Milk production responses of dairy cows to fatty acid supplements with different ratios of palmitic and oleic acids in low- and high-fat basal diets.

We evaluated the effects of fatty acid (FA) supplements with different ratios of palmitic acid (C16:0) and oleic acid (cis-9 C18:1) in low- and high-FA basal diets on production responses of lactating dairy cows. Thirty-six multiparous Holstein cows (50.2 ± 5.8 kg/d of milk; 160 ± 36 d in milk) were used in a split-plot Latin square design balanced for carryover effects. Cows were blocked by milk yield and allocated to a main plot receiving either a low-FA (LF; 1.93% FA content) basal diet (n = 18) containing cottonseed meal and cottonseed hulls or a high-FA (HF; 3.15% FA content) basal diet (n = 18) containing whole cottonseed. Within each plot, a 3 × 3 Latin square arrangement of treatments was used in 3 consecutive 21-d periods. Treatments were (1) control (CON; no FA supplementation), (2) FA supplement containing 80% C16:0 + 10% C18:1 (PA), and (3) FA supplement containing 60% C16:0 + 30% cis-9 C18:1 (PA+OA). The FA supplements were fed at 1.5% of dry matter and replaced soyhulls in CON. Preplanned contrasts were (1) overall effect of FA supplementation {CON vs. the average of the FA treatments [1/2 (PA + PA+OA)]}, and (2) the effect of the PA treatment versus the PA+OA treatment (PA vs. PA+OA). Treatment by basal diet interactions were observed for yields of milk and lactose, where FA treatments increased yields of milk and milk lactose in LF but not in HF. Basal diet had no effect on dry matter intake (DMI) or milk yield. Compared with LF, HF increased milk fat yield and 3.5% fat-corrected milk (FCM) and tended to increase milk fat content and energy-corrected milk (ECM) yield. The FA treatments decreased DMI but increased the yields of milk fat, 3.5% FCM, and ECM, compared with CON, due to increases in mixed and preformed milk FA yields. The PA+OA treatment decreased DMI and milk protein yield compared with PA. In conclusion, a high-fat basal diet increased milk fat production, and the addition of FA supplements to a low-fat basal diet increased milk lactose yield and tended to increase milk yield. Additionally, regardless of basal diet fat level, FA supplements increased production responses compared with the non-FA-supplemented control diet.

Population dynamics of Achatina fulica in a peri-urban area adjacent to the Fiocruz Atlantic Forest Biological Station (EFMA), in Rio de Janeiro, Brazil, with report on Angiostrongylus cantonensis infection.

Achatina fulica is a species native to East Africa, considered one of the 100 worst invasive alien species in the world. The present study investigated the population of the snail, A. fulica, in a peri-urban area adjacent to the Fiocruz Atlantic Forest Biological Station (EFMA), in Jacarepaguá, Rio de Janeiro state, Brazil, focusing on population dynamics and the nematodes associated with this species. To this end, specimens were collected during four climatic seasons of the years 2021 and 2022 in three fixed 20 m × 10 m plots. The abundance of A. fulica in these areas was evaluated in relation to a set of environmental variables (temperature, relative humidity air, and soil pH and calcium). The abundance of snails infected by nematodes was also evaluated in relation to the season and body size of the specimens. The molluscs were found by active search, and standardized (15 minutes/three collections). Nematode larvae were extracted from the specimens by artificial digestion and identified by their external morphology and the sequencing of molecular markers. A total of 280 specimens of A. fulica were collected, with the highest abundances being recorded in the autumn and summer, although no significant relationship was found between the number of specimens collected and the environmental variables. Overall, 192 snails were infected by nematodes: Angiostrongylus cantonensis, Cruzia tentaculata and free-living nematodes, including Caenorhabditis briggsae. These findings demonstrate the epidemiological importance of the study area and the need to implement educational measures in the community, with the aim of controlling the local A. fulica population, thereby minimizing the risk of parasitic infection in the local human population.

Randomized, double-blind, sham-controlled trial to evaluate the efficacy and tolerability of electroconvulsive therapy in patients with clozapine-resistant schizophrenia.

There is no established treatment for patients with clozapine-resistant schizophrenia (CRS). Clozapine augmentation strategies with antipsychotics or others substances are effective in comparison with placebo while and Electroconvulsive therapy (ECT) showed to be effective in comparison with treatment as usual (TAU) but not with placebo (sham-ECT). In the present double- blind randomized controlled trial, we compared 40 outpatients who received 20 sessions of ECT (n = 21) or sham-ECT (n = 19) (age = 37.40 ± 9.62, males = 77.5 %, illness duration = 14.95 ± 8.32 years, mean total Positive and Negative Syndrome Scale (PANSS) = 101.10 ± 24.91) who fulfilled well-defined CRS criteria including baseline clozapine plasma levels ≥350 ng/mL. The primary outcome was the ≥50 % PANSS Total Score reduction; secondary outcomes were the scores of the PANSS subscales, PANSS five-factor dimensions, PANSS-6 and the Calgary Depression Rating Scale (CDRS). Treatment response was analyzed by percentage reduction, Linear Mixed Models and effect sizes. At baseline both groups showed no differences except for years of school education (included as a covariate). At endpoint, only 1/19 of the completers (5.26 %) in the ECT group and 0/17 in the sham-ECT group showed a ≥50 % total PANSS score reduction. Both groups showed no significant differences of the total PANSS score (F = 0.12; p = 0.73), Positive (F = 0.27, p = 0.61), Negative (F = 0.25, p = 0.62), and General Psychopathology scores (F = 0.01, p = 0.94) as well for all PANSS five factors, the PANSS-6 and CDRS. Thus, the present study found no evidence that ECT is better than Sham-ECT in patients with CRS. Future sham-ECT controlled studies with larger sample sizes are warranted to test the efficacy of ECT for patients with CRS.

Aqueous extract OF Moringa oleifera Lam leaves added to freezing extenders damages goat sperm membranes.

BACKGROUND: Semen cryopreservation is a biotechnology used frequently in animal production; however, there are some obstacles, such as those caused by high levels of reactive oxygen species (ROS). Moringa oleifera (MO) is known as a potent source of antioxidants and might be an important adjuvant. OBJECTIVE: The objective of this study was to determine the effect of different concentrations of MO extract supplementation on goat semen cryopreservation efficiency. MATERIALS AND METHODS: Ejaculates (n=6) from four goat breeders were pooled and diluted in skimmed milk (SM) or Tris-egg yolk (TEY)-based extenders and supplemented with different concentrations of MO extract (0, 1, 2 and 5 mg/mL). After the freeze-thaw cycle, sperm kinetics and viability were assessed. RESULTS: With the SM extender, straightness, wobble and plasma membrane integrity were lower than in the control group (P < 0.05). With the TEY extender, wobble was lower in with 5 mg/mL MO extract than in the control group (P < 0.05). As regards sperm ultrastructure, evaluated by SEM, the MO extract, regardless of the diluent used, damaged the membrane of sperm cells in a dose-dependent manner. CONCLUSION: The addition of aqueous extract of MO leaves in both diluents at all concentrations tested affects the parameters of sperm progressivity and damages the plasma membrane in a dose-dependent manner. DOI: 10.54680/fr23310110712.

Orientational Ordering in Nano-confined Polar Liquids.

Water and other polar liquids exhibit nanoscale structuring near charged interfaces. When a polar liquid is confined between two charged surfaces, the interfacial solvent layers begin to overlap, resulting in solvation forces. Here, we perform molecular dynamics simulations of polar liquids with different dielectric constants and molecular shapes and sizes confined between charged surfaces, demonstrating strong orientational ordering in the nanoconfined liquids. To rationalize the observed structures, we apply a coarse-grained continuum theory that captures the orientational ordering and solvation forces of those liquids. Our findings reveal the subtle behavior of different nanoconfined polar liquids and establish a simple law for the decay length of the interfacial orientations of the solvents, which depends on their molecular size and polarity. These insights shed light on the nature of solvation forces, which are important in colloid and membrane science, scanning probe microscopy, and nano-electrochemistry.

A multicenter, open-label, randomized, phase II study of cediranib with or without lenalidomide in iodine 131-refractory differentiated thyroid cancer.

BACKGROUND: Multitargeted tyrosine kinase inhibitors (TKIs) of the vascular endothelial growth factor receptor (VEGFR) pathway have activity in differentiated thyroid cancer (DTC). Lenalidomide demonstrated preliminary efficacy in DTC, but its safety and efficacy in combination with VEGFR-targeted TKIs is unknown. We sought to determine the safety and efficacy of cediranib, a VEGFR-targeted TKI, with or without lenalidomide, in the treatment of iodine 131-refractory DTC. PATIENTS AND METHODS: In this multicenter, open-label, randomized, phase II clinical trial, 110 patients were enrolled and randomized to cediranib alone or cediranib with lenalidomide. The primary endpoint was progression-free survival (PFS). Secondary endpoints included response rate, duration of response, toxicity, and overall survival (OS). Patients (≥18 years of age) with DTC who were refractory to further surgical or radioactive iodine (RAI) therapy as reviewed at a multispecialty tumor board conference, and evidence of disease progression within the previous 12 months and no more than one prior line of systemic therapy were eligible. RESULTS: Of the 110 patients, 108 started therapy and were assessable for efficacy. The median PFS was 14.8 months [95% confidence interval (CI) 8.5-23.8 months] in the cediranib arm and 11.3 months (95% CI 8.7-18.9 months) in the cediranib with lenalidomide arm (P = 0.36). The 2-year OS was 64.8% (95% CI 43.3% to 86.4%) and 75.3% (95% CI 59.4% to 91.0%), respectively (P = 0.80). The serious adverse event rate was 41% in the cediranib arm and 46% in the cediranib with lenalidomide arm. CONCLUSIONS: Single-agent therapy with cediranib showed promising efficacy in RAI-refractory DTC similar to other VEGFR-targeted TKIs, while the addition of lenalidomide did not result in clinically meaningful improvements in outcomes.

Fluids and Electrolytes under Confinement in Single-Digit Nanopores.

Confined fluids and electrolyte solutions in nanopores exhibit rich and surprising physics and chemistry that impact the mass transport and energy efficiency in many important natural systems and industrial applications. Existing theories often fail to predict the exotic effects observed in the narrowest of such pores, called single-digit nanopores (SDNs), which have diameters or conduit widths of less than 10 nm, and have only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number of examples such as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation and quantum effects, and dielectric anomalies that are not observed in larger pores. Exploiting these effects presents myriad opportunities in both basic and applied research that stand to impact a host of new technologies at the water-energy nexus, from new membranes for precise separations and water purification to new gas permeable materials for water electrolyzers and energy-storage devices. SDNs also present unique opportunities to achieve ultrasensitive and selective chemical sensing at the single-ion and single-molecule limit. In this review article, we summarize the progress on nanofluidics of SDNs, with a focus on the confinement effects that arise in these extremely narrow nanopores. The recent development of precision model systems, transformative experimental tools, and multiscale theories that have played enabling roles in advancing this frontier are reviewed. We also identify new knowledge gaps in our understanding of nanofluidic transport and provide an outlook for the future challenges and opportunities at this rapidly advancing frontier.

Parental report of dental pain and discomfort in preschool children is associated with sleep disorders: a cross-sectional study in Brazilian families.

PURPOSE: To evaluate the prevalence of sleep disorders in Brazilian preschool children and its associations with parental report of dental pain and discomfort. METHODS: This cross-sectional study involved 604 Brazilian preschoolers (4-5 years old). Sleep disorders (SD) and the parental report of dental pain and discomfort (DPD) were evaluated using the Brazilian versions of the Sleep Disturbance Scale for Children (SDSC) and the Dental Discomfort Questionnaire (DDQ-B), respectively. Bivariate and multivariate Poisson regression analyses with robust variance were performed to analyze the association between SDSC and DP. RESULTS: Prevalence of SD ranged from 7 to 21%. 7.9% of the children had DPD indicating the need for more invasive dental procedures (DDQ-B ≥ 5). Significant associations were found between DPD and the following SDSC domains: sleep hyperhidrosis (p = 0.024; PRa = 1.38; 95% CI: 1.04-1.83), disorders of initiating and maintaining sleep (p < 0.001; PRa = 1.41; 95% CI: 1.15-1.73), parasomnias (p < 0.001; PRa = 1.82; 95% CI: 1.39-2.37), and sleep-wake transition disorders (p = 0.018; PRa = 1.28; 95% CI: 1.04-1.58). Children with higher prevalence of DPD presented 20% higher prevalence of SD than children lower prevalence of DPD (p = 0.039; PRa = 1.20; 95% CI: 1.01-1.44). CONCLUSION: Preschool children with higher prevalence of DPD are more likely to have SD, such as hyperhidrosis, disorders of initiating and maintaining sleep, parasomnias, and sleep-wake transition.

Increasing levels of calcium salts of palm fatty acids affect production responses during the immediate postpartum and carryover periods in dairy cows.

Our objective was to determine the dose-response effects of calcium salts of palm fatty acids (CSPF) on nutrient digestibility and production responses of early-lactation dairy cows grazing on tropical pastures and to evaluate carryover effects throughout mid and late lactation. Forty multiparous dairy cows (Jersey × Holstein) with (mean ± standard error of the mean) 20 ± 1.69 kg of milk/d and 20 ± 5.0 d in milk were used in a randomized complete block design. During the treatment period, all cows were kept in a grazing system. The treatments were offered for 90 d (treatment period) and consisted of 4 increasing levels of CSPF: 0 (0 kg/d), 0.2 (0.2 kg/d), 0.4 (0.4 kg/d), and 0.6 (0.6 kg/d). Each treatment had 10 animals. Increasing CSPF from 0 to 0.6 kg/d replaced an equivalent amount of a corn-based concentrate supplement offered at 10 kg/d on an as-fed basis (8.96 kg/d as a dry matter basis). All cows were housed and received a diet without fat inclusion fed as total mixed ration once a day from 91 to 258 d of the experiment (carryover period). During the treatment period, increasing CSPF linearly decreased dry matter intake (1.20 kg/d), linearly increased neutral detergent fiber digestibility (3.90 percentage units), and quadratically increased total fat digestibility (6.30 percentage units at 0.4 kg/d CSPF). Increasing CSPF linearly increased the yields of milk (4.10 kg/d), milk fat (0.11 kg/d), milk lactose (0.19 kg/d), energy-corrected milk (ECM; 3.30 kg/d), and feed efficiency (ECM/dry matter intake, 0.34 kg/kg), and linearly decreased milk protein content (0.38 g/100 g), body weight change (0.05 kg/d), and body condition score (0.37). We observed interactions between CSPF and time during the carryover period. Overall, CSPF supplementation linearly increased or tended to increase milk yield until 202 d of the experiment with a similar pattern observed for all the other yield variables. In conclusion, supplementing CSPF from 0 to 0.6 kg/d during 90 d increased neutral detergent fiber and total fat digestibility and the yields of milk, milk fat, and ECM in early-lactation dairy cows grazing on tropical pastures. Most production measurements linearly increased during the treatment period, indicating that 0.6 kg/d CSPF was the best dose. Also, supplementing CSPF from 0 to 0.6 kg/d for 90 d during early lactation had positive carryover effects across mid and late lactation.

Thermodynamics of Charge Regulation during Ion Transport through Silica Nanochannels.

Ion-surface interactions can alter the properties of nanopores and dictate nanofluidic transport in engineered and biological systems central to the water-energy nexus. The ion adsorption process, known as "charge regulation", is ion-specific and is dependent on the extent of confinement when the electric double layers (EDLs) between two charged surfaces overlap. A fundamental understanding of the mechanisms behind charge regulation remains lacking. Herein, we study the thermodynamics of charge regulation reactions in 20 nm SiO2 channels via conductance measurements at various concentrations and temperatures. The effective activation energies (Ea) for ion conductance at low concentrations (strong EDL overlap) are ∼2-fold higher than at high concentrations (no EDL overlap) for the electrolytes studied here: LiCl, NaCl, KCl, and CsCl. We find that Ea values measured at high concentrations result from the temperature dependence of viscosity and its influence on ion mobility, whereas Ea values measured at low concentrations result from the combined effects of ion mobility and the enthalpy of cation adsorption to the charged surface. Notably, the Ea for surface reactions increases from 7.03 kJ mol-1 for NaCl to 16.72 ± 0.48 kJ mol-1 for KCl, corresponding to a difference in surface charge of -8.2 to -0.8 mC m-2, respectively. We construct a charge regulation model to rationalize the cation-specific charge regulation behavior based on an adsorption equilibrium. Our findings show that temperature- and concentration-dependent conductance measurements can help indirectly probe the ion-surface interactions that govern transport and colloidal interactions at the nanoscale─representing a critical step forward in our understanding of charge regulation and adsorption phenomena under nanoconfinement.

Gelation, clustering, and crowding in the electrical double layer of ionic liquids.

Understanding the bulk and interfacial properties of super-concentrated electrolytes, such as ionic liquids (ILs), has attracted significant attention lately for their promising applications in supercapacitors and batteries. Recently, McEldrew et al. [J. Phys. Chem. B 125, 2677 (2021)] developed a theory for reversible ion associations in bulk ILs, which accounted for the formation of all possible (Cayley tree) clusters and a percolating ionic network (gel). Here, we adopt and develop this approach to understand the associations of ILs in the electrical double layer at electrified interfaces. With increasing charge of the electrode, the theory predicts a transition from a regime dominated by a gelled or clustered state to a crowding regime dominated by free ions. This transition from gelation to crowding is conceptually similar to the overscreening to crowding transition.

Polar liquids at charged interfaces: A dipolar shell theory.

The structure of polar liquids and electrolytic solutions, such as water and aqueous electrolytes, at interfaces underlies numerous phenomena in physics, chemistry, biology, and engineering. In this work, we develop a continuum theory that captures the essential features of dielectric screening by polar liquids at charged interfaces, including decaying spatial oscillations in charge and mass, starting from the molecular properties of the solvent. The theory predicts an anisotropic dielectric tensor of interfacial polar liquids previously studied in molecular dynamics simulations. We explore the effect of the interfacial polar liquid properties on the capacitance of the electrode/electrolyte interface and on hydration forces between two plane-parallel polarized surfaces. In the linear response approximation, we obtain simple formulas for the characteristic decay lengths of molecular and ionic profiles at the interface.

Electrochemical Methods for Water Purification, Ion Separations, and Energy Conversion.

Agricultural development, extensive industrialization, and rapid growth of the global population have inadvertently been accompanied by environmental pollution. Water pollution is exacerbated by the decreasing ability of traditional treatment methods to comply with tightening environmental standards. This review provides a comprehensive description of the principles and applications of electrochemical methods for water purification, ion separations, and energy conversion. Electrochemical methods have attractive features such as compact size, chemical selectivity, broad applicability, and reduced generation of secondary waste. Perhaps the greatest advantage of electrochemical methods, however, is that they remove contaminants directly from the water, while other technologies extract the water from the contaminants, which enables efficient removal of trace pollutants. The review begins with an overview of conventional electrochemical methods, which drive chemical or physical transformations via Faradaic reactions at electrodes, and proceeds to a detailed examination of the two primary mechanisms by which contaminants are separated in nondestructive electrochemical processes, namely electrokinetics and electrosorption. In these sections, special attention is given to emerging methods, such as shock electrodialysis and Faradaic electrosorption. Given the importance of generating clean, renewable energy, which may sometimes be combined with water purification, the review also discusses inverse methods of electrochemical energy conversion based on reverse electrosorption, electrowetting, and electrokinetic phenomena. The review concludes with a discussion of technology comparisons, remaining challenges, and potential innovations for the field such as process intensification and technoeconomic optimization.

Rectified and Salt Concentration Dependent Wetting of Hydrophobic Nanopores.

Nanopores lined with hydrophobic groups function as switches for water and all dissolved species, such that transport is allowed only when applying a sufficiently high transmembrane pressure difference or voltage. Here we show a hydrophobic nanopore system whose wetting and ability to transport water and ions is rectified and can be controlled with salt concentration. The nanopore we study contains a junction between a hydrophobic zone and a positively charged hydrophilic zone. The nanopore is closed for transport at low salt concentrations and exhibits finite current only when the concentration reaches a threshold value that is dependent on the pore opening diameter, voltage polarity and magnitude, and type of electrolyte. The smallest nanopore studied here had a 4 nm diameter and did not open for transport in any concentration of KCl or KI examined. A 12 nm nanopore was closed for all KCl solutions but conducted current in KI at concentrations above 100 mM for negative voltages and opened for both voltage polarities at 500 mM KI. Nanopores with a hydrophobic/hydrophilic junction can thus function as diodes, such that one can identify a range of salt concentrations where the pores transport water and ions for only one voltage polarity. Molecular dynamics simulations together with continuum models provided a multiscale explanation of the observed phenomena and linked the salt concentration dependence of wetting with an electrowetting model. Results presented are crucial for designing next-generation chemical and ionic separation devices as well as understanding fundamental properties of hydrophobic interfaces under nanoconfinement.

Structural Forces in Ionic Liquids: The Role of Ionic Size Asymmetry.

Ionic liquids (ILs) are charged fluids composed of anions and cations of different size and shape. The ordering of charge and density in ILs confined between charged interfaces underlies numerous applications of IL electrolytes. Here, we analyze the screening behavior and the resulting structural forces of a representative IL confined between two charge-varied plates. Using both molecular dynamics simulations and a continuum theory, we contrast the screening features of a more-realistic asymmetric system and a less-realistic symmetric one. The ionic size asymmetry plays a nontrivial role in charge screening, affecting both the ionic density profiles and the disjoining pressure distance dependence. Ionic systems with size asymmetry are stronger coupled systems, and this manifests itself both in their response to the electrode polarization and spontaneous structure formation at the interface. Analytical expressions for decay lengths of the disjoining pressure are obtained in agreement with the pressure profiles computed from molecular dynamics simulations.

Nonlinear ion transport mediated by induced charge in ultrathin nanoporous membranes.

Ultrathin membranes with nanoporous conduits show promise for ionic separations and desalination applications, but the mechanisms underlying the nonlinear ionic transport observed in these systems are not well understood. Here, we demonstrate how induced charge at membrane interfaces can lead to nonlinear ionic transport and voltage-dependent conductance through such channels. The application of an electric field on a polarizable membrane leads to induced charges at the membrane interfaces. The induced charges in turn are screened by diffuse charges in the electrolyte, which are acted upon by the electric field. For extremely thin membranes, the induced charge effect can be significant even for moderate applied voltages commonly used in experiments. We apply a continuum Poisson-Nernst-Planck model to characterize the current-voltage behavior of ultrathin membranes over a wide parameter space. The predictions of the model are compared to recent experiments on graphene and MoS_{2} membranes in an electric field. We expect the role of induced charge to be especially pronounced in the limit of atomically thin membranes.

Electroneutrality breakdown in nanopore arrays.

The electrostatic screening of charge in one-dimensional confinement leads to long-range breakdown in electroneutrality within a nanopore. Through a series of continuum simulations, we demonstrate the principles of electroneutrality breakdown for electrolytes in one-dimensional confinement. We show how interacting pores in a membrane can counteract the phenomenon of electroneutrality breakdown, eventually returning to electroneutrality. Emphasis is placed on applying simplifying formulas to reduce the multidimensional partial differential equations into a single ordinary differential equation for the electrostatic potential. Dielectric mismatch between the electrolyte and membrane, pore aspect ratio, and confinement dimensionality are studied independently, outlining the relevance of electroneutrality breakdown in nanoporous membranes for selective ion transport and separations.

Agonistic Behavior Is Affected by Memory in the Dusky Damselfish Stegastes fuscus.

The ability to discriminate familiar from unfamiliar conspecifics has been demonstrated in several species of fish. Agonistic interactions are among the most frequent behaviors exhibited by territorial species and could offer useful information for the individual recognition process. In agonistic situations, memory may modulate the behavioral response and affect social dynamics, but few studies have explored the memory retention acquired during aggressive encounters. The present study investigated the memory retention of an agonistic encounter in the dusky damselfish Stegastes fuscus. The experimental procedure was divided into three parts: (1) Familiarization; (2) Recognition test; and (3) Memory test. During the familiarization phase, the fish were visually exposed to the same conspecific for 5 days (10 min per day) and the behavior was recorded. On the following day (conspecific recognition test), half of the animals were paired with the same conspecific and the other half with a different conspecific for 10 min, and the behavior was recorded. The fish were retested 5, 10, and 15 days after the test to evaluate memory retention. In the memory test, they were exposed to the same conspecific as before or to a different conspecific. We found that the damselfish reduced their agonistic displays when the stimulus fish was familiar, but when it was unfamiliar, the animals were more aggressive and only reduced their mnemonic response after 10 days. These results suggest that the recognition ability of damselfish can be affected by time and that it modulates agonistic response.

Nutrient digetibility and production responses of lactating dairy cows when saturated free fatty acid supplements are included in diets: A meta-analysis.

Our objective was to perform a series of meta-analyses to evaluate the effects of diets supplemented with saturated free fatty acid (FA) supplements (SFAA) compared with nonfat supplemented control diets (CON) on nutrient digestibility and production responses of lactating dairy cows and to determine whether experimental design affects responses to SFFA. We divided SFFA into C16:0-enriched supplements (PALM, FA supplements with ≥80% C16:0) and C16:0+C18:0-enriched supplements (MIX, FA supplements with ≥80% C16:0+C18:0). The database was formed from 32 peer-reviewed publications with SFFA supplemented at ≤3% diet dry matter (DM). We completed 3 different meta-analyses to meet our objectives. We analyzed the interaction between experimental design (continuous vs. change-over) and treatments (CON vs. SFFA; Meta.1). Regardless of experimental design, we evaluated the effect of treatment (CON vs. PALM vs. MIX; Meta.2) and the effect of 1-percentage-unit increase of MIX and PALM in diet DM (Meta.3). In Meta.1, there was no interaction between treatments and experimental design for any variable. In Meta.2, compared with CON, MIX had no effect on NDF digestibility, milk protein yield and energy corrected milk (ECM), increased the yields of milk (1.20 kg/d) and milk fat (0.04 kg/d), and decreased FA digestibility (5.20 percentage units). Compared with CON, PALM increased NDF digestibility (4.50 percentage units), the yields of milk (1.60 kg/d), milk fat (0.10 kg/d), milk protein (0.04 kg/d), and ECM (2.00 kg/d), and had no effect on FA digestibility. Compared with MIX, PALM tended to increase FA digestibility (3.20 percentage units), increased NDF digestibility (3.50 percentage units), milk fat yield (0.06 kg/d), and ECM (1.20 kg/d). In Meta.3, for each 1-percentage-unit increase of supplemental FA in diet DM, MIX had no effect on NDF digestibility, decreased FA digestibility, increased the yields of milk and milk fat, had no effect on milk protein yield, ECM and milk fat content, and decreased milk protein content. For each 1-percentage-unit increase of supplemental FA in diet DM, PALM increased NDF digestibility, had no effect on FA digestibility, increased the yields of milk, milk fat, ECM and milk fat content, tended to increase milk protein yield, and had no effect on milk protein content. Our results indicate no reason for the restrictive use of change-over designs in saturated FA supplementation studies and meta-analyses. Lactating dairy cows responded better to a FA supplement enriched in C16:0 compared with one containing C16:0 and C18:0.