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The objectives of this study were: 1) to compare the effects of live yeast (LY), yeast fermentation product (YFP), a mix of Lactobacillus acidophilus and Propionibacterium freudenreichii (MLP), and Lactobacillus plantarum included as additives in dairy cows’ diets on in vitro ruminal fermentation and gas production (GP); and 2) to evaluate the effects of L. plantarum as direct-fed microbials (DFM) in dairy cows’ diets on in vitro ruminal fermentation, GP, nutrient digestibility, and N metabolism. Three experiments were carried out: Exp. 1 had the objective to compare all additives regarding ruminal fermentation parameters: an Ankom GP system was used in a completely randomized design, consisting of four 48 h incubations, and eight replications per treatment. There were eight treatments: a basal diet without additive (CTRL) or with one of the following additives: LY, YFP, MLP, or L. plantarum at four levels (% of diet Dry Matter (DM)): 0.05% (L1), 0.10% (L2), 0.15% (L3), and 0.20% (L4). In Exp. 2, a batch culture was used to evaluate ruminal fermentation, and CO2 and CH4 production using the same treatments and a similar experimental design, except for having 16 replications per treatment. Based on Exp. 1 and 2 results, Exp. 3 aimed at evaluating the effects of the L. plantarum on ruminal true nutrient digestibility and N utilization in order to evaluate the use of L. plantarum as DFM. The treatments CTRL, MLP, L1, and L2 were used in a replicated 4 × 4 Latin square design using a dual-flow continuous culture system. Data were analyzed using linear and nonlinear regression; treatment means were compared through contrasts, and L treatments in Exp. 1 and 2 were tested for linear, quadratic, and cubic effects. In Exp. 1, all treatments containing additives tended to reduce OM digestibility as well as reduced total volatile fatty acids (VFA) concentration and total GP. The YFP had greater OM digestibility than LY, and MLP treatment had greater total VFA concentration compared to L. plantarum treatments. In Exp. 2, additives reduced CO2 production, and there were no major differences in CH4. In Exp. 3, all additives reduced NH3-N concentration. In conclusion, pH and lactate concentration were not affected in all three experiments regardless of additive tested, suggesting that these additives may not improve ruminal fermentation by pH modulation; and L. plantarum may improve ruminal N metabolism when used as DFM in high-producing dairy cows’ diets, mainly by reducing NH3-N concentration.

The objective of this study was to evaluate the effect of inclusion of condensed tannins (CT) from black wattle (Acacia mearnsii) on feed intake, ruminal protozoa population, ruminal fermentation, and nutrient digestibility in Jersey steers. Five ruminally-cannulated steers were used in a 5x5 Latin square design, with five periods of 20 days each (14 days for diet adaptation and six days for sample collection per period). Treatments were composed of dietary inclusion levels of condensed tannins at 0, 5, 10, 15, and 20 g/kg of diet dry matter. Intakes of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, and total digestible nutrients were not affected by condensed tannins. The ruminal pH was reduced linearly with tannin levels. Ruminal ammonia nitrogen concentration was not affected by tannins. Tannins reduced the molar proportion of acetate and did not affect the ruminal protozoal population, which might be related to the low doses used. Digestibilities of dry matter, organic matter, and neutral detergent fiber were not altered, however, there was a linear reduction in crude protein digestibility. Based on these results, CT extracts from black wattle are not recommended for improving nutrient utilization in steers at the tested levels.

The objective of this study was to evaluate the effects of five levels of condensed tannins (CT) from black wattle (Acacia mearnsii) in the diets of lactating dairy cows on intake, nutrient digestibility, ruminal microbial protein synthesis, milk production, composition, oxidative profile, and blood metabolites. Five Holstein cows (88 &plusmn, 26.8 days in milk) were allocated in a 5 x 5 Latin square design for a period of 20 days (14 days of diet adaptation and six for sampling). Treatments were the inclusion levels of CT at 0, 5, 10, 15 and 20 g/kg of dry matter (DM) in the diet. There was no effect of CT on DM intake. The digestibility of DM and neutral detergent fiber changed quadratically, with the maximum values at 12.2 and 11.4 g/kg of DM, respectively. There was no effect on ruminal microbial protein synthesis and milk production, however, milk casein concentration was reduced linearly. There was no effect on the milk oxidative profile. Inclusion of CT at levels up to 20 g/kg of DM did not affect intake or microbial protein synthesis, however, added CT depressed the production of energy corrected milk and milk casein concentration.

The objective of the study was to evaluate the replacement of Tifton 85 hay (TH) for Tifton 85 silage (TS) in the diets of lactating cows. Five Holstein cows in middle of lactation were allocated in a 5 × 5 Latin square design and each experimental period lasted 18 days (12 days for adaptation and six days for collection). Treatments consisted of replacement of 0, 25, 50, 75, and 100% of TH for TS. The intake and digestion of nutrients, microbial protein synthesis, milk yield and composition, and the economic viability of the diets were evaluated. The intakes of dry matter, organic matter, and ether extract had a positive linear effect and the digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber decreased linearly with increasing participation of TS. Milk production and composition and microbial protein synthesis were not affected. Regarding economic viability, the treatment with 100% hay produced better results, with better gross margin. The Tifton 85 silage can be used as a replacement for Tifton 85 hay up to 100% without changing the milk production and composition of Holstein cows.

Objetivou-se avaliar a qualidade microbiológica da água e do leite provenientes de propriedades de base agroecológica e convencional no Oeste do Paraná. As coletas foram realizadas em 20 propriedades convencionais no município de Santa Helena – PR, e em 27 de base agroecológica em Diamante d’Oeste e Ramilândia – PR. Foram realizadas coletas de leite nos diferentes sistemas de produção e estações do ano. Foram analisadas a contaminação por coliformes termotolerantes (CTerm), coliformes totais (CT), enterobactérias, aeróbios mesófilos (AM), a determinação da composição química, contagem de células somáticas (CCS) e contagem bacteriana total (CBT). Não houve diferença para a composição do leite entre os sistemas de produção no verão. Em relação a CCS durante o inverno, 44,4% e 55,0% das propriedades apresentaram valores acima de 600 mil céls mL-1, nos sistemas agroecológico e convencional, respectivamente. Em ambas as estações, a maioria das propriedades agroecológicas encontram-se acima de 600 mil UFC mL-1 de CBT. Em ambos os sistemas de produção e estações, os valores de AM apresentaram valores inferiores ao permitido pela IN76, e não houve diferença para as enterobactérias no leite. A contagem de CT no leite no inverno foi semelhante entre os dois sistemas de produção. Para as amostras da água para limpeza dos equipamentos de ordenha, os valores de CT e CTerm foram superiores no sistema agroecológico. Recomenda-se a utilização de práticas de manejo visando a redução dos valores de CCS e CBT do leite produzido no Oeste do Paraná para adequarem-se aos valores exigidos pela IN76.

The objective of this study was to evaluate the effect of selenium-enriched Saccharomyces cerevisiae on the performance, composition and quality of milk from cows fed diets containing dried malt bagasse. Eight Holstein cows were distributed in a 4 × 4 double Latin square. The treatments were in a 2 × 2 factorial scheme: with or without the inclusion of malt bagasse x with or without the addition of selenium-enriched Saccharomyces cerevisiae. Dried malt bagasse was included at 24% in the dry matter (DM) of the diet; the amount of yeast supplied was 15 g/day and was composed of strain Saccharomyces cerevisiae CNCM I-1077 containing 1.0 × 109 CFU/g and 170 mg selenium/kg. Cows fed diets containing malt bagasse presented lower intakes of DM, crude protein and non-fibrous carbohydrates (NFC) and higher intakes of ethereal extract and neutral detergent fiber (P

The objective of this study was to evaluate the nutritional quality of twenty-nine cultivars of sugarcane. The design was completely randomized, with twenty-nine treatments (cultivars) and three replicates. The evaluations were performed at 540 days after planting during the phenological stage of maturation of sugar cane. Stalk length, number of nodes per plant, internodes length and stalk diameter were evaluated. The stalk samples were crushed, pre-dried and ground for achievement of chemical analysis, carbohydrate fractionation and in vitro digestibility of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF). Data were analyzed by analysis of variance and posteriorly submitted to Scott-Knott test at 5% probability. Regarding biometric measurements the cultivars differed (P0.05) in the number of nodes as well as in the average internode length and stalk diameter. The content of DM, OM, protein, ether extract, NDF and acid detergent fiber showed differences between the cultivars evaluated (P

This study aimed to evaluate the nutritional value of legumes leucaena and desmodium preserved in hay and silage form. We used a completely randomized design in a 2x2 factorial arrangement with two bulky conservation methods (hay and silage) and two legumes (leucaena and desmodium). For the bulky characterization was determined chemical composition and total digestible nutrients (TDN). For assessing the nutritional value, analysis of in vitro dry matter digestibility (IVDMD) and cell wall digestibility (IVCWD), and in situ effective degradability of dry matter (EDDM) and crude protein (EDCP) were performed. Data were submitted to ANOVA and Tukey test at 5% probability. Due to the characteristics of each specie leucaena presented a higher crude protein (CP) and TDN content compared to desmodium and lower fibrous fractions. The IVDMD presented interaction between the conservation form and forage (P

Camelina is an oil seed crop that belongs to the Brassica family (Cruciferae). Camelina meal is a by-product from the biofuel industry that contains on average 38% crude protein and between 10 to 20% of residual fat, which limits the inclusion levels of camelina meal in dairy cow diets as the main protein supplement. Thus, we conducted a solvent extraction on ground camelina seed on a laboratory scale. The objectives of this study were (1) to assess the effects of replacing canola meal (CM) with solvent-extracted camelina meal (SCAM) in lactating dairy cow diets; and (2) to determine the effects of SCAM on microbial fermentation and AA flow in a dual-flow continuous culture system. Diets were randomly assigned to 6 fermentors in a replicated 3 × 3 Latin square with three 10-d experimental periods consisting of 7 d for diet adaptation and 3 d for sample collection. Treatments were 0, 50, and 100% SCAM inclusion, replacing CM as the protein supplement. Diets contained 55:45 forage:concentrate, and fermentors were fed 72 g of dry matter/d equally divided in 2 feeding times. On d 8, 9, and 10 of each period, samples were collected for analyses of pH, volatile fatty acids (VFA), N metabolism, NH3-N, digestibility, and AA flow. Statistical analysis was performed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC), and linear and quadratic effects of SCAM inclusion were assessed. Total VFA concentration and pH were not affected by diets. Molar proportion of acetate decreased, whereas molar proportion of propionate increased with SCAM inclusion. Total branched-chain VFA concentration was the least in fermentors fed diet 0, and greatest in fermentors fed diet 50. Digestibility of NDF decreased in fermentors fed SCAM diets, and dry matter, organic matter, and crude protein true digestibility were similar across diets. Concentration of NH3-N linearly decreased, and non-NH3-N linearly increased with SCAM inclusion. Bacterial efficiency (calculated as g of bacterial N flow/kg of organic matter truly digested) tended to be greater in fermentors fed diet 100. Outflow of Arg linearly increased with SCAM inclusion, whereas overall AA flow was not affected by diet. In conclusion, replacing CM with SCAM increased propionate molar proportion and non-NH3-N flow, and decreased NH3-N flow and concentration, which may improve animal energy status and N utilization. Inclusion of SCAM did not change most AA flow, indicating that it can be a potential replacement for CM.

The objective of this study was to determine the physiological parameters of Holstein cows in milking during the winter and spring season and correlate these parameters with the bioclimatic indexes. We used nine Holstein cows in a completely randomized delimitation in a subdivided plot arrangement with repeated measures in time. Data were collected during the winter and spring, which were measured respiratory rate (RR), heart rate (HR), superficial temperature (ST) and rectal temperature (RT) from animals, besides the air temperature, the relative humidity and black globe temperature. It was calculated the temperature and humidity index (THI), the Black Globe Temperature and Humidity Index (BGTH) and Radiant Heat Load (RHL). The THI, BGTH and RHL showed increases in the afternoon suggesting an environment susceptible to stress. There were no statistical differences (P>0.05) between the seasons of winter and spring for any of the physiological variables. Only HR was above physiological limits for cattle. HR, RR and ST showed significant positive correlation (P

The objective of this study was to determine the optimal level of dried brewers' grains (DBG) to replace soybean meal in diets for lactating Holstein cows. Five cows, around 88±28 days in milk, were distributed in a 5 × 5 Latin square design and fed diets containing different levels of DBG (0, 25, 50, 75, and 100%). The forage:concentrate ratio of the diet was 50:50. Feed intake, dry matter, nutrient digestibility, microbial synthesis, milk production and composition, and the economic viability of the diets were evaluated. There was reduction in dry matter intake and, consequently, in crude protein and non-fiber carbohydrates with increased levels of DBG. This occurred due to physical limitation of rumen caused by increased neutral detergent fiber intake. Ether extract intake also increased with levels of DBG due to higher concentrations of this nutrient in the diet. Apparent dry matter, organic matter, ether extract, and neutral detergent fiber digestibility increased with replacement of soybean meal by DBG. Milk production showed a quadratic effect and the levels of fat, protein, and total solids reduced linearly. Each 1% of soybean meal replaced by DBG in concentrate led to a reduction of 0.04, 0.02, and 0.06 g kg-1 of milk fat, protein, and total solids, respectively. The milk production efficiency increased linearly and the microbial synthesis efficiency was not affected. The economic return increased along with the DBG levels. Thus, DBG levels replacing up to 75% of soybean meal can be used to feed lactating cows, since it provides improvements in digestibility, milk production efficiency, and economic return without affecting microbial efficiency.