Heat tolerance, thermal equilibrium and environmental management strategies for dairy cows living in intertropical regions.

This review makes an attempt to characterize the physical attributes of heat tolerance, thermal equilibrium and thermal stress thresholds for dairy cows living in tropical environments, with a particular emphasis on pasture-based systems. Under such circumstances, the radiant heat load is the principal climatic factor that determines rates of heat and mass exchanges between cows and the environment. This fact may explain why simple mechanistic models based on air temperature and humidity are not adequately predicting thermal stress thresholds for cattle in tropical regions. To overcome this limitation, the Index of Thermal Stress for Cows (ITSC) and Index for the time spent in shade (ITS), which account for various sources of thermal radiation, were proposed to predict autonomous and behavioral thermoregulation of cows. Overall, the evolutionary adaptation of cattle in tropics favored animals that have cutaneous surface with a skin well protected against penetration of ultraviolet solar radiation (UV), covered by a coat surface with high thermal conductivity. For Holstein breed, although predominantly black animals absorb greater levels of short-wave solar radiation, they may present better protection of skin than white ones. However, dark-colored cows in tropical pastures have potential to absorb as much as 640 W m-2 of thermal radiation. This amount of heat load would require close to 1,300 g h -1 of cutaneous evaporative water loss through sweating to prevent increases to body temperature, where cows do not have access to shade. Cows are motivated to reduce time spent grazing and to seek shade when solar irradiance exceeds 550 W m-2, levels that in equatorial latitudes are likely to occur between 08:00 and 16:00h. This information may help producers improve the welfare of cows, as they can determine more comfortable hours for them to graze, for example, by employing nocturnal grazing. Over the daytime, cows should have access to areas with shade and this could include shade provided via solar panels, which has the potential to improve thermal comfort and sustainability of dairy production in tropical areas.

Nitrogen balance and microbial protein synthesis in dairy cows fed with peanut meal to replace soybean meal.

This research was carried out to evaluate the effect of replacing dietary soybean meal with peanut meal, on intake and digestibility, microbial protein synthesis, and nitrogen balance in lactating cows. Twelve crossbred Holstein × Gyr cows at 84 days in milk (DIM) were distributed in a triple 4 × 4 Latin square. The treatments consisted of increasing peanut meal levels (0, 330, 670, and 1000 g/kg dry matter basis) in replacement of soybean meal in the diet. Replacing soybean meal with peanut meal had no effect on the intake and digestibility of dry matter and nutrients. Nitrogen balance and percentage of retained were similar among treatments. Microbial nitrogen synthesis and microbial protein synthesis efficiency were similar among treatments. Thus, in regions where its cost is lower, peanut meal can totally replace soybean meal in dairy cow diets without affecting nitrogen balance and microbial protein synthesis.

Intake and apparent digestibility of dry matter, milk production, and composition of cows fed with diets containing oilseed cakes: A meta-analysis.

Oilseed cakes can partially replace corn or soy used in the diet without losing animal performance. The objective was to carry out a meta-analysis and principal component analysis to evaluate the effects of cakes on the intake and apparent digestibility coefficient (ADC) of dry matter (DM) and milk production and composition in lactating dairy cows. The data set used in the meta-analysis came from 51 studies published between 2009 and 2019, which resulted in 119 studies with 18 types of cakes evaluated in 1350 cows. Cows fed with cakes increased dry matter intake (DMI) by 0.366 kg d-1 (P < 0.001) and DMI as a function of the animal's body weight by 0.103% (P < 0.0001) compared with the diet without cake. The milk protein content decreased by 0.050% (P < 0.010). The contents of neutral detergent fiber (NDF) (26%-%) and ether extract (EE) (3%-7%) of the cake diets did not affect ADCDM. Cakes with contents between 10% and 30% can replace corn or soy in the diet without affecting milk production, components (fat, protein, and lactose), and contents (fat and lactose), but it can reduce the milk protein content of milk.

Effect of replacing soybean meal with peanut meal on milk production and fat composition in lactating dairy cows.

The objective of this study was to evaluate the effects of replacing soybean meal with peanut meal on milk production, chemical and fatty acid composition, nutritional quality indicators of the lipid fraction, and the economic viability of the diets. Twelve crossbred cows in the initial lactation third, with a bodyweight of 545 ± 37 kg and average milk production of 28 kg/day of milk were distributed in a 4 × 4, triple Latin square design. The treatments consisted of diets with substitution levels of soybean meal for peanut meal (0; 330; 670; and 1000 g/kg in DM). The peanut meal inclusion to replace soybean meal in the diets provided a decreasing linear effect for the protein (P = 0.02) and casein (P = 0.01) concentration in milk. Milk production, total solids concentration, feed efficiency, fatty acid composition, and nutritional quality indicators of the milk lipid fraction were not influenced by the substitution levels. The diet cost per kg DM decreased due to the peanut meal inclusion as a protein source. The partial or total substitution of soybean meal for peanut meal in the feedlot cows diet reduces the cost of feed, without affecting milk production and total solids yield.

Genetic evaluation for reproductive and productive traits in Brahman cattle.

Our objectives were to estimate genetic parameters for male and female reproductive traits and their genetic correlations with body weight and carcass traits, evaluate the genetic trends over the years, and verify the effect of inbreeding on the phenotypes of Brahman cattle. The traits evaluated were body weights at 120, 210, 365, and 450 days of age (W120, W210, W365, and W450); scrotal circumference at 365 and 450 days of age (SC365 and SC450), age at first calving (AFC), gestation length (GL), stayability (STAY), ribeye area (REA), backfat thickness (BFT), and rump fat thickness (RFT). Direct heritability estimates ranged from 0.10 ± 0.03 (AFC) to 0.43 ± 0.06 (GL). Maternal heritability estimates for body weights, scrotal circumferences, and GL ranged from 0.07 ± 0.02 to 0.15 ± 0.03. The proportion of the maternal permanent environment for W120 and W210 was equal to 0.11 ± 0.02. Genetic correlations varied between -0.60 ± 0.25 (STAY and BFT) to 0.97 ± 0.01 (W365 and W450). Except for AFC, all genetic trends were significant (p < 0.05) and presented favorable annual genetic gains. Unfavorable effects due to the increase of inbreeding coefficients were observed for body weights and AFC, suggesting greater attention be paid to the applied mating systems to control inbreeding. Reproductive traits, such as AFC and STAY, could be assisted indirectly by scrotal circumference selection. The emphasis applied to body weight selection, especially at W210, may assist REA. The BFT and RFT traits presented genetic variability and have responded to selection, although not included in the Brahman selection index.

Metabolic status of lactating cows given a hepatoprotectant and different feed energy sources.

The present study aimed to evaluate the effects of hepatoprotective agents added to diets containing different energy sources on the metabolic status of lactating dairy cows in confinement. Sixteen Holstein × Gir crossbred midlactation cows with a body weight of 553 ± 85 kg were included in this feeding trial. These animals were arranged in a 4 × 4 Latin square experimental design. A 2 × 2 factorial arrangement was employed in this feeding experiment. Experimental treatments consisted of the administration of diets supplemented with a hepatoprotectant and diets without hepatoprotectant. These diets contained varying amounts of ground corn or citrus pulp as energy sources. Serum markers for energy metabolism and proteins were evaluated and liver enzymes were measured. Blood samples were collected in the morning before (0 h) and 4 h after the animals were fed these diets. There was no interaction between the hepatoprotective agent and the dietary energy sources for the metabolic status variables. Ground corn as an energy source yielded higher serum concentrations of glucose, HDL (high-density lipoprotein) cholesterol, and globulins, whereas b-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), total cholesterol, albumin, and aspartate aminotransferase (AST) yielded the highest concentrations in diets containing citrus pulp. There was interaction between time and hepatoprotective agent in serum LDL (low-density lipoprotein) cholesterol concentration. The present study shows that ground corn diets increased the synthesis of glucogenic nutrients, whereas citrus pulp used as an energy source altered the lipid status of lactating cows. The hepatoprotective agent increased postprandial serum LDL cholesterol levels.

Uso da homeopatia no gado de leite como modulador da função hepática: uma revisão / Use of homeopathy in dairy cattle as a modulator of liver function: a review / Uso de la homeopatía en ganado lechero como modulador de la función hepática: una revisión

Resumo A homeopatia pode ser utilizada na pecuária leiteira como uma alternativa segura aos antibióticos, capaz de reduzir a expansão da resistência microbiana, ao passo que mantém a saúde dos rebanhos. No entanto, os compostos homeopáticos podem também ser usados como protetores do fígado, podendo atuar na modulação da função hepática. Os medicamentos homeopáticos a base de plantas podem ser utilizados como agentes hepatoprotetores, uma vez que possuem a capacidade de prevenir e reparar desordens hepáticas que comumente acometem vacas em lactação. Assim, o conhecimento das propriedades terapêuticas de plantas permite a elaboração de preparos homeopáticos, capazes de preservar a saúde dos animais de produção. Baseado nisso, objetivou-se com esta revisão discorrer sobre compostos vegetais utilizados na homeopatia como hepatoprotetores e seus efeitos no metabolismo hepático e na resposta produtiva de animais ruminantes em lactação.

Abstract Homeopathy can be used in dairy farming as a safe alternative to antibiotics, capable of reducing the expansion of microbial resistance, while maintaining the health of herds. However, homeopathic compounds can also be used as liver protectors, and can act in the modulation of liver function. Herbal homeopathic medicines can be used as hepatoprotective agents, since they have the ability to prevent and repair liver disorders that commonly affect lactating cows. Thus, knowledge of the therapeutic properties of plants allows the preparation of homeopathic preparations, capable of preserving the health of farm animals. Based on this, the aim of this review was to discuss plant compounds used in homeopathy as hepatoprotectors and their effects on liver metabolism and on the productive response of lactating ruminant animals.

Resumen La homeopatía se puede utilizar en la producción lechera como una alternativa segura a los antibióticos, capaz de reducir la expansión de la resistencia microbiana, manteniendo la salud de los rebaños. Sin embargo, los compuestos homeopáticos también pueden usarse como protectores del hígado y pueden actuar en la modulación de la función hepática. Los medicamentos homeopáticos a base de hierbas se pueden utilizar como agentes hepatoprotectores, ya que tienen la capacidad de prevenir y reparar los trastornos hepáticos que comúnmente afectan a las vacas lactantes. Así, el conocimiento de las propiedades terapéuticas de las plantas permite la elaboración de preparados homeopáticos, capaces de preservar la salud de los animales de granja. En base a esto, el objetivo de esta revisión es discutir los compuestos vegetales utilizados en homeopatía como hepatoprotectores y sus efectos sobre el metabolismo hepático y la respuesta productiva de los rumiantes lactantes.

Carcass traits, commercial cuts, tissue composition, intake, digestibility, and performance of Sindhi bulls subjected to feed restriction / Características da carcaça cortes comerciais, composição tecidual, consumo, digestibilidade e desempenho de touros Sindi submetidos à restrição alimentar

ABSTRACT: This study showed the effect of feed restriction on performance, nitrogen balance (NB), microbial protein synthesis, carcass traits and meat cut of the thirty-two Sindhi non-castrated males (296 ± 21.3 kg initial BW and 21 ± 1.5 months old). All bulls were distributed in a completely randomized design with four treatments (feed restriction levels) (0, 15, 30, and 45% in total dry matter -DM) and the data were subjected to analysis of variance and regression. Nutrient intake, NB, final BW, total gain, feeding efficiency, carcass gain, hot and cold carcass weight, subcutaneous fat thickness, commercial cuts and fat tissue decreased linearly (P<0.05) by feed restriction level. A linear increased on digestibility of DM, NDFap, total carbohydrates and on the proportion of muscle tissue, as well as quadratic increase on non-fibrous carbohydrates and bone tissue percentage with the restriction level imposed on bulls (P<0.05). The feed restriction did not affect (P>0.05) the digestibility of crude protein, synthesis and microbial efficiency, deposition efficiency, longissimus dorsi area and muscle + fat/bone ratio. The feed restriction reduced intake and consequently performance, carcass traits and meat cuts of Sindhi bulls; however, it promoted a reduction in the N excretion, which can be important if conducted a subsequent compensatory weight gain.

RESUMO: Este estudo mostrou o efeito da restrição alimentar no desempenho, balanço de nitrogênio, síntese microbiana de proteínas, característica da carcaça e corte de carne de 32 machos Sindi não castrados (296 ± 21,3 kg de peso corporal inicial e 21 ± 1,5 meses de idade). Todos os touros foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos (níveis de restrição alimentar) (0, 15, 30 e 45% no total de matéria seca - MS) e os dados foram submetidos à análise de variância e regressão. Consumo de nutrientes, balanço de nitrogênio, peso corporal final, ganho total, eficiência alimentar, ganho de carcaça, peso de carcaça quente e fria, espessura subcutânea de gordura, cortes comerciais e tecido adiposo diminuíram linearmente (P<0,05) com o nível de restrição alimentar. Houve aumento linear na digestibilidade do DM, FDNap, carboidratos totais e quantidade de tecido muscular, além de aumento quadrático de carboidratos não fibrosos e porcentagem de tecido ósseo com o nível de restrição imposto aos touros (P<0,05). A restrição alimentar não afetou (P>0,05) a digestibilidade da proteína bruta, balanço de N, síntese e eficiência microbiana, eficiência de deposição, área do longissimus dorsi e relação músculo + gordura / osso. A restrição alimentar reduziu a ingestão e, consequentemente, o desempenho, as características da carcaça e os cortes de carne de touros Sindi, porém promoveu redução na excreção de N, o que pode ser importante se for realizado um subsequente ganho compensatório.

Dynamics of degradation of high-quality tropical forage according to levels of nitrogen supplementation.

The present study aimed to evaluate the degradation dynamics of high-quality tropical forage according to the levels of nitrogen supplementation. In this study, 4 rumen-fistulated cows with a body weight of 653 ± 47 kg were used. These animals were distributed in a 4 × 4 Latin square experimental design. Cows were kept under a grazing regime in an area formed by Panicum maximum Jacq. cv. Tanzania. These animals received 4 levels of crude protein (CP) in the supplements (122, 142, 162, and 180 g/kg of CP in DM). The degradability of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) was determined by in situ incubation of forage samples at 0, 6, 12, 24, 48, 72, 96, and 120 h. Both the concentration of ammonia nitrogen (NH3-N) and the microbial protein synthesis were affected by CP levels of the supplements (P < 0.05). There was a significant difference (P < 0.05) for fraction b, potential degradability, and effective degradability of DM and NDF, and for the c degradation rate of CP of Tanzania grass which had the highest values at 122 g/kg of CP. Overall, the greatest degradation of nutrients from Tanzania grass occurred in the diet with 122 g/kg of CP and 604 g/kg of NFC in dairy cattle supplements that resulted in the highest rates of nitrogen utilization by rumen microbes.

The use of simple physiological and environmental measures to estimate the latent heat transfer in crossbred Holstein cows.

The aim of the present study was to estimate the heat transfer through cutaneous and respiratory evaporation of dairy cows raised in tropical ambient conditions using simple environmental and physiological measures. Twenty-six lactating crossbred cows (7/8 Holstein-Gir) were used, 8 predominantly white and 18 predominantly black. The environmental variables air temperature, relative humidity, black globe temperature, and wind speed were measured. Respiratory rate and coat surface temperature were measured at 0700, 0900, 1100, 1300, and 1500 h. The environmental and physiological data were used to estimate heat loss by respiratory (ER) and cutaneous evaporation (EC). Results showed that there was variation (P < 0.01) for respiratory rate depending on the times of the day. The highest values were recorded at 1100, 1300, and 1500 h, corresponding to 66.85 ± 10.20, 66.98 ± 7.80, and 65.65 ± 6.50 breaths/min, respectively. Thus, the amount of heat transferred via respiration ranged from 19.21 to 29.42 W/m2. There was a variation from 31.6 to 38.8 °C for coat surface temperature; these values reflected a range of 55.52 to 566.83 W/m2 for heat transfer via cutaneous evaporation. However, throughout the day, the dissipation of thermal energy through the coat surface accounted for 87.9 % total loss of latent heat, and the remainder (12.1 %) was via the respiratory tract. In conclusion, the predictive models based on respiratory rate and coat surface temperature may be used to estimate the latent heat loss in dairy cows kept confined in tropical ambient conditions.

Carcass characteristics of Canindé goats subjected to feed restriction / Características de carcaça de caprinos Canindé submetidos à restrição alimentar

ABSTRACT: This study aimed to evaluate the effects of feed restriction on the carcass characteristics of castrated Canindé goat kids. A randomized block design was used, in which 21 goat kids with a body weight (BW) of 15.9±1.0kg were allocated to three levels of feed restriction: ad libitum, 20% and 40% restriction related to the ad libitum intake. The diet consisted of 55% forage (Tifton) and 45% concentrate. All animals were slaughtered when the kids fed ad libitum reached a BW of 25kg. After slaughter, the carcasses were chilled for 24 hours and subsequently measured. Kids fed ad libitum and subjected to 20% feed restriction showed similar morphometric carcass measurements, except for the chest circumference. Goat kids fed ad libitum exhibited greater values for warm and cold carcass yields compared with those subjected to 40% feed restriction and did not differ from the kids under 20% feed restriction. Weights of the commercial cuts showed decreasing mean values according to the intensity of feed restriction. Castrated Canindé goat kids subjected to 20% feed restriction presented similar carcass yields and proportion of commercial cuts to those fed ad libitum.

RESUMO: Objetivou-se com o presente estudo avaliar os efeitos da restrição alimentar sobre as características de carcaça de cabritos Canindé castrados. Foi utilizado um delineamento em blocos casualizados, no qual 21 cabritos com peso corporal (PC) de 15,9±1,0kg foram distribuídos por três níveis de restrição alimentar: ad libitum, 20% e 40% de restrição alimentar. A dieta consistiu de 55% de volumoso (Tifton) e 45% de concentrado. Os animais foram abatidos quando os cabritos alimentados ad libitum atingiram PC de 25kg. Após o abate, as carcaças foram resfriadas por 24 horas e, subsequentemente, mensuradas. Os cabritos alimentados ad libitum e submetidos à restrição alimentar de 20% apresentaram medidas morfométricas semelhantes, exceto para a circunferência do peito. Os cabritos alimentados ad libitum apresentaram maiores valores para rendimento de carcaça quente e fria em comparação àqueles submetidos à restrição alimentar de 40% e não diferiram entre os cabritos com restrição alimentar de 20%. Os pesos dos cortes comerciais apresentaram médias decrescentes com a intensidade da restrição alimentar. Cabritos Canindé castrados submetidos à restrição alimentar de 20% obtém rendimento de carcaça e proporção dos cortes comerciais similares aos alimentados ad libitum.

Milk production, intake, digestion, blood parameters, and ingestive behavior of cows supplemented with by-products from the biodiesel industry.

This study aimed to evaluate the intake, digestion, blood parameters, and feeding behavior of crossbred dairy cows (Holstein × Gir) managed on Panicum maximum Jacq. cv. Tanzania-1 and provided supplementation with groundnut cake, sunflower cake, or palm kernel cake (to replace soybean meal). Sixteen cows were randomly assigned in a Latin square design with four treatments and four experimental periods. The consumption of nutrients from the pasture did not vary between experimental treatments. Cows receiving the palm kernel cake supplement had a reduced crude protein, non-fibrous carbohydrate, and total digestible nutrient intake and an increase in the average consumption of ether extract. There was also a reduction in the digestibility of dry matter. The inclusion of supplements in the diet did not influence the average time spent eating, ruminating, or resting. The mean values of respiratory and heart rates showed thermal comfort during the trial period. There was a reduction in blood urea nitrogen with palm kernel cake supplementation, and the values of total protein, albumin, and glucose were also significantly different with this supplement. It is recommended that cakes of groundnut cake and sunflower cake seed be used for a total replacement of soybean meal supplements for lactating cows, but the use of palm kernel cake is not recommended.

Comportamento ingestivo de vacas primíparas das raças Guzerá e Sindi recebendo dietas com diferentes níveis de ureia / Ingestive behavior of cows primiparous of the Guzera and Sindi breed receiving differents diets

Objetivou-se com este trabalho avaliar parâmetros de comportamento ingestivo de vacas primíparas das raças Guzerá e Sindi recebendo dietas com diferentes níveis de inclusão de ureia, em substituição ao farelo de soja, e da cana-de-açúcar, em substituição ao capim elefante. Foram utilizadas oito vacas primíparas, sendo quatro da raça Guzerá e quatro da raça Sindi em lactação, distribuídas em dois quadrados latinos 4x4. Os tratamentos experimentais consistiram em: T1 (0,0 cana-de-açúcar + 0,0% ureia), T2 (13,0% cana-de-açúcar + 0,6% ureia), T3 (26,2% cana-de-açúcar + 1,2% ureia) e T4 (39,4% cana-de-açúcar + 1,8% ureia), na matéria seca. Os animais foram observados a cada cinco minutos, durante 24 horas, para determinação do tempo despendido em alimentação, ruminação e ócio. Não foi observada diferença significativa (P>0,05) para os tempos médios despendidos com as variáveis comportamentais alimentação, ruminação e ócio, à medida que foram aumentados os níveis de inclusão da ureia e cana-de-açúcar nas dietas. O tempo de mastigação total foi maior para os animais da raça Sindi, quando comparado ao dos animais da raça Guzerá. Animais da raça Guzerá apresentaram maior eficiência de alimentação em (g MS/h) e ruminação, quando expressa em (g MS h-1) e (g FDN h-1), quando comparada com a raça Sindi. À medida que se aumentam os níveis de inclusão da ureia e cana de açúcar na dieta, há um decréscimo da eficiência de ruminação expresso em (g FDN h-1).

This study aims to evaluate the ingestive behavior parameters of primiparous cows Sindi and Guzerá breeds under diet of different levels of urea inclusion replacing the soybean bran and the sugar cane replacing the elephant grass. It has been used eight primiparous cows, being four Guzerá breed and four Sindi lactating, distributed into two Latin squares 4x4. The experimental treatments consisted of: T1 (0.0 sugar cane + 0.0% urea), T2 (13.0% sugar cane + 0.6% urea), T3 (26.2% sugar cane + 1.2% urea) and T4 (39.4% sugar cane + 1.8% urea), in the dry matter. The animals have been observed each five minutes, during 24 hours, to determine the time spent in feeding, rumination and leisure. There was no significant difference, for the medium time spent with the behavioral variables feeding, rumination and leisure, as it has been increased the levels of urea and sugar cane inclusion in the diets. The total chewing time has been higher for the Sindi cattle when compared with Guzerá. The different levels of sugar cane and urea inclusion have not influenced in the time spent in feeding, rumination and leisure. Animals of the Guzerá breed have shown higher efficiency of feeding in (g Ms/h) and rumination, when expressed in (g Ms h-1) and (g FDN h-1), when compared with Sindi breed. As the sugar cane and urea levels increase in the diet, there is a decrease of the rumination efficiency expressed in (g FDN h-1).

Desempenho de ovinos terminados em confinamento com resíduo desidratado de vitivinícolas associado a diferentes fontes energéticas / Performance of sheep in feedlot termination fed with dried grapes residue diets associated with different energy sources

Foram avaliados os efeitos de dietas combinando o resíduo de vitivinícolas a diferentes fontes energéticas sobre consumo, ganho de peso diário e conversão alimentar em ovinos terminados em confinamento. Foram utilizados 18 ovinos sem padrão racial definido, não castrados, com idade aproximada de sete meses e peso vivo médio inicial de 23,0kg, distribuídos num delineamento em blocos casualizados, com três tratamentos e seis repetições. O período experimental constou de 63 dias, sendo as dietas compostas de 50 por cento de resíduo de vitivinícolas e 50 por cento de concentrados energéticos: grão de milho moído (Zea mays) (T1), raspa de mandioca (Manihot esculenta) enriquecida com 1,8 por cento de uréia (T2) e farelo de palma forrageira (Opuntia ficus) enriquecido com 1,1 por cento de uréia (T3). Foram avaliados os consumos de matéria seca (MS), proteína bruta (PB) e carboidratos totais (CHOT), ganho de peso diário e total e a conversão alimentar. Os consumos de MS, PB e CHOT foram de 1.085, 906 e 1.508g dia-1; 129, 139 e 220g dia-1; 846, 691 e 1.157g dia-1; os ganhos de peso médio diário foram de 117, 71 e 132g; a conversão alimentar de 9,50; 13,28 e 11,30, respectivamente para as combinações de resíduo e grão de milho moído, raspa de mandioca e farelo de palma. As médias diárias de ganho de peso vivo obtidas pelos ovinos ao longo do período de engorda revelaram um bom potencial forrageiro do resíduo de vitivinícolas combinado às diferentes fontes energéticas.

The effect of combining diets residues from grapewine industries with different energy sources on consumption, daily weight gain and feed conversion of sheep in feedlot termination were evaluated. Eighteen seven-month old male sheep, non-defined breed, were used, weighted initialy 23.0kg, distributed in randomized blocks with three treatments and six repetitions. The experimental period consisted of 63 days, being the diets composed of 50 percent of grapewine industry residue and 50 percent of energy concentrate: ground corn grain (Zea mays) (T1), cassava chips (Manihot esculenta) enriched with 1.8 percent of urea (T2) and fodder cactus dried meal (Opuntia ficus) enriched with 1.1 percent of urea (T3). Intakes of dry matter (DM), crude protein (CP) and total carbohydrate (TCHO) were evaluated, as well as daily and total weight gains and feed conversion. Respectively for the combination of residue and ground corn grain, for cassava chips and for fodder cactus dried meal, intakes of MS, PB and CHOT were 1085, 906 and 1508g dia-1; 129, 139 and 220g dia-1; 846, 691 and 1157g day-1; average daily weight gains were 117g, 71g and 132g; feed conversions were 9.50, 13.28 and 11.30. Daily averages of live weight gains obtained by sheep during the fattening period showed a good forage potential of the residues of grapewine industries combined with different energetic sources.

Composiçäo centesimal da carne de cordeiros submetidos a dietas com diferentes teores de concentrado / Centesimal composition of lamb meat submitted to diets with different concentrate levels

Foi estudada a composiçäo centesimal da carne de cordeiros submetidos a três dietas com diferentes níveis de concentrado. Foram utilizados 18 cordeiros, machos näo castrados, da raça Morada Nova, com peso vivo médio inicial de 15kg. As dietas constituíram-se em: D1 - 60 por cento de concentrado (C) e 40 por cento de volumoso (V); D2 - 45 por cento de C e 55 por cento de V e D3 - 30 por cento de C e 70 por cento de V. Quando os animais que recebiam a D1 atingiam 25kg de peso vivo, o respectivo lote, formado por três animais, era abatido. As carcaças foram refrigeradas a 4ºC por 24 horas. A meia carcaça esquerda foi seccionada em cinco cortes: pescoço, paleta, costelas, lombo e perna. As pernas foram dissecadas para a obtençäo do músculo Semimembranosus, no qual foi determinada a composiçäo centesimal. Os níveis de concentrado na dieta näo afetaram o teor de umidade, matéria mineral e gordura da carne ovina, porém afetaram (P<0,05) o teor de proteína. As dietas com 30 e 60 por cento de concentrado propiciaram mesmo teor de proteína na carne.