Mário Fonseca Paulino

Influence of incubation time and particles size on indigestible compounds contents in cattle feeds and feces obtained by in situ procedures

The aim of this work was to evaluate the effects of in situ incubation time and particles size on the estimates of indigestible fractions of dry matter (iDM), neutral detergent fiber (iNDF), and acid detergent fiber (iADF) in cattle feeds and feces. Samples of corn grain, wheat bran, corn silage, elephant grass, sugarcane, signal grass hay, corn straw, and feces obtained from cattle fed high and low concentrate diets were used. The samples were ground through 1 mm, 2 mm, and 3 mm screen sieve and put in 4 × 5 cm non-woven textile bags (20 mg DM/cm² of surface). The samples were divided in three groups, being each group incubated in the rumen of a crossbred heifer. The incubation procedure was conducted three times with the change of groups among animals. The following incubation times were used: 0, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, and 312 hours. The contents of iDM, iNDF, and iADF were evaluated sequentially in each bag. The degradation profiles were interpreted by a non-linear logistic model. The particles size did not influence the estimates of iNDF and iADF. However, the particles size altered the rumen degradation dynamic rates of DM for corn silage and corn grain; of NDF for sugarcane, corn silage, and corn straw; and ADF for sugarcane. For those samples, the particle size has been positively associated with the incubation time necessary to estimate the indigestible fraction. Incubation times of 240 hours for DM and NDF, and 264 hours for ADF were suggested for obtaining more accurate estimates of indigestible fractions. The use of 2 mm particle size can increase the precision of estimates.

Cromo e indicadores internos na determinação do consumo de novilhos mestiços, suplementados, a pasto

This experiment aimed to evaluate the dry matter intake (DMI) under grazing, obtained through the chromium, in continuous infusion of chromic oxide, dosed once (CR1x) or twice (CR2x) daily, and in mordant form (CRMord), together with the following internal digestibility markers: in vitro dry matter digestibility (IVDMD), indigestible DM (iDM) and indigestible neutral detergent fiber (iNDF) and acid detergent fiber (iADF). Five F1 Limousin x Nelore steers, fistulated in the esophagus and rumen and supplemented in pasture of Brachiaria decumbens, were used. A randomized blocks design, in split plit plot outline was used, in which the supplements were considered as main plot, the methodologies of chromium as split plots and internal markers as split split plots. Supplement effects were not observed on DMI. The use of CR1x methodology underestimated the fecal excretion and DMI (DMI of 2.11% of LW) compared to the methodologies CR2x and CRMord (3.11 and 2.93% LW) that presented better values for DMI, not differing to each other. Interactive effect was observed between supplement and markers, with no differences in the values supplied by the same marker in the different supplements. The IVDMD, the marker of larger precision, presented medium value for DMI of 3.16% LW, overestimating the intake of all supplements. The iDM and iNDF were constant among supplements (2.48 and 2.54% LW of DMI), not differing to each other, being recommended for studies with animals at pasture. The DMI estimated by iADF showed variable results among supplements; the intakes were, on average, by using iADF (2.72% LW) higher compared to iDM and iNDF and lower compared to IVDMD.

Consumo e digestões totais e parciais em novilhos F1 Limousin x Nelore alimentados com dietas contendo cinco níveis de concentrado

ABSTRACT - A trial was conducted to evaluate the effects of five dietary concentrate levels on the intake and total and partial apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF), and non structural carbohydrates (NSC). Five rumen, abomasum and ileum fistulated F1 Limousin x Nellore bulls were full fed diets containing 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate and allotted to a 5 x 5 Latin square design. The chromic oxide was used as an external marker to determine the total and partial digestibility. The addition of crescent concentrate amounts to the diet resulted in linear increases in the DM, OM, NCE, CP, EE, and TDN and reductions in NDF intake. The total apparent digestibility of DM, OM, CP, EE, CHO, and NSC linearly increased with the increment of the dietary concentrate levels. The CP apparent digestibility in the small intestine linearly increased as function of the concentrate addition in the diets. The concentrate levels in the diet did not influence the rumen and post-rumen NDF apparent digestibility. The dietary NDF levels reduction resulted on linear increases of NDT and DM total apparent digestibility.

Consumo e digestibilidades aparentes totais e parciais de rações contendo diferentes níveis de concentrado, em novilhos F1 Limousin x Nelore

The objective of this work was to evaluate the effects of five dietary concentrate levels (25.0, 37.5, 50.0, 62.5, and 75.0%) on intake and the total and partial apparent digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO) and neutral detergent fiber (NDF). Five rumen, abomasum and ileum fistulated F1 Limousin x Nellore bulls, with average initial weight of 279 kg were used, in a 5 x 5 Latin square design, with five treatments, five experimental periods and five animals. Each experimental period lasted 14 days - 10 days for animals adaptation to the diet and four days for feces, and abomasum and ileum digesta collection. Chromium oxide was used as indicator, in two doses of 10 g/day, to measure nutrient flows in the digestive tract. The ether extract and TDN intakes increased and of the NDF linearly decreased with the increase of dietary concentrate levels. The increment of concentrate levels in DM linearly increased the apparent total digestibilities of the DM, OM, CP, and CHO. The apparent total NDF digestibility and the apparent ruminal digestibilities of DM, OM, CP, CHO and FDN were not influenced by the dietary concentrate levels, with means of 45.91, 54.45, 64.67, -9.92, 79.29, and 95.90%, respectively. The increase of dietary concentrate levels did not affect the local of nutrients digestion.

Rumen dynamics of neutral detergent fiber in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds

The aim of this work was to evaluate the effects of supplementation with nitrogenous compounds on rumen dynamics of neutral detergent fiber (NDF) in cattle fed low-quality tropical forage. Five crossbred heifers with average live weight of 180 kg and fitted with rumen cannulae were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf.) hay, which had crude protein (CP) content of 4.86% of dry matter (DM). The five treatments were proposed in order to raise the CP level of diets to 0, 2, 4, 6, and 8 percentile points above the CP level of the forage. The supplement was a mixture of urea, ammonium sulfate, and albumin (4.5:0.5:1.0, respectively). The experiment was carried out according to a 5 × 5 Latin square design, with five experimental periods. The average CP levels in the diets were: 5.19, 7.11, 8.60, 11.67, and 13.02% on DM basis. The potentially degradable NDF was linearly increased according to the CP levels in diet up to 6.97% of CP. From this point, there was stabilization of estimates (47.87% of NDF). The degradation rate of potentially degradable NDF was linearly increased with the CP levels in diets. The rumen flow of fibrous particles (L) showed a linear-response-plateau pattern according to the CP levels in diets. The plateau (maximum estimate) began on 7.24% of CP. The mean retention time in the rumen and the rumen fill effect of undegradable NDF were affect by the CP levels similarly to L, with plateau (minimum) beginning on 6.90 and 6.97% of CP, respectively.

Comparação de Indicadores e Metodologia de Coleta para Estimativas de Produção Fecal e Fluxo de Digesta em Bovinos

It was aimed to compare the internal markers, indigestible neutral detergent (NDFi) and acid fiber (ADFi), and ADFi with oxide chromic to esteem the dry matter fecal production and nutrients digestibility of diets of bovine, in two outlines of collections (2 or 6 days). For the comparison among internal markers, 32 Nelore growing bulls, with 240 kg, were maintained under feedlot, receiving diets with different concentrate levels (20, 40, 60 and 80%). For the comparison among internal and external marker, five 165 kg Nelore growing bulls, rumen, abomasum and ileum fistulated, were used. The design was in blocks with four treatments and 5 collection periods. The treatments consisted of four concentrate levels (20, 40, 60 and 80%). The roughage used was Tifton 85 hay. The apparent digestibility of dry matter (DM) was smaller, when was estimated by oxide chromic, however the DM digestibility in the rumen and intestines did not differ among markers. When the collection methodology was compared (6 days vs. 2 days), there was not difference in all the studied variables, demonstrating the suggested alternative methodology as soon as can be used with safety for the estimates of fecal production and DM flows in the abomasum and ileum.

Soja Grão e Caroço de Algodão em Suplementos Múltiplos para Terminação de Bovinos Mestiços em Pastejo

Dois experimentos foram conduzidos com o objetivo de avaliar suplementos multiplos contendo soja grao (GSOI) e caroco de algodao (ALG) inteiros em relacao a suplemento padrao de milho mais farelo de soja (FSOJA), em bovinos mesticos terminados a pasto, durante a epoca seca. Os suplementos foram balanceados para atingirem 20% PB, com base na materia natural. Avaliaram-se, no primeiro experimento, as variaveis ganho medio diario (GMD - kg/dia), rendimento de carcaca quente (RC - %) e peso de carcaca (PC - kg). Foram utilizados 12 novilhos mesticos Holandes-Zebu, com idade e peso medios iniciais de 24 meses e 361 kg, manejados em tres piquetes (3 ha) de Brachiaria decumbens, recebendo 4 kg/cab/dia de suplemento. Observaram-se valores de GMD, RC e PC de 1,056, 52,21 e 241,20; 1,016, 53,04 e 242,55; e 1,137, 53,61 e 247,65, respectivamente, para os suplementos GSOI, ALG e FSOJA, que se mostraram equivalentes. No segundo experimento, objetivou-se avaliar a influencia dos suplementos sobre o comportamento de pH e a concentracao amoniacal ruminais. Empregaram-se os suplementos descritos inicialmente, acrescentando-se tratamento englobando a fonte proteica grao de soja moido (GSOM). Foram utilizados cinco novilhos mesticos, fistulados no rumen, mantidos em piquete (3 ha) de Brachiaria decumbens, os quais receberam 4 kg/cab/dia de suplemento. As mensuracoes foram realizadas 0, 2, 4 e 6 horas apos a suplementacao. O pH ruminal foi afetado por suplementos, sendo observadas quedas significativas somente em FSOJA, nao ocorrendo, contudo, niveis danosos a microbiota ruminal. Os niveis amoniacais medios para ALG, GSOI e GSOM foram de 7,23; 6,91; e 6,74 mg/dL, respectivamente, nao diferindo entre si, sendo inferiores ao FSOJA (9,51 mg/dL).

Composição corporal e exigências líquidas de proteína e energia para ganho de peso de bovinos F1 Simental x Nelore

Avaliaram-se os efeitos de cinco niveis de concentrado nas racoes sobre a composicao corporal e as exigencias liquidas de proteina e energia para ganho de peso. Vinte e nove bovinos, nao-castrados, F1 Simental x Nelore com, em media, 17 meses de idade e 354 kg PV inicial, foram usados. Cinco animais foram abatidos ao inicio do experimento, como referencia, para estimar o peso de corpo vazio (PCV) inicial e as concentracoes iniciais de gordura, proteina e energia. Os animais restantes foram distribuidos nos tratamentos, de forma inteiramente casualizada, de acordo com o nivel de concentrado nas racoes: 25; 37,5; 50; 62,5; e 75%. Os animais foram alimentados a vontade ate atingirem o peso de abate preestabelecido de 500 kg. Equacoes de regressao foram ajustadas, para cada nivel de concentrado e em conjunto, do logaritmo das quantidades de gordura, proteina ou energia, em relacao ao logaritmo do PCV. Derivando-se as referidas equacoes de regressao, obteve-se a composicao do ganho de PCV. A quantidade de gordura e o conteudo de energia no peso ganho aumentaram, a medida que se elevou o PV do animal. O conteudo corporal de proteina elevou-se com o aumento do PV, mas a concentracao em g/kg de PCV diminuiu. As exigencias liquidas de energia para um animal de 400 kg PCV para 1 kg PCV foram, em media, 3,96 Mcal/dia. As exigencias de energia liquida para ganho em peso aumentaram e as de proteina reduziram, com o aumento do peso corporal.

Estimation of fibrous compounds contents in ruminant feeds with bags made from different textiles

The aim of this work was to evaluate the contents of in situ indigestible neutral detergent fiber (iNDF) and the fibrous particles lost in aqueous environment in some ruminant feeds by using bags made with different textiles. The physical structure of the textiles was also observed. Wheat bran (WB), soybean hulls (SH), corn silage (CS), and signal grass hay (SGH) samples were used. The bags used for rumen incubation were made of nylon (50 µm); F57 (Ankom®); and non-woven textile (NWT -100 g/m²). The feed samples were ground (1 mm) and conditioned in bags (4 × 5 cm) (six bags of each feedstuff/textile), in a ratio of 20 mg of dry matter/cm2 of surface. The bags were incubated in the rumen of a cow fed with corn silage (70%) and concentrate (30%) for 144 hours. After that, the bags were removed, cleaned with running water and treated with neutral detergent. The residue was assumed as iNDF. The iNDF contents in WB, SH and CS were similar for F57 and NWT, but lower values were obtained when nylon was used For the SGH samples, all textiles produced different results, and the lowest contents were obtained with nylon. The fibrous particle losses in the aqueous environment were evaluated by cleaning the bags in warm running water (39oC) (10 bags/textile). The loss of fibrous particles was significant for nylon. This loss was considered the cause of lower iNDF contents obtained by using nylon textile, since the microscopic evaluation did not show the occurrence of ruptures during incubation or neutral detergent extraction.

Níveis de proteína em suplementos para terminação de bovinos em pastejo durante o período de transição Seca/Águas: digestibilidade aparente e parâmetros do metabolismo ruminal e dos compostos nitrogenados

The objective of this trial was to evaluate ruminal, intestinal, and total tract apparent digestibilities of nutrients as well as metabolism of ruminal and nitrogenous compounds in supplemented finishing cattle during the drought to rainy transition season. Five Holstein x Zebu steers averaging 304 kg of live weight and 24 months of age located in five paddocks (0.34 ha each) of Brachiaria decumbens were used in this trial. The supplements fed (4 kg/animal/day) contained ground corn, whole soybean, urea, ammonium sulfate, and minerals and were formulated to yield, on as fed basis, 12, 16, 20, and 24% of crude protein (CP). Four animals were assigned to a 4 x 4 Latin square with experimental periods lasting 21 days. The remaining animal was not supplemented and was used for comparative purposes (CONT). No significant differences in ruminal, intestinal, and total tract apparent digestibilities of dry matter, organic matter, and neutral detergent fiber were observed by increasing the CP contents of the supplements. Similarly, abomasal flows of total nitrogen, ammonia nitrogen, and microbial nitrogen (MICN) did not differ when the CP contents of the supplements were increased. However, concentration of ruminal ammonia nitrogen increased linearly by incrementing the CP content of the supplement from 12 to 24%. Microbial efficiency averaged 17.5 g of MICN/kg of organic matter fermented in the rumen (OMFR) across supplements and was higher than that of the CONT (10.6 g of MICN/kg of OMFR). In addition, it was observed a significant cubic effect for urinary excretion of urea by increasing the CP contents of the supplements.