Ricardo Reis e Silva

Valor nutritivo da cana-de-açúcar adicionada com óxido de cálcio para novilhas Holandês x Zebu

We evaluated the intake and apparent digestibility of dry matter, organic matter, crude protein, and intakes of digestible dry matter and total digestible nutrients (TDN) in 18 Holstein-Zebu heifers divided into blocks, fed with diets of sugarcane treated or not with 1% in the natural matter of calcium oxide (CaO), after 24 hours of hydrolysis, at different times of administration of the mixture of urea and ammonium sulfate (zero and 24 hours). Differences between means were evaluated by orthogonal contrasts at 1% significance. There was a negative effect (P<0.01) to the addition of calcium oxide in TDN intake, apparent digestibility of organic matter and the efficiency of nitrogen utilization. The administration of a mixture of urea and ammonium sulfate at the time of hydrolysis caused a decrease in consumption and apparent digestibility of crude protein. There was no benefit in the inclusion of calcium oxide nor the addition of urea 24 hours before the animal feeding.

Intake, apparent digestibility, and methane emission in bulls receiving a feed supplement of monensin, virginiamycin, or a combination

The aim of this study was to evaluate the effects of the feed supplements monensin, virginiamycin, or a combination of the two, on intake, digestibility, and methane emission in the male cattle breed F1 Holstein × Gir. We used a complete randomised design with four treatments consisting of the control, monensin, virginiamycin, and a combination of the two. The basal diets were composed of sorghum silage with Tanzania grass and the concentrate in the 1 : 1 ratio. Nutrient intake (P > 0.05) and the apparent digestibility coefficients (P > 0.05) were not affected by the supplementation with monensin, virginiamycin, or both. The combination of the supplements did affect methane emission (P < 0.05) when expressed in L/day, L/(kg DM), and L/(kg DM digestible). The lowest methane production was obtained with the combination of the supplements.

Degradabilidade ruminal da fibra das frações do resíduo industrial de tomate

The in situ procedure was used to evaluate the disappearance of neutral detergent fiber (NDF) and acid detergent fiber (ADF) of skins and whole or grounded (sieve of 2mm) seeds of tomato by-product (TBP). Three steers were used in a split-plot block design. The solubility of NDF showed low values for all the evaluated fractions, been similar among skins (3%), whole seeds (5%) and total TBP (7%). Grounded seeds showed higher NDF solubility (20%). The NDF potential degradability for grounded seeds, TBP, skins and whole seed were 78, 64, 63 and 33%, respectively. NDF degradability rates varied from 4.4 to 14.8%/h for all TBP fractions, been 9%/h for total TBP. The ADF parameters followed the same trend as NDF. TBP NDF and ADF showed good degradability rates, but the potential degradability of these fractions depends on the showed processing, since whole seeds NDF and ADF showed degradability much lower than grounded seeds.

Estimativa de consumo de matéria seca e de fibra em detergente neutro por vacas leiteiras sob pastejo, suplementadas com diferentes quantidades de alimento concentrado

The intakes of dry matter and neutral detergent fiber (NDF) by crossbred lactating cows were estimated under Brachiaria grazing. Twenty-four cows were allotted in three treatments in order to receive 4, 6, or 8kg of concentrate twice a day, during the milking. The experiment was designed in randomized blocks, being eight blocks with three cows in each. The intake of NDF was 1.1, 1.0, and 1.2 of live weight for cows fed 4, 6, and 8kg of concentrate per day, respectively. The 8kg concentrate treatment produced different results (P<0.05) from the others. The increase of concentrate supply also increased (P<0.05) the total consumption of pasture dry matter, which were 1.8, 1.8, and 2.0% of live weight for cows supplemented with 4, 6, and 8kg of concentrate per day, respectively. It was concluded that high level of concentrate offered to lactating cows under tropical grazing induced a greater intake of total pasture dry matter and NDF, regarding the live weight.

Energy metabolism and partition of lactating Zebu and crossbred Zebu cows in different planes of nutrition

The aim of this study was to determine the energy metabolism and partition of lactating Gyr and F1 Holstein x Gyr (F1 HxG) cows in different planes of nutrition. Six F1 HxG and six Gyr cows with 130 days in milking (DIM) fed corn silage and concentrate were evaluated. The experiment consisted of four periods with different levels of feeding: 1st ad libitum dry matter intake (DMI) and the others with 5, 10 and 20% restricted DMI, related to the first one. An apparent digestibility assay was performed before measurements in the respiration chamber. Total feces were collected for three days. The cows were confined for 24h in the chamber in each period to determine methane and heat production (HP). F1 HxG had higher gross energy intake (GEI), metabolisable energy intake (MEI) and digestible energy intake (DEI). GE lost in feces was higher in F1 HxG (23.7% GEI) than in Gyr (20.5%) cows. Energy lost as methane and urine was similar between the groups. The metabolisability (q) was 0.67, and the efficiency of converting ME to NE (k) was 0.56. There was no difference in the energy requirements for maintenance between breeds (426.6 MJ/kg BW0,75 average value). The energy requirements for lactation were higher in F1 HxG animals due to the higher volume of milk produced, since there was no difference in energy requirements for production of one kg of milk.

Degradabilidade ruminal in situ do sorgo grão em diferentes formas de reconstituição

Foram utilizadas tres vacas nao lactantes fistuladas no rumen com o objetivo de determinar os parâmetros de degradacao ruminal in situ da materia seca (MS) e do amido de graos de sorgo sob diferentes formas de processamento: 1) Seco e moido (2mm); 2) Seco, moido (3mm), reidratado com aspersao de agua sobre o material, e imediatamente ensilado por 30 dias; 3) Seco, inteiro, reidratado por tres dias em tubo PVC e, em seguida, moido a 5mm; 4) Seco, inteiro, reidratado por tres dias em tubo PVC com aplicacao de ar comprimido e, em seguida, moido a 5mm; 5) Seco, inteiro, reidratado por tres dias em tubo PVC e, em seguida, moido a 5mm, e ensilado por 30 dias; 6) Seco, inteiro, reidratado por tres dias em tubo PVC com aplicacao de ar comprimido, moido a 5mm e ensilado por 30 dias. Os teores de proteina bruta, amido, e fibra em detergente neutro (% da MS) variaram de 9,8 a 10,8%; 59,5 a 67,5%; e de 16,1 a 19,3%, respectivamente. Os teores de umidade nos graos que foram reidratados variaram de 35,8 a 43,9% da MS. A taxa e a extensao de degradacao do amido e a degradabilidade potencial da MS foram semelhantes (P>0,05) entre tratamentos. Os graos de sorgo reidratados com aplicacao de ar comprimido, moidos e ensilados (tratamento 6) apresentaram degradabilidade efetiva (DE) da MS e DE do amido sob taxa de passagem ruminal de 2%/h, semelhantes (P>0,05) as observadas para o tratamento 5 (sem aplicacao de ar comprimido), e superiores (P<0,05) as dos demais processamentos. Sob taxas de passagem no rumen de 5 e 8%/h, as DE do amido estimadas para os graos processados no tratamento 6 foram superiores (P<0,05) as obtidas para os demais tratamentos. O processamento de reidratacao por tres dias com aplicacao de ar comprimido e ensilagem por trinta dias aumentou a degradabilidade efetiva da materia seca e do amido dos graos de sorgo, e sua utilizacao pode ser recomendada para animais em niveis intermediario e elevado de desempenho.

Metabolic and hormonal profile of bulls during evaluation of nutritional requirements by respirometric technique under different plane of nutrition

The knowledge of animal metabolism against different nutritional conditions imposed is of great importance, since the ratio of nutrients absorbed deposited in the body or that are in full use is dependent on metabolic and hormonal status of the animal (Payne and Payne, 1987). The objective of this work was to study the hormonal and metabolic profile of bulls during evaluation of the nutritional requirements of energy, by respirometry technique, in different nutritional plans and undergoing a fasting period.