Augusto César de Queiroz

Ingestive behavior in Holstein calves fed diets with different concentrate levels

ABSTRACT - The effects of different concentrate levels on the ingestive behavior were studied with five rumen and abomasum fistulated Holstein bull calves, with average initial age of 10.8±0.8 months and average 233.4±26.1 kg BW. The animals were housed in individual stalls and ad libitum fed diets containing 30, 45, 60, 75 and 90% of concentrate, on DM basis. The diets contained, approximately, 16% CP were formulated for body weight gain of 1.0 kg/day and constituted of soybean meal corn ground grain in the concentrate and coast-cross grass hay as forage. A randomized complete blocks design, with five treatments, throughout 20 days, 12 days of adaptation and four periods of two days, relative to the data collection, was used. The eating and ruminating time decreased, while the idle time linearly increased, as the concentrate levels in the diets increased. The feeding efficiency in g DM/h showed quadratic behavior, and the maximum estimated value was 826.81 g NDF/h, for the level of 60.77% of concentrate. The rumination efficiency, g DM/h, and g NDF/h increased and decreased linearly, respectively, as the concentrate levels in the diets increased. The number of ruminate boli and the ruminating chews per day linearly decreased. The number and the ruminating chews per bolus showed a quadratic behavior, and maximum values of 73.79 ruminating chews and 66.61 seconds, per ruminate boli, were estimated for the levels of 48.51 and 54.44% of concentrate, respectively.

Comportamento ingestivo de vacas leiteiras alimentadas com dietas à base de cana-de-açúcar ou silagem de milho

Doze vacas da raca Holandesa, puras e mesticas, foram distribuidas em tres quadrados latinos 4 X 4, balanceados de acordo com o periodo de lactacao, com o objetivo de avaliar parâmetros do comportamento ingestivo. As dietas experimentais foram a base de silagem de milho com relacao volumoso:concentrado de 60:40, com base na materia seca, ou a base de cana-de-acucar, com relacao volumoso:concentrado de 60:40 ou 50:50. As vacas foram submetidas a observacao visual para avaliacao do comportamento ingestivo. Os animais foram observados a cada dez minutos, durante 24 horas, para determinacao do tempo despendido em alimentacao, ruminacao e ocio. Nao houve diferenca para os tempos medios despendidos com alimentacao e ruminacao entre as dietas experimentais. Entretanto, na dieta a base de silagem de milho, os animais ficaram menos tempo no ocio, quando comparados aqueles alimentados com cana-de-acucar. Com relacao a eficiencia de alimentacao, expressa em gFDN/h, nao houve diferenca entre as dietas experimentais. A eficiencia de ruminacao, expressa em gMS/h, foi semelhante para as diferentes dietas. A eficiencia de ruminacao, expressa em gFDN/h (ERUFDN) foi maior para a dieta a base de silagem de milho. Nao houve diferenca na ERUFDN entre dietas a base de cana-de-acucar. Vacas alimentadas com dietas a base de cana-de-acucar apresentaram maior tempo despendido em ocio e menor consumo de MS, quando comparadas aquelas alimentadas com dietas a base de silagem de milho

Evaluation of ruminal degradation profiles of forages using bags made from different textiles

The objective of this study was to evaluate the in situ degradation profiles of dry matter (DM) and neutral detergent fiber (NDF) of different forages using nylon (50 µm), F57 (Ankom®) and non-woven textile (NWT - 100 g/m2) bags. Eight forage samples were used: sugarcane, corn silage, elephant grass cut at 50 and 250 days of regrowth, corn straw, signal grass hay, coast cross hay, and fresh alfalfa. Samples were incubated for 0, 3, 6, 12, 18, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, and 312 hours. Two bags of each textile were used at each incubation time, totaling 768 bags, using two crossbred Holstein × Zebu steers fitted with ruminal canullae. There was difference in the common rate of lag and degradation (λ) of DM for all forages, except for sugarcane. In general, higher λ estimates were obtained using nylon, followed by NWT and F57. Concerning NDF degradation profiles, differences in λ were observed for all forages. Greater estimates were obtained using nylon. Degradation profiles of DM and NDF must not be evaluated using F57 and NWT. These textiles underestimate the degradation rate due to constraints regarding exchange between bags content and rumen environment.

Produção de proteína microbiana e estimativas das excreções de derivados de purinas e de uréia em vacas lactantes alimentadas com rações isoprotéicas contendo diferentes níveis de compostos nitrogenados não-protéicos

The objectives of the present work were to estimate the microbial protein production using the total purine derivatives (PD) excretion, to compare the PD and the urea excretions, obtained from spot urine collection with that observed in the 24 hours collection and to evaluate the plasma and milk N-urea and urea urinary excretion. Sixteen Holstein lactating cows were assigned to four 4X4 Latin Square with 3-wk periods in accordance with the lactation period. The four experimental isoproteic diets were formulated to contain 60% of corn silage and 40% of corn meal, soybean meal, urea and mineral salt mixture as dry matter basis. Crescent levels of urea in the concentrate 0.0, 0.7, 1.4, and 2.1% corresponded to the crude protein of 2.22, 4.18, 5.96 and 8.09% of non protein nitrogen based compounds (NPN), respectively. The urine collection was also estimated with urine samples obtained four hours post fed (spot), by the relation of the daily mean creatinine excretion and the urine spot creatinine concentration. The urinary volume and PD excretion and urea estimated through the urine spot did not differ from that obtained from 24 h urine collection. The N-Microbial production estimated and obtained presenting maximum values of 198.05 and 196.96 g/day with the NPN levels of 5.33 and 4.44%, respectively. The milk allantoin concentration linearly decreased as the NPN increased in the diet and represented 4.5% of total PD excretion. The creatinine excretion was not influenced by the dietary NPN levels (23.41 mg/kg LW), while the estimated and obtained urea excretion, the plasma and milk urea and N-urea concentration linearly increased as the NPN increased in the diet. The plasma and milk N-urea concentration of 19-20 mg/dL and 24-25 mg/dL, respectively, represented the limit values from that would occur nitrogen compounds losses.

Ingestive behavior of dairy heifers fed sugar cane based diets

The objective of this work was to evaluate the ingestive behavior of crossbred dairy heifers fed sugar-cane based diets, supplemented with non protein nitrogen [NPN] sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Twenty-four heifers, with age and average initial weight of 15 months and 247 kg, respectively, were maintained in individual stalls and ad libitum fed during the experimental period of 84 days. The animals were allotted to a completely randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The ingestive behavior of each heifer was visually determined, at 28 days, in intervals of 10 minutes, during 24 hours. There was no difference on the time spent in feeding, rumination and total chewing, in min/day, of the heifers fed different sources of NPN and probiotics. The average rumination time in min/kg of DM and NDF were higher for the animals fed urea. The ingestive behavior of the heifers was not affected by the nitrogen sources or by the probiotic addition.The objective of this work was to evaluate the ingestive behavior of crossbred dairy heifers fed sugar-cane based diets, supplemented with non protein nitrogen [NPN] sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Twenty-four heifers, with age and average initial weight of 15 months and 247 kg, respectively, were maintained in individual stalls and ad libitum fed during the experimental period of 84 days. The animals were allotted to a completely randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The ingestive behavior of each heifer was visually determined, at 28 days, in intervals of 10 minutes, during 24 hours. There was no difference on the time spent in feeding, rumination and total chewing, in min/day, of the heifers fed different sources of NPN and probiotics. The average rumination time in min/kg of DM and NDF were higher for the animals fed urea. The ingestive behavior of the heifers was not affected by the nitrogen sources or by the probiotic addition.

In situ estimation of indigestible compounds contents in cattle feed and feces using bags made from different textiles

ABSTRACT - The objective of this experiment was to evaluate estimates of concentration of indigestible dry matter(iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in samples of cattle feed andfeces processed at different particle sizes (1-, 2-, and 3-mm) using bags made from nylon (50 μm), F57 (Ankom ® ), and non-woven textile (NWT – 100 g/m²) in a in situ evaluation procedure. Eight samples of concentrates, seven samples of foragesand two samples of cattle feces were used. The samples were put in the bags according to a ratio of 20 mg of dry matter/cm²of surface by using three bags of each textile for each size of particle, totaling 405 bags, which were submitted to ruminalincubation for 264 hours. The contents of indigestible compounds in the samples were evaluated sequentially. Blank bags wereused for microscopic evaluation of textile physical integrity and for evaluation of the physical resistance. The presence ofcontaminants caused high variability of results of iDM, indicating that its using as internal marker should not be recommended.By using the textiles F57 and NWT, similar estimates for contents of iNDF and iADF were obtained whereas by using nylon(50 μm), the concentration of iNDF was underestimated, possibly because of loss of particles due to its porosity. Nylonpresented loss of resistance in all analytical stages, expanding its probality of rupture, especially after extraction with aciddetergent. For

Suplementação de lipídios em dietas para cabras em lactação: consumo e eficiência de utilização de nutrientes

The effect of different fat supplements on intake, digestibility, nitrogen balance, milk yield and efficiency of nutrient utilization was evaluated in lactating dairy goats. Twenty-four dairy goats were assigned to a completely randomized design with four treatments and six replicates/treatment. The fat supplements tested were soybean oil (SO), calcium salts of longchain fatty acids (CS) and whole soybean (WS), which contributed with 4.5% of dietary ether extract. A control diet with no added fat was also fed to the animals. Daily measurements of intake and milk yield were done from day 51 to day 138 of lactation. Intakes of DM (DMI), NDF (NDFI), TDN (TDNI), and net energy (NEI) were lower on soybean oil and whole soybean than on control and CS diets. Feeding fat supplements to lactating goats reduced digestibilities of OM, CP and TC. Digestibility of NDF was reduced by SO while that of NFC was reduced by WS. Yields of milk fat, milk protein and milk decreased when WS was fed and the feeding of all three fat supplements depressed the yield of milk lactose. No significant differences in the concentration of milk components were observed across treatments. Similarly, the net efficiency of utilization of ingested metabolizable energy for milk production (kl) did not differ among diets. The same was true for nitrogen balance and retained nitrogen.The effect of different fat supplements on intake, digestibility, nitrogen balance, milk yield and efficiency of nutrient utilization was evaluated in lactating dairy goats. Twenty-four dairy goats were assigned to a completely randomized design with four treatments and six replicates/treatment. The fat supplements tested were soybean oil (SO), calcium salts of long-chain fatty acids (CS) and whole soybean (WS), which contributed with 4.5% of dietary ether extract. A control diet with no added fat was also fed to the animals. Daily measurements of intake and milk yield were done from day 51 to day 138 of lactation. Intakes of DM (DMI), NDF (NDFI), TDN (TDNI), and net energy (NEI) were lower on soybean oil and whole soybean than on control and CS diets. Feeding fat supplements to lactating goats reduced digestibilities of OM, CP and TC. Digestibility of NDF was reduced by SO while that of NFC was reduced by WS. Yields of milk fat, milk protein and milk decreased when WS was fed and the feeding of all three fat supplements depressed the yield of milk lactose. No significant differences in the concentration of milk components were observed across treatments. Similarly, the net efficiency of utilization of ingested metabolizable energy for milk production (kl) did not differ among diets. The same was true for nitrogen balance and retained nitrogen.

Consumo e digestibilidade aparente total e parcial em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado

ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the voluntary intake and the apparent total and partial digestibilities of dry matter (DM), organic matter (OM), ether extract (EE), neutral detergent fiber (NDF) and total carbohydrates (TCH), in the rumen and in the intestines. Five rumen and abomasum fistulated Holstein calves, with initial average age of 5.8±0.7 months and initial average of 107.4±11.0 kg LW were allotted to a 5x5 Latin square design (treatment x period). The animals were housed in individual stalls and full fed diets (DM basis) containing 30.0, 45.0, 60.0, 75,0 and 90.0% of concentrate. The diets were based on coast-cross grass hay as forage and soybean meal and ground corn grain in the concentrate. The chromic oxide was used as marker to estimate the fecal and abomasal DM flows. The intakes of DM, OM, CP and TCH, in kg/day, were not affected by diets, while that of EE intake increased and NDF intake linearly decreased, when expressed in %LW and g/kg.75 as the dietary concentrate levels increased. Total apparent digestibilities of DM, OM, EE and TCH linearly increased as the dietary concentrate levels increased, but NDF digestibility was not affected. Ruminal digestibilities of DM, NDF and TCH did not vary as the dietary concentrate levels increased, but the OM digestibility increased and that of EE linearly decreased as the dietary concentrate levels increased. The intestinal digestibility of DM did not vary, but that of OM and TCH linearly increased. The EE and NDF digestibilities were not affected by the inclusion of crescent concentrate levels in the diets.

Composição químico-bromatológica de variedades de cana-de-açúcar (Saccharum spp L.) com diferentes ciclos de produção (precoce e intermediário) em três idades de corte

The objectives of this work were to determine the chemical composition, the potentialy degradable fraction of NDF (B2) and undegradable fraction (C) and to estimate the ruminal fill of sugar cane with different cycles of production (early and intermediate), in three cut times (426, 487 and 549 days). The laboratorial analysis consisted in dry matter (DM), organic matter, ash, crude protein (CP), ether extract, lignin, neutral detergent fiber (NDF), neutral detergent fiber corrected for ash and protein, acid detergent fiber (ADF), neutral detergent insoluble protein, acid detergent insoluble protein and neutral detergent protein soluble. The TDN was calculated by chemical composition. The degradable and undegradable fractions, and fiber digestion rate, as well as the ruminal fill were estimated by kinetic parameters obtained throught in situ incubation. The advanced cut time increased the DM in 9.5%. The intermediate varieties presented higher TDN than early varieties, which had the highest contents of NDF and ADF, whose respective values were 487.56 and 471.03, and 287.87 and 247,54 g/kg DM for the early and intermediate varieties, respectively. The TDN increased linearly with the cut time, varying from 62.45 to 63.50%; however the NDF and ADF contents presented quadratic behavior. The early varieties presented higher content of CP than the intermediate only in the cut time of 549 days; contrarily, the brix of the sugar cane was superior to the intermediate varieties in the last cut. The early varieties presented larger total ruminal fill and lower fiber digestion rate. The degradable fraction of the fiber was reduced and the undegradable fraction was linearly increased with the age of the plants.

Determinação das frações protéicas e de carboidratos e taxas de degradação in vitro da cana-de-açúcar, da cama de frango e do farelo de algodão

The objective of the present study was the fractionation and the degradation kinetics of the nitrogenous compounds and of the carbohydrates of the sugar cane, poultry litter and cottonseed meal. The non-protein nitrogenous compounds, soluble and insoluble nitrogen in borate-phosphate buffer, neutral detergent and in acid detergent insoluble protein nitrogen were analyzed for the determination of the nitrogen fractions. The degradation rates of the protein fractions were obtained by the In vitro incubation of the feeds with proteases isolated from ruminal ambient. The total carbohydrates, and its fractions C, B2 and the soluble neutral detergent components were calculated for the determination of the carbohydrates using the Cornell system. The potentially degradable (B2) and undegradable (C) fractions of the neutral detergent fiber, corrected for ashes and protein, and the lag dynamic rates, of degradation and of specific microbial growth, from the fraction B2, were determined. Besides, the coefficient of degradabilities and of the NDF ruminal repletion effect of the feeds, were also determined. The values of 71.01; 45.80 and 71.66% of the fraction B2 of the nitrogenous compounds were observed for sugar cane, poultry litter and cottonseed meal, respectively. The poultry litter stood out for the highest B3 and C fraction (23.57 and 10.11%). The B3 fraction degradation rates were of 0.03; 0.031 and 0.09 h-1 for sugarcane, poultry litter and cottonseed meal, respectively. The fraction C of the carbohydrates varied of 22.74, 28.00 and 32.64% for the three feeds, respectively. The sugar cane presented high soluble components fraction (35,99%), however it presented low digestion of the potentially degradable fiber (3.41% h-1) and a significant repletion effect (6,6 h-1). The feeds, sugarcane and poultry litter present low nutritional value to meet the ruminal microorganisms and of the hostess requirements.