Saul Ferreira Caldas Neto

Suplementação de novilhos nelore em pastejo de Brachiaria brizantha com diferentes níveis e fontes de concentrado

This work was carried out to study the daily average gain (DAG) of steers grazing Brachiaria brizantha cv. Marandu, supplemented, from July to December, with two levels of three different supplements. Fifty-four Nellore steers (9 for each treatment) aged approximately 20 months and initial average live weight of 370 kg were used. The experimental treatments were: AMI - supplement rich in starch (based on corn), OLE - supplement rich in fat (based on whole cottonseed) and A+O - supplement combination (based on mixture of AMI and OLE). All supplements were offered in .7 and 1.4% of liveweight (LW). The green blade availability was 5.12 kg DM/100 kg LW. Treatments and levels influenced DAG. In both levels of supplementation, the combination of feeds promoted higher performance. The lowest level (.7% LW) AMI and OLE was not different, and both were different from A+O. DAG was .44, .46, and .57 kg for AMI, OLE and A+O respectively. Similar results were registered on the higher level (1.4% LW) of supplementation. In this level A+O showed better performance than AMI and OLE that was not different. DAG was .58 kg for AMI, .61 kg for OLE and .72 kg for A+O. The supplementation with concentrates composed by the mixture of rich feeds in starch (corn) and oil (cotton seed) provided higher performance of the animals, that when supplemented separately with the respective sources, independently of the supplementation level. The higher supplementation level (1.4% of LW) showed lower economical efficiency, when compared to the smallest level (.7% PV).

Mandioca e Resíduos das Farinheiras na Alimentação de Ruminantes: pH, Concentração de N-NH3 e Eficiência Microbiana

O objetivo do presente trabalho foi avaliar a concentracao de N-NH3, o pH do liquido ruminal e a eficiencia de sintese microbiana de racoes que continham diferentes fontes energeticas: milho (MI), milho + casca de mandioca desidratada (MC), raspa de mandioca (RM) e farinha de varredura de mandioca (FV). Foram utilizados quatro novilhos da raca Holandesa (270 kg), portadores de cânulas ruminal e duodenal, distribuidos em um delineamento Quadrado Latino 4x4. A cinza insoluvel em acido foi utilizada como indicador do fluxo duodenal e fecal. Nao houve efeito das racoes experimentais no pH ruminal. No entanto, menor concentracao de N-NH3 foi observada para a racao com FV. O fluxo duodenal de materia orgânica e nitrogenio e a composicao quimica das bacterias ruminais nao foram influenciados pelas racoes experimentais. A maior eficiencia microbiana aparente foi obtida para a racao com FV. Nas condicoes do presente experimento a FV, possivelmente apresentou uma melhor sincronizacao com a fonte proteica (farelo de soja), diminuindo a perda de nitrogenio na forma de N-NH3 e aumentando a eficiencia microbiana.

Substituição do farelo de soja pela farinha de glúten de milho na alimentação de cabras leiteiras

It was carried out an experiment with goats Saanen, on the first lactation, with 50 kg of body weight, housed in individual stalls of 3 m², to evaluate the effect of substitution of soybean meal (SM) protein by the protein from the corn gluten flour (CGF), in the milk production, milk composition, voluntary intake and plasmatic urea. The experimental design was the triple Latin square 4x4, with four periods of 21 days, being 14 days of adaptation to the diet and seven days for samples collection. The goats were fed and milked in the morning and afternoon. The substitution levels studied were: 0, 10, 30 and 50% of CGF (based in the crude protein). The substitution of the soybean meal by CGM did not affect the intake (kg/day and %BW) of dry matter, crude protein and acid detergent fiber, but there was quadratic effect for neutral detergent fiber intake (kg/day and %BW). There was effect on the levels of plasmatic urea nitrogen (PUN), where the smallest values were in the intermediate levels of substitution, being the biggest values for the treatment with only SM. The milk production decreased lineally with the inclusion of CGM. The substitution levels resulted in lineal decrease in the fat production (kg/day), in the milk fat content (%) and milk total solids content (%). There was quadratic effect for lactose production, being the smallest value for 31.6% of substitution level. It was no effect on in crude protein in the milk, which average was .083 kg/day. The crude protein content, lactose and total solids did not suffer effect of the substitution levels, being the average values of 2.98, 4.35 and 11.51%, respectively.

Digestibilidade e balanço de nitrogênio de rações com diferentes teores de proteína degradável no rúmen e milho moído como fonte de amido em ovinos

Four castrated sheep averaging 38.5 kg of body weight were randomly assigned to a 4 x 4 Latin square to evaluate the apparent digestibility of nutrients and nitrogen balance (NB) on diets containing different levels of rumen degradable protein (RDP): 46, 50, 54, and 58% and ground corn. The four experimental diets were composed by 75% of forage (oat hay) and 25% of concentrate containing ground corn (GC), soybean meal (SM), cottonseed meal (CM), fish meal (FM), urea, and mineral salt. No significant differences were observed on the intakes of DM, OM, CP, starch, NDF, and ADF by increasing the dietary RDP levels. Nitrogen intake (NI), urinary N excretion, fecal N excretion, and NB expressed as % NI averaged, respectively, 31.68 g/d, 6.34 g/d, 11.31 g/d, and 47.27% and did not differ across diets. Similarly, apparent total tract digestibilities of DM, OM CP, NDF, and ADF averaged, respectively, 71.90, 73.00, 79.70, 61.10, and 52.00% and did not differ when the RDP level was increased in the diet. It can be concluded that both digestibility of nutrients and NB were not affected by different dietary RDP levels under the conditions of this trial.

Níveis de Substituição da Silagem de Milho pela Silagem de Resíduo Industrial de Abacaxi sobre o Desempenho de Bovinos Confinados 1

RESUMO - Objetivou-se com o trabalho avaliar a substituicao gradativa da silagem de milho (0, 20, 40 e 60%, base na materia seca) pela silagem de residuos industriais de abacaxi sobre ganho medio diario, ingestao de alimentos e conversao alimentar, rendimento de carcaca, gordura de cobertura e area de olho de lombo de bovinos inteiros, terminados em confinamento. Foram utilizados 28 bovinos, com 20 meses de idade e peso medio inicial de 328 kg. Os animais foram distribuidos em delineamento inteiramente casualizado, com quatro tratamentos e sete repeticoes. Alem da silagem de milho e/ou silagem de residuos industriais de abacaxi, os bovinos receberam um concentrado composto de farelo de soja, milho, sal mineral, ureia e monensina sodica. Os animais foram mantidos estabulados individualmente, alimentados ad libitum durante 96 dias. Ao final deste periodo, os animais foram abatidos para determinacao das caracteristicas de carcaca. Nao houve efeito dos niveis de substituicao da silagem de milho pela silagem de residuos de abacaxi sobre peso final, ganho medio diario, ingestao de proteina bruta, energia bruta e fibra em detergente neutro, conversao alimentar da materia seca, peso e rendimento de carcaca quente, area de olho de lombo e gordura de cobertura. Reducao linear foi observada para a ingestao de materia seca, materia orgânica, energia metabolizavel e materia seca, em funcao do peso vivo.

Proteína degradável no rúmen associada a fontes de amido de alta ou baixa degradabilidade: digestibilidade in vitro e desempenho de novilhos em crescimento

The objective of this study was to evaluate the effects of increasing levels of rumen-degradable protein (RDP = 47, 52, 57 and 62%) associated to starch sources of low (corn) and high (cassava by-product (CBP) ruminal degradability on in vitro DM digestibility (IVDMD) and average daily gain of growing steers. In vitro DM digestibility was determined by using the Tilley and Terry (1963) technique. The in vitro data was submitted to analysis of variance and regression analysis in function of dietary RDP levels. The in vivo trial was conducted using 32 crossbred steers (Nellore x Red Angus) averaging 275 kg of body weight and fed diets with 50:50 forage:concentrate ratio. Animals were housed in pairs and assigned to treatments according to a completely randomized design. No effect of increasing RDP levels was observed on IVDMD on diets supplemented with corn indicating no lack of nitrogen. Thus, corn digestibility appeared to be the limiting factor on IVDMD. A significant quadratic effect was found for IVDMD by increasing the RDP levels on diets supplemented with CBP suggesting that a better synchronization between energy availability and ammonia release improved microbial growth, which increased the efficiency of energy and RDP utilization on diets with high RDP. It was not observed effect of different RDP levels associated to a starch source rapidly degraded in the rumen on DM intake, average daily gain, and feed conversion on feedlot steers.