonisins, with a positivity rate of 74%, while deoxynivalenol and zearalenone were found in approximately 35% of the samples. Among the emerging toxins, beauvericin and enniatins exhibited the highest detection rates. In addition, milk samples were collected from 21 farms, providing insights into the carry-over of these toxins and roquefortine to milk, with an estimated rate ranging between 2% and 10%.

Intake, gain and carcass traits of Hereford and Simmental bulls offered total mixed rations based on red clover and whole-crop barley silages

Intake, gain and carcass traits of Hereford and Simmental bulls offered total mixed rations based on red clover and whole-crop barley silages

Effect of replacement of paddy straw with shredded arecanut spathe in total mixed ration on growth performance and haematobiochemical parameters of crossbred calves

Effect of replacement of paddy straw with shredded arecanut spathe in total mixed ration on growth performance and haematobiochemical parameters of crossbred calves

Study on Flat Die Wear Characteristics in Flat Die Pelletizing with Different Material Ratios Based on DEM-FEM

Wear can occur in flat die pelletizers, often reducing service life. This study explores the issue of die hole wear in the pelletizing process of a standard Total Mixed Ration (TMR) feed. The selected TMR formulation comprises varying proportions of corn, alfalfa hay, and quinoa. A coupled DEM-FEM analysis was used to examine stress–strain conditions in various die hole regions at different material ratios, predict the fatigue life of flat die materials in the pelletizing process, and validate the accuracy of investigating flat die wear through friction wear tests. It was found that the entrance of the die hole experiences the most severe conditions in terms of equivalent stress and elastic strain. The fatigue life is shortest at the entrance, with a maximum equivalent stress of 42.8 MPa, a maximum equivalent elastic strain of 2.5 × 10−3, and a minimum fatigue life stress cycle of 5.0 × 105. In contrast, the equivalent stress and equivalent elastic strain at the middle and upper parts of the die hole are minimal, with an equivalent stress of 4.8 MPa and a minimum equivalent elastic strain of 2.8 × 10−4. Material wear tests revealed that the most severe wear on the flat die specimen occurred when the ratio of corn, alfalfa hay, and quinoa straw was 7:2:1, consistent with the findings from the DEM-FEM coupling method. The pelleting process, arising from the contact between the material and metal, encompasses adhesive wear, abrasive wear, and fatigue wear.

Effects of Sweet and Forge Sorghum Silages Compared to Maize Silage without Additional Grain Supplement on Lactation Performance and Digestibility of Lactating Dairy Cows.

This study investigated the effects of replacing maize silage (MZS) with high-sugar sorghum silage (HSS) or forage sorghum silage (FSS) without additional grain supplement in the diets of dairy cows on nutrient digestibility, milk composition, nitrogen (N) use, and rumen fermentation. Twenty-four Chinese Holstein cows (545 ± 42.8 kg; 21.41 ± 0.62 kg milk yield; 150 ± 5.6 days in milk) were randomly assigned to three dietary treatments (n = 8 cows/treatment). The cows were fed ad libitum total mixed rations containing (dry matter basis) either 40% MZS (MZS-based diet), 40% HSS (HSS-based diet), or 40% FSS (FSS-based diet). The study lasted for 42 days, with 14 days devoted to adaptation, 21 days to daily feed intake and milk production, and 7 days to the sampling of feed, refusals, feces, urine, and rumen fluid. Milk production was measured twice daily, and digestibility was estimated using the method of acid-insoluble ash. The data were analyzed using a one-way ANOVA in SPSS 22.0 according to a completely randomized design. Dietary treatments were used as fixed effects and cows as random effects. The results indicate that MZS and HSS had greater crude protein but less neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and a lower pH than FSS (p ≤ 0.04). High starch contents in MZS and water-soluble carbohydrate (WSC) contents in HSS were observed (p < 0.01). While the highest starch intake was observed for the MZS-based diet, the highest WSC intake was noted for the HSS-based diet, and the highest NDF, ADF, ADL intake was observed for the FSS-based diet (p ≤ 0.05). The diets, including MZS and HSS, had greater digestibility than that of FSS (p ≤ 0.03). Feeding MZS- and HSS-based diets increased the yield, fat, and protein content of the milk, as well as feed conversion efficiency (p ≤ 0.03). However, feeding the MZS- and HSS-based diets decreased the contents of milk urea N, urinary urea N, and urinary N excretion more than the FSS-based diet (p ≤ 0.05). The N use efficiency tended to increase relative to diets containing MZS and HSS compared with FSS (p = 0.06 and p = 0.09). Ruminal ammonia-N and pH were lower, but total volatile fatty acids, acetate, and propionate were higher in cows fed the HSS- and MZS-based diets compared to those fed the FSS-based diet (p ≤ 0.03). It appears as though replacing MZS with HSS in the diet of cows without additional grain supplements has no negative influence on feed intake, milk yield, N utilization, or ruminal fermentation.

Effects of concentrate feeding sequence on VFA production, and cecal microbiota of Dezhou donkeys by metagenomic technology.

Microorganisms residing in the cecum of donkeys are crucial for physiological processes, nutrient metabolism, and immune function. Feeding methods can affect the dynamic balance of animal gut microbiota, thereby affecting indicators such as volatile fatty acids. This study explores suitable feeding methods to promote actual production by changing the feeding order of concentrate. Fifteen Dezhou donkeys with similar age and weight profiles were randomly divided into three groups with the concentrate feeding sequence: fiber-to-concentrate (FC), concentrate-to-fiber (CF), and total mixed ration (TMR). The experiment spanned a duration of 82 days. The analyses conducted were primarily aimed at determining the effects of feeding on gut microbes, primarily using metagenomic sequencing techniques. The experimental findings revealed that the levels of valeric acid were notably higher in the CF and TMR groups compared to the FC group (p < 0.05). These results suggest that the feeding sequence exerts a certain impact on the microbial composition within the cecum of Dezhou donkeys. At the phylum level, the predominant microbiota consisted of Firmicutes and Bacteroidetes, with the CF group displaying a higher relative abundance of Firmicutes compared to both the FC and TMR groups. At the genus level, Prevotella, Bacteroides, and Fibrobacter were the dominant bacterial genera identified in cecum. The functional gene annotation analysis indicated a significantly lower abundance of lacZ (K01190), Por/nifJ (K03737), and ppdK (K01006) genes in CF group relative to the FC and TMR groups (p < 0.05), highlighting their roles in galactose metabolism and glycolysis, respectively. Moreover, the CF group exhibited a higher concentration of antibiotic resistance genes (tetO and tet44) in the gut microbiota compared to the TMR and FC groups (p < 0.05), underscoring the presence of numerous antibiotic resistance genes within the phyla Bacteroidetes, Firmicutes, and Proteobacteria. In conclusion, different precision feed sequences significantly impact the levels of volatile fatty acids in Dezhou fattening donkeys, modify the composition and functional genes of the cecal microbiota, and elucidate the microbial mechanisms influenced by the feeding sequence on the growth and metabolism. These insights are anticipated to provide a foundation for the rational design of precision feed sequences in practical agricultural settings.