ABSTRACT We sought to develop a typology describing structural, production, and socioeconomic characteristics of dairy systems that produce artisanal cheese and compare it with that of systems that produce only raw milk. Data on 204 raw milk producers and 58 artisanal cheese producers in Paraná State, Brazil, were collected through on-site surveys and subjected to descriptive analysis, factor analysis, and means tests. Descriptive analyses were applied to characterize the sample and artisanal cheese production processes. Factor analysis identified the following three typological components: system production capacity, herd breed and milking characteristics, and farmer social characteristics. Farmers were divided into two groups, as follows: non-cheese producers (NCP) and artisanal cheese producers (ACP). Groups of farmers were compared in terms of typological components. It was found that ACP have smaller structure and production scale and focus less on herd breed and practices for improving milk quality than NCP. These results suggest that artisanal cheese production is a strategy to add value to milk that does not meet institutional or market requirements for transactions with the dairy industry, providing a foothold for producers to remain in the dairy business. Groups of farmers (ACP and NCP) do not differ in social indicators of typology.

ABSTRACT We aimed to compare the typology of dairy production systems (DPS) that meet Brazilian quality standards with that of non-compliant DPS. Semi-structured questionnaires were applied in 128 DPS located in Santa Izabel do Oeste, Paraná, Brazil (25°49'16" S and 53°29'04" W). In addition, milk quality reports of each DPS were analyzed. Dairy production systems were segregated into two groups: G1 – DPS that were in accordance with Brazilian regulations on milk quality, and G2 – DPS that did not comply with Brazilian regulations. Exploratory factor analysis was performed on structural, production, and technical variables. Two factors were defined: F1 – production scale and bargaining power, and F2 – autonomy and production control. Groups 1 and 2 were evaluated according to their structural, production, and technical characteristics as well as their F1 and F2 values. A small fraction (6.25%) of DPS met the minimum quality standards for milk. Dairy production systems that comply with quality regulations have larger production scale, higher productivity, and greater autonomy and control of milk production. Consequently, they have better bargaining power with the industry for the marketing of milk.

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.

The objective of this study was to evaluate the milk production, composition, milk fatty acid profile, butter texture and blood parameters of Holstein cows fed corn silage and concentrate containing one of the following: ground sunflower seeds; ground sunflower seeds treated with 50 g of lignosulfonate/kg of sunflower dry matter; pelleted sunflower seeds; or ground sunflower seeds pelleted and treated with 50 g of lignosulfonate/kg of sunflower dry matter. Four lactating cows were used, each with 130±28 days in lactation and a body weight of 569±63 kg. These animals were distributed in a Latin square design with four periods of 21 days each, with 14 days of adaptation and seven days of data collection. The diets were formulated to meet nutritional requirements and had a forage:concentrate ratio of 60:40. The milk fat was lower in the pelleted treatments. The concentrations of 16:1 n-11 and trans18:1 n-9 in the milk increased, and the n-6:n-3 ratio was higher for the pelleted treatments. The firmness and adhesiveness of the butter and the blood parameters analyzed were not affected by the treatments. Addition of lignosulfonate is not effective in protecting polyunsaturated fatty acids from the ruminal biohydrogenation process, and the pelleting process has little effect on the milk fatty acid profile and can not change the butter texture.

The objective of this study was to evaluate intake, in vitro and apparent digestibility and ruminal parameters of Holstein cows that were confined and fed corn silage and concentrate containing: ground sunflower seeds (GS); ground sunflower seeds treated with 5% lignosulfonate (GSL); pelleted sunflower seeds (PS); or ground and pelleted sunflower seeds treated with lignosulfonate (PSL). Four lactating cows with 130±28 days of lactation and body weights of 569±63 kg were used. These animals were distributed in a Latin square design with four diets and four periods of 21 days each. There were no differences in the intakes (% body weight) of dry matter (DM), organic matter (OM), mineral matter (MM), crude protein (CP), neutral detergent fiber (NDF) or acid detergent fiber (ADF). The apparent digestibility of DM, OM, CP, EE, NDF, ADF and NFC were similar for all the diets, with a tendency towards decreased CP digestibility for all the pelleted diets (65.79%) compared with the non-pelleted diets (69.66%). A negative effect of lignosulfonate was observed for the in vitro digestibility (IVD) of DM, and a negative tendency was observed for the IVD of OM. Pelleting decreased the concentration of acetic acid (55.95 × 58.82 mM) in rumen fluid. There was no effect of diet on pH (6.17) or ammonia nitrogen concentration (18.19 mg/dL). Pelleting and lignosulfonate do not promote the protective effect of sunflower seed nutrients as expected, and it may be more feasible to provide ground sunflower seed.

Four multiparous Holstein cows averaging 548 kg of body weight and 74 d in lactation were used in a Latin square design with four 21-d experimental periods to determine effects of feeding extruded versus non-extruded canola seed, with or without 50 g/kg lignosulfonate on rumen fermentation, nutrient flow to the omasum, and degradability of dry matter (DM) and N of each diet. The DM effective degradability increased with extrusion and lignosulfonate treatment had no effect. The effective degradability of N was similar between diets. Lignosulfonate treatment of extruded versus non-extruded canola seeds decreased ruminal and total tract apparent digestibility of organic matter. The lowest apparent ruminal and highest intestinal digestibilities of protein, expressed as a percentage of N intake were observed for cows fed extruded canola seeds without lignosulfonate. Lignosulfonate treatment and extrusion had no effect on pH and concentrations of ammonia N and volatile fatty acids in the rumen. Results suggest that extruded canola seed untreated with formaldehyde may stimulate efficiency of microbial protein synthesis and is an effective means of increasing the availability of protein in the small intestine without affecting the total tract apparent digestibility of protein.

The objective of this study was to evaluate the administration of different doses of calcium hydroxide mixed with sugar cane fed to cows by the pH, ammonia nitrogen and volatile fatty acids concentration in ruminal content. Four cows with fistulated rumen were distributed in a Latin square (4 × 4) in split plot. The treatments involved adding doses of 0, 8, 16 and 24 g/kg of calcium hydroxide to sugar cane in natura. Samples of rumen fluid were collected and the pH and concentration of N-NH3 was determined before (time zero) and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 hours after the feeding time. The concentration of volatile fatty acids at 0, 3, 6, 9 and 12 hours was also determined. The calcium hydroxide contributed to maintain the pH of rumen fluid close to neutral. The average concentrations of N-NH3 in the ruminal fluid was 20.59, 20.49, 17.28 and 18.22 mg/100 mL for samples with calcium hydroxide at 0, 8, 16, 24 g/kg, respectively. There was an effect of the addition of calcium hydroxide on the volatile fatty acids concentration from before feeding until 12 hours after feeding time. There was an effect on doses tested for the concentration of volatile fatty acids. The calcium hydroxide added to the sugar cane influences on ruminal parameters. The dose of approximately 10 g of calcium hydroxide per kg sugar cane in natura is recommended.

The objective of this work was to evaluate, in bovines, the intake and apparent digestibility of nutrients, ingestive behaviour and content of total digestible nutrients (TDN) of diets based on sugar cane treated with calcium hydroxide. It was used four cows with average body weight of 412.06 kg ± 37.3 kg. The study included inclusion of calcium hydroxide at the doses 0, 8, 16 and 24 g/kg of sugar cane in natural matter basis fed in diets with 65% of roughage and 35% on concentrate, based on dry matter (DM). It was used a 4 × 4 Latin square experimental design with four treatments and four periods. Calcium hydroxide doses affected nutrient intake: DM intake was 7.88 kg/day at the dose of 14.99 g of calcium hydroxide, organic matter (OM) intake was 6.75 kg/day at 10.94 g; intake of neutral detergent fiber (NDF) of 3.33 kg/day with a dose of 13.93 g; and intake of acid detergent fiber (ADF) of 2.12 kg/day with a dose of 10.51 g. Digestibility coefficients showed a quadratic effect for doses of inclusion of calcium hydroxide. Dry matter digestibility was 72.88% with a dose of 11.65 g of calcium hydroxide, OM digestibility was 75.12% with 12.09 g; NDF digestibility was 58.67% with 12.11 g; ADF digestibility was 52.97% with 9.36 g and TDN digestibility was 71.42% with 10.92 g. There was no effect of the treatment for activities of rumination and total idle. Chewing time, number of bolus chewed and time for rumination of each bolli presented effect. Calcium hydroxide enabled greater intakes and digestibility of nutrients, especially from the cell wall, favoring the use of nutrients from the diet containing sugar cane, recommending a dose of 8-12 g.

Objetivou-se propor uma metodologia de análise de sistemas de produção, tomando-se como base o fluxo quantitativo intra-anual e as características qualitativas do leite entregue pelos produtores de leite à indústria. Foram coletados dados referentes a 1.196 produtores de leite durante os anos 2005 e 2006 utilizando-se as variáveis produção mensal; teores de gordura, proteína, lactose e sólidos totais; contagem de células somáticas e contagem padrão em placas. A metodologia de análise utilizada foi a análise de componentes principais e a classificação hierárquica ascendente (tipologia). As variáveis mais importantes na construção do primeiro componente principal (CP1) são os teores de gordura, proteína e sólidos totais do leite, que explicaram 32,5% da diversidade de sistemas de produção e podem ser consideradas indicadores da qualidade nutricional do leite. Na construção do segundo componente principal (CP2), as variáveis mais importantes são teor de lactose, contagem de células somáticas e contagem microbiana do leite, que explicaram 24,04% da diversidade e representam a qualidade higiênica do leite. A distribuição intra-anual da produção não é importante para explicar a diversidade entre as unidades produtoras de leite. Para a tipologia dos sistemas de produção, foram considerados os três primeiros componentes principais, cuja explicação da variabilidade total foi de 70,52%. As 1.196 propriedades rurais produtoras de leite pertencem a 17 grupos de sistemas de produção com características de qualidade do leite próprias.

The objective of the study was to propose a methodology of production systems analysis, considering intraannual quantitative flow and the qualitative characteristics of the milk delivered by the farmers to the industry. The data were collected from 1,196 milk producers from 2005 to 2006 using month production variables, fat content, protein, lactose and total solids, counting of somatic cells, and standardized counting in plates. The method of analysis used was the main component analyses and ascending hierarchical classification (typology). The most important variables in the construction of the first principal component (PC1) are fat content, protein and total milk solid contents, which explained 32.5% of the diversity of production systems, and they can be considered as the indicator of milk nutritional quality. In the construction of the second principal component (PC2), the most important variables are lactose content, counting of somatic cells and milk microbial counting, which explained 24.04% of the diversity and represent the hygienic quality of the milk. The intra-annual distribution of the milk production is not important to explain the diversity among milk production units. For the production system typology, it was considered the first three main components whose explanation of the total variability was of 70.52%. The 1,196 milk producing rural properties belong to the 17 groups of milk production systems with their own characteristics of milk quality.

Objetivou-se com este trabalho avaliar a produção e composição química do leite, o consumo de matéria seca e a taxa de lotação em pastagens de capim-tanzânia (Panicum maximum Jacq. cv. Tanzânia), grama-estrela (Cynodon nlemfuensis Vanderyst cv. Estrela-Africana) e capim-marandu (Brachiaria brizantha Stapf cv. Marandu). As gramíneas foram manejadas sob regime de lotação rotacionada com vacas mestiças Holandês x Zebu, com 30 dias de intervalo de desfolha e três dias de ocupação do piquete e foram adubadas com 1.000 kg/ha/ano da fórmula 20:05:20 (NPK), parcelada em três vezes durante a época das chuvas. O delineamento experimental foi em blocos ao acaso com três fatores em estudo e duas repetições. Foram utilizadas quatro vacas por piquete e, quando necessário, foram acrescentados animais reguladores objetivando obter oferta de massa seca de forragem verde de 7% do peso vivo. Os animais receberam individualmente 2 kg/dia de concentrado no período experimental. A produção de leite não diferiu entre as três gramíneas, com valores de 9,1; 9,1 e 8,7 kg/vaca/dia para as pastagens de capim-tanzânia, grama-estrela e capim-marandu, respectivamente. Da mesma forma, não houve efeito da gramínea na composição química do leite. A taxa de lotação foi semelhante entre as três gramíneas, com os valores de 4,6; 4,5 e 5,0 UA/ha para o capim-tanzânia, a grama-estrela e o capim-marandu. Maior consumo de matéria seca foi observado no capim-tanzânia com 2,6% do PV, enquanto a grama-estrela (2,3%) e o capim-marandu (2,4%) não diferiram entre si. O maior consumo de matéria seca na pastagem de capim-tanzânia não refletiu na produção de leite por animal. A produção e composição química do leite e a taxa de lotação sao similares entre as gramíneas avaliadas.

The objective of this study was to evaluate milk yield and composition, dry matter intake, and stocking rate in pastures with tanzania grass (Panicum maximum cv. Tanzânia), star grass (Cynodon nlemfuensis cv. Estrela-Africana), and marandu grass (Brachiaria brizantha cv. Marandu). The grasses were managed in a rotational grazing system with Holstein x Zebu crossbreed cows, with a 30-day resting period and three days of paddock occupation. The pastures were fertilized with 1,000 kg/ha/year using the 20:05:20 (NPK) formula, split in three applications during the rainy season. It was used a complete random block experimental design with three factors being studied and two replications. In the experiment, four cows/paddock were used and, when it was necessary, regulator animals were added in order to obtain a supply of 7% body weight green forage dry matter. The animals were individually fed concentrate at 2 kg/day during the experimental period. Milk yield did not differ among the three grasses, with values of 9.1; 9.1; and 8.7 kg/cow/day for pastures with tanzania grass, star grass and marandu grass, respectively. Similarly, grass did not affect milk chemical composition. Stocking rate was similar among the three grasses, with values of 4.6; 4.5 and 5.0 UA/ha for tanzania grass, star grass and marandu grass, respectively. The highest dry matter intake was observed for tanzania grass with 2.6% of the body weight while stargrass (2.3%) and marandu grass (2.4%) did not differ among each other. The highest dry matter intake on tanzania grass pasture was not reflected on milk yield per animal. Milk yield and composition and stocking rate are similar among the evaluated grasses.

O experimento foi conduzido para estudar os efeitos da substituição da silagem de milho pela silagem da rama de mandioca para vacas gestantes não-lactantes. Os níveis de substituição da silagem de milho pela silagem da rama de mandioca foram 0, 20, 40 e 60%. Foram avaliados o consumo e as digestibilidades de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos totais (CT) e carboidratos não-fibrosos (CNF), o pH e o nitrogênio amoniacal ruminal antes e 2, 4, 6 e 8 horas depois da alimentação da manhã. Foram utilizadas quatro vacas da raça Holandesa não-lactantes e no terço final de gestação, canuladas no rúmen, distribuídas em um quadrado latino 4 × 4. Não foi observado efeito do nível de substituição da silagem de milho pela silagem da rama de mandioca sobre o consumo, a digestibilidade dos nutrientes e os parâmetros ruminais, exceto a digestibilidade aparente de proteína bruta e as concentrações de nitrogênio amoniacal. Verificou-se efeito linear negativo para digestibilidade aparente da proteína à medida que a silagem de milho foi substituída pela de rama de mandioca. Também para o nitrogênio amoniacal foi observado efeito linear negativo 8 horas pós-prandial. A substituição da silagem de milho pela silagem da rama de mandioca, em todos níveis estudados, pode ser feita na alimentação de vacas gestantes não-lactantes, pois não modifica o consumo, os parâmetros ruminais e a digestibilidade da matéria seca e dos nutrientes, exceto proteína bruta e nitrogênio amoniacal no tempo de 8 horas pós-prandial.

The objective of this trial was to study the effects of substituting corn silage by cassava foliage silage in the diets of non lactating, pregnant dairy cows. The levels of substitution of corn silage by cassava foliage silage were 0, 20, 40 and 60%. Intake and apparent digestibilities of dry matter, organic matter, crude protein, neutral detergent fiber, total carbohydrates, no fiber carbohydrates were evaluated, and pH and ruminal ammonia nitrogen before and 2, 4, 6 and 8h after the morning feeding were also evaluated. Four non lactating pregnant cows (third trimester of gestation) rumen cannulated were allotted to a 4 × 4 Latin square design. The substitution of corn silage by different levels of cassava foliage silage did not affect the intake, digestibilities of nutrients and ruminal parameters, except for crude protein apparent digestibility and ruminal ammonia nitrogen. The crude protein apparent digestibility decreased as the corn silage was substituted by cassava foliage silage. Ruminal ammonia nitrogen also showed a linear negative effect eight hours after the morning feeding. The substitution of corn silage by cassava foliage silage, in all studied levels could be used for non lactating, pregnant dairy cows diets because did not change intake, ruminal parameters and digestibility of dry matter and nutrients, except for crude protein and ruminal ammonia nitrogen eight hours after morning feeding.

Neste experimento objetivou-se avaliar o poder discriminatório dos n-alcanos para estimar com acurácia e precisão a composição botânica da dieta em ovinos alimentados com diferentes proporções de Arachis pintoi Koprov & Gregory cv. Amarillo (0, 15, 30, 45 e 60%) e Brachiaria decumbens Stapf. Foram utilizados 20 ovinos em delineamento inteiramente casualizado, com período experimental de dez dias de adaptação à dieta e cinco dias de coleta de fezes. Nas amostras (compostas) de fezes do período e nos fenos, foi analisada a concentração de n-alcanos. Para o cálculo da composição botânica, utilizou-se minimização da soma dos quadrados dos desvios, considerando as concentrações dos alcanos nos componentes da dieta e nas fezes. Para a escolha dos alcanos mais discriminatórios, foram utilizadas as análises multivariadas e as variáveis canônicas. As estimativas calculadas foram submetidas à análise de variância. As médias foram comparadas pelo teste t e as correções dos valores estimados em relação aos valores reais foram ajustadas em regressão linear. As variáveis canônicas indicaram que os alcanos C35, C33, C30, C31, C27, C29 e C36 são os de maior potencial discriminatório. O uso desses alcanos nos cálculos foi mais acurado e preciso para estimar a proporção de A. pintoi na dieta que o uso de apenas dois ou três alcanos com poder discriminatório. O melhor ajuste da regressão também foi encontrado para esses alcanos. O teste t para o intercepto da equação (a) e o coeficiente de regressão (b) indicaram que a = 0 e b = 1, comprovando que os valores estimados são equivalentes aos valores reais. As análises multivariadas mostraram-se ferramentas de grande importância na escolha dos n-alcanos nos cálculos nas estimativas.

The objective of this experiment was to use n-alkane to estimate accurately and precisely the botanical composition of dietary forage in sheep fed different proportions of Arachis pintoi Koprov & Gregory cv. Amarillo and Brachiaria decumbens Stapf (0, 15, 30, 45 e 60% of Arachis pintoi). Twenty lambs were used in a completely randomized design with 10 days for diet adaptation and 5 days for fecal collection. Both fecal composites and hay samples were analyzed for n-alkane concentration. Dietary forage proportions were estimated from measured concentrations of n-alkanes in feces and forage by the least square sum of deviations. Multivariate analyses and canonical variables were used to select the most discriminatory alkane with the obtained data submitted to analysis of variance. Means were compared using the "t" test and the adjustments of the estimated values in relation to the observed were done by linear regression. The canonical variables indicated that the alkanes C35, C33, C30, C31, C27, C29 and C36 had the greatest discriminatory potential. Therefore, the use of all these alkanes in the calculation was more accurate and precise (P <0.05) than the use of a combination of 2 or 3 alkanes to estimate the proportion of A. pintoi in the diet. The best adjustment of the regression was also found for these alkanes. The "t" test for the intercept of the equation (a) and the regression coefficient (b) showed that a = 0 and b = 1, indicating that the estimated values are equivalent to the observed. The multivariate analysis appears to be an important tool to select n-alkanes for diet evaluation.

O experimento foi realizado com os objetivos de avaliar a técnica de n-alcanos para estimar o consumo e a digestibilidade da MS em ovinos e definir a estratégia de coleta de fezes e os alcanos internos a serem utilizados no cálculos. Vinte ovinos foram distribuídos em delineamento inteiramente casualizado e alimentados com dietas formuladas com diferentes proporções de amendoim forrageiro (Arachis pintoi Koprov & Gregory cv. Amarillo) e braquiária decumbens [Urochloa decumbens (Stapf), Webster] (0, 15, 30, 45 e 60% de amendoim forrageiro, base da MS). O período experimental teve duração de 18 dias, dez de adaptação à dieta, três para administração do indicador externo (C32 em péletes de celulose) e cinco de coleta de fezes. As fezes foram coletadas seis vezes ao dia (9, 13, 17, 21, 1 e 5h), diretamente no reto do animal. Os dados foram submetidos à análise de variância e as comparações das médias estimadas aos valores reais foram feitas utilizando-se o teste t a 5% de significância. Para determinação da digestibilidade aparente da MS, os animais foram equipados com bolsas coletoras de fezes. O consumo foi calculado utilizando-se os alcanos internos C31 e C33 isoladamente ou em conjunto. Para o cálculo da digestibilidade da MS, foram utilizados os alcanos internos C33 a C35. Para obtenção de estimativas adequadas de digestibilidade, é necessária a correção para os valores de recuperação fecal dos indicadores internos, observando-se que os melhores resultados foram obtidos quando se utilizou o alcano interno C33 nos cálculos. Para estimar o consumo de MS, devem-se utilizar, de forma conjunta nos cálculos, os alcanos internos C31 e C33, sem necessidade de correção para recuperação fecal, podendo-se coletar uma única amostra de fezes por animal por dia, pela manhã (9 h) ou à tarde (13 h).

The objective of this trial was to use n-alkanes to estimate dry matter intake (DMI) and DM digestibility in sheep. It was also of particular interest to compare two methodologies of fecal collection (total collection vs. grab samples) as well as to identify which n-alkanes best estimate DMI and DM digestibility. Twenty animals were assigned to a completely randomized design and were fed diets containing different proportions of forage peanut (Arachis pintoi Koprov & Gregory cv. Amarillo) and signalgrass hays [Brachiaria decumbens, (Stapf), Webster] (0, 15, 30, 45 and 60% of forage peanut; DM basis). The experiment lasted 18 days with 10 days for diet adaptation, three days for marker administration (C32 in cellulose pellets), and five days for fecal collection. Data were submitted to analysis of variance and observed and estimated means were compared by t test. Fecal grab samples were collected six times daily at 4 hours intervals (9:00, 13:00, 17:00, 21:00, 01:00 and 05:00) for five consecutive days. The internal alkanes C31, C33, and C31 + C33 were used for estimating DMI while DM digestibility was estimated by C33, C35, and C33 + C35. Results showed that reliable estimation of DM digestibility was obtained by using the internal alkane C33 corrected for fecal recovery. The combination of the internal alkanes C31 + C33 resulted in the best estimation of DMI with no need for fecal recovery correction. In addition, only one daily fecal grab sample (9 h or 13 h) was necessary to accurately estimate DMI.

Este estudo foi realizado com o objetivo de estimar a digestibilidade da MS, a produção fecal e o consumo de MS em ovinos alimentados com feno de aveia e concentrado. Os tratamentos consistiram de dois métodos de administração do n-alcano externo (C32): equilíbrio; dose pulso. No tratamento equilíbrio, durante oito dias (quatro de adaptação e cinco de coleta), os animais receberam diariamente um pélete de celulose contendo 100 mg de C32. Os animais do tratamento dose pulso receberam um único pélete de celulose contendo 150 mg de C32, sendo realizadas amostragens de fezes diretamente do reto dos animais, durante cinco dias a intervalos de 8 horas. A concentração de n-alcanos internos nos ingredientes da dieta foi baixa, inferior a 50 mg/kg de MS, sendo superior no feno de aveia. Não houve efeito dos tratamentos nas estimativas de digestibilidade da MS, mas houve diferenças entre os n-alcanos internos utilizados, obtendo-se o melhor valor com o alcano C33 (65,01%). As estimativas de produção fecal foram menos variáveis nos animais do tratamento equilíbrio, embora não tenha havido diferenças entre as médias dos tratamentos. O tratamento equilíbrio resultou em melhores estimativas do consumo de MS pelos animais, considerando-se os desvios em relação ao observado (-1,68 vs 26,14%), sendo as estimativas obtidas nos animais do tratamento dose pulso consideradas inadequadas.

This experiment was conducted to estimate DM digestibility, fecal output, and DM intake of sheep fed a diet containing oat hay and concentrate. Treatments consisted of two methods of administration of the external marker alkane (C32): equilibrium and pulse dose. In the equilibrium treatment, animals received one daily pellet of cellulose containing 100 mg of C32 during eight days (four days for reach steady state conditions and five days for sample collection). Animals in the pulse dose treatment received only one pellet of cellulose containing 150 mg of C32 followed by 5 days of fecal collection with 8 hours intervals between sampling. Concentrations of most of the internal n-alkanes in the dietary ingredients were lower than 50 mg/kg DM and were greater on oat hay compared to the concentrate. No significant differences for estimation of DM digestibility were observed between treatments. However, there were significant differences among the internal n-alkanes for estimation of DM digestibility. Only the alkane C33 was able to estimate a value of DM digestibility that did not differ of that measured through total fecal collection. Estimates of fecal output were less variable in the equilibrium treatment but no difference was detected between treatment means. The equilibrium treatment resulted in better estimates of DM intake because of the smaller deviation (observed - estimated/observed x 100) compared to the pulse dose method (-1.68 vs. 26.14%) that was considered inadequate.

Realizou-se um experimento com cabras Saanen, primíparas, pesando em média, 50 kg, alojadas em baias individuais de 3 m², objetivando avaliar a substituição da proteína do farelo de soja (FS) pela proteína da farinha de glúten de milho (FGM), na produção e composição do leite, consumo voluntário e níveis de uréia plasmática. O delineamento experimental foi o triplo quadrado latino 4x4, com quatro períodos de 21 dias, sendo 14 dias de adaptação à dieta e sete dias para colheita das amostras. As cabras foram alimentadas e ordenhadas pela manhã e tarde. Os níveis de substituição estudados foram 0, 10, 30 e 50% de FGM (base na proteína bruta). A substituição do farelo de soja pela farinha de glúten de milho não afetou o consumo (kg/dia e %PV) de matéria seca, proteína bruta e fibra em detergente ácido, mas houve efeito quadrático, para o consumo de fibra em detergente neutro (kg/dia e % PV). Houve efeito sobre os níveis de uréia plasmática (UP), que foram inferiores para os menores níveis de substituição, sendo os maiores valores de UP observados para o tratamento que possuía somente FS. A produção de leite decresceu linearmente com a inclusão da farinha de glúten de milho. Os níveis de substituição resultaram em decréscimos lineares na produção de gordura (kg/dia), no teor de gordura do leite (%) e no teor de sólidos totais. Houve efeito quadrático para produção de lactose (kg/dia), observando-se o menor valor estimado para o nível de substituição de 31,6%. Não foi observado efeito sobre a produção de proteína bruta no leite, cujo valor médio foi de 0,083 kg/dia. Os teores de proteina bruta, lactose e sólidos totais não sofreram efeito dos níveis de substituição, sendo os valores médios percentuais de 2,98; 4,35 e 11,51%, respectivamente.

It was carried out an experiment with goats Saanen, on the first lactation, with 50 kg of body weight, housed in individual stalls of 3 m², to evaluate the effect of substitution of soybean meal (SM) protein by the protein from the corn gluten flour (CGF), in the milk production, milk composition, voluntary intake and plasmatic urea. The experimental design was the triple Latin square 4x4, with four periods of 21 days, being 14 days of adaptation to the diet and seven days for samples collection. The goats were fed and milked in the morning and afternoon. The substitution levels studied were: 0, 10, 30 and 50% of CGF (based in the crude protein). The substitution of the soybean meal by CGM did not affect the intake (kg/day and %BW) of dry matter, crude protein and acid detergent fiber, but there was quadratic effect for neutral detergent fiber intake (kg/day and %BW). There was effect on the levels of plasmatic urea nitrogen (PUN), where the smallest values were in the intermediate levels of substitution, being the biggest values for the treatment with only SM. The milk production decreased lineally with the inclusion of CGM. The substitution levels resulted in lineal decrease in the fat production (kg/day), in the milk fat content (%) and milk total solids content (%). There was quadratic effect for lactose production, being the smallest value for 31.6% of substitution level. It was no effect on in crude protein in the milk, which average was .083 kg/day. The crude protein content, lactose and total solids did not suffer effect of the substitution levels, being the average values of 2.98, 4.35 and 11.51%, respectively.