Coat Weight Research Articles

Laccase-catalyzed chitosan-monophenol copolymer as a coating on paper enhances its hydrophobicity and strength

An enzymatic method for functionalization of chitosan (CTS) with a hydrophobic monophenol compound (4-hexyloxyphenol, HP) using laccase was presented, yielding a chitosan derivative (Lac/HP-CTS) as a coating on the Kraft paper sheet. The dissolve oxygen, UV/vis, FT-IR and 1H NMR spectra were used to characterize the chemical structure of the resulting copolymer. The results showed that HP was oxidized into the semi-quinone structure, and then was bonded onto the chitosan via Schiff-base reaction and electrostatic interaction. The hydrophobicity and strength of paper were evaluated after coated by the pure chitosan or chitosan derivative. Compared with paper coated by pure chitosan, the hydrophobicity and wet strength of the coated paper via the chitosan derivative were improved significantly at the coating concentration of 0.6 g/100 mL with the coat weight of 1.53 g/m2. Meanwhile, the different enhancement behaviors in the strength (dry or wet) performance were observed, due to the greatly influenced interaction of the hydrogen bonding between the copolymer coating and the cellulose fibers by the grafted HP. Further, the hydrophobicity and strength were observed to be enhanced even at a diluted concentration of 0.1 g/100 mL and a relatively low coating weight of 0.26 g/m2 for the chitosan derivative. Taken together, this study is significant for broadening the coating application of the biomodified chitosan on the packaging papers.

Film formation and foamability of cellulose derivatives: Influence of co-binders and substrate properties on coating holdout

Foams were prepared from hydrophobically modified ethyl(hydroxyethyl) cellulose (EHEC), methyl nanocellulose, and native microfibrillated cellulose (MFC). Their film- and foam-forming abilities, stabilities, and suitabilities for foam coating on different substrates were investigated. The role of EHEC as a polymeric stabilizing agent was also studied. The EHEC-MFC foams showed greater stability and water-holding ability under pressurized dewatering than MFC foams prepared in the presence of a surfactant. A foam could be created with methyl nanocellulose without any foaming agent. Selected nanocellulose gels and foam formulations were used to coat various substrates. The surface was efficiently closed by gel and foam coatings prepared from the methyl nanocellulose and EHEC solutions, which was ascribed to good coating holdout. Coatings on papers with different levels of smoothness/density and hydrophobicity/ hydrophilicity confirmed that foam-substrate interactions affected the coat quality. The air permeance was reduced by 99% and 64% with a methyl nanocellulose coating and an EHEC-MFC coating, respectively. An EHEC-MFC coating created a hydrophobic surface on a hydrophilic substrate, and methyl nanocellulose improved the oil resistance even at a low coat weight.

Microfibrillated Cellulose Based Barrier Coatings for Abrasive Paper Products

Paper-based abrasive products are multilayer structures in which the first layer on the paper substrate is usually a latex barrier coating to prevent the migration of adhesive glue into the substrate. The high coat weight (10 g/m2) of latex barrier layers is a cause of environmental concerns. Hence, alternative materials that can provide the barrier function at lower coat weights are desired. In this work, microfibrillated cellulose (MFC) combined with poly(vinyl) alcohol (PVA) were explored as suitable alternatives to the current latex coatings. Barrier coating formulations containing PVA, MFC, and silica (SiO2) were developed and applied to a paper substrate using a rod coating method on a pilot scale. Coating quality and barrier performance were characterized using scanning electron microscope images, air permeance, surface roughness, water contact angle, KIT test, and oil Cobb measurements. The barrier coatings were also studied for adhesion to the subsequent coating layer. An optimal barrier function was achieved with the developed coatings at a low coat weight of ca. 3 g/m2. The adhesion of pure PVA and PVA-MFC barrier coatings to the subsequent coating layer was inadequate; however, silica addition was found to improve the adhesion.

The Weight of the White Coat

The Weight of the White Coat

Effect of insect-proof net house on flowering and seeds quality of cucumber (Cucumis sativus)

An experiment was carried out during kharif 2013-14 under insect proof net house and open field at Centre for Protected Cultivation Technology, IARI, New Delhi and CCR (PG) College, Muzaffarnagar (UP) in Cucumber cv. (Pant Sankar Khira-1). Opening of first female and male flower in seed and pollen parents (39.0 and 34.90 days) was significantly lower under insect proof net house compared to open field condition (44.15 and 41.37 days). The production of number of female and male flowers (25.42 and 36.57) in seed and pollen parents was significantly higher under insect proof net house compared to open field condition (8.81 and 18.16). Seed length was significantly higher under insect proof net house (11.32 cm) in compared to open field condition (10.36 cm). Seed width(mm), seed coat weight(mm), cotyledon weight(g) and 100 seeds weight(g) were also significantly higher under insect proof net house (4.11, 0.13, 0.13 and 3.48 respectively) than open field condition (3.39, 0.10, 0.14 and 2.59, respectively). The germination percentage, seedling length, vigour index I and II also exhibited the same trend being significantly higher under insect proof net house (87.21, 31.43 cm, 2825.54 and 11.08, respectively) compared to open field condition (82.02, 26.38 cm, 2224.83 and 7.62, respectively). Electrical conductivity was lower under insect proof net house (11.22) but higher in open field condition (12.03).

Physiochemical properties and nutritional profile of Mediterranean oak acorn

Oaks cover a vast area of Jordanian forests, and their fruit (named acorns) have good nutritional value. In this study, we investigated the physical, chemical, and nutritional characteristics of the acorns produced by three Jordanian oak species, Quercus aegilops (QA), Quercus infectoria (QI), and Quercus calliprinus (QC). The physicochemical (acorn length, weight; cupule weight, coat weight, cotyledon weight, coat weight percent, cotyledon weight percent and acorn volume) and nutritional quality (protein, fat, fiber, ash, carbohydrate, amino acid, fatty acid and mineral compostions) of the acorns from the three oak species were determined using standard procedures. The acorn of QA showed significantly greater values compared to QC for all physical characteristics assessed while QC exhibited the lowest values; QI presented intermediate values.The chemical composition of the three species showed that fat content varied from 8.18% to 8.99% and the crude fiber and the total carbohydrate content ranged from 3.27% to 3.86% and 76.20% to 81.43%, respectively According to obtained results, oak acorn can be considered a significant source of protein (9.54% for QC to 10.9% for QA). Oak acorncontained 18 known amino acids (AAs); with total essential amino acids (TEAA) levels in these oak species as 2307.9, 1699.1, and 2262.8 mg/100 g dry weight, respectively. The most abundant essential amino acid found varied between species: in QA it was leucine (446 mg/100 g dry weight), in QC it was arginine (526 mg/100 g dry weight), and in QI it was phenylalanine (395 mg/100 g dry weight). The ratio of TEAA to total amino acids (TAA) was 0.90: 0.50 and 0.79 for QA, QC and QI, respectively, which indicates that QA is the best species in terms of essential amino acid (EAA) proportion. The EAA scores showed that (phenylalanine + tyrosine) and (methionine + cysteine) were the most abundant AAs in oak acorns, while lysine and leucine were the most limited. The ratio of unsaturated fatty acids to saturated fatty acids in the acorn oil ranged from 3.45:1.00 to 3.93:1.00. Therefore, oak acorn oil may be considered healthy for a human diet. The most abundant minerals in decreasing order were K, P, Ca, Cl, S, Fe, and Mn. These results demonstrate that oak acorns from Jordan have great potential to be included in human feeding. Key words: Amino acids, Fatty acids, Nutritional value, Oak acorn, Quercus L

Barrier coatings with various types of cellulose nanofibrils and their barrier properties

Needs for biodegradable packaging materials are growing to reduce the negative environmental impact of petroleum-based polymer packaging. Barrier paper packaging is in demand as environmentally-friendly barrier coating materials to improve biodegradability and recyclability. Cellulose nanofibril (CNF) is considered an alternative to conventional polymers for barrier coatings due to the barrier properties of its films. In this work, various types of CNFs were prepared and coated on linerboard and wood-free paper to evaluate the barrier properties of these papers against air, liquid water, water vapor, oxygen, and grease, and the major factors of the barrier performance of the CNFs-based coatings were investigated. A coat weight of at least 10 g/m2 was desirable to impart efficient the barrier properties to papers. The average fibril size and hydrophobicity were strongly related to the barrier properties. CNFs with smaller fibril sizes are beneficial for enhancing barrier properties, and hydrophobization improves the water resistance. Hydrophobic functional groups with sufficient chain lengths decreased the water vapor barrier properties. The average fibril diameter of CNFs may be related to the air resistance, oxygen barrier properties, and grease resistance.

Exogenous application of 6-BA and GA3 collaboratively improves cottonseed yield and seed quality via altering production of carbohydrates in the embryo

ABSTRACT Cottonseed produces oil for human consumption and protein meals for ruminant feed, and carbohydrate metabolism takes responsibility for seed oil and protein biosynthesis. Here, 6-BA and GA3 were evaluated by seed or foliar application for its effect on physiological and productive parameters of cottonseed in two-year field experiment. Results showed that 6-BA and GA3 significantly enhanced cottonseed yield because of increased boll number and seed index. Boll number was the dominant driver of yield increment for seed priming with 6-BA, and the increase was greater than GA3, resulting in higher yield for seed priming with 6-BA (18.8–20.1%) than with GA3 (10.7–14.5%) while the increase in yield was statistically at par between spraying of 6-BA and GA3. Although seed coat weight was not affected by 6-BA and GA3, embryo weight, oil and carbohydrate content were significantly increased by any given treatments. Higher carbohydrate content was attributed to increased sucrose, hexose and starch contents, which were closely associated with higher sucrose synthase, acid invertase, and sucrose phosphate synthase activities. Moreover, increases in the activities of these sucrose metabolism enzymes were larger for seed priming with 6-BA than GA3, accounting for the difference observed in sucrose content between 6-BA and GA3 seed application.

Effect of skin and coat characteristics on growth and milk production traits in Tharparkar cattle

The present study was conducted on a total of 68 Tharparkar cattle (Bos indicus) at Cattle and Buffalo farm (Indian Veterinary Research Institute) from December 2016 to April 2017. The objective was to study the effect of skin and coat characteristics like coat colour, coat score (CS) coat thickness, hair density, hair length, hair diameter and weight of hair coat on growth (live body weights at birth, 3, 6, 12, 18 and 24 months of age) and milk production (Lactation lengths, lactation milk yield) traits. Physiological parameters studied were skin temperature (ST), rectal temperature (RT) and respiration rate (RR). Animals were divided into 2 groups: light grey (LG) and dark grey (DG), on the basis of coat colour. Higher average body weights were found in light grey animals at 3, 6, 12, 18 and 24 months of age. An increase in coat score (higher coat score implies rough, long and a more wooly hair coat) tended to have a negative effect on body weight gain as well as on milk production. The average previous lactation yields of LG were higher than DG group. Cattle with lower hair densities (<400 hair/cm2) had higher milk yields than with higher hair densities (>400 hair/cm2). Considering the results of the present study, it can be concluded that skin and coat characteristics can be used as a potential selection tool to improve growth and production potential of cattle especially in tropics.

Design Strategies for High Power vs. High Energy Lithium Ion Cells

Commercial lithium ion cells are now optimised for either high energy density or high power density. There is a trade off in cell design between the power and energy requirements. A tear down protocol has been developed, to investigate the internal components and cell engineering of nine cylindrical cells, with different power–energy ratios. The cells designed for high power applications used smaller particles of the active material in both the anodes and the cathodes. The cathodes for high power cells had higher porosities, but a similar trend was not observed for the anodes. In terms of cell design, the coat weights and areal capacities were lower for high power cells. The tag arrangements were the same in eight out of nine cells, with tags at each end of the anode, and one tag on the cathode. The thicknesses of the current collectors and separators were based on the best (thinnest) materials available when the cells were designed, rather than materials optimised for power or energy. To obtain high power, the resistance of each component is reduced as low as possible, and the lithium ion diffusion path lengths are minimised. This information illustrates the significant evolution of materials and components in lithium ion cells in recent years, and gives insight into designing higher power cells in the future.

Cellulose fibre- perlite depth filters with cellulose nanofibre top coating for improved filtration performance

Depth type composite filters are used to remove contaminants from liquids by combining mechanical entrapment and adsorption. Commonly, depth filters can adsorb either anionic or cationic charged contaminants, but not both, as well as filter micron-sized particles. Therefore, there is still a need to improve the existing depth filter performance. In this study, we developed a two-layer filters with enhanced functionality by spray coating an anionically charged cellulose nanofibre (CNF) layer onto a cationically charged depth filter layer. The depth filter layer was prepared via papermaking technique of vacuum filtration from wood pulp fibres, perlite adsorbent and cationic polyamide-amine epichlorohydrin (PAE) wet strength resin. The CNF coat weight ranged from 4 to 30 g per square metre (gsm). The two layer filters were proven to have triple functionality, capable of adsorbing anionic molecules in the cationic depth filter layer, while the anionic CNF layer could adsorb cationic molecules and was also a microfiltration membrane. A gradual increase in CNF coat weight improved filtration performance but decreased the filter flux. The optimum performance was found at an 8 gsm CNF coat weight, where the membrane layer rejected 80% of 5000 kDa molecular weight polyethylene glycol, at a flux of 133 Litres per square meter per hour (LMH) under 1.5 bar pressure, while still achieving a good breakthrough curve when absorbing cationic methylene blue dye.

Designing High Power Lithium Ion Cells

Applications like hybrid electric vehicles (HEV) require batteries with high volumetric and gravimetric power densities, in both charge and discharge modes. Lithium ion cells are now being designed with different power : energy ratios, for specific applications. Many cells are rated for high rate discharge (> 10 C), but not for high rate charge (< 2 C). However, even 10 C is not enough. A selection of commercial lithium ion cells, mainly cylindrical 18650 cells, were disassembled and characterised. The cells had a variety of different power : energy ratios, and this was correlated with key design parameters. For example, cells with a high power density had relatively low coat weights and areal capacities, and used active materials with a smaller particle size. However, most of the cells had the same tag arrangement, when high power cells were predicted to use more tags. Having disassembled the cells, the harvested electrodes were tested in coin cell half cells. The tests included resistance measurements, continuous discharge tests at relatively low rates, and pulse charge and discharge tests at high rates. During lithiation pulses, all the anode voltages went negative of zero volts vs. Li/Li+ by around 5 C. However, the reaction still appeared to be under solid state diffusion control, based on the linearity of the voltage vs. time0.5 GITT plots. These and other results will be presented at the meeting.

Coating performance and rheological characteristics of novel soybean oil-based wax emulsions

Aqueous emulsions of soybean oil-based coating materials consist of ethylene glycol and propylene glycol mono- and di-esters of stearic acid (EGMD and PGMD, respectively) and compound emulsions (mixtures of EGMD emulsion with four commercial polymer emulsions) were formulated and tested for paperboard coating. Paper coated with compound emulsions had excellent water resistance and grease resistance. With EGMD accounting for as high as 60% of the emulsion’s solid content, 5-min Cobb value of about 1.0 gsm (gram per square meter) was achieved. Increased number of drawdowns (coating) significantly improved water and grease resistance of the coated papers. With three-drawdown and coat weight of 14.93–23.00 gsm, 5-min Cobb value of less than 2 gsm and oil penetration of less than 2% were achieved. Greater heat exposure during drying resulted in better water resistance. Increasing the drying temperature from 100 to 200 °C for 30 s reduced the 5-min Cobb value of papers coated with PGMD compound emulsions from 34.1 to 1.1 gsm. The addition of cross-linking agent, zinc ammonium carbonate (ZAC), in the emulsions improved water repellency but not grease resistance. The effect of different emulsifiers on coating performance, rheology and stability of W/O and W/O/W PGMD emulsions were also investigated. The yield stress of cetyltrimethylammonium bromide (CTAB) based emulsions (1.61–21.32 Pa) were much higher than those of Tween 80 based emulsions (0.023–0.066 Pa). Both the W/O and W/O/W emulsion had higher viscosity than the compound emulsions. The compound emulsions had comparable surface energy but lower gluability compared to the commercial emulsions.

Components of phenotypic variance of seed traits and germination characteristics of 20 ponderosa pine half-sib families

A study was conducted to estimate phenotypic variance components of seed traits and seed vigor of 20 ponderosa pine seed lots. A high intraspecific within-group variation in seed germination and seedling growth has been observed in both half-sib and full-sib families of conifers. Some seed traits may influence seed lot quality and seedling survival. Wind-pollinated cones were collected from 20 ponderosa pine maternal trees, 10 cones per tree, in a stand located in Fort Defiance, Arizona. Air-dried seeds were sown under laboratory conditions, by using a completely randomized design to estimate components of phenotypic variance for seed weight (SW), seed coat weight (SCW), seed imbibition (IMB), five germination characteristics, and three Weibull parameters (a, b and c). About 80 % of size classes had a seed weight (SW) e» 41 mg and e» 97 % final germination. The within-plot (within- family) variance component for SW (64.5 %) and IMB (70.4 %) was higher than among-family variation (35.3 and 24.8 %, respectively). The among-family component varied from 35.1 % (Weibull parameter a) to 62.3 % (Peak Value). Results suggest a significant maternal contribution and a high within-family genetic influence on seed quality and germination characteristics. Finally, heavier seeds (SW e» 60 mg), whose time of germination (TOG) occurred at day 3, increased 38.3 % of their seed weight due to water absorption before reaching 50 % germination; on the other hand, seeds whose SW was e» 45 mg and TOG = 7, showed 102.2 % increase in SW before reaching 50 % germination. DOI: https://doi.org/10.54167/tch.v12i3.189

A Novel approach for rbc depletion in abo incompatible allogenic peripheral blood stem cell transplant using modified hydroxyethyl starch method

Background & Aim Apheresis derived Peripheral Blood Stem cell(PBSC) products usually contain very few RBCs, so RBC depletion is not routinely performed for these products. Though rare, an acute hemolytic transfusion reaction was observed at the authors' Institution, when a blood group O positive patient was transfused with PBSC product of group B, having relatively lower hematocrit (9. 6 %). After this adverse event, RBC depletion was carried out in this case as well as all other subsequent major ABO-incompatible PBSC Transplants, using a modified Hydroxy Ethyl Starch (HES) sedimentation method.There is very limited literature which describes the process of RBC depletion in PBSC product. There were multiple challenges faced and the procedure was carried out after various modifications in the conventional method. Methods, Results & Conclusion Method During the process of removal of RBCs using 6 % HES, a major source for the loss of buffy coat was identified as the formation of a Vortex, due to the relatively heavier weight of the buffy coat. Various modifications, like ensuring a controlled release of sedimented RBCs, pausing the flow of RBCs as soon as the Vortex appeared and breaking down the procedure into time-dependent smaller phases, mitigated the loss of buffy coat and stem cells. The time taken for depletion was increased to 4 hours, compared to 2 hours described for marrow-derived HSCs. Encouraged by the success of result of first RBC depletion, it was carried out in four more ABO Incompatible PBSC transplants. Results CD 34 count, TLC, and Hb of the product were measured before as well as after RBC depletion (Table attached). Recovered CD 34 was found to be in the range of 75-80 % in all the cases. The depletion process was highly effective as the final product had less than 1 gm% of hemoglobin. No adverse transfusion reaction was observed during transfusion of PBSCs in any recipient. Chimerism studies by VNTR analysis showed increasing donor chimerism. Successful engraftment was achieved in 80% of these cases. Conclusion As automated platforms and cell sorters for RBC depletion in PBSC are not available at most of the centers in developing counties, use of HES can be successfully employed using the modified method suggested, especially in case of an unexpected acute hemolytic transfusion reaction. Considering the limited literature available regarding this procedure, this case series provides significant insight into the expected challenges and modifications to resolve them.

Comparison of Thermal Fatigue of Superni 718 SGTBCs and APSTBCs

This paper presents a comparison of thermal fatigue behavior of sol–gel-derived dip-coated nanostructured nonconventional and conventional air plasma-sprayed seven percent weight of yttria-stabilized zirconia thermal barrier coatings (TBCs). The thermal fatigue test was performed on the thermal cyclic furnace in the temperature range of room temperature and 1100 °C. Microstructural evaluation and elemental analysis were done by using scanning electron microscopy/energy-dispersive spectroscopy, respectively. It was observed that the failure of both nanostructured and conventional TBCs ensured the crack-induced spallation of ceramic top coat. The results demonstrated that spinel oxide (mixed oxide of Cr, Co, Ni) formation over thermally grown oxides layer played a crucial role in both of the case of conventional TBCs and sol–gel-coated nonconventional TBCs. The thermal cyclic fatigue life of the sol–gel coatings was found to be 1.31 times higher than the conventional air plasma. The AFM images also confirmed the coating consisting of nanostructure as well as the surface irregularities which increased with rising temperature.

Feedforward and Feedback Control of a Pharmaceutical Coating Process.

This work demonstrates the use of a combination of feedforward and feedback loops to control the controlled release coating of theophylline granules. Feedforward models are based on the size distribution of incoming granules and are used to set values for the airflow in the fluid bed processor and the target coat weight to be applied to the granules. The target coat weight of the granules is controlled by a feedback loop using NIR spectroscopy to monitor the progress of the process. By combining feedforward and feedback loops, significant variation in the size distributions and ambient conditions were accommodated in the fluid bed coating of the granules and a desired dissolution profile was achieved. The feedforward component of the control system was specifically tested by comparing the performance of the control system with and without this element by Monte Carlo simulation.

Quasi layer by layer spray deposition of high-quality Ag coatings with excellent micro mechanical properties

In this paper, quasi layer by layer (quasi-LbL) spray deposition has been developed to produce pure and homogeneous metallic coatings on plastic surfaces. Comparing with Ag coatings by electroless deposition, the surfaces prepared by quasi-LbL show reflective and white characteristics that made of uniform nanoparticles of uneven size. By changing pH of spraying solution and spray passes, the surface morphology, roughness, composition, deposition weight and electrical properties of the Ag coatings by quasi-LbL were studies in details. The Ag coating with excellent electrical conductivity was face centered cubic (fcc) metallic state without any other phase, but with less oxides on the top surfaces than Ag coatings prepared by electroless plating. The deposition weight of Ag coatings would increase as the spray passes steps up, and Ag salts were the defining parameter for deposition weight even the spray atmosphere is air or N2. Nanoindentation tests were used to studies the micro mechanical properties. The modulus and the hardness of Ag coatings are 2.649 GPa and 0.118 GPa respectively, which are higher than those of electroless Ag coatings. The quasi-LbL method shows the possibility of producing high-quality metallic coatings and also be exploited to produce other kinds of metallic coatings, such as Ni and Cu.

Application of the Modified Tangential Spray-Fluidized Bed to Produce Nonpareils from Primary Crystals.

Coating of fine primary drug particles by a fluidized bed processor has been reported to be potentially challenging. This work aimed to develop a spray layering process to produce nonpareils by a side spray fluid bed with swirling air flow. The first part examined the effects of various parameters for producing lactose nonpareils by using Box-Behnken design. The factors considered were atomizing air pressure, spray rate, and fluidizing air temperature. This was followed by an in-depth investigation on the effects of inlet airflow rate, air temperature, and spray rate on properties of the product, in addition to process optimization. The results indicated a negative correlation between atomizing air pressure and D90 (particle size at 90th percentile in the cumulative undersize plot) as well as span (size distribution). Temperature had a positive correlation with D90 and span while spray rate affected span. Both atomizing air pressure and temperature correlated negatively with span. It was also found that spray rate negatively affected roundness at different coat weight gain levels across the study design space. Inlet airflow rate was found to correlate negatively with roundness at 15%, w/w coat weight gain. The mean useful yield of the optimized runs was about 91%. In the second part of this study, the metformin hydrochloride crystals as starter seeds were converted into nearly spherical shaped spheroids with 1:1 crystals to coat weight deposition over a processing time of about 3.5h. The processor studied shows promise for direct spheronization of crystals into spherical seeds.

Milk yield and hair coat characteristics of Holstein cows in a hot environment.

This study was conducted to evaluate the effects of hair coat characteristics on thermophysiological variables and body surface temperatures (BST), measured with infrared thermography, as well as milk yield of Holstein cows in a hot environment. Physiological and milk yield variables were assessed using 103 pluriparous Holstein cows. Also, hair angle (HA), density of hair coat (D), diameter of hair (HD), hair length (HL), weight of hair coat (Wt), and coat thickness (CT) were recorded. Biplot analysis (principal components analysis) revealed that HL was closely associated with Wt, CT, and HD and all these variables had a positive association with rectal temperature. Both CT and HL were found to be negatively associated with shoulder and neck temperature; tympanic temperature showed no association with BTS. Cows with short hair coat (length < 17mm) did not produce more milk in 305days than cows with longer hair coat (9673 ± 1604 vs. 9277 ± 817; P = 0.12). On the other hand, milk fat percentage at the middle of lactation was higher (P < 0.01) in cows with longer hair relative to cows with coat hair < 17mm (3.71 vs. 3.35%, respectively). In conclusion, physical characteristics of the coat of Holstein cows were not associated with the 305-day milk yield but cows with longer hair produced a greater milk fat percentage at the middle of lactation compared to cows with short hair.