ABSTRACT. The aim of this study was to examine the effect of longer cutting intervals on morphogenetic and structural traits, herbage production, nutritional value, and in vitro digestibility of Guinea grass cv. Mombaça (Mombaça grass). Four cutting intervals (49, 63, 77, and 91 days) were evaluated in two crop years (2015-2016 and 2016-2017) during the rainy season, in two replicates. Cutting intervals influenced structural and morphogenetic traits, except for number of live leaves (4.35 leaves tiller-1) and final leaf length (72.94 cm) in the 2015-2016 crop year. As the cutting intervals increased, dry matter yield and stem percentage increased, whereas leaf percentage and leaf-to-stem ratio declined. Regardless of the evaluated crop year, the dry matter, acid detergent fiber, and lignin contents increased linearly; however, the neutral detergent fiber content was unaffected. Cutting intervals affected the crude protein content and in vitro digestibility. Considering leaf appearance rate, stem appearance rate, and leaf-to-stem ratio, the recommended harvest age for Mombaça grass for optimum yield and nutritional value is 77 days. ABSTRACT traits production cv grass. . grass) 49, 49 (49 63 9 days 20152016 2015 2016 (2015-201 20162017 2017 2016-2017 season replicates 4.35 435 4 35 (4.3 tiller1 tiller 1 tiller-1 72.94 7294 72 94 (72.9 cm 2015-201 year leaftostem declined linearly however unaffected rate 7 (4 6 2015201 201 (2015-20 2016201 2016-201 4.3 43 3 (4. tiller- 72.9 729 (72. 2015-20 ( 201520 20 (2015-2 201620 2016-20 4. 72. (72 2015-2 20152 2 (2015- 20162 2016-2 (7 2015- (2015 2016- (201 (20 (2

Resumo O objetivo deste estudo foi caracterizar os partos com leve ou severa dificuldade e diferenciá-los com base no desempenho produtivo e reprodutivo de vacas leiteiras. Os partos foram agrupados em partos sem assistência, partos com baixa assistência e partos com elevada assistência. O banco de dados original continha 1902 registro de partos que foram obtidos de uma grande fazenda comercial localizada no Sudeste do Brasil. A análise fatorial foi aplicada através do programa estatístico SAS® Studio 3.8 por meio de procedimento fatorial, considerando a categoria de análise multivariada. Os teores de gordura do leite (0,92– 0,79) e de sólidos totais (0,91–0,80) foram altamente correlacionados com o fator 1. Intervalo entre partos (0,87–0,68) e número de IA (inseminações artificiais) por concepção (0,87–0,71) apresentaram alta correlação com o fator 2. Produção de leite (0,84–0,76) e produção acumulada de leite (0,84–0,77) foram altamente correlacionados com o fator 3. Baseados nos resultados, é possível concluir que as três situações de parto foram caracterizadas por fatores independentes e bem definidos. Vacas que necessitaram de alta assistência ao parto apresentaram menor variância explicada pelo modelo para teores de gordura e sólidos totais do leite, intervalo entre partos e número de IA por concepção.

Abstract The objective of this study was to characterize calvings with low and high difficulty based on the productive and reproductive performance of dairy cows. Calvings were grouped in no calving assistance, calving with low assistance, and calving with high assistance. The original data set comprised 1,902 calving records obtained from a large dairy farm in Southeast Brazil. Factor analysis was applied using the SAS® Studio 3.8 statistical program through the factor procedure, considering the Multivariate Analysis category. Milk fat (0.92–0.79) and total solids (0.91–0.80) were strongly correlated with Factor 1. Calving interval (0.87– 0.68) and the number of AI (artificial inseminations) per conception (0.87–0.71) showed high correlations with Factor 2. Milk yield (0.84–0.76) and accumulated milk yield (0.84–0.77) were strongly correlated with Factor 3. Based on the results, we conclude that the three calving scenarios were characterized by well-defined and independent factors. Cows which required a high assistance at calving showed a lower variance explained by the model for milk fat and total solids contents, calving interval, and the number of AIs per conception.

Abstract This research article describes the effect of different concentrations of iodine in the teat-dipping before milking and post-dipping solution on milk, urine, thyroid hormone, chemical composition and somatic cell count. Four multiparous cows were distributed in a 4 x 4 Latin square experimental design in a tie-stall system. The treatments were 0.5%, 1%, and 2% iodine and the control was treated with chlorhexidine. The iodine concentration of milk, food and urine was quantified. Thyroid hormones were analyzed by chemiluminescence microparticle immunoassay. Milk composition by differential absorption of infrared waves and somatic cell countby (SCC) flow cytometry. There was no significant effect of iodine concentrations in teats soaking solution before milking on urine iodine concentration and thyroid hormones (T3 and T4). Likewise, no effect of treatments was observed for the contents of protein, fat, lactose, total solids, Milk urea nitrogen and SCC. However, increasing iodine concentrations in the teat soaking solution before milking linearly increased the iodine concentration in milk. Therefore, the iodine concentration in the pre-milking and post-dipping solutions can change the iodine concentration in the milk.

Abstract Our hypothesis was that different sources of unsaturated fatty acids from oilseeds (sunflower, soybeans, and cottonseed) could alter milk yield, fatty acid profile, and the amount of unsaturated fatty acids yielded in milk. It aimed to evaluate the effects of lipid sources on yield and composition and fatty acids in milk of primiparous Girolando cows. Five cows in lactation (35 ± 8 days), with 410 ± 7.15 kg BW were randomly distributed in a 5 x 5 Latin square. Five experimental diets, namely a control diet without an additional source of lipid and four diets with different lipid sources: cottonseed, sunflower seed, whole soybean, or soybean oil, as lipid source, to reach 70 g/kg of ethereal extract dry matter basis were used. Cottonseed and soybean oil addition reduced daily yield by 15 and 22%. Oilseed can alter fatty acid profile in milk. Whole soybean provided greater daily milk and fatty acids yields.

ABSTRACT We evaluated the association of monthly milk urea N (MUN) concentrations before conception and days open in high-producing dairy cows from commercial herds in Southern Brazil. Other herd traits were also investigated regarding their relationship with days open. A database containing 16,569 monthly test-day records (obtained from 3,926 lactations of 2,145 cows) for productive, reproductive, and milk quality data was assembled from three different herds. Maximum MUN before conception was divided into quartiles as follows: ≤15.5 mg/dL (1), from 15.6 mg/dL to 18.0 mg/dL (2), from 18.1 to 20.5 mg/dL (3), and >20.5 mg/dL (4). When cows calved in spring and winter, days open averaged (mean±SE) 171.2±2.71 and 155.4±2.31, corresponding to an increase in 12 and 2%, respectively, related to cows that calved in summer (152.7±2.44). When cows calved in fall, a 12% reduction in days open (135.5±1.79) compared with cows that calved in summer was observed. The estimated regression coefficients showed that multiparous cows are expected to have an increase of 12 and 6% in days open when compared with primiparous and secondiparous cows, respectively. Days open were positively associated with the highest MUN value obtained until conception. Cows in the highest quartile of maximum MUN (>20.5 mg/dL) had more days open (184.6±2.93) than cows in quartiles 1, 2, and 3 (123.7±2.12, 150.2±2.16, and 160.5±2.29, respectively), which represents reductions of 40, 21, and 14%, respectively. These results suggest that a maximum MUN concentration before conception higher than 15.5 mg/dL may negatively impact the fertility of high-producing dairy cows.

ABSTRACT The objective with this study was to evaluate the effect of including dried distillers grains with solubles (DDGS) as a replacement for soybean meal on feed intake, digestibility, and total digestible nutrients (TDN), as well as plasmatic glucose and serum urea concentrations. Fifteen Saanen goats were distributed in a completely randomized design with three treatments and five replicates. Treatments were soybean meal (SBM), SBM+DDGS (12.28% of dry matter [DM]), and DDGS (23.16% of DM), as protein source in diets, common to all corn ground and mineral-vitamin supplement, and corn silage (60% of DM). Response variables were evaluated every 30 d, from 1 to 120 d after parturition. Measurements included body weight, DM intake, DM and nutrient digestibility, and blood samples. Indigestible neutral detergent fiber was used to estimate fecal excretion. There was a difference in neutral detergent fiber intake from 1 to 30 d after parturition. In the four phases of lactation evaluated, there were treatment effects on DM, organic matter, ether extract, and total carbohydrate digestibility, as well as on TDN concentration. Neutral detergent fiber digestibility was affected by treatments, except from d 61 to 90. There was no treatment effect on non-fibrous carbohydrate digestibility, regardless of period. Therefore, SBM+DDGS (12.28% of DM), as protein source on diets may be used in Saanen goat diets from 1 to 120 d of lactation without negative effects on feed intake, digestibility, and plasma glucose and urea concentrations.

ABSTRACT This study aimed to investigate the influence of forage production area, concentrate supply, and farm labor on characterization of milk production systems (MPS) and their productive results. Milk volume data provided in 2014 by 110 dairy farms located in the eastern region of Santa Catarina State, Brazil, were obtained from a dairy industry. Forty-four farms with different production levels were selected, in which interviews were carried out aiming to characterize the management practices related to forage production area, concentrate supply, and farm labor. A principal component analysis (PCA) was performed. Then, regressions were made between the principal components (PC) and indicator variables of productive response (annual milk production, milk production per area, milk production per cow, milk production per worker on farm, and number of cows per hectare). Finally, we performed a hierarchical agglomerative cluster analysis based on the PCA, followed by comparison of the means between clusters. Three PC were generated: indicator of scale and intensification, indicator of age of the manager and his experience on dairy farming, and indicator of specialization and permanent family labor available. The three PC were influencing the production results, especially PC1. It was possible to form five clusters: cluster 1, characterized by the highest value in PC1, showed the highest production results, followed by the cluster 2, with intermediate values in PC1; clusters 3, 4, and 5, characterized by lower values in PC1 and distinguished by PC2 and PC3, had the lowest productive results. Aspects related to forage production area, concentrate supply, and workforce are important for MPS characterization and have significant influence on productive results.

ABSTRACT The presence of mycotoxins or related fungi in animal feed is a major problem for animal and human health. Silage and concentrated feed samples were collected from 21 dairy farms in the Western part of Paraná state in Southern Brazil. Water activity and pH of all samples were measured, and each sample was analyzed to check for the presence of aflatoxigenic Aspergillus. Water activity was observed to be lower in the concentrated feed samples. The pH was lower in the silage samples, indicating fermentation processes. Two silage samples and four concentrated feed samples were contaminated with Aspergillus spp. Seven isolates of Aspergillus spp. were obtained and their potential to produce aflatoxins was evaluated. Four of the isolates, two from the silage samples and two from the concentrated feed samples, produced the aflatoxins B1, B2, G1, and G2 in culture media. These isolates were identified as Aspergillus parasiticus and Aspergillus nomius. The presence of aflatoxigenic isolates of Aspergillus spp. in silage and concentrated feed samples is a matter of concern, because of the risk of aflatoxin production and contamination of the animal feed.

RESUMO. Os coprodutos da agroindústria constituem uma alternativa para a utilização na nutrição animal. Foram realizados ensaios com oito tipos de coprodutos e alimentos para avaliar a composição bromatológica, a digestibilidade in vitro da matéria seca, a proteína bruta e a fibra em detergente neutro, bem como a produção de gases gerados por eles. Os coprodutos utilizados neste estudo foram: casca de café; polpa cítrica peletizada; resíduo de uva; casca de grão de soja; caroço de algodão; rama de mandioca e alimentos tradicionalmente empregados na alimentação de ruminantes: silagem de milho e concentrado de grão de milho moído. Os dados de digestibilidade in vitro da matéria seca, da proteína bruta e da fibra em detergente neutro foram interpretados por uma análise de variância, utilizando o método de quadrados mínimos; os resultados da produção de gás foram interpretados por uma regressão não linear pelo método de Gauss-Newton; e os efeitos de tratamentos foram avaliados por teste de médias (Teste de Tukey). Os coeficientes da digestibilidade in vitro da matéria seca, da proteína bruta e da fibra em detergente neutro dos alimentos analisados foram distintos. A produção de gases também foi distinta para os coprodutos e alimentos avaliados em relação ao volume de gás produzido nas frações de degradação rápida e lenta, taxa de degradação e para o tempo de colonização das bactérias e para o volume de gás total produzido. Os coprodutos avaliados apresentaram maior digestibilidade in vitro da matéria seca em relação à silagem de milho, com exceção do caroço de algodão, do resíduo de uva e da rama de mandioca. Além disso, os coprodutos apresentaram maiores valores de digestibilidade in vitro da proteína bruta em relação à silagem de milho, e redução da digestibilidade in vitro da fibra em detergente neutro, exceto para a polpa cítrica peletizada e a casca de grão de soja. A silagem de milho apresentou o maior volume de gás produzido na fração de degradação rápida comparada aos coprodutos e ao concentrado de milho. Os coprodutos analisados apresentaram características nutricionais adequadas pelas técnicas utilizadas e podem ser adicionados à dieta de ruminantes.

ABSTRACT. Agroindustrial co-products are a viable alternative for use in animal nutrition. Tests were conducted using eight different types of co-products and feed to evaluate the chemical composition, in vitro digestibility of dry matter, crude protein and neutral detergent fiber, and gas production by them. The co-products tested were: coffee hulls; pelleted citrus pulp; grape residue; soybean hulls; cottonseed; cassava foliage; and foods usually supplied to ruminants: corn silage and ground corn concentrate. Data of in vitro digestibility of dry matter, crude protein and neutral detergent fiber were tested by analysis of variance using the least square method; the results of gas production were interpreted by a non-linear regression by the Gauss-Newton method; and the effects of treatments were evaluated by the Tukey’s test. The coefficients of in vitro digestibility of dry matter, crude protein and neutral detergent fiber of co-products were different. Gas production was also different between co-products and feeds evaluated for the volume of gas produced from the fast and slow degradation fractions, degradation rate, bacterial colonization time, and the total volume of gas produced. The evaluated co-products exhibited greater in vitro dry matter digestibility compared to corn silage, except for cottonseed, grape residue, and cassava foliage. Co-products showed higher values of in vitro crude protein digestibility compared to corn silage, and a reduced in vitro digestibility of neutral detergent fiber, except for pelleted citrus pulp and soybean hulls. Corn silage produced larger volume of gas from the fast degradation fraction compared to the co-products and corn concentrate. Co-products analyzed had appropriate nutritional characteristics according to the techniques applied and can be included in ruminant diets.

ABSTRACT This study was conducted to evaluate the effects of long-chain fatty acid soaps (LCFAS) of soybean oil on the production and quality of aspirated cumulus-oocyte complexes (COC) of lactating Nellore (Bos taurus indicus) cows. The effects of LCFAS on the plasma concentration of lipoproteins, total cholesterol, triacylglycerol, urea N, and insulin were also addressed. Thirty lactating Nellore cows were randomly assigned to one of two dietary groups. Cows were grazed on a Tifton 85 pasture throughout the experiment (100 days). Treatments consisted of a supplement with no fat included (CONT); and a supplement containing 47.2 g/kg of LCFAS on a dry matter basis. After 14 days of treatment, animals were subjected to 4.93±1.55 rounds of consecutive ovum pickup (OPU) at intervals of 21.71±11.76 days. Blood samples were collected from all cows throughout the experiment at 25-day intervals (four samples per cow). Cows that were fed LCFAS supplements and cows that were fed CONT supplements had similar numbers of total aspirated oocytes (viable and not viable) by OPU and grades of viable oocytes. Plasma concentrations of high-density lipoprotein (HDL) were increased in cows supplemented with LCFAS. Plasma concentrations of LDL and total cholesterol were increased by LCFAS supplementation after 50 days on dietary treatment and insulin concentration was increased from 75 days on treatment. Long-chain fatty acid soaps from soybean oil added at 47.2 g/kg have no effect on the number of aspirated COC or their quality in Nellore lactating cows even with changes in plasma concentration of HDL, LDL, total cholesterol, and insulin. Thus, this supplementation has no benefits when the main objective is to improve oocyte production and quality.

RESUMO. Objetivou-se no presente trabalho caracterizar alimentos utilizados nas rações de cabras Saanen. Os alimentos avaliados foram: feno de Tifton 85 (Cynodon spp.), farelo de soja, milho moído, casca do grão de soja, milho desintegrado com palha e sabugo e resíduo seco de fecularia de mandioca. Foram determinados os teores de matéria seca, cinzas, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, fibra fisicamente efetiva e lignina, e estimados a matéria orgânica, os carboidratos totais e os carboidratos não fibrosos. Os carboidratos foram divididos nas frações A + B1 (rapidamente degradáveis), B2 (potencialmente degradáveis) e C (não degradáveis); e a proteína, nas frações: A (solúvel), B1 (rápida degradação ruminal), B2 (degradação intermediária), B3 (lenta degradação) e C (indigestível). Para determinar a produção de gás foi utilizada a técnica automática in vitro, modificada pela Ankom(r). Foram observadas diferenças entre os alimentos para os parâmetros A, B, C, E e A + D da cinética de degradação ruminal, sendo que os alimentos com alto teor de carboidratos não fibrosos apresentaram maior fração A (rápida degradação), e o feno apresentou maior tempo de colonização (fração C). A produção total de gás foi maior para o milho moído, milho desintegrado com palha e sabugo e resíduo seco de fecularia de mandioca.

ABSTRACT. This study was performed to characterize feed used in diets for Saanen goats. The feedstuffs were: Tifton 85 hay (Cynodon spp.), soybean meal, ground corn, soybean hulls, ground ear corn and dried cassava residue. Contents were determined for dry matter, ash, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, physically effective fiber and lignin, and organic matter, total carbohydrates and non-fiber carbohydrates were estimated. Carbohydrates were divided into fractions A + B1 (rapidly degradable), B2 (potentially degradable) and C (non-degradable); and the protein in fractions A (soluble), B1 (rapid ruminal degradation), B2 (intermediate degradation), B3 (slow degradation) and C (indigestible). To determine the gas production an automatic technique in vitro was used, modified by Ankom(r). Significant differences were observed among feed for the parameters A, B, C, E and A + D of ruminal degradation kinetics, and feed with high non-fibrous carbohydrates content presented higher fraction A (rapid degradation), and the hay showed longer lag time (fraction C). The total gas production was higher for ground corn, ground ear corn and dried cassava residue.

O objetivo definido neste trabalho foi verificar se produtores de leite que participam de arranjos horizontais (AH) possuem menor assimetria de informações, frente àqueles que não participam desses arranjos. Parte-se do pressuposto de que o maior acesso à informação resulta em menor risco para o produtor rural. Foram aplicados 120 questionários semiestruturados junto a produtores rurais de leite, localizados em quatro macrorregiões do Estado do Paraná. Foi realizada a análise fatorial exploratória (AFE) para definição de fatores relacionados à assimetria de informação em Sistemas Produtivos Leiteiros (SPL's). Os 120 produtores entrevistados foram divididos em dois grupos: aqueles que participavam de arranjos horizontais (AH) e aqueles que não participavam. Esses grupos foram confrontados com os fatores gerados na análise anterior. Foi encontrada diferença significativa (P<0,05) para os fatores "Informações relacionadas às transações" e "Informações globais para a atividade", sendo que produtores de leite que participavam de arranjos horizontais obtiveram melhores resultados. Por fim, conclui-se que produtores que participam de AH têm mais acesso à informação, o que pode criar um ambiente de menor assimetria de informações e consequentemente de menor risco, comparativamente a produtores que não participam de AH

An empirical investigation was conducted to study whether dairy farmers involved in horizontal arrangements (HA) have lower information asymmetry than those who do not participate in HA. Our assumption is that greater access to information results in fewer risky decisions in production systems. One hundred and twenty semi-structured questionnaires were applied to dairy farmers located in four different geographical regions in Paraná State, Brazil. Exploratory factor analysis was used to define factors related to information asymmetry in dairy agribusiness system (DAS) and four factors were defined. In a second step, the 120 dairy farmers were split into two groups: the first one involved in HA and the second one not involved in HA. Mean test (t-student) were performed to compare these groups between factors. Significant differences (P<0.05) were observed for factors related to transaction information and for general market information, and dairy farmers participating in HA achieved the greatest values. Finally, it can be concluded that dairy farmers who participate in HA have higher access to information, which can create an environment with lower information asymmetry and, consequently, be subject to lower risks than dairy farmers who do not participate in HA

De acordo com a fonte de gordura incluída na dieta de cabras, a produção de leite pode ser aumentada e a composição de ácidos graxos do leite pode ser melhorada. Este estudo foi conduzido para avaliar a inclusão de gordura protegida (SCAG - sais de cálcio de ácidos graxos) nas dietas de cabras Saanen lactantes, sobre a produção e composição do leite. Cinco cabras Saanen (63,23 ± 9,08 kg de peso corporal e 105 ± 3 dias de lactação) foram distribuídas em delineamento quadrado Latino (5 × 5) em cinco dietas: controle (sem adição de SCAG) e os demais, dietas com: 6,25; 12,50; 18,75 e 25 g de SCAG por kg de matéria seca (g/kg MS), respectivamente. A ingestão de matéria seca (IMS) e a produção de leite (PL) foram avaliadas. Amostras de leite foram coletadas para determinar a composição e o perfil de ácidos graxos. A eficiência alimentar (EA) foi estimada. A suplementação de SCAG em até 25 g/kg MS não influencia a IMS, PL e a EA. A produção de componentes do leite (g/d) não foi influenciada pela inclusão de SCAG na dieta, no entanto,houve redução linear de 0,87 g de proteína por kg de leite para cada 1% de inclusão de SCAG na dieta. A concentração de ácido linolênico (18:3n-3) no leite aumentou com o ponto de máxima de 24 g de SCAG por kg de MS. A gordura protegida pode ser incluída na dieta de cabras Saanen em lactação, em até 25 g/kg MS sem interferir na IMS e PL.

According on the fat source included in the diets for goats, the milk production can be increased and milk fatty acid composition can be improved. This study was conducted to evaluate the inclusion of protected fat (CSFA - calcium salts of fatty acids) in the diets of lactating Saanen goats on milk production and composition. Five Saanen goats (63.23 ± 9.08 kg body weight and 105 ± 3 days of lactation) were distributed in a Latin square design (5 × 5) with five diets: control (without the addition of CSFA) and the other diets with: 6.25, 12.50, 18.75 and 25.0 g CSFA per kg dry matter (g/kg DM), respectively. Dry matter intake (DMI) and milk production (MP) were evaluated. Milk samples were collected to determine milk composition and fatty acid profile. Feed efficiency (FE) was estimated. The supplementation of CSFA up to 25 g/kg DM did not influence the DMI, MP and FE. Milk components production (g/d) was not influenced by the inclusion CSFA in the diet; however, there was a linear reduction of 0.87 g protein per kg of milk for each 1% CSFA included in the diet. The concentration of linolenic acid (18:3n-3) in milk was improved with a maximum point of 24 g of CSFA per kg DM. CSFA can be included in the diets of lactating Saanen goats up to 25 g/kg DM with no interference on DMI and MP.

The objective of the present study was to characterize the food sources, as well as the composition and quality of milk obtained from household farms of western Paraná State (Brazil) with and without technical assistance during the different seasons. For such, 24 properties were selected, 12 of which only received assistance and technical support. Four milk samples were taken (summer, autumn, winter and spring) to assess the physicochemical composition, somatic cell count and total bacterial count and feed supplied to the animals to assess the chemical composition (crude protein, ash, dry matter and neutral detergent fiber). The data were analyzed in a completely randomized design with a 2 × 4 factorial arrangement; the first factor was the presence and absence of technical assistance and the second factor was the four seasons of the year. Due to the dairy tradition of properties in the region, technical assistance had no significant effects on the health and nutritional quality of food, the number of animals, the production, or total bacterial count, which suffered oscillations only depending on the seasons of the year. However, the presence of assistance contributed to reducing somatic cell counts of milk produced and marketed. The technical assistance does not affect the quality of forages and concentrates used or the milk composition; however, it improves the sanitary quality of the milk produced throughout the four seasons of the year in household farms of western Paraná.

O estudo avaliou os efeitos da suplementação com líquido da casca da castanha de caju (LCCC) em ração de vacas em lactação sobre o consumo, a digestibilidade dos nutrientes, a produção e composição do leite, e a composição de ácidos graxos da gordura do leite. Foram usadas quatro vacas Holandesas (600±43 kg), e o delineamento estatístico foi o quadrado latino 4 x 4, com períodos experimentais de 21 dias. Os tratamentos experimentais consistiram na inclusão de LCCC na ração total misturada, como segue: 1) LCCC 0% (controle, CON); 2) LCCC 0,012% (0,012); 3) LCCC 0,024% (0,024) e 4) LCCC 0,036% (0,036). O consumo de matéria seca e de nutrientes, a digestibilidade aparente dos nutrientes, a composição e a produção de leite corrigida para gordura não foram influenciados pelos tratamentos (p > 0,05). O uso de LCCC diminuiu linearmente a concentração de C6:0 (p < 0,02), produziu uma resposta quadrática na concentração de C13:1n-5 (p < 0,03) e um aumento linear no C16:1n-7 (p < 0,04). Os resultados mostram que o consumo de até 7 g dia-1 de LCCC por vacas leiteiras pode alterar a composição de ácidos graxos da gordura do leite, mas não influencia o consumo, a digestibilidade dos nutrientes e a produção de leite.

The study evaluated the effects of supplementing cashew nut shell liquid (CNSL) in the diet of lactating dairy cows on the intake, nutrient digestibility, milk yield and composition, and fatty acids composition of milk fat. Four Holstein cows (600±43 kg) were used in a 4 x 4 Latin square design with 21 days experimental periods. Experimental treatments consisted of CNSL inclusion in a total mixed ration (dry matter basis), as follows: 1) CNSL 0% (control, CON), 2) CNSL 0.012% (0.012), 3) CNSL 0.024% (0.024) and 4) CNSL 0.036% (0.036). Dry matter and nutrients intake, apparent digestibility of nutrients, fat corrected milk yield and milk composition were not affected (p > 0.05) by the inclusion of CNSL in the ration. CNSL linearly decreased the C6:0 concentration (p < 0.02), produced a quadratic response on C13:1n-5 concentration (p < 0.03) and a linear increase on C16:1n-7 concentration (p < 0.04). Results show that an intake of up to 7 g cow-1day-1 (0.036%) of CNSL may alter the milk fatty acid composition but does not influence intake, nutrient digestibility and milk yield.