The latest freshwater giants: a new Peltocephalus (Pleurodira: Podocnemididae) turtle from the Late Pleistocene of the Brazilian Amazon.

Overkill of large mammals is recognized as a key driver of Pleistocene megafaunal extinctions in the Americas and Australia. While this phenomenon primarily affected mega-mammals, its impact on large Quaternary reptiles has been debated. Freshwater turtles, due to the scarcity of giant forms in the Quaternary record, have been largely neglected in such discussions. Here we present a new giant podocnemidid turtle, Peltocephalus maturin sp. nov., from the Late Pleistocene Rio Madeira Formation in the Brazilian Amazon, that challenges this assumption. Morphological and phylogenetic analyses of the holotype, a massive partial lower jaw, reveal close affinities to extant Amazonian species and suggest an omnivorous diet. Body size regressions indicate Pe. maturin possibly reached about 180 cm in carapace length and is among the largest freshwater turtles ever found. This finding presents the latest known occurrence of giant freshwater turtles, hinting at coexistence with early human inhabitants in the Amazon.

Ruminal passage rate and digestibility of fiber from dairy cows consuming diets containing alfalfa and orchardgrass hays with different concentrations of undegradable neutral detergent fiber (uNDF).

This study aimed to evaluate the effect of feeding diets with different fractions of undegraded NDF (uNDF) and potentially degradable (pdNDF) on ruminal NDF degradation and passage kinetics of lactating dairy cows. Six rumen-cannulated (533 ± 43 kg BW and 122 ± 15 DIM) and 6 non-cannulated (558 ± 62 kg BW and 126 ± 16 DIM) primiparous Holstein dairy cows were randomly assigned to 1 of 2 experimental diets in a crossover design with 2 28-d periods. The experimental diets were formulated to include either alfalfa hay (ALFA) or orchardgrass hay (ORCH) in addition to corn silage. Rations were formulated to contain 30% NDF (DM basis), where the concentrate, corn silage, and each of the hays provided one third of the dietary NDF. The marker dilution technique was used to measure the passage rate utilizing a pulse dose of marked corn silage fiber. On d 17 and 24 of each period, ruminal contents were evacuated to determine ruminal pool size. Following the return of the ruminal contents containing the pulse dose of marked corn silage to the rumen, ruminal grab samples were collected at 0, 3, 6, 9, 12, 24, 36, 48, 60, and 72 h. Samples from each time point were separated into solids and liquid, and the solids were analyzed for NDF, uNDF, and marker concentration. Alfalfa hay had a higher concentration of CP (16.4 vs. 10.7%) and a lower concentration of NDF (38.0 vs. 63.2) than orchardgrass hay. Alfalfa hay had a greater concentration of uNDF than orchardgrass hay (36.5 vs. 32.8% uNDF; NDF basis). Cows consuming the ALFA diet had similar milk yield (39.1 kg/d) and similar milk fat and protein concentrations (3.72% fat and 3.24% protein, respectively) than cows consuming the ORCH diet. Cows consuming the ALFA diet consumed more DM (26.7 vs. 24.6 kg/d) and uNDF (2.7 vs. 2.3 kg/d), than cows consuming the ORCH diet. Cows consuming the ALFA diet digested more NDF and pdNDF than cows consuming the ORCH diet (3.3 vs. 2.8 kg/d). Even though cows consuming the ALFA diet had a smaller pool size of NDF than cows consuming the ORCH diet (5.4 vs. 6.7 kg), the pool size of uNDF did not differ between groups (2.4 kg). Cows consuming the ALFA diet had a faster rate of passage of uNDF than cows consuming the ORCH diet (5.02 vs. 4.03%/h). This translated into a shorter mean retention time of uNDF for cows consuming the ALFA diet relative to cows consuming the ORCH diet (21.0 vs. 26.2 h). In conclusion, cows consuming diets containing alfalfa hay had a faster ruminal passage rate and a shorter mean retention time of uNDF than cows consuming diets containing orchardgrass hay, and this occurred despite the greater concentrations of dietary uNDF in the alfalfa-based diet. These findings suggest that the kinetics of ruminal digestion and passage influence NDF degradation in ways beyond uNDF concentration or forage quality.

Graduate Student Literature Review: System, plant, and animal factors controlling dietary pasture inclusion and their impact on ration formulation for dairy cows.

Diet formulation in a pasture-based dairy system is a challenge as the quality and quantity of available pasture, which generally constitutes the base diet, is constantly changing. The objective of this paper is to cover a more in-depth review of the nutritional characteristics of pasture-based diets, identifying potential system, plant, and animal factors that condition pasture dietary inclusion in dairy cows. In practice, there is a wide diversity of pasture-based systems with predominant to minimal use of pasture requiring a more specific classification that potentially considers the amount and time of access to pasture, access to housing, length of grazing season, seasonality of calving, and level and method of supplementation. There are important differences in the nutritional quality between pasture species and even cultivars. However, under management practices that promote maintenance of pasture in a vegetative state as well as controlling the availability of pasture, it is possible to achieve high dry matter intakes (∼2.9%-3.4% of live weight) of pasture with moderate to high diet energy density, protein supply, and digestibility. The amount of pasture to include in the diet will depend on several factors, such as the type of production system, the cost of supplementary feeds, and the farmer's objectives, but inclusions of ∼40% to 50% of the diet seem to potentially reduce costs while apparently not limiting voluntary feed intake. Considering that there seems to be a continuum of intermediate management systems, a better understanding of the factors inherent to the feed ingredients used, as well as the use of nutrients by cows, and potential interactions between animal × system should be addressed in greater depth. This requires a meta-analysis approach, but given the diversity of the pasture-based system in practice, the existing information is highly fragmented. A clear definition of "subsystems" is necessary to direct the future research and development of mechanistic models.

Improvement in clinical outcomes following arthroscopic all-inside medial lateral ligament reconstruction for rotational ankle instability.

PURPOSE: Rotational ankle instability can be diagnosed in up to 18% of cases of chronic lateral ankle instability. It is characterised by an abnormal increase of talar rotation within the tibiofibular mortise, due to an injury in the most anterior component of the deltoid ligament secondary to a chronic deficiency of the lateral collateral ligament. The aim of this prospective observational study was to investigate the clinical outcomes following arthroscopic all-inside medial and lateral ligament reconstruction for rotational ankle instability. METHODS: A prospective observational study of consecutive patients undergoing arthroscopic all-inside medial and lateral ligament reconstruction for rotational ankle instability with minimum 6-month follow-up. The primary outcome was a validated patient-reported outcome measure (PROM), the Manchester-Oxford Foot Questionnaire. Secondary outcomes included the EQ-5D, European Foot and Ankle Society score and complications. RESULTS: Between 2020 and 2023, 12 patients underwent primary arthroscopic all-inside medial and lateral ligament reconstruction for rotational ankle instability with pre- and post-operative PROMs available for all 12 patients. The mean ± standard deviation age was 33.9 ± 7.2 years and the mean follow-up was 1.9 ± 1.2 (range: 0.5-3.8, interquartile range: 0.9-3.0) years. There was a significant improvement in all Manchester-Oxford Foot Questionnaire domain scores (p < 0.05): Index 53.1 ± 19.1 to 26.4 ± 27.6, Pain 46.7 ± 20.3 to 26.2 ± 26.8, Walking/Standing 58.7 ± 26.0 to 27.0 ± 30.0 and Social Interaction 51.2 ± 19.5 to 25.6 ± 30.1. There were improvements in EQ-5D-5L Index, VAS and VAS Pain; however, these were not statistically significant. There was one complication-a superficial peroneal nerve injury which resolved with a corticosteroid injection. CONCLUSION: The arthroscopic all-inside medial and lateral ligament reconstruction technique is a reliable and safe method for treating rotational ankle instability, demonstrating significant improvement in PROMs at a mean 1.9-year follow-up. LEVEL OF EVIDENCE: Level IV.

Comparative biomechanical study of different screw fixation methods for minimally invasive hallux valgus surgery: A finite element analysis.

BACKGROUND: There are different screw configurations utilised for minimally invasive hallux valgus (HV) deformity despite limited biomechanical data assessing the stability and strength of each construct. We aimed to compare the strength of various screw configurations for minimally invasive HV surgery using finite element analysis (FEA). METHODS: A FEA model was developed from a CT of a female with moderate HV deformity. Five screw configurations utilizing one or two bicortical or intramedullary screws were tested. Stress analysis considered osteotomy displacement, maximum and minimum principal stresses, and von Mises stress for both implants and bone for each screw configuration. RESULTS: Fixation with two screws (one bicortical and one intramedullary) demonstrated the lowest values for osteotomy displacement, minimum and maximum total stress, and equivalent von Mises stress on the bone and screws in both loading conditions. CONCLUSION: The optimal configuration when performing minimally invasive surgery for moderate HV is one bicortical and one intramedullary screw. LEVEL OF EVIDENCE: Level III.

Do national health priorities align with Global Burden of Disease estimates on disease burden? An analysis of national health plans and official governmental websites.

OBJECTIVE: To investigate the alignment of national health priorities with a country's burden of disease as measured by disability-adjusted life years (DALYs). METHODS: We identified priorities in national health plans and the 20 most burdensome conditions measured by DALYs from the 2017 Global Burden of Disease Study. We computed point-biserial correlations (rpb) between DALYs and being nominated as a health priority and the pooled proportion (95% confidence intervals [CIs]) of the 20 most burdensome conditions nominated as a priority across countries. RESULTS: We identified national health plans and official governmental websites in 145 countries. There was little to no correlation (rpb = 0.06, 95% CI: 0.02 to 0.09) between national DALY data and whether a condition was nominated as a health priority. The pooled proportion of the 20 most burdensome conditions nominated as priorities across countries was 46%. HIV/AIDS had the greatest number of nominations as a national health priority (62 countries) as well as the greatest match with the burden of disease (among the top 20 most burdensome conditions in 51 [82%] countries). Low back pain, headache disorders and congenital birth defects had the lowest proportion of nominations as health priorities in countries where they were in the top 20 most burdensome conditions (6%, 6% and 11%, respectively). CONCLUSION: Globally, there were low correlations between national health priorities and GBD estimates on disease burden. Failing to prioritise health priorities according to burden may mean that insufficient resources have been directed to improve health outcomes for people with those health conditions.

Oral amyloidosis: an update.

BACKGROUND: Amyloidosis is a disease characterized by the progressive deposition of abnormal proteins that can occur in any organ. In the oral cavity, the tongue is the most common affected site, usually causing macroglossia. Biopsy is essential for the diagnosis and the occurrence of its systemic form is mandatory to be investigated. This systematic review evaluated the existing information in the literature on Amyloidosis in the oral cavity to allow a more comprehensive and updated analysis of its clinicopathological characteristics, as well as to explore the main forms of treatment and prognostic factors. MATERIAL AND METHODS: Electronic searches were undertaken in five databases supplemented by manual scrutiny. RESULTS: A total of 111 studies were included with 158 individuals. CONCLUSIONS: The disease had a higher prevalence in women, the tongue was the most affected site, as well as the systemic form of the disease. The worst prognosis was for cases of systemic amyloidosis associated with multiple myeloma.

Genetic parameters for frame size and carcass traits in Nellore cattle.

Our study aimed to evaluate the frame size as a genetic selection criterion as well as the association of scores with carcass characteristics measured via ultrasound to the genetic improvement of carcass quality in Nellore cattle. The variance components were estimated using the restricted maximum likelihood method for the thoracic perimeter (TP), frame size score (FRAME), yearling weight (YW), visual scores of body structure (BS), muscularity (MUSC), and precocity (PREC). The carcass traits included loin eye area (REA), backfat thickness (BF), rump fat (FR), and intramuscular fat (IF). The estimated heritabilities ranged from moderate to high. The FRAME showed a positive genetic correlation with YW (0.82 ± 0.07), TP (0.58 ± 0.09), and BS score (0.62 ± 0.07), but it had a negative correlation with the MUSC and PREC visual scores (- 0.34 ± 0.09 and - 0.50 ± 0.08, respectively). The genetic correlation between FRAME and REA was positive (0.26 ± 0.09). However, FRAME presented a correlation close to zero with BF, RF, and IF. TP had a positive genetic correlation with body size traits such as YW (0.76 ± 0.05) and BS score (0.55 ± 0.08) and with muscularity traits such as REA (0.44 ± 0.01). Frame size has the potential to be used as a parameter in the selection of precocious beef cattle, but a study of its use is necessary to determine the ideal biotype for each production system.

Anti-staphylococcal effects of Myracrodruon urundeuva lectins on nonresistant and multidrug resistant isolates.

AIMS: To evaluate the anti-staphylococcal effects of lectins isolated from bark (MuBL), heartwood (MuHL) and leaves (MuLL) of Myracrodruon urundeuva. METHODS AND RESULTS: The lectins were evaluated for: effects on growth, aggregation, haemolytic activity and biofilm-forming ability of Staphylococcus aureus clinical isolates nonresistant (8325-4) and multidrug resistant (LAC USA300); interference with the expression of virulence genes (hla, rnaIII and spa) of the Agr system of S. aureus; and synergistic effect with the antibiotics cefoxitin and cefotaxime. MuBL, MuHL and MuLL reduced growth (minimal inhibitory concentration (MIC): 12·5-50 µg ml-1 ) and viability (minimal bactericidal concentration (MBC): 100 µg ml-1 ) of 8325-4 and LAC USA300 cells. MuLL (at ½MIC and MIC) reduced LAC USA300 agglutination. The lectins did not interfere with haemolytic activity and expression of hla, rnaIII and spa genes. Only MuHL was able to reduce the biofilm production by 8325-4 (50-400 µg ml-1 ) and LAC USA300 (400 µg ml-1 ). CONCLUSION: The M. urundeuva lectins showed antibacterial activity against nonresistant and resistant clinical isolates of S. aureus and synergistic effects with antibiotics in reducing growth and biofilm formation. SIGNIFICANCE AND IMPACT OF THE STUDY: This work reports bioactive molecules capable of acting as anti-staphylococcal agents, since there are increasing reports of multiresistant isolates of this bacterium.

Antibacterial effects of the lectin from pomegranate sarcotesta (PgTeL) against Listeria monocytogenes.

AIMS: To investigate the effects of the lectin from Punica granatum sarcotesta (PgTeL) on growth, viability, cell structure, biofilm formation and chitinase activity of Listeria monocytogenes. In addition, the effect of PgTeL on the adhesion and invasion of human cells (HeLa) was determined. METHODS AND RESULTS: PgTeL showed bacteriostatic and bactericidal effects on the strains L. monocytogenes N53-1 and EGD-e, causing morphometric alterations, cell aggregation, strong deformation and cell disruption. PgTeL inhibited biofilm formation by EGD-e and N53-1 and also interfered with the adhesion and invasion processes of EGD-e and N53-1 in HeLa cells. Finally, the chitinase activity of L. monocytogenes EGD-e was reduced in the presence of PgTeL, which can be involved in the inhibition of adhesion process. CONCLUSION: PgTeL is an antibacterial agent against L. monocytogenes, inhibiting growth and promoting cell death, as well as impairing biofilm formation and bacterial adhesion and invasion into human cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The results stimulate future investigations on the potential of PgTeL for protection of contamination in food products.

The use of outdoor gyms is associated with women and low-income people: a cross-sectional study.

OBJECTIVE: To examine the prevalence, and the demographic, socio-economic, and health correlates to Outdoor Gyms (OGs) use for adults from a southern Brazilian city. STUDY DESIGN: Population-based cross-sectional study. METHODS: A total of 431 adults (66.8% women) aged 18-87 years living in the surroundings of four OGs distributed in different regions of the city were randomly selected. Information about OG use for physical activity (PA) practice, and demographic, socio-economic, and health variables were collected by household interviews. Associations between independent variables and OG use were analyzed with results expressed as odds ratio (OR) and 95% confidence interval (95% CI). RESULTS: About one-third of participants (30.4%; 95% CI: 26.1-34.7) informed using OGs for PA practice, and 20.4% (95% CI 16.8-24.4) informed using it twice or more times a week (≥2x/week). Adjusted analysis indicated that the OG use ≥2x/week is higher for women (OR: 1.93; 95% CI: 1.11-3.35) and for those with lower family income (OR: 2.13; 95% CI: 1.03-4.13) than men and those with higher family income, respectively. CONCLUSION: About 30% of the population uses OGs for PA practice. Women and low-income people are those who more commonly use OGs for PA practice. The installation of these facilities in public spaces may reduce social inequities related to leisure-time PA.

The mediator role of unmet needs on quality of life in myeloma patients.

PURPOSE: The diagnosis of multiple myeloma (MM) has a significant impact on patients. This study analyzed the mediating role of patients' unmet needs in the relationship between psychological morbidity/social support and quality of life (QoL). METHODS: This study included 213 patients with MM recruited from the outpatient medical oncology and clinical hematology services from five hospitals. Patients who meet the study criteria were referred by physicians and invited to participate in the study by the researcher. All participants answered the following questionnaires: Hospital Anxiety and Depression Scale, Satisfaction with Social Support Scale, Short-Form Survivor Unmet Needs Survey, and The European Organization for Research and Treatment of Cancer's Multiple Myeloma Module. Descriptive statistics, bivariate correlations, and structural equation modeling were performed to analyze the data. RESULTS: The indirect effect of psychological morbidity on patients' future perspectives (MYFP) was partially mediated by information unmet needs (INF), while the indirect effect of psychological morbidity on treatment side effects (MYSE) was partially mediated by relationship and emotional unmet needs (REH). In turn, the indirect effect of psychological morbidity on disease symptoms (MYDS) was fully mediated by REH. Social support had an indirect effect on MYDS and MYSE fully mediated by REH. CONCLUSION: Intervention programs tailored to promote MM patients' QoL should specifically address information and emotional needs, raising awareness and training health professionals, caregivers, and family members to attend  MM patients' unmet needs.

Orbital Pseudospin-Momentum Locking in Two-Dimensional Chiral Borophene.

Recently, orbital-textures have been found in Rashba and topological insulator (TI) surface states as a result of the spin-orbit coupling (SOC). Here, we predict a px/py orbital texture, in linear dispersive Dirac bands, arising at the K/K' points of χ-h0 borophene chiral monolayer. Combining "first-principles" calculations with effective Hamiltonians, we show that the orbital pseudospin has its direction locked with the momentum in a similar way as TIs' spin-textures. Additionally, considering a layer pseudospin degree of freedom, this lattice allows stackings of layers with equivalent or opposite chiralities. In turn, we show a control of the orbital textures and layer localization through the designed stacking and external electric field. For instance, for the opposite chirality stacking, the electric field allows for an on/off switch of the orbital-textured Dirac cone.

Layertronic control of topological states in multilayer metal-organic frameworks.

We investigate the layer localization control of two-dimensional states in multilayer metal-organic frameworks (MOFs). For finite stackings of (NiC4S4)3 MOFs, the weak van der Waals coupling between adjacent layers leads to a Fermi level dependent distribution of the electronic states in the monolayers. Such distribution is reflected in the topological edge states of multilayer nanoribbons. Moreover, by applying an external electric field parallel to the stacking direction, the spatial localization of the electronic states can be controlled for a chosen Fermi energy. This localization behavior is studied comparing density functional theory calculations with a kagome lattice tight-binding model. Furthermore, for infinite stacked nanoribbons, a new V-gutter Dirac state is found in the side surfaces, which allows anisotropic current control by tuning the Fermi energy. Our results can be immediately extended to other kagome MOFs with eclipsed stackings, introducing a new degree of freedom (layer localization) to materials design.

Peptide receptor radionuclide therapy with 177Lu-DOTA-TATE as a promising treatment of malignant insulinoma: a series of case reports and literature review.

INTRODUCTION: Insulinomas are a rare type of pancreatic neuroendocrine tumours characterized by insulin hypersecretion. They are considered malignant when metastases are present. Traditional therapies often promote only temporarily symptomatic relief and may be associated with severe adverse effects. There is scarce experience in treating malignant insulinomas with peptide receptors radionuclide therapy (PRRNT). PATIENTS AND METHODS: We describe PRRNT results in four patients with inoperable malignant insulinomas with poorly controllable hypoglycaemia. All patients received therapy with 177Lu-DOTA-TATE after conventional therapies failed in controlling disease progression and symptoms. The activity administered per cycle was 4.8-7.4 GBq. The interval between cycles was 10-16 weeks. Haematology, liver and kidney function tests were performed before treatment initiation and 5 and 10 weeks after each cycle. RESULTS: Patient 1 presented significant clinical benefit for 13 months after PRRNT, with imaging improvement. Patient 2 obtained reduction of the number and severity of hypoglycaemic episodes during 15 months after therapy. Patient 3 is asymptomatic since PRRNT first cycle performed 23 months ago and revealed significant imaging improvement. Patient 4 had resolution of hypoglycaemia only 3 days after PRRNT first cycle and today, 16 months after therapy, the disease seems to be in remission and the patient maintains euglycaemic state. PRRNT was well tolerated, with only hematologic grade 2 toxicity in patient 1 and mild kidney toxicity in patient 3. CONCLUSIONS: After the start of 177Lu-DOTA-TATE all patients achieved hypoglycaemia symptomatic control and had evident improvement of their quality of life. Three patients showed imagiological improvement suggesting reduced tumour load.

Short communication: Production performance and nutrient digestibility of lactating dairy cows fed diets with and without addition of a live-yeast supplement.

The objective of this study was to evaluate the use of a live-yeast product when feeding relatively high-forage diets to high-producing cows in mid lactation. Eight primiparous [607 ± 43 kg of body weight (BW) and 130 ± 16 d in milk (DIM) at the beginning of the experiment] and 16 multiparous (706 ± 63 kg of BW and 137 ± 22 DIM at the beginning of the experiment) Holstein cows were blocked by parity and DIM, and randomly assigned to 1 of 2 diets (control vs. yeast) for a 12-wk period according to a randomized complete block design. The formulated diets contained 50.4% corn silage, 10.4% alfalfa hay, and 39.2% concentrate. The yeast diet was formulated to provide approximately 5.4 × 1011 cfu/d of Saccharomyces cerevisiae (BeneSacc; Global Nutritech Biotechnology LLC, Richmond, VA). Total-tract nutrient digestibility was estimated using 240-h undigested neutral detergent fiber (NDF) as an internal marker. Supplementing live yeast to lactating dairy cows did not affect dry matter intake (25.0 kg/d), milk yield (38.6 kg/d), milk fat concentration (4.78%), milk fat yield (1.83 kg/d), milk protein concentration (3.09%), milk protein yield (1.18 kg/d), milk lactose concentration (4.79%), milk lactose yield (1.84 kg/d), BW gain (-0.05 kg/d), or body condition score gain (0.16 units). The digestibility of dry matter was greater for the control treatment than for the yeast treatment (69.3 and 67.1%, respectively), but the digestibilities of crude protein (61.5%), NDF (40.5%), and starch (98.6%) were not affected by treatment. In conclusion, supplementation of live yeast did not affect production performance or nutrient digestibility of high-producing cows in mid lactation. The reasons for the lack of effect are not clear, but an evaluation of interactions between yeast and rumen buffer supplementation is warranted.

Short communication: Effect of corn planting population on phosphorus concentration and uptake in corn silage.

Greater utilization of nutrients reduces the potential runoff of nutrients to bodies of water. The objective of this study was to determine the concentration of P in corn biomass to estimate the removal of P from the soil when planting corn at different population levels. Whole-plant corn samples were collected during an on-farm research project conducted previously. The study included 7 different growing and harvesting conditions. In each cornfield, corn was planted in plots at a theoretical seeding rate of 55,000, 70,000, 85,000, and 100,000 seeds/ha. Each seeding rate had 4 replicates within each field. At harvesting time, 5 consecutive plants from the 2 center rows and at 2 randomly selected spots within each plot were cut by hand at 15 cm above ground. Whole plants were weighed and chopped. After mixing thoroughly, a sample of the chopped material was placed in a bag, immediately placed in a cooler with dry ice, and transferred to the laboratory for storage. After thawing and drying, samples were ground and analyzed for P concentration. Single plant biomass and the number of standing plants at harvesting were used to determine dry matter yield. Total extraction of P was estimated as the product between plant biomass and P concentration. All variables were analyzed using a statistical model that included the effects of field, planting population, planting population nested within field, and random residual error. The concentration of P in the corn plant was greatest for 55,000 and 70,000 plants/ha (0.250% dry matter) and least for 85,000 and 100,000 plants/ha (0.235% dry matter), whereas the uptake of P through the harvested biomass increased when corn planting population increased. In conclusion, increasing the planting population of corn for silage can increase P uptake from the soil, therefore reducing the potential runoff of P to bodies of water.

Production performance and nutrient digestibility of lactating dairy cows fed low-forage diets with and without the addition of a live-yeast supplement.

We aimed to evaluate the use of a live-yeast product as a means to attenuate plausible nutritional disturbances when feeding relatively low-forage diets containing rapidly fermentable carbohydrates (i.e., wheat) to high-producing cows in early to mid lactation. Eight primiparous [mean ± SD; 569 ± 35 kg of body weight (BW) and 80 ± 29 d in milk (DIM) at the beginning of the experiment] and 16 multiparous (665 ± 67 kg of BW and 64 ± 10 DIM at the beginning of the experiment) Holstein cows were blocked by parity and DIM, and randomly assigned to 1 of 2 diets (control vs. yeast) for a 12-wk-long period according to randomized complete block design. The formulated diets contained 36.7% corn silage, 8.3% alfalfa hay, and 55% concentrate. The yeast diet was formulated to provide approximately 5.4 × 1011 cfu/d of Saccharomyces cerevisiae (BeneSacc; Global Nutritech Biotechnology LLC, Richmond, VA). Total-tract nutrient digestibility was estimated using 240-h undigested neutral detergent fiber (NDF) as an internal marker. Dry matter intake, milk yield, and milk component concentrations and yields were analyzed using repeated measures. The statistical model for these variables included the effects of block, treatment, the block by treatment interaction, week, the treatment by week interaction, and the random residual error. The statistical model for analyzing BW gain, body condition score gain, and dry matter and nutrient digestibilities included the effects of block, treatment, and the random residual error. Supplementing live yeast to lactating dairy cows did not affect dry matter intake (26.0 kg/d), milk yield (48.1 kg/d), milk fat concentration (3.61%), milk fat yield (1.72 kg/d), milk protein concentration (2.96%), milk protein yield (1.43 kg/d), milk lactose concentration (4.84%), milk lactose yield (2.35 kg/d), milk urea nitrogen (7.99 mg/dL), body weight gain (0.62 kg/d), and body condition score gain (0.02 units; all averages of the 2 treatments). The digestibilities of dry matter (70.2%), crude protein (71.4%), NDF (36.4%), and starch (99.8%) were not affected by treatments. In conclusion, the supplementation of the live yeast did not affect production performance and nutrient digestibility of high-producing dairy cows. A potential interaction between live-yeast supplementation and NDF passage rate, which may have hindered the beneficial effects of live-yeast supplementation on production performance and nutrient utilization, deserves further research.

Production performance, nutrient digestibility, and milk fatty acid profile of lactating dairy cows fed corn silage- or sorghum silage-based diets with and without xylanase supplementation.

The objective of this study was to evaluate the effects of supplementing xylanase on production performance, nutrient digestibility, and milk fatty acid profile in high-producing dairy cows consuming corn silage- or sorghum silage-based diets. Conventional corn (80,000 seeds/ha) and brown midrib forage sorghum (250,000 seeds/ha) were planted, harvested [34 and 32% of dry matter (DM), respectively], and ensiled for more than 10 mo. Four primiparous and 20 multiparous Holstein cows were randomly assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments and 19-d periods. Treatment diets consisted of (1) corn silage-based diet without xylanase, (2) corn silage-based diet with xylanase, (3) sorghum silage-based diet without xylanase, and (4) sorghum silage-based diet with xylanase. The xylanase product was supplemented at a rate of 1.5 g of product/kg of total DM. Corn silage had higher concentrations of starch (31.2 vs. 29.2%), slightly higher concentrations of crude protein (7.1 vs. 6.8%) and fat (3.7 vs. 3.2%), and lower concentrations of neutral detergent fiber (36.4 vs. 49.0%) and lignin (2.1 vs. 5.7%) than sorghum silage. Xylanase supplementation did not affect DM intake, milk yield, milk fat percentage and yield, milk protein percentage and yield, lactose percentage and yield, and 3.5% fat-corrected milk yield. Cows consuming corn silage-based diets consumed 13% more DM (28.8 vs. 25.5 kg/d) and produced 5% more milk (51.6 vs. 48.9 kg/d) than cows consuming sorghum silage-based diets. Milk from cows consuming sorghum silage-based diets had 16% greater fat concentrations (3.84 and 3.30%) than milk from cows consuming corn silage-based diets. This resulted in 8% greater fat yields (1.81 vs. 1.68 kg/d). Silage type did not affect milk protein and lactose concentrations. Xylanase supplementation did not affect nutrient digestibility. Cows consuming corn silage-based diets showed greater DM (77.3 vs. 73.5%), crude protein (78.0 vs. 72.4), and starch (99.2 vs. 96.5%) digestibilities than cows consuming sorghum silage-based diets. In conclusion, xylanase supplementation did not improve production performance when high-producing dairy cows were fed corn silage- or sorghum silage-based diets. In addition, production performance can be sustained by feeding sorghum silage in replacement of corn silage.