ABSTRACT We aimed to evaluate the effects of the addition of oregano (Origanum vulgare) or green tea (Camellia sinensis L.) extracts (separately and associated) on feed intake, milk production, and hematological and antioxidant profiles of dairy cows. For that purpose, 16 Holstein and 16 Holstein-Gyr cows with 526.3±10.2 kg and within the first third of lactation were distributed according to a complete block design with measurements repeated in time. Treatments were control (CON), addition of 0.056% of oregano extract (OR), addition of 0.028% of green tea extract (GT), addition of a mixture of OR and GT extract (0.056% each) in the diet (MIX). Hematological and antioxidant profiles were monitored. Data were subjected to ANOVA, with block, treatment, days, and their interactions considered as fixed effects and animal and the residue as random effects. In Holstein cows, GT increased feed intake and milk yield compared with CON; in Holstein-Gyr crossbred cows, OR showed increased intake and GT increased milk yield compared with CON. Compared with CON, GT and OR decreased eosinophils concentration; OR showed the highest neutrophils concentration and neutrophils to leukocyte ratio. Compared with CON, OR presented increased catalase (CAT) activity, while GT increased the reduced glutathione concentration. The MIX treatment reduced CAT activity compared with OR, presented the lowest concentration of oxidized dichlorofluorescein in the erythrocytes (DCFER) and plasma (DCFPLA), and increased eosinophils concentration compared with GT and OR. Extracts differently affected feed intake and milk yield depending on genetic group. Feeding green tea and oregano extracts separately or associated distinctly affects the antioxidant indicators of lactating dairy cows.

ABSTRACT The objective was to investigate the effects of available shaded area on behavioural characteristics of lactating cows during the warm season in the subtropics. Twelve Holstein cows were divided into groups, with 2 (SH2) or 10 m2 (SH10) of available shade per cow (six cows per treatment). The behaviour was recorded when animals were grazing from 09.00 to 16.00 h (GMT −02.00 h) throughout the trial. Data considered in the statistical analysis were restricted to the five days when the maximum temperature was ≥ 25 °C. Cows in the SH10 group had lower panting score, but higher proportions of time in shade and lying down and stayed more time per visit in the shaded area than cows in the SH2 group. Cows in the SH10 group had less events of competition near the water trough and in the shaded area than cows in the SH2 group. The solar radiation threshold that triggered the use of the shade was lower in SH10 than in SH2 group. Hourly proportion of time spent grazing or ruminating differed between shaded areas at specific times. The 2 m2 of available shaded area per cow is sufficient for all cows to enter the shaded area at the same time. In spite of that, 2 m2 of available shaded area per cow negatively affects the proportion of time spent lying and in the shaded area; in addition, it enhances agonistic behaviours between cows when compared with 10 m2 of shade per cow.

ABSTRACT The objective of this research was to determine the variation of milk stability evaluated with ethanol, boiling, and coagulation time tests (CTT) to identify milk components related with stability and verify the correlation between the three methods. Bulk raw milk was collected monthly at 50 dairy farms from January 2007 to October 2009 and physicochemical attributes, somatic cell (SCC), and total bacterial counts (TBC) were determined. Milk samples were classified into low, medium, and high stability to ethanol test when coagulation occurred at 72 °GL, between 74 and 78 °GL, and above 78 °GL, respectively. Univariate analysis was performed considering the effects of year, months, and interaction in a completely randomized design. Principal factor analysis and logistic regression were done. There was an interaction between months and years for stability to the ethanol test and coagulation time. All samples were stable at the boiling test. Boiling test was not related to ethanol and coagulation time tests. Coagulation time was weakly but positively correlated with ethanol test. Broken line analysis revealed that milk stability measured with CTT and ethanol tests decreased sharply when SCC attained 790,000 or 106 cell/mL of milk, respectively. Milk stability measured with ethanol test decreased when TBC was higher than 250,000 cfu/mL, while there was no inflexion point between TBC and stability measured with CTT. Milk with high stability presented lower values for acidity, TBC, and SCC but higher values for pH, lactose, protein, and CTT compared with low-stability milk. Due to the execution easiness, single-point cut-off result and low cost, we do not recommend the replacement of ethanol test for boiling or coagulation time test.

Foi avaliado o efeito de diferentes frequências de suplementação sobre o uso da pastagem (fluxo de tecido foliar, intensidade e frequência de desfolhação) em papuã (Urochloa plantaginea (Link) Hitch). As bezerras de corte permaneceram exclusivamente em pastejo ou receberam grão inteiro de aveia durante sete ou cinco dias por semana (de segunda à sexta feira). A quantidade semanal de suplemento foi similar nas duas frequências. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, três tratamentos e duas repetições de área. Os fluxos de tecidos, a frequência e intensidade de desfolhação são similares quando as bezerras permanecem exclusivamente em pastejo ou recebem grão de aveia em diferentes frequências.

The effects of several supplementation frequencies on forage use (leaf tissue flow, intensity and frequency of defoliation) in Alexandergrass (Urochloa plantaginea (Link) Hitch) were evaluated. The heifers remained exclusively on pasture or received whole oat grain seven days/week or five days/week (Monday to Friday). The weekly amount of supplement was similar for both frequencies. The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two area replications. Leaf tissue flow, frequency and intensity of defoliation are similar when heifers remain exclusively on Alexandergrass pasture or receive oat grain on different frequencies.

Foi avaliada a dinâmica de perfilhamento de azevém (Lolium multiflorum Lam), sob duas taxas de lotação: 'baixa' e 'alta'. Essas taxas foram determinadas por bezerras, exclusivamente, em pastejo ou em pastejo e recebendo grão de milho ou de aveia branca como suplemento. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, com duas taxas de lotação, três e seis repetições de área para a taxa de lotação 'baixa' e 'alta', respectivamente. A taxa de aparecimento (1,0 perfilhos perfilho-1 m-2), sobrevivência de perfilhos (0,8 perfilhos perfilho-1 m-2), o índice de estabilidade da população (1,6) e a ocupação de sítios (0,3) foram similares nas taxas de lotação 'alta' e 'baixa'. A densidade populacional de perfilhos foi similar nas diferentes taxas de lotação. A primeira geração de perfilhos representa 56% dos perfilhos existentes no final do ciclo do azevém. O aumento de 22,5% na taxa de lotação ocasionado pelo uso de suplementos para bezerras em pastejo não altera a dinâmica de perfilhamento do azevém.

This study investigated the tiller dynamics of Italian ryegrass (Lolium multiflorum Lam) under low and high stocking rates. These rates were determined by heifers exclusively on pasture or grazing and supplemented with oats and corn grain. The experimental design was completely randomized with repeated measurements over time, with two stocking rates, three and six replications of area for low and high stocking rates, respectively. The appearance rate (1.0 tillers tiller-1 m-2), survival rate (0.8 tillers tiller-1 m-2), population stability index (1.6) and site occupation (0.3) were similar for high and low stocking rates. The tiller density was similar for different stocking rates. The first generation of tillers was 56% of the tiller population at end of the ryegrass cycle. The increase by 22.5% in the stocking rate derived from the use of supplements for grazing heifers did not alter the tiller dynamics of ryegrass.

O consumo de forragem foi avaliado em novilhas de corte exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou recebendo farelo de arroz integral (FAI) com ou sem adição de ionóforo. Foi usado o óxido de cromo como indicador da produção fecal. O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, com três tratamentos e três repetições de área. Os animais foram considerados as unidades experimentais nas avaliações de consumo. O consumo de pasto pelas novilhas foi similar nos diferentes sistemas alimentares, ocasionando taxa de lotação semelhante. O fornecimento de farelo de arroz integral, com ou sem monensina, aumenta o consumo de matéria seca total. A adição de ionóforo ao FAI aumenta o desempenho individual das novilhas, sendo o seu uso recomendado quando existe o objetivo de reduzir a sua idade ao primeiro acasalamento.

The forage intake was evaluated in beef heifers exclusively in Italian ryegrass (Lolium multiflorum Lam.) pasture or receiving rice bran with or without addition of ionophore. Chromic oxide was used as a fecal production indicator. The experimental design was completely randomized with repeated measures on time, three treatments and three area replicates. The animals were considered experimental units for intake evaluations. The pasture intake by heifers was similar at different feeding systems causing similar stocking rate. The supply of rice bran with or without monensin increased the total dry matter intake. The individual heifers performance was increased with ionophore addition to rice bran. Ionophore is recommended when there is a goal to reduce the age of beef heifers at their first mating.

O experimento foi conduzido para avaliar os fluxos de biomassa foliar, intensidade e frequência de desfolhação em papuã (Urochloa plantaginea (Link) Hitch), pastejado por bezerras de corte exclusivamente em pastejo ou em pastejo e recebendo sal proteinado. O delineamento foi inteiramente casualizado, com medidas repetidas no tempo, dois tratamentos e duas repetições de área, com três bezerras testes da raça Angus por piquete. O fluxo de consumo de lâminas foliares é 18% superior quando as bezerras permanecem exclusivamente em pastejo. A intensidade de pastejo (59,8%) é semelhante quando as bezerras recebem sal proteinado ou não. Bezerras que recebem suplemento reduzem em um dia a frequência de desfolhação dos perfilhos. O fornecimento de sal proteinado para bezerras de corte em pastejo em papuã resulta em alterações na relação herbívoro-planta reduzindo o fluxo de consumo e a frequência de desfolhação de lâminas foliares.

The experiment aimed at evaluating leaf biomass flow, intensity and frequency of defoliation of Alexandergrass (Urochloa plantaginea (Link) Hitch) by beef heifers exclusively on pasture or that grazed and received protein salt. A completely randomized experimental design was used with repeated measures over time, two treatments and two area replications, with three Angus test heifers by paddock. Leaf blade intake flow is 18% superior for heifers exclusively on pasture. Grazing intensity (59.8%) is similar when heifers receive protein salt or not. Heifers receiving protein salt reduce by one day the defoliation frequency of tillers. The supply of protein salt for beef heifers grazing Alexandergrass affects the herbivore-plant relationship, decreasing intake flow and leaf blade defoliation frequency.

Em método intermitente de pastejo, com três dias de ocupação dos piquetes, foi avaliado o comportamento ingestivo de borregas. Esses animais permaneceram em pastagem exclusiva de azevém (Lolium multiflorum Lam.) ou em pastagem de azevém recebendo 1,2% de MS em relação ao peso corporal de grão de arroz em casca, grão de milho moído ou farelo de arroz integral como suplemento durante os estádios fenológicos vegetativo, pré-florescimento e florescimento do azevém. O delineamento experimental foi o inteiramente casualizado em parcelas sub-subdivididas, sendo considerados os tipos de suplemento como parcelas principais, os estádios fenológicos como subparcelas e os dias de ocupação como sub-subparcelas. As borregas pastejaram por maior tempo quando permaneceram exclusivamente em azevém. As borregas pastejaram por menor tempo no estádio vegetativo do azevém e no terceiro dia de ocupação dos piquetes. O comportamento ingestivo de borregas é alterado quando é fornecido suplemento nos diferentes estádios fenológicos do pasto e nos dias de ocupação dos piquetes.

The ingestive behavior of hoggets was assessed under intermittent grazing method with three days of paddock occupation. These animals remained exclusively on Italian ryegrass (Lolium multiflorum Lam) pasture or on ryegrass pasture and receiving 1.2% of DM in relation to body weight of rice paddy, corn grain or whole rice bran as a supplement during the vegetative, pre-flowering and flowering phenological stages of ryegrass. The experimental design was a randomized split-split plots wherein the types of supplement were considered as main plot, phenological stages as subplot and the days of occupation as sub-subplots. The hoggets grazed for a longer time when kept exclusively on ryegrass pasture. The hoggets grazed for less time in the vegetative stage of ryegrass and on the third day of paddock occupation. Feeding behavior of hoggets is changed when supplementation is provided in different phenological stages of the grass and days of paddock occupation.