Eight multiparous Holstein cows averaging 570 +/- 43 kg of body weight and 60 +/- 20 d in milk were used in a double Latin square design with four 21-d experimental periods to determine the effects of feeding ground or whole flaxseed with or without monensin supplementation (0.02% on a dry matter basis) on milk production and composition, feed intake, digestion, blood composition, and fatty acid profile of milk. Intake of dry matter was similar among treatments. Cows fed whole flaxseed had higher digestibility of acid detergent fiber but lower digestibilities of crude protein and ether extract than those fed ground flaxseed; monensin had no effect on digestibility. Milk production tended to be greater for cows fed ground flaxseed (22.8 kg/d) compared with those fed whole flaxseed (21.4 kg/d). Processing of flax-seed had no effect on 4% fat-corrected milk yield and milk protein and lactose concentrations. Monensin supplementation had no effect on milk production but decreased 4% fat-corrected milk yield as a result of a decrease in milk fat concentration. Feeding ground compared with whole flaxseed decreased concentrations of 16:0, 17:0, and cis6-20:4 and increased those of cis6-18:2, cis9, trans11-18:2, and cis3-18:3 in milk fat. As a result, there was a decrease in concentrations of medium-chain and saturated fatty acids and a trend for higher concentrations of long-chain fatty acids in milk fat when feeding ground compared with whole flaxseed. Monensin supplementation increased concentrations of cis9 and trans11-18:2 and decreased concentrations of saturated fatty acids in milk fat. There was an interaction between flaxseed processing and monensin supplementation, with higher milk fat concentration of trans11-18:1 for cows fed ground flaxseed with monensin than for those fed the other diets. Flaxseed processing and monensin supplementation successfully modified the fatty acid composition of milk fat that might favor nutritional value for consumers.

Milk production is an important economic and social activity in Brazil. Failure to meet institutional and market demands for quality and sustainability has led farmers, particularly small-scale farmers, to leave agriculture. The aim of this study was to assess and compare the sustainability of dairy farms in Paraná, Brazil. A semi-structured questionnaire was administered to 75 dairy farm operators. Sustainability indicators were generated on the basis of economic, environmental and social data using exploratory factor analysis. Factor scores were subjected to hierarchical clustering, which resulted in the formation of three groups of dairy farms. Groups 1, 2 and 3 had high, intermediate and low levels of sustainability, respectively. Group 1 comprised large-scale dairy farms with high productivity. Dairy farms with intermediate sustainability (group 2) had medium production capacity, and farms with low sustainability (group 1) had the smallest production scale and capacity. Large-scale dairy farms have greater economic, environmental and social sustainability and are, therefore, more likely to survive in the medium and long term.

An empirical investigation was conducted to study whether dairy farmers involved in horizontal arrangements (HA)

Pesq. agropec. bras., Brasília, v.34, n.4, p.709-715, abr. 1999 Foram utilizadas 24 vacas da raça holandesa, em diferentes estágios de lactação e níveis de produção, mantidas em dois currais tipo free stall, com ou sem coberturas com lonas plásticas nas extremidades sudeste-noroeste da área coberta. Os parâmetros comportamentais estudados foram: tempos despendidos e freqüências nas atividades de alimentação, ruminação, ócio e procura pelo bebedouro. A proteção da área de descanso dos animais não influenciou as variáveis estudadas. Os tempos despendidos diariamente nas atividades de alimentação, ruminação e ócio foram 3,4, 7,0 e 9,0 horas, respectivamente. As maiores freqüências de alimentação ocorreram antes e depois das ordenhas. A ruminação ocorreu principalmente no período noturno; o ócio foi mais freqüente no período de maior radiação solar. Os animais permaneceram mais tempo na área coberta (13,4 vs 2,5 h/dia). As maiores freqüências de procura pelo bebedouro ocorreram, principalmente, nas horas mais quentes do dia e nos momentos próximos às ordenhas. RESPOSTAS COMPORTAMENTAIS DE VACAS HOLANDESAS 709 RESPOSTAS COMPORTAMENTAIS DE VACAS HOLANDESASTermos para indexação: abrigo, comportamento alimentar, conforto térmico, estresse térmico, vacas leiteiras. BEHAVIOR RESPONSES OF HOLSTEIN DAIRY COWS WITH CONSTANT OR LIMITED ACCESS TO SHADEABSTRACT -The experiment was carried out at Piracicaba, São Paulo, Brazil, from January to February 1993, with the objective of evaluating the behavior responses of Holstein cows, with constant or limited access to shade. The experimental design used was completely randomized. Twenty four dairy cows were used, at different lactation stages and production levels, kept in two free stall barns, with or without protection against solar radiation in south-east and north-west edge. The behavior parameters studied were: alimentation, rumination, rest time and frequency and water ingestion frequency. The protection of the free stall barn didnt affect the behavior responses. The alimentation, rumination and rest time, daily, were 3.4, 7.0 e 9.0 hours, respectively. The highest alimentation frequencies were before and after milking. The rumination was mainly during nocturnal period; the rest was more frequent during the period with higher solar radiation. The animals stayed more time in the shelter (13.4 vs 2.5 h/day). The highest daily water ingestion frequencies were in the hot time and next milking, mainly.

RESUMO -Objetivou-se determinar o consumo de matéria seca (MS), a digestibilidade aparente da MS, matéria orgânica (MO), proteína bruta (PB) e fibra em detergente neutro (FDN) e a digestibilidade in vitro da MS (DIVMS) e, também, quantificar as frações de proteína e carboidratos do feno de Tifton 85, cortado aos 28, 42, 63 e 84 dias de crescimento. O delineamento experimental utilizado para a análise dos dados referentes ao consumo e digestibilidade aparente foi em Quadrado Latino 4 x 4 e, para o fator idade de corte, foi usada regressão. Houve decréscimo linear, à medida que se aumentou a idade de corte para o consumo de MS e para a digestibilidade aparente da MS, MO, PB e FDN. Os valores encontrados para a digestibilidade in vitro da matéria seca (DIVMS) foram bastante próximos aos encontrados para digestibilidade aparente. Para as frações de proteína e carboidratos, observaram-se aumentos para a fração C, com o aumento na idade de corte, que variaram de 17,4 a 22,8 e de 10,9 a 14,3%, respectivamente. Da mesma forma, a fração B3 da proteína aumentou e a B2 apresentou pouca variação, com o aumento da idade de corte, enquanto as frações A e B1 dos carboidratos totais diminuíram. Os resultados referentes ao consumo de MS e digestibilidade da MS foram de 2,4, 2,2, 2,1 e 1,1% e de 60,5, 58,8, 56,3 e 53,8%, para as idades de crescimento de 28, 42, 63 e 84 dias, respectivamente.Palavras-chave: Cynodon, digestibilidade aparente, DIVMS, fibra em detergente ácido, fibra em detergente neutro, fibra em detergente neutro corrigida para cinza e proteína Feed Intake, Digestibility, Protein and Carbohydrate Fractions of Tifton 85 Hay with Different Harvest AgesABSTRACT -The objectives of this experiment were to determine dry matter intake (DMI), apparent digestibility of dry matter (ADMD), organic matter (ADOM), neutral detergent fiber (ADNDF), in vitro DM digestibility (IVDMD) and protein and carbohydrate fractions of Bermuda grass hay harvested at 21, 42, 63 and 84 days. The experimental design used to estimate the feed intake and the apparent digestibility was a 4 x 4 Latin square and to evaluate age effect was used regression analysis. Dry matter intake (DMI) and apparent digestibility of DM, OM, CP and NDF showed a negative linear response for harvest age. Results for in vitro DM digestibility (IVDMD) were similar to apparent digestibility. Protein and the carbohydrate C fractions increased with harvest age and average values ranged from 17.4 to 22.8 and 10.9 to 14.3%, respectively. B3 protein fraction increased with harvest age and B2 fraction showed little variation with harvest age. A and B1 carbohydrate fractions decreased with harvest age. Results for DMI were 2.4, 2.2, 2.1 and 1.1% and for IVDMD were 60.5, 58.8, 56.3 and 53.8% for the 28, 42, 63 and 84 days of harvest age, respectively.Key Words: apparent digestibility, Cynodon, acid detergent fiber, neutral detergent fiber, neutral detergent fiber corrected for ash and protein, IVDMD IntroduçãoUsualmente, a baixa produção e a redução na qualidade da forragem, apre...