Effects of different moist orange pulp inclusions in the corn grain rehydration for silage production on chemical composition, fermentation, aerobic stability, microbiological profile, and losses.

This study evaluated the effects of different moist orange pulp (MOP) inclusions in corn grain rehydration for silage production as a strategy to store and use MOP and whether these inclusions result in adequate fermentation and aerobic stability (AE) and acceptable losses. Ground corn grain and MOP were weighed separately and mixed to obtain MOP inclusions of 21%, 34%, or 42%. The control treatment was obtained with corn rehydrated with distilled water and MOP inclusion of 0%, with five laboratory silos (15-L buckets) per treatment. Acid detergent fiber, acid detergent insoluble protein, acid detergent lignin, lactic acid, acetic acid, and ethanol contents increased linearly with increasing MOP inclusion, whereas starch, in vitro dry matter (DM) digestibility and butyric acid contents and pH decreased linearly. NH3 -N/TN content reduced quadratically and was minimal with 8.34 g/kg DM at 14% MOP inclusion. Total DM losses increased quadratically with maximal losses of 4.26% DM at 25% MOP inclusion. AE reduced by 2.8 h for each 1% increase in MOP inclusion. Rehydration of corn grain with MOP results in an adequate fermentation process. The inclusion of 34% MOP was the best because DM losses were lower and AE was not drastically reduced.

Energy metabolism of pregnant zebu and crossbred zebu dairy cattle.

The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).

Optimization Tifton-85 grass cutting for productivity and nutrient value

The objective of this work was to determine the impact of cutting Tifton-85 grass at 14, 28, 42, 46, 70, and 80 days of regrowth on its production and nutritional characteristics during the rainy season. The study area of 238 m2 was divided into four sub-area, with 6 plots of 2 × 2 m spaced 1 m between plots and 2 m between sub-area. Random block design was used. The statistical analyses were performed following a randomized block design. Results were obtained as means from evaluations conducted in two consecutive years. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) increased as the cutting age increased. However, crude protein, NDF nitrogen, ADF nitrogen and leaves/stem relationship decreased as the cutting age increased. The production of digestible dry matter increased linearly as the cutting age increased. Similarly, grass height, green matter and dry matter production (DMP) increased as the cutting age increased. The different cutting age did not influence the nitrogen A, B1 + B2, and B3 fractions of the grass. However, the C fraction increased as the cutting age increased. Longer intervals between cuts increased the grass productivity per cut, but compromised its nutritional composition and leaves/stem relationship. For Tifton -85, the regrowth age of 28 days allows greater production of dry matter and greater accumulated production of crude protein and digestive dry matter in the rainy season or over time.

Energy partitioning in cattle fed diets based on tropical forage with the inclusion of antibiotic additives.

The aim of this study was to describe energy partitioning in dairy crossbreed bulls fed tropical forage-based diets supplemented with different additives. Twenty F1 crossbred bulls (Holstein x Gyr) with initial and final live weight (LW) averages of 190 ± 17 and 275 ± 20 kg were fed sorghum (Sorghum bicolour) and Tanzania grass (Panicum maximum cv. Tanzania) silage (70:30 DM basis) with supplemented concentrate at a forage to concentrate ratio of 50:50. The bulls were allocated to four treatment: control groups (without additives), monensin [22 mg/kg monensin dry matter (DM)] (M), virginiamycin (30 mg/kg virginiamycin DM) (V), and combination (22 mg/kg DM of monensin and 30 mg/kg DM of virginiamycin) (MV), in a completely randomised design. The intake of gross energy (GE, MJ/d), digestible energy (DE, MJ/d), metabolizable energy (ME, MJ/d), as well as energy losses in the form of faeces, urine, methane, heat production (HE), and retained energy (RE) were measured. Faecal output was measured in apparent digestibility trial. Right after the apparent digestibility trial, urine samples were collected in order to estimate the daily urinary production of the animals. Heat and methane production were measured in an open circuit respirometry chamber. The intake of GE, DE, and ME of the animals receiving monensin and virginiamycin alone or in combination (MV) showed no differences (P>0.05) from the control treatment. However, the MV treatment reduced (P<0.05) the methane production (5.44 MJ/d) compared to the control group (7.33 MJ/d), expressed in MJ per day, but not when expressed related to gross energy intake (GEI) (CH4, % GEI) (P = 0.34). Virginiamycin and monensin alone or in combination did not change (P>0.05) the utilization efficiency of ME for weight gain, RE and net gain energy. This study showed that for cattle fed tropical forages, the combination of virginiamycin and monensin as feed additives affected their energy metabolism by a reduction in the energy lost as methane.

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.

Respirometria e emissão de metano por ovinos alimentados com capim-elefante cortado com diferentes idades / Respirometry and methane emissions by sheep fed elephantgrass at different cutting ages

Objetivou-se com este trabalho mensurar a respirometria e a emissão de metano entérico por ovinos alimentados com o capim-elefante cortado aos 56, 84 e 112 dias de crescimento. Foram utilizados 18 carneiros adultos sem raça definida, com peso médio de 34,7 ± 6 kg alojados em gaiolas de estudo de metabolismo. A mensuração dos gases foi realizada através de uma câmara respirométrica de fluxo aberto. O delineamento experimental utilizado foi inteiramente casualizado, com seis repetições, e as médias foram comparadas pelo teste SNK (P<0,05). Os animais alimentados com o capim colhido após 56 dias de rebrotação consumiram mais oxigênio e produziram mais dióxido de carbono e metano. As produções de calor variaram 87,19 a 143,57 Kcal/kg 0,75/dia. O coeficiente respiratório foi semelhante entre os tratamentos, com valor médio de 0,98. A produção de metano variou entre 11,74 e 22,51 g/dia, havendo redução com o aumento da idade da planta forrageira. Quando expressa em g/kg0,75/dia, a produção deste gás foi superior para animais que receberam o capim-elefante-verde cortado aos 56 dias de idade (1,53 g/kg 0,75/dia). A emissão de metano (g) por quilo de matéria seca (MS) e de fibra insolúvel em detergente neutro (FDN) consumido para o capim colhido mais novo (56 dias) foi superior à do capim colhido no estádio mais avanço de maturação (112 dias). Porém, as emissões de metano em gramas por quilo de MS digestível (27,2 g/kg) e FDN digestível (44,4 g/kg) foram semelhantes para os capins colhidos nas diferentes idades de corte. A emissão diária de metano (g/kg 0,75/dia) foi maior em animais alimentados com a planta forrageira colhida mais nova, enquanto que se expressa em gramas por quilo de MS ou FDN digestível a emissão deste gás não sofreu influência do capim-elefante no momento do corte.

The aim of this work was to determinate the respirometry and enteric methane emission from sheep fed fresh elephant grass cut at 56, 84 and 112 days of regrowth. Eighteen crossbred sheep (34.7 ± 6 kg) individually housed in metabolic crates were used in this experiment. The gases measurements were accomplished with an open circuit respirometric chamber. The experimental design was completely randomized with three treatments (grass regowth age) and six repetitions (sheep). The data were subjected to ANOVA and means were compared by SNK test (P<0.05). The animals fed with elephant grass harvested at 56 days of regrowth had higher oxygen uptake and carbon dioxide and methane emissions. Heat production ranged from 87.19 to 143.57 Kcal/kg 0.75/day. The respiratory quotients were similar (P>0.05) among treatments, averaging 0.98. Methane emissions ranged from 11.74 to 22.51 g/day. When expressed in g/kg 0.75/day, methane emissions were higher for sheep fed fresh elephant grass with 56 days of regrowth (1.53 g/kg 0.75/day). Methane emissions expressed in g/kg of dry matter (DM) intake or neutral detergent fiber (NDF) intake were higher (P<0.05) for the grass harvested with 56 days of regrowth compared to the grass harvested in more advanced stage of maturity (112 days). However, methane emissions in g/kg of digestible DM (27.2 g/kg) and digestible NDF (44.4 g/kg) were similar among treatments. While daily methane emissions (g/kg 0.75/day) were higher in sheep fed fresh elephant grass harvested with 56 days of regrowth, it was not affected by regrowth age when expressed as g/kg of digestible DM or digestible NDF.

Determinação do momento de colheita da Brachiaria brizantha (Hochest. ) Stapf. cv. Marandu para produçaõ de silagem / Determination of the harvest moment of Brachiaria brizantha cv. Marandu for ensilage prodution

Conduziu-se este trabalho, com o objetivo de determinar o momento de colheita da Brachiaria brizantha para produção de silagem. As silagens foram abertas após 56 dias de fermentação. Os tratamentos utilizados foram quatro idades de crescimento: 28, 56, 84 e 112 dias. Foi utilizado delineamento inteiramente casualisado, com quatro repetições por tratamento. As produções de MS aumentaram com o avanço da maturidade da planta, variando de 3,04 a 11,47 t/ha. O menor teor de MS entre as silagens ocorreu aos 28 dias 17,16%, sendo semelhante aos 84 dias (p>0,05), enquanto o maior valor de 22,62% foi observado para a idade de 112 dias de crescimento. Os valores de digestibilidade “in vitro” da matéria seca (DIVMS) variaram de 67,40% a 57,40% com o avanço da maturidade e apenas as idades de 84 e 112 dias foram semelhantes (p>0,05). Os valores de nitrogênio amoniacal por nitrogênio total (N-NH3/NT) apresentaram diferença apenas para a idade de 28 dias com valor mais elevado que as demais (p<0,05). Foi observadadiferença (p<0,05) apenas no pH da silagem do material colhido com 28 dias de crescimento, sendo superior aos demais com valor de 5,45. A Brachiaria brizantha apresenta potencial para produção de silagem com altas produções de matéria seca, entretanto, em idades jovens o baixo teor de MS da planta prejudica o processo fermentativo. O corte aos 68 dias de crescimento se apresenta como melhor opção para esta forrageira, uma vez que concilia alta produção de MS com bom valor nutritivo e características desejáveis para confecção de uma boa silagem.

The aim of this work was to determine the harvest moment of Brachiaria brizantha for silage production. The silages were opened at 56 days of fermentation. The treatments used were four growth ages (28, 56, 84, and 112 days). The experimental procedure followed a completely randomized design with four replications for each treatment. The dry matter (DM) production increased with the advance of the plant maturity, varying from 3.04 to 11.47 t/ha. The lower dry matter value among the ensilages was observed for the 28-day treatment (17.16%), which was similar to the 84-day treatment (p>0.05), while the highest value of 22.62% was observed for the age of 112 days of growth. The values of in vitro dry matter digestibility (IVDMD) in the silages varied from67.40% to 57.40% with the advance of the maturity and were similar only (p<0.05) between the ages of 84 and 112 days. The values of ammoniacal nitrogen for total nitrogen (N-NH3/NT) were higher at the age of 28 days than the other ages (p<0.05). The pH of theanalyzed silages varied from 4.87 to 5.45 among the evaluated ages. The Brachiaria brizantha presents potential for silage production with high productions of dry matter. However, at younger ages, the low percentage of dry matter of the plant impairs the fermentation process. The harvest at 68 days of growth presents the better option for this plant, since it conciliates high production of DM with good nutritional value and desirable characteristic for a good silage confection.

Avaliação das silagens de girassol (hibrido m734) obtidas em diferentes épocas de ensilagem pela técnica in vitro semi-automática de produção de gases / Evaluation of silages from hybrid m734 of sunflower obteined in diferent cutting times using the semi-automated in vitro gas production technique

Para que o girassol possa ser utilizado com sucesso na forma de silagem, é necessário que se determine o ponto ideal de ensilagem. O objetivo desse experimento foi avaliar através da técnica in vitro semi-automática de produção de gases a cinética de degradação da matéria orgânica (MO) e matéria seca (MS) das silagens do híbrido M734 ensilado com 100, 107, 114 e 121 dias após o plantio. As leituras de pressão dos gases foram feitas através de um transdutor de pressão às 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72, 96 h pós-inoculação. A cinética ruminal foi descrita matematicamente por meio dos parâmetros: potencial máximo de produção de gases, lag time, taxa de produção de gases (mü) e degradabilidade efetiva da MO e MS para diferentes taxas de passagem (2,5 e 8 %/h) por um modelo unicompartimental. Verificou-se que o corte da cultura em estádios mais tardios levaram a redução no potencial máximo de produção de gases para a MO (162, 155, 144 e 139 mL) e MS (138, 129, 121 e 119 mL); elevação da lag time para MO (2,4, 2,5, 2,8 e 2,9 h) e MS (2,46, 2,54, 2,98 e 2,99 h); e diminuição do mü para a MO (0,023, 0,022, 0,017 e 0,018 mL/h) e MS (0,022, 0,020, 0,015 e 0,016 mL/h) para as épocas 100, 107, 114 e 121 dias após o plantio, respectivamente. As épocas mais indicadas para a ensilagem do híbrido M734 foram aos 100 e 107 dias após o plantio.

Degradabilidade in situ da matéria seca e da proteína bruta das silagens de seis genótipos de sorgo (Sorghum bicolor (L. ) Moench), com e sem tanino no gräo, ensilados no estádio de gräo farináceo / Dry matter and crude protein degradability of six sorghum silage genotypes (Sorghum bicolor (L. ) Moench) harvested at hard dough stage, with or without grain containing tannin

Este experimento foi conduzido para avaliar o valor nutricional (matéria seca e proteína bruta) de seis genótipos de sorgo para silagem, com e sem tanino no gräo, colhidos no estádio de gräo farináceo, utilizando a técnica da degradabilidade in situ. Seis silagens de genótipos de sorgo foram utilizadas: BR 303, BR 304, BR 601 e AG 2006 (sem tanino no gräo) e BR 700 e BR 701 (com tanino no gräo). Quatro bovinos machos, canulados no rúmen foram utilizados. Os tempos de incubaçäo foram: 6, 12, 24, 48, 72 e 96 horas. Utilizou-se o tempo zero (t0) para cálculo da solubilidade das silagens. A silagem do sorgo BR 304 apresentou os melhores resultados para a média de desaparecimento da MS e da PB às 96 horas de incubaçäo, seguida pela do AG 2006. O tanino presente nos gräos dos genótipos BR 700 e BR 701 ensilados no estádio de gräo farináceo, näo respondeu por nenhum efeito depressivo sobre os parâmetros estudados de degradaçäo da matéria seca e da proteína bruta