Does macauba cake alter nutrient digestibility and microorganism population in the rumen of sheep?

Twenty Santa Inês male sheep were used in a randomized block design to evaluate the effects of different levels of macauba cake (MC) on nutrient digestibility and the population of microorganism in the rumen. The animals were divided into four groups according to MC levels (0, 10, 20, and 30% of DM) and initial body weight ranging from 32.75 to 52.17 kg. Diets were isonitrogenous and formulated to attend metabolizable energy requirements, and feed intake was regulated with 10% allowance for leftovers. Each experimental period lasted 20 days, with the final 5 days reserved for sample collection. Macauba cake inclusion did not affect the dry matter, organic matter, or crude protein intake but increased the ether extract, neutral detergent fiber, and acid detergent fiber intake, mainly because of changes in the concentrations of these components in diets with a higher level of MC. With MC inclusion, a linear decreasing effect was observed for the dry matter and organic matter digestibility, and a quadratic effect with a maximum point of 21.5% was observed for the acid detergent fiber digestibility. A relative reduction of 73% in anaerobic fungal populations was observed with the lowest level of MC inclusion, and a relative increase of 162% in methanogenic populations was observed with the highest level of MC inclusion. The increasing level of macauba cake up to 30% of the diet of lambs reduced the dry matter digestibility and reduced anaerobic fungi but increased methanogenic population.

Screening microchip sites to predict body temperature in young calves.

Thermal microchip sensors can automate body temperature measurements. The best site of implantation is still unknown, and the accuracy and precision of body temperature predictions based on microchip data need to be investigated. The aim of this study was to investigate the best site for microchip implant for monitoring body temperature in dairy calves. Seventeen calves were used (32.2 ± 5.2 kg of body weight) and the microchips were implanted four days after birth. The microchips were implanted at navel, ear and tail base (subcutaneous), neck (cleidocephalicus) and internal face of leg (gracilis) (intramuscular). Rectal temperature (RT, °C), obtained with a clinical thermometer, was considered as core temperature. Air temperature (AT), relative humidity (RH) and the temperature and humidity index (THI) were evaluated at the same time of rectal and microchip temperature measurements over 56 days. The range of AT, RH and THI was 7.6-34.4 °C, 17.5-99.0% and 50.6 to 91.5. The average for rectum, ear, neck, tail, leg, and navel were 38.7; 36.9; 38.0; 37.0, 37.8 and 37.0 °C. The intramuscular implantations had closest values to RT. The correlations between RT and ear, neck, tail, leg, and navel temperatures were 0.56, 0.60, 0.60, 0.53 e 0.48. The RT prediction based on microchip data had precision (rc) ranged between 0.49 and 0.60 and accuracy (Cb) between 0.79 and 0.88. The inclusion of AT, RH and THI as predictive variables in models decrease the mean absolute error (23%) and increase the precision (21.3%) and accuracy (10.2%). The Concordance Correlation Coefficient and root-mean-square error for equations using tail or neck microchips were 0.68 and 0.67, and 0.29 and 0.28 °C, respectively. The tail base is a promising site for microchip implantation to predict rectal temperature. The inclusion of air temperature as a predictive variable in the models is recommended.

Inclusion of licuri meal in the diet of pasture dairy cows.

The objective of this study was to evaluate the inclusion of increasing levels of licuri meal as a substitute for soybean bran in the diet of pasture-based dairy cows and its effects on the intake, nutrient digestibility, and milk production and composition. Eight crossbred Holstein/Zebu cows were used in two 4 × 4 Latin square plots. The diets contained increasing percentage of licuri meal (0.0, 4.16, 7.09, and 9.45%) in the total diet, replacing soybean bran. The inclusion of licuri meal in the diet affected total dry matter intake and dry matter intake in relation to body weight, which presented a quadratic effect. The same behavior was observed for the consumption of EE, CP, TDN, and NDFap. The NFC consumption showed a linear decrease with the addition of the by-product in the diet. There was no influence of the inclusion of the licuri meal on the digestibility of the DM, CP, NFC, and TDN, while the digestibility of the NDFap and EE presented increasing linear effect. There was a reduction of milk production and food efficiency with the inclusion of increasing levels of the meal. The fat content in milk showed a linear increasing effect. Ditto for cholesterol. It is recommended to include not more than 7.00% of licuri meal for lactating cows with an average production of 20 kg day-1.

Bastonetes Gram-negativos aeróbios e anaeróbios facultativos no fluido ruminal de bovinos de corte alimentados em pastagem lignificada e em novilhos com acidose ruminal / Aerobes and anaerobe facultative Gram-negative rod-shaped bacteria in the ruminal fluid of beef cattle fed lignified pasture and steers with ruminal acidosis

Objetivou-se analisar a população de bastonetes Gram negativos aeróbios e anaeróbios facultativas no suco ruminal bovinos zebuínos de diferentes categorias, alimentados em pastagem tropical, e de novilhos alimentados com alto teor de grão e sem volumosos. Foram coletados fluido ruminal de 32 vacas, 50 novilhos e 50 bezerros alimentadas em pastagem de Brachiaria spp. e de 20 novilhos com acidose ruminal. Após diluições decimais, amostras foram inoculadas em placas contendo ágar MacConkey a 39°C. Para a identificação dos gêneros mais frequentes foram utilizadas provas bioquímicas. A concentração dessas bactérias não diferiu no ambiente ruminal de vacas, novilhos e bezerros de corte alimentados com pastagem tropical lignificada. Os gêneros mais frequentemente identificados para esses animais foram Escherichia, Enterobacter e Klebsiella. Novilhos alimentados sem volumoso e com acidose apresentaram maior taxa de detecção e maior população dessas bactérias no ambiente ruminal (>6 log/ml) quando comparados aos novilhos alimentados somente em pastagem. A espécie Escherichia coli foi predominante entre as bactérias isoladas do fluido ruminal de novilhos alimentados com dieta com alta concentração de grãos e com acidose (p<0,01). Constatou-se que em bovinos de corte, criados em pastagem tropical lignificada, a população desses microrganismos é baixa no ambiente ruminal e com maior diversidade de gêneros bacterianos. Entretanto em novilhos confinados e alimentos sem volumoso, apresentando acidose ruminal subaguda, ocorre desequilíbrio populacional com aumento da população de E. coli...

This study aimed to analyze the population of Gram negative bacteria, rod-shaped aerobic and facultative anaerobes, in ruminal fluid of health Zebu cattle of different categories fed in tropical pasture and steers fed high levels of grain and without bulky. Rumen fluid from 32 cows, 50 steers and 50 calves fed on Brachiaria spp. and 20 steers with ruminal acidosis were collected. After decimal dilutions, the samples were inoculated on petri dishes with agar MacConkey at 39°C. Biochemical tests were used to identify the most common genera these bacteria. The concentration of these bacteria did not differ in the rumen of cows, calves and calves fed lignified tropical pasture and the most frequently identified genera for these animals were Escherichia, Enterobacter and Klebsiella. However, steers fed without forage and with acidosis showed a higher detection rate and larger population of these bacteria in the rumen (>6 log/ml) compared to steers fed only pasture. The Escherichia coli species was predominant among theses bacteria isolated from the rumen fluid of steers with acidosis (p<0.01). In beef zebu cattle raised on pasture lignified, the population of these microorganisms in the rumen is low showing greater diversity of genera. However in confined zebu steers fed without forage and with sub acute ruminal acidosis occur disequilibrium with increased E. coli population...

Characterization of fungi from ruminal fluid of beef cattle with different ages and raised in tropical lignified pastures.

The objective of this study was to evaluate the aerobic rumen mycobiota from three age groups of Nelore beef cattle reared extensively on lignified pasture. The experiment was randomized and sampled 50 steers, 50 cows, and 50 calves grazed on Brachiaria spp. pasture during the dry season. Rumen fluid in all animals was aromatic, slightly viscous, and greenish-brown in color. Microscopic examination revealed monocentric and polycentric anaerobic fungi in similar proportions (P > 0.05) in the rumen fluid of cows and steers. However, these microorganisms were not identified in any of the samples from calves. In culture exams, aerobic filamentous population was significantly higher for rumen fluid of cows compared to the other two groups. Microculture and rDNA sequence analyses showed Aspergillus spp. as the most frequent aerobic fungus among the isolates from the three bovine groups evaluated. Biochemical profiles were determined by the growth level of yeast isolates with 44 nutrient sources. Ten different yeast profiles were obtained, and yeast isolates from cow ruminal fluid showed ability to catabolize greater diversity of carbon and nitrogen sources. The differences in the fungal populations observed in this study could be explained by microbial and physiological interactions existing in the ruminal ecosystem of each age bovine group. The present study showed the fungal population of the rumen related with differences among age of cattle raised in lignified pastures. Metabolic capabilities of mycelial fungi or yeast identified in this study may be employed in new probiotics or microbial additives for different bovine categories.