Productive, thermoregulatory, and hormonal responses of dairy goats supplemented with selenium-enriched yeast in the Brazilian semi-arid region.

The aim of this study was to evaluate the effect of adding selenium-enriched yeast (SE) in the diet of dairy goats during 60 days of lactation and its effect on productive, thermoregulatory, and hormonal responses of animals managed in a semi-arid region. Sixteen Saanen × Toggenburg crossbred goats were used in a completely randomized design. Goats were weighed, and their milk yield was monitored weekly. Before the animals entered the treatments and at every 20-day milk producing, blood samples were collected to determine the SE levels. At 20, 40, and days of the lactation cycle, individual milk samples were collected to determine composition, casein, urea nitrogen, and selenium content. Measurements of respiratory rate (RR), rectal temperature (RT), coat surface temperature (CST), and epidermal temperature (ET) were performed weekly during the experimental period in two shifts, one in the morning (9 am) and the other in the afternoon (3 pm). No difference (P > 0.05) was detected for body weight, milk yield, composition, selenium concentration, and urea nitrogen. Lower RR and ET (P < 0.05) were observed for animals that received SE supplementation. Thyroid hormone concentrations were similar between treatments (P > 0.05). The positive results of the SE supplementation were concentrated in thermoregulatory responses, and there was no effect on productive, hormonal responses, and plasmatic concentration of selenium in the milk. The SE supplementation for dairy goats managed in a Brazilian semi-arid region was able to promote reduction of RR and coat temperatures.

Thermoregulatory capacity of goat kids from birth to weaning in a dry hot climate.

This study aimed to evaluate the thermoregulatory capacity and performance of Saanen goat kids from birth to weaning in a hot climate. Twelve newborn males and female goat kids with an initial body weight of 4.17 ± 0.81 kg were used. Physiological responses, climatic variables, and biometric traits data were collected. Univariate and multivariate analysis techniques were used. Heart rate (HR) was high up to the 6th week of life, with a reduction from the 7th week on (P < 0.001). Rectal temperature (RT) was lower in the first 2 weeks (P < 0.001), with an increase and stabilization occurring in the 7th and 8th weeks. Coat surface temperature (ST) was more activated from the 5th week onwards (P < 0.001). Body weight (BW) and withers height (WH) were higher in later weeks of the calving phase with a linear effect (P < 0.001). The first principal component demonstrated the relationship of sensible heat dissipation × body area of the goat kids; the second component shows the relationship of meteorological data with RT, having a positive relationship between RT with RH and negative with AT, and the third component points to the association of RR and HR. Of the animals, 81.3% were correctly classified in their group of origin in discriminant canonical analysis, with emphasis on the classification of the kids in the 1st-2nd and 3rd-4th weeks (classification percentage Æ© = 95.8%). It is concluded that (i) newborn kids activate latent mechanisms to maintain their homoeothermic during the first 2 weeks of life, and as they grow, they use sensitive heat loss processes, especially from the 5th week of life onwards and (ii) male and female goats do not show sexual dimorphism effect on body performance and body morphometric measurements up to 60 days of life.

Organic selenium supplementation on metabolic profile of dairy goats.

The aim of this study was to evaluate the effect of organic selenium (SE) supplementation on blood constituents related to hematology and serum biochemistry of dairy goats in the productive phase. A total of 16 lactating Saanen × Toggenburg crossbred goats, aged between 2 and 3, lactating, nonpregnant, clinically healthy, and having a body weight (BW) of 40.75 ± 8.31 kg were selected for this study. Higher SE concentrations were observed on the 42nd day of supplementation, and on the 63rd day, the SE concentrations were similar ([Formula: see text]) to the 21st and 42nd days. There was no interaction for plasma constituents comparing treatment effects and days of supplementation ([Formula: see text]). SE supplementation reduced ([Formula: see text]) plasma proteins with a gradual increase in available SE. There was no difference ([Formula: see text]) for the blood count comparing the effects of treatment and days of supplementation. There was no interaction ([Formula: see text]) for serum biochemical constituents between treatments and periods, except for urea ([Formula: see text]). Animals that received SE supplementation had similar plasma urea concentrations before and after supplementation, while animals that did not receive SE in the diet had increased serum urea concentrations. The main action of selenium in metabolism occurred in the reduction of plasma proteins and urea levels, which leads us to conclude that it influenced protein metabolism. Finally, hematology, liver function, and energy metabolism are not affected by selenium supplementation in dairy goats reared in semiarid conditions.

Effect of a 60-day organic selenium-supplemented diet on the decrease of somatic cell counts in goat milk.

Selenium is an important element in nutrition, showing great potential in the udder health of dairy goats and in the control of subclinical mastitis. However, there are few studies that evaluated the influence of selenium supplementation on subclinical mastitis in goats. The aim of this study was to evaluate the incidence of subclinical mastitis in dairy goats supplemented with organic selenium (Se yeast) in a semi-arid region. Sixteen Saanen × Toggenburg crossbred lactating goats were allocated randomly into two treatments: with and without addition of organic selenium (Se) to the concentrate. Milk samples were collected every 20 days from each udder half to determine the somatic cell count (SSC), chloride content, pH, electrical conductivity, microbiological isolation, composition, and selenium contents. The highest serum selenium concentrations in the blood of these goats occurred at 42 days of supplementation (P < 0.001). Goats which received organic selenium supplementation had higher serum selenium concentrations (P < 0.05). The milk composition variables did not differ (P > 0.05) between the tested treatments, teats, and collections. After 60 days of supplementation, a difference was observed (P < 0.05) between treatments for SSC, chloride content, and pH. Addition of organic selenium to the diet of dairy goats after 60 days of supplementation was promising in reducing the somatic cell count, consequently improving milk quality.

Understanding the dairy production systems in rural settlements in the Brazilian semi-arid region: characterization, typology, and holistic perception.

The objective of this study was to characterize and typify dairy farms and to evaluate society's perception of dairy production in rural settlements in the Brazilian semi-arid region. A questionnaire containing questions related to socioeconomic, livestock, physical, herd management, and production indicators was applied to 17 milk farmers for typological analysis. A second questionnaire was subsequently applied to the same 17 farmers for the holistic perception of dairy farming in rural settlements, in addition to 47 technicians in the area of animal science and 140 laypeople. Milk samples were collected in the settlement's community cooling tank, while the water used for milking management was collected in the milking parlor at the 17 farms. Multivariate analysis techniques and thematic analysis were performed. Three dairy production systems were identified: low production group (0-25 L), medium production group (25-50 L), and high production group (50-100 L). The physicochemical properties (composition, density, and cryoscopy) of milk attended the Brazilian regulation values. The microbiological parameters of milk and water used for milking are at odds with regulations. Regarding the typology, the indicators, livestock, and productivity showed discriminatory power (P < 0.05) between the productive systems. The responses from the segments of society showed different views on dairy production in rural settlements. It is concluded that the dairy farmers have low education and the cleaning product and water used in milking are out of regulation. The livestock and production indicators typified mainly dairy farms, while the holistic perception showed a lack of efficiency in rural extension, ignorance of the potential of the productive system. Finally, the creation of public policies focusing on the development of the milk production system in settlements is recommended.

Thermoregulatory capacity of Santa Inês hair ewes of different genotypes associated with coat colors raised in a hot environment.

The relationship between hair color characteristics and thermoregulatory responses in ewes raised in hot environment were evaluated. 15 Santa Inês hair ewes of different genotypes associated with coat colors (light brown, dark brown and black) with body weight of 41.2 ± 8.1 kg were evaluated during three consecutive days. Rectal temperature (RT, °C) and coat surface temperature (CST, °C) of seven anatomical points (front, back, croup, loin, side, thigh, and belly) were measured during the morning and afternoon periods. Thermoregulatory responses were recorded along with meteorological variables. Heat tolerance index (HTI) and thermal gradient (TG, °C) were estimated for each genotype. RT and CST were influenced by periods of the day (P < 0.05), being higher in the afternoon, but TG did not differ (P > 0.05) between periods. HTI, CST, and TG were equal (P > 0.05) among the three genotypes. Only RT was higher in animals with dark brown coats compared to light brown, but equal to the black coat. It was observed that animals with black or dark brown hairs have a strong association between the CST under study, and yet these had an inverse behavior with the RT. Animals with a darker coat tend to trigger heat dissipation in various anatomical regions of the body, presenting dynamics in thermoregulatory responses in relation to those with lighter coats. Santa Inês ewes have heat dissipation mechanisms as a function of different genotypes associated with coat colors, but have the same thermoregulatory aspects to maintain homeostasis, demonstrating an excellent adaptive mechanism in a hot environment.

Development of an animal adaptability index: Application for dairy cows.

The objective of this study was designed to evaluate the association between thermoregulatory responses, hormonal, hematological and serum biochemical values features aiming to propose an adaptability index (AI) for dairy cows under tropical conditions. Thirty adult dairy cows were used, including 15 Sindi and 15 Girolando breeds with mean weight of 338.52 ± 42.79 kg and 487.54 ± 60.67 kg, respectively. These data included rectal temperature (RT) and respiratory rate (RR). For the serum of blood sample, the levels of glucose (GLU), cholesterol (CHO), triglycerides (TRI), total protein (TP), creatinine (CRE), albumin (ALB), urea (URE), aspartate aminotrasferase (AST) and alanine aminotrasferase (ALT) and hormonal concentrations (triiodothyronine - T3 and thyroxine - T4). For the total blood samples were analyzed for hematology variables: red blood cell count (RBC); hemoglobin concentration (HC); packet cell volume (PCV); mean corpuscular volume (MCV); white blood cell (WBC). The AI was development using multivariate analysis to "weigh" the influence of each variable in the animal responses. The variables more important for adaptive aspects of Sindi and Girolando cows were respectively: GLU; MCV; AST; PCV; RBC; HE; TP; ALB; ALT; RR; T4; RT; T3; URE; CHO; TRI; CRE; WBC and ALB; GLU; TP; AST; RR; ALT; CRE; CHO; RT; RBC; T4; HE; PCV; MCV; URE; TRI; WBC; T3. The difference between breeds was just over 8% for AI. We developed a preliminary AI, able to measure the level of adaptability of dairy cows under tropical region. The methodological framework has potential to inform decision-makers on the adaptability animal conditions and high inference of the blood values from adaptability of cows.

Ingestive behavior, ruminal and blood kinetics in lambs fed cow cheese whey / Comportamento ingestivo, cinéticas ruminal e sanguínea em ovinos alimentados com soro de queijo bovino

The objective of this study was to evaluate the inclusion of cow cheese whey (CCW) in the diet for lambs on the ingestive behavior, ruminal and blood parameters. Twenty crossbred, male, non-castrated lambs with 25 kg body weight were assigned to four treatments: control diet (composed of corn, soybean meal and native pasture silage) and test diets (control diet + inclusion of CCW in increasing levels of 1.6, 2.7 and 4.0% in DM), in a completely randomized design with four treatments and five replications. Means were compared by Tukeys test, and the strength of association between variables was tested by Pearsons correlation. Regression analysis was also performed for data from the collection of ruminal fluid and blood. Behavioral assessments were made at a 24-hour interval in measurements taken every five minutes. The inclusion of CCW in the diet did not impair ruminal pH, but promoted a decrease in rumination and feeding times, also causing a lower number of cuds and a lower number of cud chews. The lowest concentration of ammonia nitrogen and total protein were found in lambs receiving the diet with 4% CCW. However, these values were within the range recommended for microbial growth. CCW is a potential protein alternative in lambs feed as it does not interfere with nutrient intake, ruminal and blood parameters, and favors a positive nitrogen balance.

Objetivou-se avaliar a inclusão de soro de queijo bovino (SQB) na dieta para ovinos sobre o comportamento ingestivo, os parâmetros ruminais e sanguíneos. Vinte ovinos mestiços, machos, não castrados, com 25 kg de peso corporal foram distribuídos em quatro dietas: dieta controle (composta por milho, farelo de soja e silagem de pasto nativo) e as dietas teste (dieta controle + inclusão de SQB em níveis crescentes 1,6; 2,7 e 4,0% na MS), em um delineamento inteiramente ao acaso com quatro tratamentos e cinco repetições. A comparação de médias foi realizada pelo teste Tukey e foram testadas as correlações de Pearson entre as variáveis. Também foi feita a análise de regressão para os dados provenientes da coleta de líquido ruminal e de sangue. As avaliações de comportamento foram feitas em um intervalo de 24 horas em medições realizadas a cada cinco minutos. A inclusão de SQB na dieta não comprometeu o pH ruminal, mas promoveu a queda nos tempos de ruminação e de alimentação, ocasionando também menor número de bolos ruminais e menor número de mastigações merícicas. A menor concentração de nitrogênio amoniacal e proteínas totais foram encontradas nos ovinos que receberam a dieta com 4% de inclusão de SQB. Entretanto, esses valores ficaram dentro do padrão estabelecido para crescimento microbiano. O SQB é uma potencial alternativa proteica na alimentação de ovinos por não interferir no consumo de nutrientes, nos parâmetros ruminais e sanguíneos, e favorecer o balanço positivo de nitrogênio.

Adaptive profile of dairy cows in a tropical region.

The objectives of this study were to determine the main variables which act in the adaptive profile and the dynamic of the thermoregulatory responses of Sindi and Girolando dairy cows in tropical conditions using multivariate analyses as the auxiliary method. Thirty dairy cows were evaluated, in which the data were collected monthly during 12 months. Rectal temperature (RT) and respiratory rate (RR) were measured twice a day (morning and afternoon), along with meteorological variables (air temperature, relative humidity, and wind speed), and later the Black Globe and Humidity Index and Radiant Heat Load were calculated. Blood samples were collected for estimating the levels of triiodothyronine (T3), thyroxine (T4), hemoglobin concentration (HC), red blood cells (RBC), packet cell volume (PCV), mean corpuscular volume (MCV), white blood cells (WBC), glucose (GLU), cholesterol (CHO), triglycerides (TRI), creatinine (CRE), total protein (TP), urea (URE), albumin (ALB), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). The more active variables in the adaptive profile for Sindi cows were T4, PCV, RBC, WBC, TRI, CRE, HC, T3, and URE, while PCV, RBC, ALB, TP, RT, RR, URE, ALT, and AST variables were more active for Girolando cows. All animals were classified according to their corresponding group when considering all variables under study. The classification error percentage was > 40% in the Sindi cows when the physiological responses were considered, whereas an 80% success rate was observed in Girolando cows in the winter and summer seasons. The physiological responses of the dairy cows are similar in winter and distinct in summer in tropical conditions.

Ingestive behavior, ruminal and blood kinetics in lambs fed cow cheese whey / Comportamento ingestivo, cinéticas ruminal e sanguínea em ovinos alimentados com soro de queijo bovino

The objective of this study was to evaluate the inclusion of cow cheese whey (CCW) in the diet for lambs on the ingestive behavior, ruminal and blood parameters. Twenty crossbred, male, non-castrated lambs with 25 kg body weight were assigned to four treatments: control diet (composed of corn, soybean meal and native pasture silage) and test diets (control diet + inclusion of CCW in increasing levels of 1.6, 2.7 and 4.0% in DM), in a completely randomized design with four treatments and five replications. Means were compared by Tukeys test, and the strength of association between variables was tested by Pearsons correlation. Regression analysis was also performed for data from the collection of ruminal fluid and blood. Behavioral assessments were made at a 24-hour interval in measurements taken every five minutes. The inclusion of CCW in the diet did not impair ruminal pH, but promoted a decrease in rumination and feeding times, also causing a lower number of cuds and a lower number of cud chews. The lowest concentration of ammonia nitrogen and total protein were found in lambs receiving the diet with 4% CCW. However, these values were within the range recommended for microbial growth. CCW is a potential protein alternative in lambs feed as it does not interfere with nutrient intake, ruminal and blood parameters, and favors a positive nitrogen balance.(AU)

Objetivou-se avaliar a inclusão de soro de queijo bovino (SQB) na dieta para ovinos sobre o comportamento ingestivo, os parâmetros ruminais e sanguíneos. Vinte ovinos mestiços, machos, não castrados, com 25 kg de peso corporal foram distribuídos em quatro dietas: dieta controle (composta por milho, farelo de soja e silagem de pasto nativo) e as dietas teste (dieta controle + inclusão de SQB em níveis crescentes 1,6; 2,7 e 4,0% na MS), em um delineamento inteiramente ao acaso com quatro tratamentos e cinco repetições. A comparação de médias foi realizada pelo teste Tukey e foram testadas as correlações de Pearson entre as variáveis. Também foi feita a análise de regressão para os dados provenientes da coleta de líquido ruminal e de sangue. As avaliações de comportamento foram feitas em um intervalo de 24 horas em medições realizadas a cada cinco minutos. A inclusão de SQB na dieta não comprometeu o pH ruminal, mas promoveu a queda nos tempos de ruminação e de alimentação, ocasionando também menor número de bolos ruminais e menor número de mastigações merícicas. A menor concentração de nitrogênio amoniacal e proteínas totais foram encontradas nos ovinos que receberam a dieta com 4% de inclusão de SQB. Entretanto, esses valores ficaram dentro do padrão estabelecido para crescimento microbiano. O SQB é uma potencial alternativa proteica na alimentação de ovinos por não interferir no consumo de nutrientes, nos parâmetros ruminais e sanguíneos, e favorecer o balanço positivo de nitrogênio.(AU)

Consumption, apparent digestibility and nutrient balance of diets with bovine milk whey for goats / Consumo, digestibilidade aparente e balanço de nutrientes de dietas com soro de leite bovino para caprinos

Increasing milk production in countries such as Brazil, India and Pakistan implies the generation of dairy by-products such as nutrient-rich bovine whey which, if used in feeding small ruminants would reduce environmental waste and add value to this by-product. Twenty entire male kids weighing an average 17 kg and 5 months age were used. The diet control was composed by Aruana hay, milled whole maize, pelleted soybean and limestone. Bovine cheese whey at 1.5; 3.0 and 4.5% (DM basis) was added to experimental diets. Variables measured included intake, nutrient apparent digestibility, energy balance, and nitrogen balance. Regression equations and Pearson correlations (P ≤ 0.05) were determined. The 3% diet resulted in greater ether extract (EE) (g/kg0.75) and digestible EE (P ≤ 0.05) concentrations compared to 0% whey. The consumption of cellulose (g/kg0.75) was greater (P ≤ 0.05) for kids on the 3.0% diet compared to 0 or 1.5%. Nutrient apparent digestibility was not affected (P > 0.05) by the inclusion of whey. Kids on the 4.5% diet excreted more (P ≤ 0.05) fecal N than those fed no whey; these also retained less N (P ≤ 0.05) compared to animals fed 3.0% or less whey in their diet. All diets resulted in positive energy and nitrogen balances. Bovine whey can be included in male kid diets up to 4.5% of diet without negatively affecting consumption or apparent digestibility of those diets.(AU)

O aumento da produção de leite em países como Brasil, Índia e Paquistão implica na geração de coprodutos lácteos, como o soro bovino rico em nutrientes, e cuja utilização na alimentação de pequenos ruminantes reduziria o desperdício e menores impactos na poluição ambiental, além de agregar valor a esse coproduto. Foram utilizados 20 cabritos sem padrão racial definido, com peso vivo médio de 17 kg e cinco meses de idade. A dieta controle foi composta por feno de capim Aruana, milho moído, farelo de soja e calcário. Para as dietas teste, foram adicionados 1,5; 3,0 e 4,5% (base de matéria seca) de soro de leite bovino. As variáveis estudadas foram o consumo e digestibilidade aparente dos nutrientes, o balanço energético e o balanço de nitrogênio. Equações de regressão e correlações de Pearson (P ≤ 0,05) foram determinadas. A dieta a 3% resultou em maior concentração de extrato etéreo (EE) (g/ kg0,75) e EE digestível (P ≤ 0,05) em comparação com 0% de soro de leite. O consumo de celulose (g/kg0,75) foi maior (P ≤ 0,05) para caprinos machos inteiros na dieta 3,0% comparado a 0 ou 1,5%. A digestibilidade aparente dos nutrientes não foi afetada (P > 0,05) pela inclusão de soro de leite. Os animais que receberam a dieta com 4,5% excretaram mais (P ≤ 0,05) N fecal do que aquelas que não receberam soro de leite; estes cabritos machos inteiros também retiveram menos N (P ≤ 0,05) em comparação com animais alimentados com 3,0% ou menos de soro de leite em sua dieta. Todas as dietas resultaram em balanços positivos de energia e nitrogênio. O soro bovino pode ser incluído em dietas para caprinos em até 4,5% da dieta sem afetar negativamente o consumo ou a digestibilidade aparente.(AU)

The dynamic adaptation of Brazilian Brahman bulls.

Heat stress is one of the most important factors that affect the performance of some Bos taurus breeds and crosses in tropical regions. The Brahman breed was developed in hot regions of the world and often has genes that confer resistance to heat stress compared to other breeds of beef cattle. The goal of this work was to evaluate the adaptive responses of Brahman bulls, based on physiological, hormonal and hair characteristics according to season. The physiological, hormonal and hair characteristics were rectal temperature (RT), respiratory rate (RR), sweating rate (SR), triiodothyronine (T3), thyroxine (T4), cortisol concentrations (CO), coat thickness (CT), hair length (HL), hair diameter (HD) and hair density (ND). These were recorded in Brahman bulls from a Cerrado biome during four seasons: spring (21 September to 20 December), summer (21 December to 17 March), autumn (18 March to 20 June) and winter (21 June to 20 September). Data was analyzed using a general linear model that included season as a fixed effect; in addition, multivariate tests and logistic regression were also used to characterize the animals within each season. The meteorological variables defined the four seasons, besides identifying climatic differences between them. Significant differences (P > 0.05) were found for most of the physiological, hormonal and hair characteristics according to season. The Brahman bulls presented particular adaptive characteristics in each season. Individually, most of the Brahman bulls presented the same adaptive reaction in each season; particular similarity occurred for the summer and autumn. This pattern is a reflection of the inter-relationships between physiological responses and hair characteristics.

Produção e valor nutritivo da canarana erecta lisa (Echinocloa piramidalis Lam. ) em resposta a intervalos de corte / Production and nutritive value of canarana erecta lisa (Echinocloa piramidalis Lam. ) in response to harvest intervals

The objective of this study was to compare and explain the variations in the production and nutritive value of canarana erecta lisa grass (Echinocloa pyramidalis Lam.) at different harvest intervals. The treatments corresponded to the cut intervals of 20, 27, 34, 41, 48, 55, 62, and 69 days. The experimental design was a randomized complete block design with three replications. Each experimental unit had 6m2 (3m ×2m). The variables studied included forage production, canopy height, and nutritive value o harvested forage. Forage production varied from 11517 to 12324 kg ha-1; Plant heights from 48.8 to 234 cm; Neutral detergent fiber (NDF) from 68.8% to 71.13%; Acid detergent fiber (ADF) from 36.20% to 44.15%; Crude protein (CP) from 11.43% to 5.85% and in “in vitro” dry matter digestibility (IVDMD) from 63.30% to 47.42%. These values indicated that the nutritive value of canarana erecta lisa was reduced at longer harvest intervals. It is recommended to harvest the grass at 35 days of regrowth favoring productivity, nutritive value and forage digestibility.(AU)

O objetivo do estudo foi comparar e explicar as variações na produção e valor nutritivo do capim canarana erecta lisa (Echinocloa pyramidalis Lam.) em diferentes intervalos de corte. Os tratamentos corresponderam aos intervalos de corte de 20, 27, 34, 41, 48, 55, 62 e 69 dias. O delineamento utilizado foi o de blocos completos casualizados com três repetições, totalizando 24 unidades experimentais de 6m2 (3m x 2m) cada. Foi avaliado a produção de forragem, altura do dossel e valor nutritivo da forragem colhida. A produção de forragem variou de 11,517 a 12,324 kg MS ha-1 e a altura dossel de 48,8 a 234 cm com menores valores quando o capim foi cortado no menor intervalo de corte. Os teores de fibra detergente neutro (FDN) variaram de 68,80 a 71,13%, fibra detergente ácido (FDA) de 36,20 a 44,15%; proteína bruta (PB) de 11,43 a 5,85%; e digestibilidade “in vitro” da matéria seca (DIVMS) de 65,3 a 47,42%, ou seja, foram reduzidos quando os pastos foram cortados em intervalos de corte mais longos. Recomenda-se o corte do capim aos 35 dias de rebrotação favorendo a produção, valor nutritivo e a digestibilidade da forragem.(AU)

Produção e valor nutritivo da canarana erecta lisa (Echinocloa piramidalis Lam. ) em resposta a intervalos de corte / Production and nutritive value of canarana erecta lisa (Echinocloa piramidalis Lam. ) in response to harvest intervals

The objective of this study was to compare and explain the variations in the production and nutritive value of canarana erecta lisa grass (Echinocloa pyramidalis Lam.) at different harvest intervals. The treatments corresponded to the cut intervals of 20, 27, 34, 41, 48, 55, 62, and 69 days. The experimental design was a randomized complete block design with three replications. Each experimental unit had 6m2 (3m ×2m). The variables studied included forage production, canopy height, and nutritive value o harvested forage. Forage production varied from 11517 to 12324 kg ha-1; Plant heights from 48.8 to 234 cm; Neutral detergent fiber (NDF) from 68.8% to 71.13%; Acid detergent fiber (ADF) from 36.20% to 44.15%; Crude protein (CP) from 11.43% to 5.85% and in “in vitro” dry matter digestibility (IVDMD) from 63.30% to 47.42%. These values indicated that the nutritive value of canarana erecta lisa was reduced at longer harvest intervals. It is recommended to harvest the grass at 35 days of regrowth favoring productivity, nutritive value and forage digestibility.

O objetivo do estudo foi comparar e explicar as variações na produção e valor nutritivo do capim canarana erecta lisa (Echinocloa pyramidalis Lam.) em diferentes intervalos de corte. Os tratamentos corresponderam aos intervalos de corte de 20, 27, 34, 41, 48, 55, 62 e 69 dias. O delineamento utilizado foi o de blocos completos casualizados com três repetições, totalizando 24 unidades experimentais de 6m2 (3m x 2m) cada. Foi avaliado a produção de forragem, altura do dossel e valor nutritivo da forragem colhida. A produção de forragem variou de 11,517 a 12,324 kg MS ha-1 e a altura dossel de 48,8 a 234 cm com menores valores quando o capim foi cortado no menor intervalo de corte. Os teores de fibra detergente neutro (FDN) variaram de 68,80 a 71,13%, fibra detergente ácido (FDA) de 36,20 a 44,15%; proteína bruta (PB) de 11,43 a 5,85%; e digestibilidade “in vitro” da matéria seca (DIVMS) de 65,3 a 47,42%, ou seja, foram reduzidos quando os pastos foram cortados em intervalos de corte mais longos. Recomenda-se o corte do capim aos 35 dias de rebrotação favorendo a produção, valor nutritivo e a digestibilidade da forragem.

Characterize of production systems and milk quality of production units in the semiarid region of Ceará / Caracterização dos sistemas de produção e qualidade do leite de unidades produtoras no semiárido do Ceará

The aim of this study was to characterize the production systems and milk quality of eight milk production units (MPU) in the semiarid region of the state of Ceará, Brazil. Individual interviews were conducted through a questionnaire on the characteristics of the properties and production systems. Samples of milk and water were collected for a period of 12 months. Four MPUs were classified as semi-specialized and four as non-specialized. No differences were observed in milk composition between the two production systems, and both showed protein, fat, and solids-not-fat levels. Differences were observed for somatic cell count. The semi-specialized systems showed an average somatic cell and total bacterial count which is above the limit established by the 62nd Normative Instruction. All water samples showed presence of Escherichia coli. Somatic cell count was positively correlated (fat) and negatively (lactose). For total bacterial count, correlations were negative for fat, total solids, and somatic cell count. The microbiological quality of milk is not in accordance with the 62st and 7th Normative Instructions. The specialization of the production systems did not result in improved microbiological aspects of milk.(AU)

O objetivo deste estudo foi caracterizar os sistemas de produção e a qualidade do leite de oito unidades de produção de leite (UPL) na região semiárida do estado do Ceará. Entrevistas individuais foram realizadas por meio de um questionário sobre as características das propriedades e sistemas de produção. Amostras de leite e água foram coletadas por um período de 12 meses. Quatro UPLs foram classificadas como semiespecializadas e quatro como não especializadas. Não foram observadas diferenças na composição do leite entre os dois sistemas de produção, e ambos apresentaram níveis de proteína, gordura e sólidos não gordurosos. Diferenças foram observadas para contagem de células somáticas. Os sistemas semiespecializados apresentaram contagem média de células somáticas e bacterianas totais acima do limite estabelecido pela 62ª Instrução Normativa. Todas as amostras de água mostraram presença de Escherichia coli. A contagem de células somáticas foi correlacionada positivamente (gordura) e negativamente (lactose). Para contagem bacteriana total, as correlações foram negativas para gordura, sólidos totais e contagem de células somáticas. A qualidade microbiológica do leite não está de acordo com as Instruções Normativas 62ª e 7ª. A especialização dos sistemas de produção não resultou em melhores aspectos microbiológicos do leite.(AU)

Characterize of production systems and milk quality of production units in the semiarid region of Ceará / Caracterização dos sistemas de produção e qualidade do leite de unidades produtoras no semiárido do Ceará

The aim of this study was to characterize the production systems and milk quality of eight milk production units (MPU) in the semiarid region of the state of Ceará, Brazil. Individual interviews were conducted through a questionnaire on the characteristics of the properties and production systems. Samples of milk and water were collected for a period of 12 months. Four MPUs were classified as semi-specialized and four as non-specialized. No differences were observed in milk composition between the two production systems, and both showed protein, fat, and solids-not-fat levels. Differences were observed for somatic cell count. The semi-specialized systems showed an average somatic cell and total bacterial count which is above the limit established by the 62nd Normative Instruction. All water samples showed presence of Escherichia coli. Somatic cell count was positively correlated (fat) and negatively (lactose). For total bacterial count, correlations were negative for fat, total solids, and somatic cell count. The microbiological quality of milk is not in accordance with the 62st and 7th Normative Instructions. The specialization of the production systems did not result in improved microbiological aspects of milk.

O objetivo deste estudo foi caracterizar os sistemas de produção e a qualidade do leite de oito unidades de produção de leite (UPL) na região semiárida do estado do Ceará. Entrevistas individuais foram realizadas por meio de um questionário sobre as características das propriedades e sistemas de produção. Amostras de leite e água foram coletadas por um período de 12 meses. Quatro UPLs foram classificadas como semiespecializadas e quatro como não especializadas. Não foram observadas diferenças na composição do leite entre os dois sistemas de produção, e ambos apresentaram níveis de proteína, gordura e sólidos não gordurosos. Diferenças foram observadas para contagem de células somáticas. Os sistemas semiespecializados apresentaram contagem média de células somáticas e bacterianas totais acima do limite estabelecido pela 62ª Instrução Normativa. Todas as amostras de água mostraram presença de Escherichia coli. A contagem de células somáticas foi correlacionada positivamente (gordura) e negativamente (lactose). Para contagem bacteriana total, as correlações foram negativas para gordura, sólidos totais e contagem de células somáticas. A qualidade microbiológica do leite não está de acordo com as Instruções Normativas 62ª e 7ª. A especialização dos sistemas de produção não resultou em melhores aspectos microbiológicos do leite.

Multivariate approach to milk production and some physiological traits of crossbred dairy cows / Abordagem multivariada da produção de leite e algumas características fisiológicas de vacas leiteiras mestiças

The aim of the present study was to evaluate the changes in physiological responses and serum biochemical panel in crossbred dairy cow populations kept in a hot climate environment. We used a population of 384 dairy cows of genetic groups ½Holstein × ½Guzerá (n = 105) and ¾Holstein × »Guzerá (n = 279) derived from the Brazilian semiarid region. The physiological responses analyzed were: respiratory rate (RR, movements/minute), rectal temperature (RT, C), free thyroxine (T4, µg/mL) and thyroid-stimulating hormone (TSH, µUI/mL). The values of RR, RT, T4, TSH and serum levels of glucose, cholesterol, total protein, urea and creatinine were determined and correlated with milk production for 305 days, correlation lying only with TSH. Significant differences were observed just in milk production, RR and TSH comparing the genetic groups ½Holstein × ½Guzerá and ¾Holstein × »Guzerá. In conclusion, ¾Holstein × »Guzerá cows showed higher thyroid activity and milk production than ½Holstein × ½Guzerá cows, and may therefore be a better option for dairy production systems in semiarid regions.(AU)

O objetivo do presente estudo foi avaliar as mudanças de algumas respostas fisiológicas e dos parametros bioquímicos séricos em vacas leiteiras mestiças mantidas em um ambiente de clima quente. Utilizou-se uma população de 384 vacas leiteiras de grupos genéticos ½Holstein × ½Guzerá (n = 105) e ¾Holstein × »Guzerá (n = 279) criadas no semiárido brasileiro. As respostas fisiológicas analisadas foram: freqüência respiratória (RR, movimentos/minuto), temperatura retal (RT, C), tiroxina livre (T4, ug/mL) e hormônio estimulante da tireóide (TSH, ?UI/mL). Os valores de RR, RT, TR, T4, TSH e níveis séricos de glicose, colesterol, proteínas totais, uréia, creatinina foram determinados e correlacionados com a produção de leite corrigida para os 305 dias, encontrando-se correlação apenas com TSH. Foram observadas diferenças significativas apenas na produção de leite, RR e TSH entre os grupos genéticos ½Holstein × ½Guzerá e ¾Holstein × »Guzerá. Concluiu-se que, vacas ¾Holstein × »Guzerá apresentaram maior atividade da tireóide e produção de leite do que as vacas ½Holstein × ½Guzerá, podendo ser uma melhor opção para sistemas de produção leiteira no semiárido.(AU)

Multivariate approach to milk production and some physiological traits of crossbred dairy cows / Abordagem multivariada da produção de leite e algumas características fisiológicas de vacas leiteiras mestiças

The aim of the present study was to evaluate the changes in physiological responses and serum biochemical panel in crossbred dairy cow populations kept in a hot climate environment. We used a population of 384 dairy cows of genetic groups ½Holstein × ½Guzerá (n = 105) and ¾Holstein × »Guzerá (n = 279) derived from the Brazilian semiarid region. The physiological responses analyzed were: respiratory rate (RR, movements/minute), rectal temperature (RT, C), free thyroxine (T4, µg/mL) and thyroid-stimulating hormone (TSH, µUI/mL). The values of RR, RT, T4, TSH and serum levels of glucose, cholesterol, total protein, urea and creatinine were determined and correlated with milk production for 305 days, correlation lying only with TSH. Significant differences were observed just in milk production, RR and TSH comparing the genetic groups ½Holstein × ½Guzerá and ¾Holstein × »Guzerá. In conclusion, ¾Holstein × »Guzerá cows showed higher thyroid activity and milk production than ½Holstein × ½Guzerá cows, and may therefore be a better option for dairy production systems in semiarid regions.

O objetivo do presente estudo foi avaliar as mudanças de algumas respostas fisiológicas e dos parametros bioquímicos séricos em vacas leiteiras mestiças mantidas em um ambiente de clima quente. Utilizou-se uma população de 384 vacas leiteiras de grupos genéticos ½Holstein × ½Guzerá (n = 105) e ¾Holstein × »Guzerá (n = 279) criadas no semiárido brasileiro. As respostas fisiológicas analisadas foram: freqüência respiratória (RR, movimentos/minuto), temperatura retal (RT, C), tiroxina livre (T4, ug/mL) e hormônio estimulante da tireóide (TSH, ?UI/mL). Os valores de RR, RT, TR, T4, TSH e níveis séricos de glicose, colesterol, proteínas totais, uréia, creatinina foram determinados e correlacionados com a produção de leite corrigida para os 305 dias, encontrando-se correlação apenas com TSH. Foram observadas diferenças significativas apenas na produção de leite, RR e TSH entre os grupos genéticos ½Holstein × ½Guzerá e ¾Holstein × »Guzerá. Concluiu-se que, vacas ¾Holstein × »Guzerá apresentaram maior atividade da tireóide e produção de leite do que as vacas ½Holstein × ½Guzerá, podendo ser uma melhor opção para sistemas de produção leiteira no semiárido.

Produção e composição do leite de ovelhas da raça Rabo Largo criadas em região tropical / Production and milk composition of sheep amaintained in tropical region

Objetivou-se quantificar a produção e a composição química do leite das ovelhas Rabo Largo, mantidas sob dois sistemas de alimentação durante a fase lactacional. Foram utilizadas 60 ovelhas, primíparas e multíparas entre um e quatro anos de idade, amamentando um ou dois cordeiros, mantidas sob dois sistemas de alimentação, com peso vivo médio inicial de 43 kg e 40,5 kg para o lote suplementado e lote não suplementado, respectivamente. Foi medida a produção de leite semanalmente, através do método indireto da dupla pesagem, após o período do colostro. Foram coletadas também amostras do leite, a cada semana, para a determinação da composição química. Os dados de produção de leite foram analisados como medidas repetidas no tempo e entre grupo de fatores. Os fatores considerados foram ano e períodos chuvoso e seco no início de lactação, ordem de lactação, interação tipo de parto e sexo das crias e entre os lotes. Para efeito de comparação de médias entre os lotes, utilizou-se o teste de média dos mínimos quadrados com nível de significância de 5%. Verificou-se que o lote suplementado obteve maior produção de leite do que o lote não suplementado, exceto nas duas últimas semanas de lactação. O pico de produção ocorreu durante a segunda semana de lactação para ambos os lotes. As ovelhas da raça Rabo Largo sem acesso a suplementação responderam de maneira positiva expressando adaptabilidade as condições semiáridas com potencial leiteiro semelhante a outras raças ovinas, e quando suplementadas obtém-se maior produção e manutenção dos mais elevados níveis dos componentes químicos do leite na última semana de lactação.(AU)

The aim of this study was to quantify the production and the chemical composition of the milk of ewes of Rabo Largo breed raised under two feeding systems during the lactation. Sixty ewes, primiparous and multiparous, aged one to four, years nursing one or two lambs were raised under two feeding systems, with average body weight of 43 kg and 40.5 kg for the groups supplemented and not supplemented, respectively. The milk yield were measured weekly, using the indirect method of double weighing, after a period of colostrum. Milk samples were also collected every week for determination of the chemical composition. The data of daily milk production were analyzed with repeated measures over time and across groups of factors. The subject factors considered were year and rainy and dry periods in early lactation, lactation order, interaction between type of lambing and sex of the offspring and between the batches. For comparison of means between batches, we used the average of the least squares with a significance level of 5%. It was found that the supplemented group presented a higher milk yield than the not supplemented group, except to the two last weeks old lactation. Already peak production occurred during the second week of lactation for both lots. The dietary supplementation increases the production and maintained the highest levels of the chemical components of milk in the last week of lactation.(AU)

Produção e composição do leite de ovelhas da raça Rabo Largo criadas em região tropical / Production and milk composition of sheep amaintained in tropical region

Objetivou-se quantificar a produção e a composição química do leite das ovelhas Rabo Largo, mantidas sob dois sistemas de alimentação durante a fase lactacional. Foram utilizadas 60 ovelhas, primíparas e multíparas entre um e quatro anos de idade, amamentando um ou dois cordeiros, mantidas sob dois sistemas de alimentação, com peso vivo médio inicial de 43 kg e 40,5 kg para o lote suplementado e lote não suplementado, respectivamente. Foi medida a produção de leite semanalmente, através do método indireto da dupla pesagem, após o período do colostro. Foram coletadas também amostras do leite, a cada semana, para a determinação da composição química. Os dados de produção de leite foram analisados como medidas repetidas no tempo e entre grupo de fatores. Os fatores considerados foram ano e períodos chuvoso e seco no início de lactação, ordem de lactação, interação tipo de parto e sexo das crias e entre os lotes. Para efeito de comparação de médias entre os lotes, utilizou-se o teste de média dos mínimos quadrados com nível de significância de 5%. Verificou-se que o lote suplementado obteve maior produção de leite do que o lote não suplementado, exceto nas duas últimas semanas de lactação. O pico de produção ocorreu durante a segunda semana de lactação para ambos os lotes. As ovelhas da raça Rabo Largo sem acesso a suplementação responderam de maneira positiva expressando adaptabilidade as condições semiáridas com potencial leiteiro semelhante a outras raças ovinas, e quando suplementadas obtém-se maior produção e manutenção dos mais elevados níveis dos componentes químicos do leite na última semana de lactação.

The aim of this study was to quantify the production and the chemical composition of the milk of ewes of Rabo Largo breed raised under two feeding systems during the lactation. Sixty ewes, primiparous and multiparous, aged one to four, years nursing one or two lambs were raised under two feeding systems, with average body weight of 43 kg and 40.5 kg for the groups supplemented and not supplemented, respectively. The milk yield were measured weekly, using the indirect method of double weighing, after a period of colostrum. Milk samples were also collected every week for determination of the chemical composition. The data of daily milk production were analyzed with repeated measures over time and across groups of factors. The subject factors considered were year and rainy and dry periods in early lactation, lactation order, interaction between type of lambing and sex of the offspring and between the batches. For comparison of means between batches, we used the average of the least squares with a significance level of 5%. It was found that the supplemented group presented a higher milk yield than the not supplemented group, except to the two last weeks old lactation. Already peak production occurred during the second week of lactation for both lots. The dietary supplementation increases the production and maintained the highest levels of the chemical components of milk in the last week of lactation.