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Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441 ± 27 kg of BW, 3.5 ± 0.3 of body condition score (BCS), and 2.7 ± 1.8 lactations were selected at approximately 28 d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control ? CON), addition of 10 g per day of oregano extract (OR), and addition of 5 g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period. Made available in DSpace on 2021-10-13T19:01:20Z (GMT). No. of bitstreams: 1 Vizzotto-2021.pdf: 650189 bytes, checksum: 7bf537d2a8aaba258df849eb653c703f (MD5) Previous issue date: 2021

The aim of this study was to evaluate the effects of green tea (Camellia sinensis) and oregano (Origanum vulgare) extracts on behavior, weight gain, and health indicators of dairy calves from birth to 60 days of age. Twenty-one Jersey calves were distributed into three treatments: without additives (CON); green tea extract (GT): supply of 30 mg/kg of body weight/day; and oregano extract (OR): supply of 60 mg/kg of body weight/day. Observers registered animal?s behavior at 5-minute intervals from 8:00 to 16:00, three times a week, from day 1 to day 60 of life. The behavioral variables considered were time spent in standing, lying down, ruminating, frequency of visits to feeders, frequency of eating pasture and straw, as well as body weight gain, body temperature, heart and respiratory rates, and health conditions. GT and OR anticipated the occurrence of the first rumination and the ingestion of straw in approximately 7 days compared with CON but did not modify the body weight gain, incidence of diarrhea, health conditions, and other behavioral variables. Supply of GT and OR stimulated the onset of dry feed intake and rumination without changing performance and health status. Made available in DSpace on 2020-05-23T04:40:02Z (GMT). No. of bitstreams: 1 Heisler-2020.pdf: 519556 bytes, checksum: aeccb4ba4631d131377121d7b1c82ac1 (MD5) Previous issue date: 2020

RESUMO Objetivou-se com este estudo desenvolver e validar uma ferramenta semiológica para diagnóstico do nível de adoção e conformidade das boas práticas agropecuárias em fazendas de produção de leite, segundo requisitos preconizados pela Food and Agriculture Organization of the United Nations (FAO) e pela International Dairy Federation (IDF). A ferramenta foi testada em 62 fazendas de produção de leite, em seis diferentes regiões do estado do Rio Grande do Sul, como parte das ações do Projeto Protambo - "Transferência de tecnologias para o desenvolvimento da atividade leiteira no RS com base nas boas práticas agropecuárias" - da Empresa Brasileira de Pesquisa Agropecuária, Embrapa, entre janeiro de 2014 e março de 2017. A validação da ferramenta não apontou divergências estatisticamente significativas entre avaliadores, satisfazendo o parâmetro de exatidão para métodos de medições exigidos pela ISO/IEC 17025. Foi evidenciado um espaço de variação que mostrou desenvolvimento de métrica, em que se obteve consistência (coerência) de medição. O teste t-Student aproximado para a comparação de médias de não conformidades nas BPA mostrou melhora significativa no grupo tratamento (diagnóstico seguido de plano de ajuste) quando comparado ao controle (diagnóstico sem plano de ajuste subsequente). Essa nova abordagem semiológica contribui para a adoção das BPA em fazendas leiteiras, para a melhoria da qualidade do leite e da segurança na cadeia produtiva de lácteos.

The objective of this study was to evaluate the biomarkers of the redox state of pre-weaned Jersey dairy calves that consumed milk from cows supplemented with green tea (Camellia sinensis) or oregano extracts (Origanum vulgare). A completely randomized design was used with repeated measures in time. From their birth to 60 days of life, 8, 8 and 7 calves received milk from cows fed on a basal diet without addition of plant extracts (CON), with addition of 10.0 g of oregano extract (OE) per day and with 5.0 g of green tea extract (GT) per day, respectively. On days 1, 30, and 60 after birth redox state biomarkers were evaluated. Body weight was eval-uated every two weeks, rectal temperature and fecal score were accessed every two days and concentrate intake was measured every day. Statistical analyses for body weight, body weight gain, concentrate intake, rectal temperature, variables of redox status were performed using the procedure Mixed, evaluating the fixed effects of treatment, day of measurement and their interaction. Statistical analyses for the mean fecal score and the number of days to the first diarrhea occurrence were performed using the procedure Mixed, evaluating the fixed effect of treatment. On day 1, calves fed with milk from GT group had higher plasma glutathione peroxidase activity (GPx) than CON. However, the reverse occurred on day 60. On the day 1, calves in the CON group presented higher concentrations of thiol groups (also known as sulfhydryl groups) than those in GT and OE groups, with reverse occurring on day 30. Calves in the OE group had lower oxidation of dichlorofluorescein in the erythrocytes compared to the others; while calves in the GT group presented higher concentration of GSH and higher activity of the catalase enzyme compared to CON and OE, respectively. Pre-weaned calves fed with milk of cows supplemented with extracts of green tea and oregano did not change... Made available in DSpace on 2020-12-02T09:02:50Z (GMT). No. of bitstreams: 1 Paris-2020-Livestock-Science.pdf: 468473 bytes, checksum: 9b39777d6f7a8090f464df337801e354 (MD5) Previous issue date: 2020

Data from five experiments with dairy cows where feed was restricted to 0, 40, and 50 % of the ad libitum amount, with 259 observations, were subjected to multivariate analyses to determine the effects of severity and duration of feed restriction on production, physical-chemical characteristics, ethanol stability, and somatic cell score of milk. A negative relationship was seen between the severity and duration of feed restriction with milk production, lactose content, titratable acidity, and milk stability to the ethanol test. The milk stability to the ethanol test, protein content, milk yield, and somatic cells score were the most important attributes retained by the discriminant analysis. Milk stability to the ethanol test, live weight, days in restriction, and pH were the most important characteristics explaining the variance within the different levels of feed restriction. Milk production and ethanol stability were significantly lower in both levels of feed restriction compared with the group fed ad libitum. When feed restriction was followed by refeeding, the difference observed in ethanol stability was the first discriminant variable, followed by the difference in unstable milk frequency and titratable acidity. Increments in the severity and duration of feed restriction negatively affect milk production and milk ethanol stability. Made available in DSpace on 2022-09-28T17:05:28Z (GMT). No. of bitstreams: 1 Milk-traits-of-lactating-cows-submitted-to-feed-restriction-2016.pdf: 493070 bytes, checksum: df59ce3b34285894a31372b719e930f0 (MD5) Previous issue date: 2016

Background: Milk is one of the most used foodstuffs by humans in their diet. The quality of goat milk is already regulated by Law, which takes into consideration its physical-chemical and microbiological composition parameters. Several factors contribute for the alteration of the physical-chemical and microbiological parameters of caprine milk. These include breed, age, lactation phase and diet, among others. The health status of animals may interfere in the quality of the milk produced, both regarding food safety and milk processing and, for that reason, the identification of mastitis-causing agents is important, so that prevention and control measures can be implemented. The present study aimed at analyzing the occurrence of mastitis and the milk composition of dairy goats in a semi-intensive production system. Materials, Methods & Results: In a private goat farm with a flock composed of 32 female animals of breeds such as Saanen and Anglo-Nubian, raised on a semi-confined system, the diagnosis of mastitis was made through methods such as California Mastitis Test (CMT), Somatic Cells Count (SCC) and bacterial isolation. A total of 136 milk samples were analyzed, which were individualized per teat. Additionally, the study determined the volume of milk produced individually and the chemical composition of milk samples (fat, raw protein, lactose and total solids). In 37 (27.2%) samples, subclinical mastitis caused by CNS was identified. A negative response to CMT was observed in 125 (91.92%) samples. Only four samples presented a coincidence (OR =1.239) between CMT and bacterial isolation (P =0.7470). It was observed that the daily milk production ranged between 207.90 mL and 2.68 L. Moreover, it became clear that the milk production in half of the teats with subclinical mastitis was smaller (P =0.0026). A tendency to a significant reduction (P

O leite tipo A, produzido e beneficiado em granja leiteira, possui padrões de qualidade específicos. O objetivo desse trabalho foi avaliar a qualidade físico-química e microbiológica do leite cru e pasteurizado tipo A e de pontos de contaminação em uma granja leiteira do RS. De novembro de 2006 a abril de 2008 foram realizadas seis coletas. A cada coleta foram amostrados: leite cru e pasteurizado, swabes de tetos e teteiras para contagem de coliformes totais, termotolerantes, bactérias mesófilas aeróbias e psicrotróficas. Foi realizada análise físico-química do leite. A contagem de coliformes totais e termotolerantes no leite pasteurizado indicou que 50% e 33,3% das amostras estavam fora do padrão, respectivamente. Na contagem de mesófilos aeróbios no leite pasteurizado, duas amostras apresentaram resultados acima do limite estabelecido pela Instrução Normativa 51 (IN51). No leite cru, 3 amostras apresentaram elevadas contagens de mesófilos aeróbios (>1,0 x 104UFC/mL). A quantidade de psicrotróficos do leite cru variou entre as coletas. Houve aumento dos valores entre a primeira e a última coleta para as contagens na superfície das teteiras do início para o fim do período da ordenha. Na análise físico-química do leite foi verificado que duas amostras de leite cru e uma amostra de leite pasteurizado apresentaram teores de gordura abaixo do mínimo permitido (3,0%). A contagem de células somáticas apresentou valores acima do permitido para 3 amostras de leite cru e 1 amostra de leite pasteurizado. Verificou-se a necessidade de correções no manejo de ordenha, a fim de melhorar a qualidade do leite produzido e se adequar às normas da IN51. Grade A milk is produced and processed by rigid and specific standard of quality. This research aimed to evaluate microbiological, physical and chemical characteristics of raw and pasteurized grade A milk and know some critical points of contamination at a dairy farm in Rio Grande do Sul. For November, 2006 to April, 2008 we carried out six visits and sample collection at the property. At each one, there were collected samples of raw and pasteurized milk, swabs of teats skin and milking machine liners. There were performed aerobic mesophiles counting and total and fecal coliforms (MPN). To raw milk, it was also performed psychrotropic counting. About total and fecal coliforms counting, 50 and 33.3% of the pasteurized milk samples were above the legal standard (IN 51). About aerobic mesophilic bacteria counting, 2 samples were considered inappropriate. Raw milk presented high aerobic mesophiles counting (>1.0 x104 CFU/mL in 3 samples) At liners, we observed that counts increase between the first and the last sampling. The first raw milk and fifth pasteurized milk presented low fat percent (

A Expointer e um dos principais eventos da pecuaria na America Latina, que reune os melhores exemplares das principais especies e racas de animais de producao. O objetivo deste trabalho foi avaliar a composicao quimica e a contagem de celulas somaticas do leite das vacas que participaram do concurso leiteiro da Expointer 2007, e correlacionar dois metodos analiticos de determinacao da composicao quimica. Foram coletadas amostras de leite de 9 vacas da Raca Holandes, de tres ordenhas, totalizando 24 horas. Foram realizadas as analises de: gordura, proteina bruta, lactose e solidos totais, por radiacao infravermelha e contagem de celulas somaticas (CCS), por citometria de fluxo. Tambem foi utilizado o metodo de ultra-som para determinacao dos teores de gordura, proteina bruta e solidos desengordurados, visando fazer uma correlacao entre os metodos. A media de producao de leite dos animais do concurso foi de 68,79 kg/animal/dia e a composicao media do leite foi: 2,13% gordura, 2,98% proteina, 4,53% lactose, 9,39% solidos desengordurados e 11,52% de solidos totais. Dois animais apresentaram valores de CCS acima de 200.000 CS/mL. Houve diferenca significativa das analises realizadas pelo metodo de ultra-som em comparacao com o infravermelho, para os teores de gordura (P=0,0005) e solidos desengordurados (P=0,0001), mas nao para proteina (P=0,1782). Os resultados demonstraram correlacoes positivas e significativas, sendo: gordura (r=0,98, P=0,0001), proteina (r=0,83, P=0,0051) e solidos desengordurados (r=0,85, P=0,0041), o que indica que a tecnica de ultra-som pode ser utilizada como metodo de avaliacao da qualidade do leite em industrias, cooperativas e mesmo em centros de pesquisa. Entretanto, um numero maior de amostras e necessario para permitir maiores inferencias.

A melhoria da qualidade do leite é um grande desafio para o setor leiteiro, tendo em vista que uma matéria prima de boa qualidade resulta num maior rendimento e qualidade dos derivados lácteos produzidos, trazendo benefícios para a indústria e para o consumidor. A análise da composição (teor de gordura e proteína bruta), a contagem de células somáticas (CCS) e a contagem bacteriana total (CBT) são instrumentos importantes na avaliação da qualidade do leite. O Ministério da Agricultura, Pecuária e Abastecimento implantou a Instrução Normativa 51/2002, que estabeleceu parâmetros para os componentes do leite. O objetivo deste trabalho foi verificar a situação da qualidade do leite na região do Vale do Taquari, sua variação ao longo do ano e sua adequação aos parâmetros da IN51. O estudo foi realizado no período de agosto de 2006 a agosto de 2007 (13 meses). Foram coletadas amostras de leite de 11 propriedades selecionadas, totalizando 143 amostras. Foram realizadas as análises de: CCS, CBT e composição do leite (teores de gordura e proteína bruta). Os valores médios das análises realizadas foram: gordura - 3,34%, proteína bruta - 3,09%, CCS - 6,0x105 células/mL e CBT - 1,07x106 UFC/mL. Com relação aos padrões da IN51, encontravam-se fora dos padrões estabelecidos para gordura, proteína bruta, CCS e CBT, respectivamente 9,79; 7,69; 14,69% e 29,37% das amostras. A composição química e a CCS do leite analisado, na região do Vale do Taquari, demonstraram a boa qualidade da matéria prima. A contagem bacteriana total foi o fator limitante para a adequação do leite à IN51. Improving the quality of milk is a great challenge for the dairy industry, since that a raw material of good quality results in a higher yield and quality of milk products produced, bringing benefits to industry and consumers. The analysis of the composition (fat content and crude protein), the somatic cell count (SCC) and total bacterial count (TBC) are important tools in assessing the quality of milk. The Ministry of Agriculture, Livestock and Supply deployed the Normative Instruction 51/2002, which established parameters for the components of milk. The aim of this study was to assess the situation of milk quality in the Vale do Taquari, its variation over the year and its appropriateness to the parameters of the IN51. The study was conducted from August 2006 to August 2007 (13 months). Milk samples were collected from 11 selected properties, totaling 143 samples. Were performed the analysis of: SCC, TBC and milk composition (fat levels and crude protein). The average values of the tests conducted were: fat - 3.34%, crude protein - 3.09%, CCS - 6.0x105 cells/mL and TBC - 1.07x106 CFU/mL. With regard to standards of the IN51, were outside the established standards for fat, crude protein, SCC and TBC, respectively 9.79, 7.69, 14.69% and 29.37% of the samples. The chemical composition of milk and SCC discussed, in the Valley of Taquari, demonstrated the good quality of raw materials. The total bacterial count was the limiting factor for the adequacy of the milk to IN 51.

No Rio Grande do Sul, assim como no resto do país, a produção agrícola ecológica vem se tornando cada vez mais frequente, como resposta à demanda de mercado e à diversificação dos sistemas de produção. Com isso, cresce a necessidade de caracterização do produto a ser comercializado. Existem poucos relatos a respeito da composição química ou da contagem de células somáticas do leite obtido a partir desse tipo de sistema produtivo no estado. Com o objetivo de fazer uma caracterização inicial da qualidade do leite produzido num sistema de produção ecológico, que está em processo de credenciamento como orgânico, foi analisado o leite de uma pequena propriedade rural localizada no Vale dos Sinos, RS. Foram utilizadas quatro amostras do leite de mistura dos animais, coletadas no tanque de resfriamento, em diferentes dias, no mês de agosto de 2007. As amostras foram encaminhadas ao laboratório de análise de leite da Embrapa Clima Temperado, em Pelotas/RS, para determinação da composição química e contagem de células somáticas (CCS). A composição média encontrada foi: 3,14% gordura, 3,19% proteína bruta, 4,1% lactose, 12,71% sólidos totais e 9,3% sólidos desengordurados. A média da CCS foi 1,26 x 106 cél/mL de leite, ficando acima dos limites estabelecidos pela Instrução Normativa 51. Ecological production is coming more frequent in Rio Grande do Sul state, as in all Brazilian territory. It is a response for a growing market and production systems diversity. Because of these, standards must be defined to allow safe trade. There are few researches about milk composition and somatic cells count (SCC) in these system production in Rio Grande do Sul. This research aims to get information about composition and SCC, in milk produced in a ecological system. This property is being certified as an organic production system. The property is located at Vale dos Sinos. Four milk bulk samples were collected in August, 2007. The analyses were performed in Embrapa Clima Temperado, Pelotas/RS, to determinate composition and SCC. The compositions values (average) were: 3,14% fat, 3,19% protein, 4,1% lactose, 12,71% total solids and 9,3% solids non fat. SCC average was 1,26 x 106cel/mL. This value does not agree with legal standards (IN51).

This study aimed to evaluate the effects of feeding oregano or green tea extracts on feeding and social behavior, intake and health status of dairy cows during the transition period. Twenty-four Jersey cows were randomly assigned to treatments: control (CON), 10 g / day of oregano extract (OE) or 5 g / day of green tea extract (GT). Dry matter intake (DMI) was evaluated from 7 days pre-calving until the 16 days of lactation using chromium oxide. Feeding and social behaviors as well as the occurrence of health problems were monitored throughout the experimental period. Plant additives did not affect dry matter intake before calving, but after calving Oregano supplementation tended to increase DMI in 1.3 kg compared with Control. Before calving, during the daytime period, OR tended to decrease time spent lying down in 38 min and eating the concentrate in 8.6 min compared with GT. After calving, Oregano reduced time spent eating the concentrate in 9.8 and 7.5 min compared with GT and CON, respectively. The number of total visits to the feeder was lower for cows supplemented with OE compared to the others. Before calving, when GT was added to the diet, cows visited 3.3 times more the feeder and tended to interact 1.2 and 1.6 times less compared to cows in OE and CON groups, respectively. The number of metabolic disorders and clinical and subclinical infectious diseases was similar between treatments, but cows in OE group that were affected by some disease or disorder, tended to present clinical symptoms or subclinical diagnosis on average 8 days later than those supplemented with GT. Oregano and green tea extracts administered into the diet of lactating Jersey cows during the transition periods change several traits of feeding and social behavior but do not change diet intake and the occurrence of diseases.

In the tropics, milk production systems present high diversity and distinct ability to adapt to the demands of consumers and market conditions. Knowledge of the factors that affect the quality of milk and agglomerate of production systems into fewer groups can facilitate analysis and the decisions needed to improve them. The objective of this paper was to characterize, classify and analyze dairy production systems in the Brazilian southern region, and relate their productive aspects to the physical–chemical attributes of the milk produced. A multivariate analysis was conducted with 26 indicators obtained from a survey covering 328 dairy farms. Variance was fully explained by the first three principal factors. The first factor included feeding strategies, the second included the farm’s structure traits and the third included milk composition. Canonical analysis revealed distribution of farmers into three clusters. All feeding strategies, except salt supplementation, as well as monthly milk production, herd size, number of lactating cows in farm and unstable milk frequency were important discriminant variables to determinate cluster formation. The clusters were differentiated by feeding strategies used and the high standard deviation in some of these strategies demonstrated the adoption of specific strategies in different seasons. Cluster 3 had the largest monthly milk production and larger number of lactating cows, but the productivity of cows in the different clusters was not significantly different. The lower unstable milk frequency in cluster 3 is associated with more intensive use of silage, mineral-vitamin premix and commercial concentrate in the diet of animals. The physical–chemical composition of milk and the somatic cell count did not differ between clusters.

Objetivou-se avaliar os efeitos da inclusão de sal aniônico na dieta sobre as características físicas e a composição química do leite, o perfil bioquímico sanguíneo, a produção de leite, o peso e a condição corporal de vacas em lactação. Foram utilizadas 20 vacas da raça Jersey distribuídas em duas dietas, uma sem adição de sal aniônico e outra com adição de 0,25 kg/dia de cloreto de amônio. O delineamento empregado foi o completamente casualizado. As vacas sob suplementação com sal aniônico apresentaram menor pH urinário e aumento das concentrações sanguíneas de ureia, cálcio e magnésio. Com a dieta aniônica, o leite precipitou com menores concentrações de etanol, apresentou menor densidade, porcentagens de lactose, proteína e imunoglobulina, porém maior teor de cálcio iônico. O fornecimento de dieta aniônica durante a lactação resultou em acidose metabólica, o que alterou o perfil bioquímico sanguíneo e as características físico-químicas do leite. The objective of this work was to evaluate the inclusion of anionic salt in the diet on the physical characteristics and chemical composition of milk, biochemical blood profile, milk yield, body weight and condition. It was used 20 Jersey cows, distributed into two diets, a diet with no addition of anionic salt and one diet with addition of 0.25 kg/day of ammonium chloride. It was used a completely randomized design. Cows supplemented with anionic salt presented lower urinary pH and increase of blood contents of urea, calcium and magnesium. With the anionic diet, milk precipitated with lower ethanol concentration and it presented lower density, percentages of lactose, protein and immunoglobulin, but higher ionic calcium content. Supply of anionic diet during lactation resulted in metabolic acidosis, which altered the blood biochemical profile and milk physical-chemical characteristics.

Background : : : : The increase in the goat’s milk production chain has been intensified in recent years. However, little is known about the quality characteristics of goat’s milk. In this sense, the present assay aimed to evaluate the physical parameters of goat’s milk: titratable acidity, alcohol and heat stability and its possible relations. Materials, Methods & Results : 71 samples of Saanen and Alpine goat’s milk were collected during the second lactation phase. In the milk samples were determined the titratable acidity and thermal and alcohol stability. Besides milk samples, date of individual milk production, race, date of birth and order of birth were collected. The titratable acidity values ranged between 11 and 20°D. The median stability of alcohol 52oGL was verified and 76.4% of the samples presented an alcohol stability in which the graduation was lower than 60oGL. A low negative (r = - 0.1914) and non significant (P = 0.1073) correlation was determined between milk production and alcohol stability. In addition to this, a low negative (r = - 0.05702) non-significant (P = 0.6223) correlation between alcohol stability and acidity, measured in Dornic degrees was determined; however, these results did not present a significant association between each other (k = - 0.006). During the clot-on boiling test, a coagulation rate of 39.46% (30/76) from the samples was observed, from which 32% (16/50) was originated from Saanen goats and 53.85% (14/26) from Alpine goats. Discussion : At the time of milking, the acidity of the goat milk varies from 12 to 14oD. This natural acidity is determined by lactation stage and, at the end of this, the acidity is from 16 to 18oD in bulk tank milk. However, in this study, the samples were related to the individual milk production and that may result in different values. Studies have shown significant differences in mean values of acidity according to race, ranging between 12 and 23oD; similar to those observed in this study, but with less individual variability. Data on the stability of goat milk are scarce and the large number of samples that showed no precipitation with alcohol 50°GL is close to the values found in a previous study (40 and 44oGL). Similarly, there are few data on the thermal stability in goat milk. In bulk tank milk samples the thermal stability was determined to 124.5 and 133oC. However, in another study, a low stability of milk coagulation occurs at temperatures from 92 to 110oC. The low thermal stability may be related to the physic-chemical properties of goat milk like protein concentrations and pH. Another factor to consider is that due to its protein composition, the micelles of goat’s milk are less hydrated than those of cow’s milk. This factor, coupled with the highest level of milk proteins and calcium, give to the goat milk a lower thermal stability. It was found that the stability test to alcohol has no correlation with the acidity and contains a wide variability, considering the individual goat milk. Other studies, aiming at correlating the alcohol and heat instability proof to the overall net production of milk in the industrial manufacturing of dairy products, should be performed, considering the growth of the market of caprine dairy products in Brazil.

A composição do leite é um fator de suma importância, seja por seu melhor aproveitamento industrial, seja pelo pagamento dado ao produtor. O teor de nutrientes do leite, principalmente gordura e proteína, é resultado do somatório de vários fatores relacionados à produção. O objetivo desse trabalho é relatar uma situação de desequilíbrio nutricional, ocorrida em uma propriedade da Bacia Leiteira Central da Argentina, e as conseqüentes variações na composição do leite. A dieta das vacas em lactação era composta por alfafa ad libitum sob pastoreio direto, grãos de milho e/ou sorgo, silagem de milho ou sorgo, feno de setária ou alfafa e permeado de lactose. Foi observada a ocorrência nos animais de: claudicação, pododermatites, diarréia profusa e alimentos não digeridos nas fezes, diminuição dos sólidos totais e aumento do teor de nitrogênio uréico no leite. Os sintomas indicaram acidose. Foram realizadas medidas de correção da dieta, com aumento do aporte de fibra efetiva e redução do permeado de lactose. Houve diminuição da sintomatologia observada, com redução do nitrogênio uréico e aumento do teor de sólidos totais do leite. The composition of milk is a factor of the utmost importance, be it for its best industrial usage, be it for the payment of it to the producer. The nutrient content of milk, mainly fat and protein, is due to the sum of several factors related to production. The objective of this work is report a situation of nutritional unbalance, occurred in a property in the Central Dairy Belt of Argentina and the consequent variations in the composition of milk. The diet of cows in lactation was composed of alfalfa ad libitum under direct grazing, corn and/or sorghum grains, corn and/or sorghum silage, setaria or alfalfa hay and lactose permeate. It was observed in the animals the occurrence of: limping, pododermatitis, profuse diarrhea and non-digested feed in the feces, decrease of total solids and increase of uric nitrogen content in the milk. Symptoms indicated acidosis. Corrective measures in the diet were done, with an increase of effective fiber contribution and reduction of lactose permeate. There was a decrease in the symptomatology observed, with a decrease of uric nitrogen and an increase in the content of milk total solids.

The unstable non-acid milk (UNAM) is characterized by loss of casein stability, which results in its precipitation at the alcohol test even though titratable acidity be lower than 18oD. This trial aimed to estimate the occurrence of UNAM in the Northwest of Rio Grande do Sul, state and to verify seasonal variation and its effects on milk composition. From September 2002 to August 2003, approximately 200 dairy farms were monthly monitored. Milk samples from bulk tank were collected and analyzed for titratable acidity; precipitation at alcohol 76% test; percentages of fat, crude protein, lactose, total solids; and somatic cells count, totalizing 2,396 milk samples. UNAM occurrence was 55.2%, being highest in February and March 2002. UNAM occurrence was reduced as milk production of farms increased. Fat percentage did not vary between normal milk and UNAM. However, crude protein, lactose, total solids, and solids non-fat contents were lower in UNAM than in normal milk. Keywords: milk composition, milk quality, stability, alcohol test

A total of twelve lactating Jersey cows were used in a 5-week experiment to determine the effects of severe feed restriction on the permeability of mammary gland cell tight junctions (TJs) and its effects on milk stability to the alcohol test. During the first 2 weeks, cows were managed and fed together and received the same diet according to their nutritional requirements (full diet: 15 kg of sugar cane silage; 5.8 kg of alfalfa hay; 0.16 kg of mineral salt and 6.2 kg of concentrate). In the 3rd week, animals were distributed into two groups of six cows each. One group received the full diet and the other a restricted diet (50% of the full diet). In the 4th and 5th weeks, all animals received the full diet again. Milk composition and other attributes, such as titratable acidity, ethanol stability, pH, density and somatic cell count (SCC) were evaluated. Cortisol levels indicated the stress condition of the cows. Plasma lactose and milk sodium were measured to assess mammary TJ leakiness. Principal factor analysis (PFA) showed that the first two principal factors (PFs) contributed with 44.47% and 20.57% of the total variance in the experiment and, as feeding levels increased, milk stability to the ethanol test became higher and plasma lactose levels decreased, which indicates lower permeability of the mammary gland cell TJ. Correspondence analyses were consistent with PFA and also showed that lower feeding levels were related to reduced milk stability, high plasma lactose, high sodium in milk, low milk lactose (another parameter used to assess TJ permeability) and higher cortisol levels, indicating the stress to which animals were submitted. All observations were grouped in three clusters, with some of the above-mentioned patterns. Feeding restriction was associated with higher permeability of TJ, decreasing milk stability to the ethanol test.

O leite de cabra é produzido em pequena escala, o que torna necessária sua estocagem, permitida pela legislação brasileira. O presente trabalho teve por objetivo avaliar a ação do resfriamento e congelamento sobre as características físico-químicas e microbiológicas do leite de cabra. Não foi observada variabilidade nos valores médios de acidez, estabilidade ao álcool, densidade, gordura, proteína, sólidos totais e lactose após armazenamento sob frio. Não foi observada instabilidade ao calor em nenhuma das amostras analisadas. Verificou-se tendência à diminuição na contagem de células somáticas (CSS) no leite congelado em relação ao fresco e ao refrigerado. A quantificação (NMP) de coliformes totais e termotolerantes variou de < 3 (ausência de crescimento) à > 1.100 UFC/mL, independentemente do armazenamento. Entretanto, determinou-se contagem de coliformes totais e termotolerantes significativamente maior (p < 0,0001) nas amostras mantidas sob refrigeração. Na prova de lactofermentação, observaram-se coágulos digeridos, floculosos e sulcados sem estabelecer correlação entre estes e a contagem bacteriana. A CCS e a contagem microbiana são critérios adotados no pagamento pela qualidade no leite caprino, e a temperatura de armazenamento pode influir sobre elas. The small-scale goat milk production requires its storage, and such operation is allowed by Brazilian laws. This study aimed at evaluating the cooling and freezing effects on physical-chemical and microbiological characteristics of goat milk. However, no variability was verified in average acidity, alcohol stability, density, fat protein, total solids and lactose values after cold storage. Heat instability was not observed in any of the analyzed samples. There was a decreasing tendency in the somatic cell count (SCC) of frozen milk in comparison to fresh and refrigerated milk. The quantification (NMP) of total and thermo-tolerant coliforms varies from < 3 (no growth) to > 1,100 UFC/mL, regardless of the storage method. However, a slightly higher count (p < 0.0001) was observed for total and thermo-tolerant coliforms in the samples kept under refrigeration. In the lacto-fermentation test, digested, flocculated and grooved clots were observed without establishing a correlation between them and the bacterial count. SCC and microbial count are the criteria adopted when paying for the quality of goat milk, and the storage temperature may affect these criteria.

O objetivo deste trabalho foi avaliar a inclusão de citrato de sódio e de bicarbonato de sódio na dieta de vacas lactantes Jersey e seus efeitos sobre os atributos metabólicos, a produtividade e a estabilidade do leite. Foram avaliados o pH urinário, os níveis sanguíneos de glicose e ureia, o peso e o escore de condição corporal, a produção e a estabilidade do leite (teste do álcool) e as propriedades físico‑químicas do leite de 17 vacas, alimentadas com dietas com citrato de sódio (100 g por vaca por dia), bicarbonato de sódio (40 g por vaca por dia) ou sem aditivos. As avaliações foram feitas no 28o e 44o dias. O fornecimento de citrato ou de bicarbonato de sódio não influencia os atributos metabólicos, a produtividade, o peso e o escore de condição corporal das vacas, nem a composição ou a estabilidade do leite. The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body condition score, milk yield, milk stability (ethanol test), and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day), sodium bicarbonate (40 g per cow per day) or no additives. Assessments were made at the 28th and 44th days. Supply of sodium citrate or bicarbonate has no influence on the metabolic attributes, productivity, body weight, and body condition score of the cows, neither on the composition and stability of milk.

O objetivo deste trabalho foi avaliar os efeitos da restrição alimentar sobre a produção de leite bovino e sobre seu perfil eletroforético de proteínas, bem como relacioná‑los à estabilidade do leite pelo teste do álcool. Foram conduzidos dois experimentos com vacas Jersey: no primeiro, avaliou-se o efeito da redução de 40% na alimentação fornecida a vacas semiconfinadas; no segundo, avaliou-se o efeito da restrição de 30% do conteúdo de nutrientes digestíveis totais na alimentação de vacas confinadas. As frações proteicas foram determinadas por eletroforese, e sua quantificação por meio de análises de imagens. As amostras de leite foram classificadas conforme estabilidade no teste do álcool a 72°GL. A restrição alimentar de 40% a vacas semiconfinadas reduziu a produção de leite, mas não alterou a composição de proteínas lácteas e a estabilidade do leite; neste caso, o leite instável apresentou maiores teores de β‑caseína e de proteínas totais, porém menor proporção de κ‑caseína em comparação ao leite estável. A restrição de 30% do aporte energético a vacas confinadas não reduziu a produção leiteira, porém diminuiu a percentagem de albumina sérica bovina e a estabilidade no teste do álcool; neste caso, o leite instável e o estável não diferiram quanto às proteínas lácteas. The objective of this work was to evaluate the feeding restriction effects on milk yield and on its electrophoretic protein profile, and to relate them to milk stability to the alcohol test. Two experiments were carried out with Jersey cows: in the first one, the effect of 40% feed restriction was evaluated on semiconfined cows; in the second one, the effect of 30% reduction in total digestive nutrients was evaluated on confined cows. Protein fractions were determined by electrophoresis and their quantification was done by image analysis. Milk samples were classified according to their stability in the 72°GL‑alcohol test. The 40% feed restriction for semiconfined cows decreased milk yield, but it did not change milk protein contents and stability; in this case, unstable milk showed larger contents of β‑casein and total proteins, but lower κ‑casein in comparison to stable milk. The 30% restriction of energy supply for confined cows did not reduce milk yield, but decreased the percentage of serum bovine albumin and milk stability; in this case, unstable and stable milk did not differ as for protein fractions.

O objetivo deste trabalho é apresentar os principais resultados da pesquisa sobre o leite instável não ácido ou LINA. A proporção de amostras de leite com estabilidade térmica, abaixo do mínimo exigido pela indústria brasileira, configura um sério problema, com uma ocorrência mais elevada durante os períodos de carência alimentar. Trata-se de um problema multifatorial, cujos fatores intervenientes são relacionados à execução do teste (concentração do álcool), ao manejo (alimentação, clima, relação homem-animal), ao animal (suscetibilidade ao estresse, potencial produtivo, estádio da lactação, sanidade, problemas digestivos e metabólicos, frações da caseína), entre outros. Existem dúvidas quanto à capacidade do teste do álcool em estimar a estabilidade térmica do leite. A indústria necessita de um teste rápido, de baixo custo e que realmente identifique o leite adequado ao processamento térmico. O manejo correto dos animais, aliado ao uso de parâmetros realistas de execução do teste do álcool, pode contribuir para melhorar a estabilidade do leite. This paper aimed to present the main results about the unstable non acid milk (LINA). The proportion of milk samples with thermal stability below the Brazilian dairy industry standard is a serious problem, with highest occurrence at short food supply periods. It is a multi factorial problem, which causing factors are related to test execution (ethanol concentration used), to management (feeding, climate, human-animal relation), to animal (stress susceptibility, productive potential, lactation stage, sanitary condition, digestive and metabolic disorders), among others. There are doubts to the accuracy and precision of the alcohol test to detect stability problems. Dairy industry needs a fast, low price and easy test, but that can identify milk suitable to thermal processing. An adequate animal's management besides realistic parameters of milk test might contribute to improve milk stability.

Avaliaram-se o efeito da suplementação de selênio, na dieta ofertada aos animais, sobre a concentração do mineral no sangue e no leite e as alterações nas características físico-químicas, contagem de células somáticas (CCS) e produção de leite. O experimento durou 63 dias, dos quais os primeiros 21 foram préexperimental. Foram utilizadas 32 vacas em lactação da raça Jersey, as quais apresentavam, ao início, peso corporal de 402,5+58,4kg, escore de condição corporal de 3,19+0,31, produção de leite de 10,4+2,1kg e número de dias em lactação de 141,4+69,3. Os tratamentos foram: sem suplementação (grupo-controle); com suplementação de selênio inorgânico 0,3 (dieta-padrão + 0,3mg selenito de sódio/kg de concentrado – SI0,3); com suplementação com selênio orgânico 0,3 (dieta-padrão + 0,3mg seleniometionina/kg de concentrado – SO0,3) e com suplementação de selênio orgânico 0,6 (dieta-padrão + 0,6mg seleniometionina/kg de concentrado – SO0,6). As quantidades totais de selênio das dietas foram, respectivamente, 2,38; 4,18; 4,18 e 5,98mg/dia para os tratamentos controle, SI0,3, SO0,3 e SO0,6. O delineamento experimental foi o completamente ao acaso. O número de dias em lactação e os valores obtidos no início do experimento foram usados como covariáveis. Foram realizadas avaliações da produção de leite, do peso, da condição corporal, da composição do leite e do sangue nos dias 0, 14, 28 e 42 do período experimental. Entre os tratamentos, não foram detectadas alterações quanto à produção de leite, peso, condição corporal, características físico-químicas e microbiológicas do leite, e perfil bioquímico do sangue, exceto em relação à concentração de selênio no sangue entre o tratamento-controle e os tratamentos suplementados. Não houve diferenças quanto aos teores de selênio no sangue entre as fontes de selênio e as doses. Os teores de selênio no sangue evoluíram distintamente durante o experimento conforme a dose e a fonte. A suplementação com selênio não alterou os demais componentes do leite e do sangue. The effects of the dietary supplementation with selenium were evaluated on the concentration of the mineral in blood and milk, as well as changes in milk yield, physical and chemical characteristics, and somatic cells count (SCC). The trial lasted 63 days, the first 21 were designed to adaptation of animals to experimental conditions and standard diet. Thirty-two lactating Jersey cows were used and, at the beginning of the trial, they presented body weight of 402.5+58.4kg, body condition score of 3.19+0.31, milk yield of 10.4+2.1kg/day, and 141.4+69.3 days in milking. Treatments were: control (standard diet without added selenium), inorganic selenium (standard diet + 0.3mg sodium selenite/kg concentrate – SI0.3), organic selenium 0.3 (standard diet + 0.3mg selenomethionine/kg concentrate – SO0.3), and organic selenium 0.6 (standard diet + 0.6mg selenomethionine/kg concentrate – SO0.6). Total daily amounts of selenium were 2.38, 4.18, 4.18, and 5.98mg/cow, respectively, for control, SI0.3, SO0.3, and SO0.6 treatments. The trial was conducted as a completely randomized design. The number of days in milking and the values for all attributes measured at the end of the adaptation period were used as covariates. Measurements of body weight and condition score, milk yield and composition, and blood composition were performed on days 0, 14, 28, and 42 of the experimental period. No differences were detected among treatments for milk yield and composition, body weight and condition score, physicalchemical characteristics of milk, somatic cells count, and biochemical profile of the blood, except for Se contents of blood of control compared to supplemented. There were no differences caused by selenium sources or levels. Selenium supplementation did not alter neither milk nor blood components.

O objetivo deste trabalho foi avaliar o efeito de duas dietas: baixo e alto nível de suplementação, fornecidas a vacas em estádio avançado de lactação sobre os aspectos produtivos, as características físico-químicas do leite e o perfil bioquímico sanguíneo. Foram utilizadas 12 vacas da raça Holandês, com média de 514kg de peso corporal, escore de condição corporal 3,5, produção de leite de 13 litros vaca-1 dia-1, com média de 349 dias de lactação. Os tratamentos foram: baixo e alto nível de suplementação para vacas mantidas em campo natural. Foram avaliados o peso vivo, o escore de condição corporal, a produção leiteira individual, as características físico-químicas e a contagem de células somáticas do leite (CCS), além do perfil bioquímico do sangue. As vacas, mesmo em estádio lactacional avançado, responderam ao aumento do aporte nutricional, com incrementos de ganho de peso, ganho de condição corporal e de produção de leite e produção leiteira corrigida para gordura, além de maiores teores de gordura e de sólidos totais. As demais características do leite e do sangue não foram alteradas. O aumento do aporte nutricional de vacas lactantes com estádio de lactação avançado pode ser uma opção viável para alcançar maior nível de produção leiteira e melhores condições físicas das vacas em sistemas de produção baseadas na utilização de pastagem, sem afetar adversamente a concentração dos componentes lácteos. The trial aimed to verify the effects of two feeding supplements: low and high level supplementation given to cows at an extended lactation stage upon productive aspects, physical-chemical composition of milk and blood biochemical profile. Twelve lactating Holstein cows, with 514kg of body weight, body condition score of 3.5, yielding 13L milk cow-1 day-1 and approximately 349 days of lactation were used. Treatments were low or high level of supplementation for lactating cows grazing natural range pasture. Cow's body weight and body condition score, individual milk yield, physical and chemical characteristics and somatic cells count, besides biochemical blood profile were evaluated. Increased nutrient supply augmented body weight gain, body condition score, fat corrected milk, milk fat and total solids contents, but did not change the others milk components nor blood biochemical profile. Increasing nutrient supply for cows at an extended lactation might be a valuable option to match milk productivity and improved physical aspects of dairy cows kept on grazing systems, without adverse effects upon milk components yield.

Objetivou-se avaliar o efeito de suplementos contendo três combinações de energia e proteína sobre a produção leiteira, as características físico-químicas do leite, o peso e a condição corporal e o perfil bioquímico sanguíneo de vacas. Foram utilizadas 24 vacas lactantes em campo natural, distribuídas em delineamento completamente casualizado, recebendo um dos seguintes suplementos: baixos níveis de energia e proteína; baixo nível de energia e alto nível de proteína; ou altos níveis de energia e proteína. Em comparação ao suplemento com baixos níveis de energia e proteína, aquele com altos níveis de energia e proteína reduziu a instabilidade do leite na prova do álcool, aumentou em 50% a produção de leite e em 18% o escore de condição corporal das vacas. Além disso, ocasionou aumento dos componentes do leite e do perfil bioquímico sanguíneo das vacas: 13% no teor de lactose; 9% no de extrato seco desengordurado; 21% nos níveis plasmáticos de glicose; 24% no teor de fósforo; 16% no nível de creatinina; 9% no teor de magnésio; e reduziu em 40% o teor de nitrogênio ureico. O suplemento com altos níveis de energia e proteína foi mais eficiente que os demais em melhorar a estabilidade do leite na prova do álcool, o escore de condição corporal e os teores de alguns componentes químicos do leite e do sangue. The aim of the study was to evaluate the effects of supplements with three combinations of energy and protein on milk production, milk physical and chemical characteristics, body weight, body condition score and blood biochemical profile of the cows. It was used, in this experiment, 24 lactating cows on natural fields distributed in a complete random design, receiving one of the following supplements: low levels of energy and protein, low level of energy and high level of protein or high levels of energy and protein. Compared to the low energy and protein supplement, high energy and protein supplement reduced milk instability in the alcohol test, it increased milk production in 50%, and body condition score of the cows in 18%. In addition, it increased milk components and blood biochemical profile of the cows: 13% in lactose content; 9% in non-fat dry extracts; 21% in glucose plasmatic levels, 24% in phosphorus content, 16% in creatinine content, 9% in magnesium contents; and it reduced ureic nitrogen in 40%. The supplement with high levels of energy and protein was more efficient than the others in improving milk stability in the alcohol test, body condition score and contents of some chemical components of the milk and of blood.

O objetivo deste trabalho foi caracterizar a produção e a qualidade do leite em sistemas de produção da bacia leiteira de Pelotas. Entre setembro de 2001 e agosto de 2002, foram monitoradas, durante 11 meses, nove unidades produtoras de leite, classificadas nos seguintes sistemas de produção: especializado (ES), semi-especializado (SE) e nãoespecializado (NE). Em amostras coletadas no tanque resfriador, foram determinadas características físico-químicas do leite e contagem de células somáticas. O percentual de mastite e a e produção leiteira corrigida para 4% de gordura foram avaliados. Adotou-se o delineamento completamente casualizado em parcelas subdivididas. A crioscopia, apesar de apresentar diferença estatística entre ES e NE (P

O objetivo deste trabalho foi avaliar o efeito da restrição alimentar na incidência do leite instável não-ácido (LINA) e na composição do leite de vacas Jersey. Foi realizado um experimento piloto de indução ao LINA, com oito vacas Jersey em lactação, confinadas e separadas em dois grupos, às quais havia sido fornecida uma dieta equilibrada ad libitum. Em dois períodos de 18 dias, foram fornecidos dois tratamentos com 100 e 60% das exigências nutricionais. Foram realizados os testes de acidez titulável e do álcool 76%; pH, densidade, crioscopia, caseína, gordura, proteína bruta, lactose, extrato seco total, número de células somáticas e produção de leite foram determinados. A restrição alimentar aumenta a ocorrência de LINA e diminui a produção de leite e a quantidade total dos componentes produzidos; entretanto, não altera os teores dos componentes lácteos. The objective of this work was to evaluate the effects of feed restriction on unstable nonacid milk occurrence and milk composition of Jersey cows. A pilot trial of feed restriction was conducted with eight lactating Jersey cows. Animals were confined and allocated to two groups which received a balanced diet ad libitum. They received sequentially two treatments, at different periods: 100 and 60% of nutritional requirements. Milk was analyzed for titrated acidity and precipitation at alcohol test 76%; pH, density, cryoscopy, casein, fat, crude protein, lactose, total solids, number of somatic cells and milk production were determined. Feed restriction increases unstable nonacid milk occurrence, reduces milk production and amount of components; however, it does not change the concentration of the milky components.

O experimento foi desenvolvido com a finalidade de avaliar os efeitos de suplementação energética com sorgo moído sobre o desenvolvimento corporal de novilhos de corte em pastejo. Sessenta e cinco novilhos (12 a 15 meses de idade, sem raça definida, com 140 kg de peso vivo médio) foram mantidos em pastejo contínuo em uma pastagem natural melhorada com Lotus subbiflorus e invadida por Eragrostis planna, Ness. Os tratamentos consistiram de controle (T0), sem suplemento; 0,75% do peso vivo (T0,75); e 1,5% do peso vivo (T1,5) de grão de sorgo moído fornecido. Os animais foram distribuídos aleatoriamente nos tratamentos, segundo o delineamento completamente casualizado. Na média geral do experimento, houve efeito linear dos níveis de suplemento sobre o ganho de peso diário, de 0,36; 0,52 e 0,76 kg/animal/dia, respectivamente, para os tratamentos T0, T0,75 e T1,5. A suplementação energética permitiu maior ganho de peso nos animais suplementados em relação aos controle, durante todo o período experimental. The trial was conducted to evaluate the effects of energy supplementation with ground sorghum grain on grazing beef steers weight gain. Sixty five steers without definite breed, aging 12 to 15 months and weighing an average 140 kg of live weight were kept under set stocking on a natural pasture improved with Lotus subbiflorus. Treatments consisted of control or without supplement (T0); 0.75% of mean live weight (T0.75) and 1.5% of mean live weight (T1.75) of ground sorghum grain. Animals were randomly assigned to treatments according to a complete randomized design. Considering the overall mean of the trial, supplement levels showed a linear positive effect on daily weight gain, of 0.36, 0.52 and 0.76 kg/animal for T0, T0.75 and T1.5, respectively. Energy supplementation resulted in greater weight gains for supplemented animals compared to not supplemented animals, during all the experiment.

0308-521X/$ see front matter 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.agsy.2013.09.001 DOI of original article: http://dx.doi.org/10.1016/j.agsy.2013.07.004 ⇑ Corresponding author. Address: Programa de Pos-Graduacao em Zootecnia, Faculdade de Agronomia, UFRGS, Av. Bento Goncalves, 7712, Porto Alegre 91540 Brazil. Tel.: +55 51 33086027; fax: +55 51 33086048. E-mail address: vfried@portoweb.com.br (V. Fischer). A.M. Gabbi , C.M. McManus , A.V. Silva , L.T. Marques , M.B. Zanela , M.T. Stumpf , V. Fischer a,⇑

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Resumo Esta pesquisa tem por hipótese que a elaboração de planos de ajuste específicos, baseados no diagnóstico prévio das não conformidades nas práticas agropecuárias adotadas individualmente nas fazendas, influencia o sucesso de programas de fomento à qualidade do leite. Depois do diagnóstico do nível de adoção e o desempenho das práticas adotadas pelos produtores, foram elaborados e executados planos de ajuste de não conformidades baseados na avaliação de 33 grupos de indicadores, agrupados segundo as seis áreas-chave do Guia FAO-IDF de Boas Práticas Agropecuárias na Produção de Leite. Os grupos de indicadores foram avaliados segundo uma escala de desempenho cuja amplitude variou de -2, o menor índice de desempenho aceitável para o grupo, até 2, sendo a conformidade em zero, centro da escala. A definição das áreas a serem priorizadas foi baseada em dois critérios de decisão: 1) impacto na segurança do alimento; e 2) impacto no resultado econômico da atividade produtiva. Foram incluídas 14 propriedades na pesquisa, e os grupos de indicadores foram avaliados antes e depois da execução dos planos de ajuste. A análise estatística comparou os desempenhos inicial e final dos indicadores. Houve melhora significativa (p < 0,05) em 13 das 14 propriedades estudadas, o que mostra que a hipótese testada não deve ser rejeitada. Made available in DSpace on 2019-06-28T01:29:22Z (GMT). No. of bitstreams: 1 ArtigoRevPolAgricDeretiBPRPA2018.pdf: 300460 bytes, checksum: 40c9cae291836f79de6e2fc378b12cff (MD5) Previous issue date: 2018

Made available in DSpace on 2017-12-18T23:22:12Z (GMT). No. of bitstreams: 1 ZanaellaFatoresetiologicosqueafetamaqualidadedoleiteeoLeite.pdf: 370989 bytes, checksum: ae59f539682d2005ccf8cc0e98b8ff12 (MD5) Previous issue date: 2017-12-18

The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body condition score, milk yield, milk stability (ethanol test), and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day), sodium bicarbonate (40 g per cow per day) or no additives. Assessments were made at the 28th and 44th days. Supply of sodium citrate or bicarbonate has no influence on the metabolic attributes, productivity, body weight, and body condition score of the cows, neither on the composition and stability of milk. Made available in DSpace on 2013-09-10T00:30:48Z (GMT). No. of bitstreams: 1 Stumpf2013PAB.pdf: 416394 bytes, checksum: 8337a7adbe68eaf3679351ee295ff871 (MD5) Previous issue date: 2013-09-06 Notas científicas.

O objetivo desse trabalho é apresentar os principais resultados de pesquisa sobre o leite instável não ácido ou LINA. A proporção de amostras de leite com estabilidade térmica abaixo do mínimo exigido pela indústria configura em um sério problema, com uma ocorrência mais elevada durante os períodos de carência alimentar. Trata-se um problema multifatorial cujos fatores intervenientes são relacionados à execução do teste (concentração do álcool), manejo (alimentação, clima, relação homem-animal), ao animal (suscetibilidade ao estresse, potencial produtivo, estádio da lactação, sanidade, problemas digestivos e metabólicos, frações da caseína), entre outros. Existem dúvidas quanto à capacidade do teste do álcool em estimar a estabilidade térmica do leite. A indústria necessita de um teste rápido, de baixo custo e que realmente identifique o leite adequado ao processamento térmico. O manejo correto dos animais aliado ao uso de parâmetros realistas de execução do teste do álcool podem contribuir para melhorar a estabilidade do leite. Made available in DSpace on 2012-12-12T12:50:38Z (GMT). No. of bitstreams: 1 16069.pdf: 198817 bytes, checksum: d1a529f5416033939fc60ceb448230b7 (MD5) Previous issue date: 2012-12-11

Objetivou-se avaliar os efeitos da inclusão de sal aniônico na dieta sobre as características físicas e a composição química do leite, o perfil bioquímico sanguíneo, a produção de leite, o peso e a condição corporal de vacas em lactação. Foram utilizadas 20 vacas da raça Jersey distribuídas em duas dietas, uma sem adição de sal aniônico e outra com adição de 0,25 kg/dia de cloreto de amônio. O delineamento empregado foi o completamente casualizado. As vacas sob suplementação com sal aniônico apresentaram menor pH urinário e aumento das concentrações sanguíneas de ureia, cálcio e magnésio. Com a dieta aniônica, o leite precipitou com menores concentrações de etanol, apresentou menor densidade, porcentagens de lactose, proteína e imunoglobulina, porém maior teor de cálcio iônico. O fornecimento de dieta aniônica durante a lactação resultou em acidose metabólica, o que alterou o perfil bioquímico sanguíneo e as características físico-químicas do leite. Made available in DSpace on 2020-04-03T00:38:55Z (GMT). No. of bitstreams: 1 MARQUES2011.pdf: 51327 bytes, checksum: 78f3626f49f9b536c7af10cf7b2e0114 (MD5) Previous issue date: 2011