Age at first calving and productive performance of primiparous Holsteins.

This study investigated the age at first calving in Holstein heifers and its impact on various production parameters. A sample of 737 Holstein heifers born between 2015 and 2018 and finishing their first lactations between 2018 and 2020 was included. Cluster analysis revealed three groups based on age at first calving: high precocity, medium precocity and low precocity. Medium-precocity group exhibited the highest 305-day milk yield and peak milk production. Additionally, the same group demonstrated superior mean production per lactation, 305-day milk protein content, and 305-day milk yield. The lowest somatic cell count was found in the low-precocity group. In conclusion, medium-precocity cows showed better results such as higher 305-day milk yield and peak milk production.

Prediction models of intake and productive performance of non-castrated Nellore cattle finished in the feedlot system under tropical conditions.

The objective of this study was to understand and predict the intake and performance of Nellore cattle finished in the feedlot. Individual data from 144 non-castrated male Nellore steers finished in the feedlot between the years 2016 and 2020 were used. Descriptive statistical analyses and Pearson's correlation were performed. The outliers were tested by evaluating the studentized residuals in relation to the values predicted by the equations. Residues that were outside the range of - 2.5 to 2.5 were removed. The goodness of fit of the developed equations was evaluated by the coefficients of determination (r2) and root mean square error (RMSE). The mean dry matter intake (DMI) was 10.2 kg/day, neutral detergent fiber intake (NDFI) was 3.4 kg/day, corresponding to 33.3% of DMI, crude protein intake (CPI) was 1.6 kg/day, and total digestible nutrient intake (TDNI) was 7.1 kg/day. The CPI to ADG ratio was 1.3 kg CPI/kg ADG and the TDNI to CPI ratio was 4.5 kg TDNI/kg CPI. The averages of productive performance were 1.3 kg/day for average daily gain (ADG), 152.6 kg for total weight gain (TWG), and 497.8 kg for final body weight (FBW) in average days in the confinement of 115.7 days. The intake measures correlated significantly with the performance measures, except for carcass yield and days in the feedlot. TWG had a high positive correlation with ADG (r = 0.84), while FBW had a positive correlation (r = 0.86) with hot carcass weight (HCW). Measures of intake, performance, and days in the feedlot can be used as predictors of DMI, FBW, HCW, TWG, and ADG. The prediction equations had satisfactory precision and accuracy for non-castrated Nellore cattle finished in feedlot systems under tropical conditions.

Effects of heat-stress-reducing systems on blood constituents, milk production and milk quality of Holstein and Jersey cows and heifers on pasture.

The objective of this study was to evaluate the influence of different heat-stress-reducing systems, i.e., sprinkler + artificial shade, shower + artificial shade, and artificial shade, on serum mineral, hormonal, hematological, and metabolite profiles, on milk production, and milk composition in lactating cows and pubertal heifers of Holstein and Jersey breeds. For this purpose, 12 animals were used: 3 Holstein cows with an average (mean ± SD) body weight of 600 ± 30 kg, 53 ± 11 months of age, and milk yield of 27 ± 3.5 kg/day; 3 Jersey cows with an average body weight of 370 ± 11 kg, 40 ± 6 months of age, and milk production of 11 ± 1.5 kg/day; 3 Holstein heifers (325 ± 25 kg and 16 ± 0.6 months of age); and 3 Jersey heifers (250 ± 25 kg and 13 ± 0.6 months of age). Animals were used in a replicated 3 × 3 Latin square design with a 3 × 2 × 2 factorial arrangement of treatments that included three treatments (sprinkler + artificial shade, shower + artificial shade, and artificial shade), two breeds (Holstein, Jersey), and two physiological stages (lactating cows, heifers). The experimental treatments influenced (P < 0.05) the concentrations of triiodothyronine, with the shower and shade systems showing greater and similar concentrations (99.5 and 96.3 µg/dL, respectively) when compared with sprinkler treatment (89.2 µg/dL). There was an effect (P < 0.05) of breed on the concentrations of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume levels with the Holsteins having lower levels of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume (101.1, 4.0 ng/mL, 11.2 g/dL, 24.7%, and 42.3 µm3, respectively) than the Jerseys (106.5 and 4.3 ng/mL, 12.4 g/dL, 27.7%, and 46.3 µm3, respectively. Total cholesterol and high-density lipoproteins were influenced by physiological stage (P < 0.05). Concentrations of cholesterol and high-density lipoproteins were higher for cows (94.1, and 56.9 mg/dL, respectively) than for heifers (56.9 and 42,9 mf/dL, respectively). Milk production and fat content were affected (P < 0.05) by breed (P < 0.05), with Holstein cows producing more milk (23.9 kg/day) than Jersey cows (12.0 kg/day), but Jersey cows had higher fat concentration (4.6%) than Holstein cows (3.0%). Therefore, the three different thermal-stress-reducing-systems tested were able to maintain the serum biomarkers within normal physiological ranges. However, the most appropriate thermal-stress-reducing-systems would be a sprinkler systema because it uses less water compared with the shower system.

Prediction models of carcass characteristics from non­castrated Nellore cattle finished in the feedlot system under tropical conditions.

Our objective was to use measures of intake and productive performance to adjust prediction models for the carcass traits of non-castrated Nellore cattle finished in a feedlot. Individual data from 168 non-castrated male Nellore steers finished in feedlot between the years 2016-2021 were used. Descriptive statistical analyzes and Pearson correlation coefficients were performed. The outliers were tested by evaluating the studentized residuals in relation to the values predicted by the equations. Residues that were outside the range of -2.5 to 2.5 were removed. The goodness of fit of the developed equations was evaluated by the coefficients of determination (R2) and root mean square error (RMSE). Models for carcass yield, subcutaneous fat thickness, ribeye area, and shear force were adjusted. Means of 53.5% carcass yield, 4.8 mm subcutaneous fat thickness, 73 cm2 loin eye area, and 8.1 kg shear force were observed. The observed average intakes were 9.9 kg/day of dry matter, 3.3 kg/day of neutral detergent fiber content, 1.5 kg/day of crude protein, and 7.1 kg/day of total digestible nutrients. The average confinement time was 113 days, the average total weight gain was 152.2 kg and the average daily gain was 1.35 kg/day. Intake measures significantly correlated with shear force and subcutaneous fat thickness and ribeye area. Carcass yield was significantly correlated with total weight gain, feedlot time, and hot carcass weight. Measures of nutrient intake, performance, and confinement time can be used as predictors of carcass yield, ribeye area, fat thickness, and shear force of non-castrated Nellore cattle finished in a feedlot. The prediction equations for ribeye area, carcass yield, subcutaneous fat thickness, and shear force showed sufficient precision and accuracy for non-castrated Nellore cattle finished in confinement systems under tropical conditions. All equations can be used with caution to estimate carcass traits of cattle finished in a feedlot using measures of intake and productive performance.

Ruminal responses, digestibility, and blood parameters of beef cattle fed diets with different oilseeds.

It aimed to evaluate the effects of different whole oilseeds in lipid-rich diets on nutrient intake, apparent digestibility, ingestive behavior, and ruminal and blood parameters of steers. A control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean) were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five diets, being a control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean), were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five rumen fistulated crossbreed steers, in a 5 × 5 Latin square design were distributed using five periods of 21 days. The steers fed cottonseed and canola diets had lower dry matter intakes (6.6 kg/day). Steers showed higher averages of time in rumination for treatments with sunflower, soybean, and cottonseed (406, 362, and 361 min/day, respectively). There was no treatment effect for the ruminal pH and ammonia (NH3) variables. There was an effect of the treatment on the volatile fatty acid concentrations. The animals that received soybean showed a higher plasma urea concentration (50.7 mg/dL). Animals fed the control diet showed lower serum cholesterol levels (111.8 mg/dL) than those fed diets containing whole cottonseed, canola, sunflower, and soybean (152.7, 137.1, 146.9, and 138.2 mg/dL, respectively). We recommended using whole soybean or sunflower seeds to formulate lipid-rich diets with 70 g/kg of ether extract for crossbreed steers in the feedlot.

Antioxidant action of yerba mate on carcass and meat characteristics and fatty acid profile in meat and fat of lambs finished in tropical pastures.

The objective was to evaluate the effect of the supplementation with natural antioxidants from Yerba mate (Ilex paraguariensis St. Hil.) on the performance, carcass and meat characteristics, and fatty acid profile in meat and fat of Texel × Ile de France lambs kept in Brachiaria-grass pasture. Twenty lambs with a mean age of 90 days and 26.3 kg of BW were distributed in a completely randomized design in two treatments with 10 replicates/treatment: Control-protein-energy supplement based on corn and soybean meal (150 g/kg DM of crude protein) without the addition of natural antioxidant yerba mate and Yerba Mate - energy protein supplement with the addition of yerba mate (110 g/kg DM). There was no treatment effect on animal performance and carcass characteristics. The subcutaneous fat thickness was significantly higher for lambs treated without yerba mate. There was no effect of nutritional treatments on the oxidative markers of lamb meat. The muscle of the animals treated with yerba mate showed a higher concentration of unsaturated and polyunsaturated fatty acids elaidic, linolenic, thymnodonic, docosadienoic, and ceorvonic. The fat of the animals treated with yerba mate showed a higher concentration of palmitoleic acid, linoelaidic acid, heneicosanoic acid, dihomo-γ-linolenic acid, and arachidonic acid. The concentration of polyunsaturated fatty acids was significantly higher in meat and fat of lambs treated with yerba mate. Including yerba mate in the diet of lambs kept on Brachiaria pastures improves the lipid profile of polyunsaturated fatty acids in meat and fat, without altering the performance of the animals.

Prediction of weaning weight in Santa Inês lambs using the body volume formula.

Weaning weight (WW) is one of the most important information within production systems, as it is a reflection of management during the breastfeeding phase and will influence the performance of animals in subsequent phases. This study aimed to develop and evaluate linear, quadratic, and exponential models to predict WW using the body volume (BV) formula in Santa Inês lambs for meat. Eighty-five lambs at 90 days of age with WW 17.52 ± 3.79 kg and BV 13.29 ± 2.86 dm3 were evaluated. The quality of fit of the models was evaluated using the coefficient of determination (R2), mean squared error (MSE), and root MSE (RMSE). For the external evaluation of the models, an independent dataset from 43 lambs at 90 days of age was used. The first-degree linear model showed the lowest values of MSE (1.02) and RMSE (1.01). In the external evaluation, all models exhibited estimates of mean WW and standard deviation of this weight similar to the external dataset, as well as high values (above 0.89) for the R2 of predicted vs. observed data. Concordance correlation coefficient (CCC) analysis also revealed that all models showed accuracy and precision (CCC > 0.90). There was no difference between the models in terms of accuracy (P > 0.05). The comparison in terms of precision indicated that the linear model is more precise than the exponential model and that the quadratic model is as precise as the linear model. The first-degree linear model should be used due to its simplicity of interpretation and ease of estimation.

Characterization and in vitro evaluations of Baru pulp from almond production waste ensiled with different additives.

The silage process is an efficient way of storing nutrients for animal nutrition. Our hypothesis was that the Baru pulp can be preserved in the form of silage, regardless of the use of additives to aid the process. Silages of Baru pulp containing different additives were evaluated through in vitro analysis, fermentation parameters, and composition and thermal analysis including differential scanning calorimetry and thermogravimetry. The treatments consisted of (1) silage with Baru pulp (BP) in natura without additive; (2) BP in natura with acetic acid; (3) BP in natura with formic acids; and (4) BP in natura added with microbial inoculums in a randomized experimental design with three replications per treatment and analyzed in duplicate. The ensiled material was kept in anaerobic conditions for a period of 30 days. BP before and after the silage process presented averages of 67.31 and 66.24% for in vitro digestibility of DM (IVDMD). Microbial inoculant additive was the most effective in reducing pH, followed by acetic acid and formic acid. There were effects of additives on silages for all degradation parameters in ruminal liquid in vitro. It was observed that BP before ensiling had the highest A fraction (7.9 mL gas/100 mg DM), without differing from the silage treated with formic acid (7.1 mL gas/100 mg DM). Similar effects were observed on mass loss (TG) and heat flux (DSC) between the silages. Our findings suggest that Baru pulp with formic acid is more efficient in the conservation and preservation of fermentable carbohydrates as well as in silage production.

Yerba mate (Ilex paraguariensis) as a source of antioxidants with soybean grain in supplementation of lactating ewes reared in tropical pastures.

The hypothesis tested is that the association of soybean grain and yerba mate as an antioxidant source can increase the concentration of polyunsaturated fatty acids (PUFA) with lower oxidation of milk from lactating ewes reared in tropical pastures. Sixteen ewes were randomly distributed in a 2x2 factorial scheme (with or without yerba mate at 110 g / kg of dry matter (DM); with or without soybean grain at 210 g/kg of DM). Yerba mate intake reduced DM intake, and concentrations of ether extract (EE), protein, lactose, defatted dry extract, density, omega-3 concentrations, and the ratio between saturated/monounsaturated fatty acids (FA), but increased the concentration of monounsaturated FA and the sequestering power of free radicals by DPPH without altering the concentrations of conjugated dienes and the concentrations of substances reactive to thiobarbituric acid in milk. Supplementation with soybean grain decreased the birth weight of the lambs and increased the concentrations of conjugated linoleic acid (CLA), PUFA, omega - 6, omega ratio - 6/omega - 3, and total blood cholesterol. The addition of yerba mate did not influence the oxidative profile of milk. Supplementation with soybean grain improved the FA profile of milk, increasing the concentrations of CLA and PUFA. The results suggest that the association of yerba mate and soybean grain helps to improve the fat quality of milk from ewes raised in tropical pastures, as shown by the enhanced antioxidant activity, although it does not help prevent oxidation of milk rich in PUFA.

Starter bacteria as producers of CLA in ripened cheese.

The profile of polyunsaturated fatty acids in cheeses obtained through fermentation by lactic acid bacteria Lactobacillus helveticus and Streptococcus thermophilus were evaluated. The milk used to make the cheeses came from cows fed with flaxseed oil and annato. The cheeses presented microbiological and physic-chemical quality with in the standards established by the legislation for Staphylococci and Listeria. With maturation, there was a reduction in the coliform values ​​for both treatments. Regarding the counts of lactic acid bacteria, these remained viable until the 30th day of maturation and the proteolytic bacteria decreased. For antioxidant capacity, the treatment containing the combination of the strains obtained high ABTS values. There was no significant difference between the treatments with respect to the color of the samples. For texture, there was a significant difference for the parameters cohesion and elasticity. No increase in CLA content was observed in the form of its two main isomers, however, the levels of polyunsaturated fatty acids were increased.

Feeding okara, a soybean by-product, to dairy cows as partial protein source enhances economic indexes and preserves milk quality, intake, and digestibility of nutrients.

This study was carried out to evaluate the potential of dietary inclusion of okara (a soybean by-product) on feed intake, apparent in vitro digestibility of dry matter, production and milk quality of dairy cows, and economic indexes. Four lactating Holstein cows were assigned to a 4 × 4 Latin square design. Treatments were control diet with no okara, diet with 35 g/kg okara, diet with 65 g/kg okara, and diet with 95 g/kg okara in dry matter basis. There was no effect of the inclusion of okara in the diet on the intake of dry matter, crude protein, and ether extract. The inclusion of okara did not affect the in vitro digestibility of nutrients either. However, neutral detergent fiber intake differed between levels 0 and 35 g/kg of okara in the diet, with lower (8.15 kg/day) and higher (9.30 kg/day) values for these treatments, respectively, with values intermediates for the other treatments. There was no significant difference for milk production, fat, protein, lactose, milk urea, somatic cell score, and conjugated diene. However, there was an effect of including okara on thiobarbituric acid reactive substance content in milk. Regarding the economic analysis, the inclusion of 95 g/kg of okara in the diet (dry matter) showed the best results for average feed cost, gross margin, breakeven, and profitability index. Okara can be included in diets of lactating dairy cows up to 95 g/kg of total mixed ration on dry matter basis without interfering on milk production, milk solids, nutrient digestibility, and providing beneficial economic indexes, being economically feasible.

Ruminal degradation kinetics of diets with different lipid sources and its influence on intake and milk yield of early lactation crossbred Holstein × Gir cows.

The hypothesized that the dietary inclusion of different lipid sources does not alter diet quality, feed intake, and, consequently, milk yield of cows. Thus, this study aimed to evaluate the effects of supplemental lipid sources for early lactation crossbred cows on milk yield, intake, and diet quality through in vitro digestibility and fermentation kinetics, and to demonstrate which variables have the most impact on each diet using principal component analysis (PCA). Five early lactating crossbred ¾ Holstein × » Gir cows (35 ± 8 days in milk), with a mean body weight of 410 ± 7.15 kg of body weight, were randomly allotted to a 5 × 5 Latin square. The treatments consisted of five experimental diets: a control diet with no additional lipid source and four diets with different lipid sources: cottonseed (242.6 g/kg of dry matter (DM)), sunflower seed (243.0 g/kg of DM), whole soybeans (234.0 g/kg of DM), and soybean oil (42.0 g/kg of DM), which were included at a rate to provide 70 g/kg of lipid. Diets with no additional lipid source and containing whole soybeans had higher DM, OM, and CP digestibility than other treatments. The diet containing soybean oil had the highest EE digestibility. Gas production was highest in the diet containing soybean oil. The dietary treatments did not affect DM intake. Milk yield was lower in cows receiving diets containing cottonseed. Whole soybeans can be included in diets for lactating cows to increase the energy intake without impairing the feed intake and milk yield.

Prediction of dry matter intake by meat sheep on tropical pastures.

This study was undertaken to determine whether equations for prediction of dry matter intake (DMI) by meat sheep are valid for animals raised solely on tropical pastures and to propose a new equation to predict the DMI of sheep raised on tropical pastures. The DMI prediction from published equations was evaluated by regressing the predicted and observed values, using the F test, for the identity of the parameters (ß0 = 0 and ß1 = 1) of the regression of predicted on observed data. If the null hypothesis is not rejected, the tested equation accurately estimates DMI. The proposed equation was evaluated in the same way as the published equations. The animal performance and pasture structure and chemical composition data used originated from an experiment conducted with 32 Santa Inês sheep raised on tropical pastures. In the analysis of model adequacy, the null hypothesis was rejected (P < 0.001) and the equations generated predictions that differ (ß0 = 0 and ß1 = 1) from the DMI observed under practical feeding conditions for grazing sheep. The proposed equation, DMI (%LW) = 7.16545 (± 0.76522) - 0.21799 (± 0.01812) * LW + 0.00273 (± 0.00034) * LW2-0.00688 (± 0.00299) * GT + 0.000007 (± 0.000002) * GT2 + 0.00271 (± 0.00108) * GHA, where LW is live weight (kg), GT is grazing time (min/day), and GHA is green herbage allowance (kg DM/100 kg LW), should be used to more accurately predict DMI by grazing sheep.

Lipid rich diet from sunflower seeds can alter the proportion of fatty acids on hybrid Beefalo × Nellore cattle.

We evaluated the lipid level effects in the diet on performance, carcass, and meat characteristics of forty-eight steers and heifers, F1 Beefalo (Bostaurus taurus × Bison bison hybrid) × Nellore (Bos taurus indicus), 22 months old, being 24 steers (393.2 ± 15 kg) and 24 heifers (278.4 ± 8 kg). The animals were distributed in a completely randomized design in a 4 × 2 factorial scheme (lipid levels in diet 55-, 65-, 75-, and 85-g/kg dry matter obtained by whole sunflower grain Helianthus annuus and two sexes). Increased amounts of sunflower grain in diet linearly reduce the proportion of saturated fatty acids (FA) in longissimus thoracis. Diets containing up to 85 g/kg of lipid can be used without negative effects on intake, carcass, and meat quality of Beefalo-Nellore steers and heifers and can be an effective strategy to reduce the proportion of saturated FA and increase unsaturated FA on the meat, which can be beneficial for human consumption.

Crambe meal and crude glycerin from biodiesel production in diets for finishing of crossbred cattle in feedlot.

Our hypothesis is that crambe meal can totally substitute soybean meal and crude glycerin can partially replace the corn in the diet without leading to losses of nutrient intake and productive performance. Two assays were performed using heifers and steers. In the first assay, 24 Beefalo-Nellore heifers with 18 months old with 311.5 ± 5.5 kg, and in the second assay, 24 Beefalo-Nellore steers with 18 months old with 317.0 ± 6.4 kg were evaluated. The experiment was carried out in a randomized complete design, in a 2 × 2 factorial scheme, consisting of two energy sources (corn and crude glycerin) and two protein sources (soybean meal and crambe meal). Both assays had 104 experimental days of feedlot. There was no interaction between the variation sources. There was an effect of protein source on nutrient intake for heifers except to neutral detergent fiber intake, which presented effect of energy source. Heifers fed soybean meal showed higher results for total weight gain and daily weight gain. There was observed effect of energy source on rib eye area and subcutaneous fat thickness. Steers fed soybean meal showed higher neutral detergent fiber intake and non-fibrous carbohydrates. Steers fed corn + crude glycerin showed higher results for total weight gain and daily weight gain. The steers fed soybean meal showed higher averages for subcutaneous fat thickness. Crambe meal and crude glycerin can be used as alternative sources of energy and protein to replace 100% of soybean and 50% of corn, respectively, for finishing Beefalo-Nellore cattle in a feedlot.

Orange juice industry by-product silage can increase fat and protein in Holstein cow's milk.

We aimed to evaluate the effect of replacing corn silage by orange peel silage on nutrient intake, ruminal parameters and milk production of multiparous lactating Holstein cows. Eight fistulated Holstein cows averaging 587.5 ± 39.6 kg and 111 ± 22 d in milking were randomly assigned to a double 4 × 4 Latin square design carried out two times to determine the effects of feeding with orange peel silage (OPS) in substitution of whole plant corn silage (WPCS). The treatments were a control diet with WPCS only or diets with OPS replacing WPCS in the total mixed diet (250, 500, or 750 g/kg DM). All cows were fed the same 750 : 250 g/kg roughage : concentrate ratio. The DM intake and milk production were reduced with the OPS inclusion, with decreases in consumption of neutral detergent fibre and increased consumption of non-fibrous carbohydrates. Diets with 250 and 500 g/kg OPS showed similar milk production and protein content in milk to the standard WCPS diet, whilst 750 g/kg orange peel silage as roughage increased fat and protein contents significantly. The orange peel silage as a substitute for corn silage for feeding dairy cows did not show adverse changes in the rumen environment and showed promising results in the increase of fat in milk of Holstein cows.

Combination of pelleting and monensin does not affect antioxidant properties and fatty acids in milk of grazing dairy cows supplemented with a concentrate containing soybean seeds.

This study was performed with the main objective of evaluating the effect of the combination of pelleting and monensin on fatty acids (FA) composition, the concentration of total polyphenols and flavonoids, and the oxidative stability of milk in cows fed a concentrate containing soybean seeds. Eight Holstein multiparous cows were distributed in a replicated Latin square design. The four supplement treatments consisted of the combination of two factors (pelleting and monensin) and one concentrate as follows: (1) unpelleted concentrate with no monensin (CO); (2) pelleted concentrate with no monensin (PE); (3) unpelleted concentrate with 96 mg of monensin/kg of dry matter, DM (MO); and (4) pelleted concentrate with 96 mg of monensin/kg of DM (PM). There was no interaction between pelleting and monensin for milk production and concentration of milk protein, lactose, total polyphenols, flavonoids, conjugated dienes (CD), and reducing power. Fat and total solids concentration in milk were decreased when cows were fed pelleted (PE and PM) concentrates. Feeding cows with PE and PM concentrates increased the CD concentration in milk. Regarding milk FA concentration, there was no difference among treatments for total saturated, monounsaturated, and polyunsaturated FA. The most prominent result was that pelleting increased the milk concentration of omega-3 FA. Altogether, the present study suggests that the pelleting process can improve the milk fat quality by increasing the omega-3 FA, while the combination of pelleting and monensin in the diet of grazing dairy cows fed soybean-based concentrate adds no further improvements to FA profiles and oxidative stability of milk.

Effect of supplementation with Yerba Mate (Ilex paraguariensis) and vitamin E on milk lipoperoxidation in cows receiving diets containing ground soybean seeds.

This research communication addresses the hypothesis that the association of dietary vitamin E and Yerba Mate could help to prevent or decrease oxidation of milk enriched in unsaturated fatty acids (UFA). Four multiparous lactating Holstein cows were used in a 4 × 4 Latin square. Treatments were: (1) control diet with no Yerba Mate or vitamin E; (2) diet containing 375 IU/kg vitamin E; (3) diet containing 30 g/kg Yerba Mate; and (4) diet containing 375 IU/kg vitamin E and 30 g/kg Yerba Mate. To increase unsaturated fatty acids in milk, cows were fed 172 g/kg soybean seeds (on a dry matter basis). There was no interaction between vitamin E and Yerba Mate supplementation for milk antioxidant-related (polyphenols, reducing power, conjugated dienes, and TBARS) analyses. Milk reducing power was increased when cows were supplemented with Yerba Mate. Our results suggest that the association of dietary vitamin E and Yerba Mate does not help to prevent or decrease oxidation of milk in UFA.

Energy balance in grazing Jersey cows in early lactation supplemented with peanut and sunflower oils.

In this study, we evaluated the effects of supplementation with peanut and sunflower oils on intake and digestibility, milk yield and composition, energy balance (EB), changes in weight and body condition score (BW and BCS), and blood metabolites of Jersey cows on pasture in early lactation. Twenty-four cows were distributed in a randomized block design where they received the following treatments: concentrate without oil (CON), concentrate plus 59.6 g/kg DM peanut oil (PEA), concentrate plus 59.6 g/kg DM sunflower oil (SUN), and concentrate plus 59.6 g/kg DM of a 1:1 mixture of peanut oil and sunflower oil (MIX). The data were analyzed at 30 and 60 days in milk (DIM). Oil supplementation did not affect total dry matter intake or forage intake. The treatment SUN reduced daily milk yield, 4% fat-corrected milk yield, and milk fat, while the other treatments generated similar results. The treatment SUN reduced the milk net energy and the use efficiency of the NEL for milk production and BW and BCS changes, and improved EB up to 60 DIM. On tropical pastures, supplementation with unsaturated oils for cows in early lactation does not result in better milk performance. The supplementation with sunflower oil improves the energy balance in early lactation.

Pelleting in Associated with Sodium Monensin Increases the Conjugated Linoleic Acids Concentration in the Milk of Dairy Cows Fed Canola Seeds.

To evaluate the effects of the pelleting and the addition of sodium monensin on production, the chemical and lipid composition of milk and butter physical characteristics, 4 Holstein dairy cows (135 days of lactation) with an average milk production of 14.7 kg/d, were supplemented with a concentrate containing ground canola seeds. The cows were assigned to a 4×4 Latin square design with a 2×2 factorial arrangement of treatments: i) ground maize, soybean meal, mineral and vitamin supplements, and ground canola seeds (CG); ii) CG concentrate with 31.5 mg of monensin added per kg of dry matter (DM); iii) CG pelleted concentrate; iv) CG concentrate with monensin addition pelleted. There was no difference in milk production and composition. The addition of monensin increased milk concentration of polyunsaturated fatty acids (PUFA), the PUFA/saturated fatty acids (SFA) ratio, and omega 6. The pelleting increased the concentration of monounsaturated fatty acids, the PUFA/SFA ratio, and the omega 6/omega 3 ratio, but decreased the concentration of SFA. The association between pelleting and the addition of monensin increased the concentration of conjugated linoleic acids by 46.9%. The physical characteristics of butter were not affected by the evaluated diets. We concluded that the concentrate with 31.5 mg of monensin added per kg DM basis combined with the pelleting improves the lipid composition of milk from Holstein cows that are on pasture and supplemented with ground canola seeds, without changing the production, milk composition, and spreadability of butter.