Eduardo Henrique Bevitori Kling de Moraes

Composição Corporal e Requisitos Energéticos e Protéicos de Bovinos Nelore, Não-Castrados, Alimentados com Rações Contendo Diferentes Níveis de Concentrado e Proteína

Forty Nellore bulls, with average initial live weight (LW) of 240 kg, were used. Four reference bulls and four bulls fed for maintenance were used, and the remaining was assigned to eight treatments, with four different concentrate levels in the diets (20, 40, 60 and 80%) and two (15 and 18%) levels of crude protein (CP). The protein, fat and energy contents retained in the body were estimated by regression equations of the logarithm of protein, fat or energy body content, as a function of the logarithm of empty body weight (EBW). By deriving the prediction equations of body content of protein, fat, or energy, as a function of the EBW logarithm, the net requirements of protein and energy, for gains of 1 kg EBW, were determined. The deriving equation was Y = b. 10a. Xb-1, being a and b intercept and regression coefficient, respectively, of the prediction equations of protein or energy body contents. Net energy requirement for maintenance (NEm) was estimated as the intercept anti-log of the equation obtained by linear regression among the logarithm of heat production and the metabolizable energy intake. The net energy requirement for weight gain of zebu bulls can be obtained by the equation: NEg = 0.0413 x EBW0.75 x gain of EBW0.978. The NEm for these animals was 83.70 kcal/EBW0.75. The following equation was obtained to estimate the retained protein (RP), as a function of EBW gain and retained energy (RE): RP = - 39.0169 + 200.638 gain of EBW + 0.4166 RE. The net protein requirement of Nellore bulls decreased as the LW increased, being 183.22 and 173.72 g/kg of EBW gain for animals with 200 and 400 kg of LW, respectively.

Cana-de-açúcar tratada com óxido de cálcio fornecida com diferentes níveis de concentrado para novilhas de corte em confinamento

This research was carried out to evaluate the performance, total apparent digestibility, efficiency of microbial synthesis, nitrogen balance (NB) of crossbreed Holstein × Zebu heifers fed sugarcane treated or not with calcium oxide (CaO - 1.0%) and different concentrate levels (CL), in feedlot. A total of 24 animals with initial average 177.0 kg BW and 8-12 months old was allotted to a complete randomized design with a 2 × 3 factorial arrangement, sugarcane in nature and sugarcane treated or not with 1.0% CaO and three CL (0.0, 0.5 and 1.0% BW). No interaction between forage and CL for nutrients intake was observed. Except for NDF intake, diet based in sugarcane treated with CaO reduced the nutrients intake (kg/day and % BW). Only the NDF intake was unaffected by CL, the other nutrients showed a positive linearly behavior as CL increased. No effects of the treatment of sugarcane with CaO and interaction between forage and CL on nutrient digestibilities were observed, except for NDF that increased with the CL in the diets. The microbial N and N urea content in serum was smaller in animals that were fed sugarcane treated with CaO. The efficiency of microbial synthesis, with mean value of 12.10 gCPmic/100 g TDN, was unaffected by the sugarcane treated with CaO to and nor by CL. Sugarcane treated with CaO reduced the average daily gain, which increased with the CL. Sugarcane treated with 1.0% CaO, fed after 24 hours of storage, prejudice most of nutrient intakes and worse the animal performance, while the concentrate offer levels up to 1.0% BW improve animal performance.

Desempenho, digestibilidade e características de carcaça de novilhos zebuínos alimentados com dietas contendo diferentes níveis de concentrado

This research was developed to evaluate the intake and digestibility of nutrients; feed/gain conversion (FC); average daily live weight (LWG), empty body weight (EBWG) and carcass (CG) gains; the carcass dressing percentage and the basic cuts percentage; the carcass length (CL); the loin eye area (LEA) and the subcutaneous fat thickness (SFT) of Zebu steers, with initial average live weigth of 270 kg, fed with 5, 35 e 65% of concentrate, in feedlot. The dry matter and organic matter intake were quadractily influenced by the increasing levels of concentrate in the diet. The ether extract and nonfiber carbohydrate intakes increased and the neutral detergent fiber intake decreased linearly as the concentrate level increased. The crude protein intake was not affected by the concentrate level. The TDN level and digestibility of the dry matter, organic matter, ether extract and non-fiber carbohydrate increased and the neutral detergent fiber digestibility decreased linearly as concentrate level in the ration incresead. The digestibility of the CP was not affected, when Brachiaria brizantha haylage was used as roughage. However, the digestibility of the CP increased linearly, when the Cynodon dactylon was used in the feeding of the animals. The FC decreased and the LWG, EBWG, CG, LEA and SFT increased linearly as the concentrate levels in the diets increased. The CL, the carcass dressing percentage and the basic cuts percentage, excluding leg percentage, were not affected by the concentrate levels in the diet. The inclusion of concentrate in the diets increased the digestibility and improved the productive performance of the animals.

Avaliação qualitativa da pastagem diferida de Brachiaria decumbens Stapf., sob pastejo, no período da seca, por intermédio de três métodos de amostragem

ABSTRACT - An experiment was conducted to evaluate the quality of the differed pasture of Brachiaria decumbens under grazingin the dry season. Samples were collected by the total harvesting (TH), hand-plucking sample (HPS) and Extrusa (EXT) collected usingfour Holstein-Zebu steers, with esophageal fistula. The samples were analysed for dry matter content (DM), crude protein (CP), etherextract (EE), mineral matter (MM), total (TC) and non-fibrous carbohydrates (NFC), neutral detergent fiber (NDF), neutral deter gentfiber corrected for ash and protein (NDFap), acid detergent fiber (ADF), insoluble acid detergent fiber (iADF), lignin and in vitro drymatter digestibility (IVDMD). TH was superior (P<0,05) in DM, TC, NDf, NDFap, ADF, iADF and lignin contents. These observationsreflected the low IVDMD for TA. The EXT and HPS did not differ on CP, EE, NFC, NDF, NDFap, ADF, iADF, lignin and IVDMD.The CP content were 5.60 and 6.50 and the ones of NDF were 71.87 e 71.70, respectively to EXT and HPS. These results indicate t hatthe sample HPS, in comparasion with sample TH, would better represent those diet selected by grazing animals.Key Words: beef cattle, extrusa, hand-plucking sample, total harvesting

Uréia em suplementos protéico-energéticos para bovinos de corte durante o período da seca: características nutricionais e ruminais

Four Zebu × Holstein steers were fistulated in rumen, abomasums and esophagus, with 430 kg of live weight grazing in four paddocks of Brachiaria decumbens (.40 ha), feed supplements were used to evaluate intake, digestibility, pH and ammonia ruminal concentration, nitrogen in serum and urine and microbial yield. The animals received 4.0 kg/animal/day of supplement based on grounded corn grain, cottonseed meal, mineral mix (MM), ammonium sulfate and urea in four levels (0, 1.2, 2.4 and 3.6%) as fed basis. The intake of total (TDM) and pasture (DMP) dry matter, organic matter (OM), OM from pasture, crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), total carbohydrate (TO) and non-fiber carbohydrate (NFC) presented quadratic behavior. The maximum responses on the urea levels were: 2.0% (10.9 kg/day), 2.3% (7.1 kg/day), 2.2% (9.7 kg/day), 2.3% (6.3 kg/day), 1.9% (1.3 kg/day), 3.6% (0.4 kg/day), 1.9% (5.8 kg/day), 2.3% (8.2 kg/day) and 2.9% (4.1 kg/day), respectively, for TDM, DMP, OM, OMP, CP, EE, NFD, TC and NFC. The OM digestibility was affected with a linear behavior. No differences were observed for the pH values. However, ammonia concentration increased linearly as the urea level in the supplement increased. The urea level in supplement increased linearly the nitrogen in serum and urinary excretion of nitrogen from urea. No effect from the urea level on the microbial efficiency, expressed by different forms, was observed.

Fontes de proteína em suplementos múltiplos para bovinos em pastejo no período das águas

The effect of feeding, in the rainy season, multiple supplements formulated with different sources of protein on nutritional characteristics of growing beef cattle was evaluated. Five Holstein-Zebu crossbred steers with initial live weight of 300 kg, fistulated in the esophagus and in the rumen, were assigned to five paddocks (0.3 ha) of Brachiaria decumbens in a 5 × 5, incomplete Latin square design, with 5 supplements and 4 periods in 4 (14 days). Supplements evaluated were based on soybean meal (SM), cotton seed meal (CS, 38% CP), corn gluten meal (CGM, 60% CP) and wheat bran + urea (WBU) and a control supplement, consisting only of mineral mix (MM). The amount of daily supplement fed was set to provide approximately 180 g of CP/day. Protein sources affect only the non-fibrous carbohydrates and CP intakes, which was higher when, was fed supplement based on cottonseed meal and lower when fed mineral mix. There was no effect of protein sources on the total and partial digestibility of nutrients. The pH and of ruminal nitrogen ammonia levels were not influenced by protein sources, but all values have remained within the limits of digestion of forage. Protein sources did not affect the microbial efficiency (9.96 g CPmic/100 g TDN), neither the concentration of plasma urea nitrogen (12.78 mg/dL), and urinary nitrogen excretion (NUr)(63.14 g/day).

Associação de diferentes fontes energéticas e protéicas em suplementos múltiplos na recria de novilhos mestiços sob pastejo no período da seca

Two trials were conducted to investigate different protein and energy sources in multiple supplements fed to growing crossbred bulls. In the first experiment, performance of 20 crossbred growing bulls averaging 17 months of age and 265±18 kg of body weight was evaluated in the dry season. Animals were maintained in 1.5 ha paddocks of Brachiaria brizantha with supplements being offered daily in a proportion of 0.75% of the body weight. A completely randomized design with a 2 x 2 factorial arrangement was used. Supplements contained whole soybean (WSB) or whole cottonseed (WCS) as the protein sources and rice bran (RB) or wheat bran (WB) as the energy sources. No significant differences on the average daily weight gain (ADG), final body weight (FBW), and total weight gain were observed among diets in this trial. The ADG and FBW averaged 0.589 and 318.2, 0.530 and 317.2, 0.620 and 319.6 and 0.606 kg/day and 323.6 kg for animals fed supplements containing WSB/WB, WSB/RB, WCS/WB, and WCS/RB, respectively. The objective of the second study was to estimate the carbohydrate fractions of the pasture and that of the feeds used in multiple supplements as well as their digestion rates using the gas production technique. Forage had higher indigestible fraction (C) and lower potentially degradable fraction (B2) compared to the supplements. Among supplements, WCS had the lowest C fraction while WSB and WB had the highest proportion of non-fiber carbohydrates (NFC). Although WCS had the highest content of C fraction, it also showed the fastest rate of digestion of the B2 fraction. Digestion rate of NFC were: 35.06, 14.86, 17.83 and 58.80, respectively for RB, WB, WSB and WCS. The choice of each protein and energy source will depend on market price and availability because there were no significant differences among treatments. The structural carbohydrates (B2 e C) are responsible for the high concentrations of total carbohydrates in Brachiaria brizantha during the dry season, which averaged 80%. It was observed variations in the carbohydrate fractions as well as in the degradation rates across supplements.

Nutritional requirements of zebu cattle: energy

A trial involving nineteen zebu steers with initial live weight of 270 kg were conducted with the objective of determining their energy requirements and the efficiency of utilization of the metabolizable energy for gain (kg) and maintenance (km). Four steers were slaughtered at the beginning of the trial, performing the reference group, three were fed at maintenance level and the remaining were uniformly allotted to a complete randomized design, in three treatments, with different levels of concentrate in the diets [...]

Níveis de proteína em suplementos para novilhos mestiços em pastejo durante o período de transição seca/águas

Two experiments were conducted to evaluate different crude protein (CP) levels of a mixture of mineral and concentrate (multiple supplement) fed to crossbreed steers grazing Panicum maximum cv. Mombaca pasture during the transition between the dry and the rainy season. The multiple supplement contained ground corn and soybean grains and was formulated to yield 8.0, 16.0 or 24.0% of CP. Each animal received 1.0 kg of the multiple supplement per day or only ad libitum mineral mix (control treatment). In the first trial, 20 crossbred steers averaging 19 months of age and 339.4±14.8 kg of body weight were used. The average daily gain (ADG) increased linearly from 0.992 to 1.258 kg/d when the CP level of the supplement increased from 8.0 to 24%. Total weight gain also increased linearly by increasing the CP level of the supplement. Economical analysis of the supplements showed greater gross income for the supplement containing 24% CP. In the second trial, four crossbreed steers fitted with ruminal and esophageal cannulas and averaging 400 kg of body weight were used to investigate different CP levels of the supplements on ruminal pH and ruminal ammonia ruminal concentration. The different CP levels of the supplement did not significantly change ruminal pH. However, ruminal ammonia increased linearly from 8.41 to 12.2 mg/dL when the CP level of the supplement increased from 8.0 to 24%.

Parâmetros nutricionais de novilhas de corte alimentadas com cana-de-açúcar tratada com óxido de cálcio e diferentes níveis de concentrado

This research was carried out to evaluate the intake, total and ruminal digestibilities, microbial efficiency synthesis, nitrogen balance (NB) and ruminal parameters of beef heifers, fed sugarcane treated or not with calcium oxide (CaO - 1.0%) and different concentrate levels (CL), in feedlot. Six animals (170.0 kg BW) were allotted to a 6 × 6 Latin square design in a 2 × 3 factorial arrangement (sugarcane in nature treated or not with 1.0% CaO and three CL 0.0, 0.5 and 1.0% BW). No interaction was observed between forage and CL for nutrients intake and total digestibilities. With exception for DM and NDF intakes (% BW) and of EE and NDF total digestibilities, sugarcane treated with CaO prejudice the intake and digestibility of others nutrients. NDF intake was unaffected by CL, however the intake of the other nutrients showed a positive linearly behavior as CL increased. The total apparent digestibilities of nutrients linearly as CL increased. Ruminal digestibilities were unaffected by sugarcane treated with CaO. The increase of CL showed a positive linear behavior for DM, OM, CP, NDF ruminal digestibilities. There was no effect of sugarcane treated or not CaO on microbial nitrogen and microbial DM, which increased as CL increased in the diet. The lesser nitrogen retention was observed in animals fed sugarcane treated with CaO. Sugarcane treated with 1.0% CaO, fed after 24 hours of storage, prejudice the intake of most nutrients. Nitrogen balance and CL up to 1.0% BW improve DM intake, digestibility of most nutrients and nutrient balance.