Effects of protein source and lipid supplementation on conservation and feed value of total mixed ration silages for finishing beef cattle.

The objective of this study was to examine the conservation process and feed value of total mixed ration (TMR) silages. In exp. 1, we evaluated the fermentation pattern and aerobic stability of TMR silages containing different protein and lipid supplementations. In exp. 2, we compared the performance of finishing beef heifers fed those TMR silages. In both experiments, treatments were as follows: ensiled TMR with urea (U); ensiled TMR without a protein supplement at ensiling, but soybean meal supplemented at feeding to balance diet crude protein (CP) in exp. 2 (SMnf; where the acronym nf indicates nonfermented); ensiled TMR with soybean meal (SM); and ensiled TMR with rolled soybean grain (SG). Thirty-two Nellore heifers (313 ± 8.8 kg shrunk body weight [SBW]) were blocked by initial SBW, housed in individual pens, and enrolled in exp. 2 for 82 d. In exp. 1, treatment without a protein supplement (SMnf) had a lower content of CP, soluble CP, NH3-N, pH, and Clostridium count compared with U (P ≤ 0.03). Lactic acid concentrations tended to be reduced for SMnf compared with U (P = 0.09). Ethanol concentration was reduced in SG compared with SM (P < 0.01). 1,2-Propanediol concentration was increased in SMnf compared with U (P < 0.01), reduced in SM compared with SMnf (P = 0.02), and increased in SG compared with SM (P = 0.02). Dry matter (DM) loss during fermentation was low and similar among treatments (~3.7%). All silages remained stable during 10 d of aerobic exposure after feed out. Considering fermentation traits, such as pH (≤4.72), NH3-N (<10% of N, except for U treatment), butyric acid (<0.05 % DM), and DM losses (<3.70% DM), all silages can be considered well conserved. In exp. 2, diets were isonitrogenous because soybean meal was added to SMnf before feeding. Compared with SM, cattle fed SG made more meals per day (P = 0.04) and tended to have a decreased intermeal interval (P = 0.09). DM intake, average daily gain, final SBW, hot carcass weight, Biceps femoris fat thickness, and serum levels of triglycerides and cholesterol were increased for SG compared with SM (P ≤ 0.05). In brief, TMR silages exhibited an adequate fermentation pattern and high aerobic stability. The supplementation of true protein did not improve animal performance, whereas the addition of soybean grain as a lipid source improved the performance of finishing cattle fed TMR silages.

Effects of processing, moisture, and storage length on the fermentation profile, particle size, and ruminal disappearance of reconstituted corn grain.

Our objective was to examine the effects of processing, moisture, and anaerobic storage length of reconstituted corn grain (RCG) on the fermentation profile, geometric mean particle size (GMPS), and ruminal dry matter disappearance (DMD). Dry corn kernels were ground (hammer mill, 5-mm screen) or rolled, then rehydrated to 30%, 35%, or 40% moisture, and stored for 0, 14, 30, 60, 90, 120, or 180 d in laboratory silos. Rolled corn had an increased GMPS compared with ground corn (2.24 and 1.13 mm, respectively, at ensiling). However, there was a trend for an interaction between processing and moisture concentration to affect particle size, with GMPS increasing with increased moisture concentration, especially in ground corn. Longer storage periods also slightly increased GMPS. Processing, moisture, and storage length interacted to affect the fermentation pattern (two- or three-way interactions). Overall, pH decreased, whereas lactic acid, acetic acid, ethanol, and NH3-N increased with storage length. RCG with 30% moisture had less lactic acid than corn with 35% and 40% moisture, indicating that fermentation might have been curtailed and also due to the clostridial fermentation that converts lactic acid to butyric acid. Ensiling reconstituted ground corn with 30% of moisture led to greater concentrations of ethanol and butyric acid, resulting in greater DM loss than grain rehydrated to 35% or 40% of moisture. Ammonia-N and in situ ruminal DMD were highest for reconstituted ground corn with 35% or 40% of moisture, mainly after 60 d of storage. Therefore, longer storage periods and greater moisture contents did not offset the negative effect of greater particle size on the in situ ruminal DMD of rolled RCG. Nonetheless, RCG should be ensiled with more than 30% moisture and stored for at least 2 mo to improve the ruminal DMD and reduce the formation of ethanol and butyric acid.

Digestibility of canola seeds treated by autoclaving and/or condensed tannins / Digestibilidad de la canola tratada en autoclave y/o con taninos condensados / Digestibilidade de grãos de canola tratados em autoclave e/ou com tanino condensado

Background: plant proteins are susceptible to rapid degradation in the rumen therefore it is important to explore the best way to improve protein utilization. Objective: to evaluate the effect of heat treatment and/ or condensed tannins on ruminal degradability and in vitro digestibility of crude protein (CP) and dry matter (DM) of canola seeds. Methods: in situ and in vitro DM and CP digestibility of canola seeds treated with water (control; CCL), heat in autoclave (CLE), condensed tannin (CTN), and condensed tannin followed by autoclaving (CTA) were evaluated. Results: the DM effective degradability values (EDDM) by CCL, CLE, CTN, and CTA were 66.8%, 73.6%, 58.5%, and 77.5%, respectively. Effective degradability of crude protein (EDCP) by CCL, CLE, CTN, and CTA at a 5%/h passage rate (k) was 75.2, 77.2, 60.2, and 80.5%, respectively. Addition of condensed tannin and/or autoclaving reduced both DM and CP digestibility. Conclusions: treatment with condensed tannins protected canola seeds DM and CP from ruminal degradability, while treatment with heat or tannins combined with heat showed the opposite effect, increasing degradability of those fractions. Addition of condensed tannins and/or autoclaving decreased in vitro DM and CP digestibility.

Antecedentes: es importante estudiar la mejor manera de utilizar fuentes de proteínas vegetales, ya que son rápidamente degradadas en el rumen. Objetivo: evaluar el efecto del tratamiento térmico y/o adición de taninos condensados sobre la degradabilidad ruminal y digestibilidad in vitro de la proteína bruta (PB) y la materia seca (MS) en granos de canola. Métodos: se evaluó la degradabilidad in situ y la digestibilidad in vitro de la MS y PB en granos de canola tratados con agua (control - CCL), térmicamente utilizando autoclave (CTE), taninos condensados (CTN), y taninos condensados seguido por autoclavado (CTA). Resultados: los valores de degradabilidad efectiva de la materia seca (DEMS) para CCL, CTE, CTN, y CTA fueron 66,8, 73,6, 58,5 y 77,5% respectivamente; y para la degradabilidad efectiva de la proteína bruta (DEPB ) fueron 75,2, 77,2, 60,2 y 80,5%, respectivamente -a una tasa de pasaje (k) de 5%/h. La adición de taninos condensados y/o tratamiento térmico provocó la reducción de los valores de digestibilidad, tanto de la MS como de la PB. Conclusiones: el tratamiento con taninos condensados protegió la MS y la PB de las semillas de canola de su degradación ruminal. Los tratamientos con calor húmedo y asociación taninos más calor mostraron el efecto contrario, promoviendo el aumento de la degradabilidad ruminal de esas fracciones. La adición de taninos condensados y/o el autoclavado resultaron en menores valores de digestibilidad para la MS y PB.

Antecedentes: é importante estudar a melhor maneira de utilizar as fontes de proteína vegetal, uma vez que essas são normalmente degradadas no rúmen. Objetivo: avaliar o efeito do tratamento térmico e/ou a adição de tanino condensado sobre a degradabilidade ruminal in situ e a digestibilidade in vitro da proteína bruta (PB) e da matéria seca (MS) de grãos de canola. Métodos: avaliou-se neste trabalho a degradabilidade in situ e a digestibilidade in vitro da MS e PB de grãos de canola tratados com água (controle - CCL), termicamente em autoclave (CTE), tanino condensado (CTN) e tanino condensado seguido de autoclave (CTA). Resultados: os valores de degradabilidade efetiva da matéria seca (DEMS) para CCL, CTE, CTN e CTA foram 66,8; 73,6; 58,5 e 77,5% respectivamente, e para a degradabilidade efetiva da proteína bruta (DEPB) foram 75,2; 77,2; 60,2 e 80,5%, para taxa de passagem (k) igual a 5%/h. A adição de tanino condensado e/ou tratamento com autoclave provocaram a diminuição da digestibilidade, tanto da MS como da PB. Conclusões: concluiu-se que o tratamento com tanino condensado promoveu efetiva proteção da MS e PB dos grãos de canola frente à degradabilidade no rúmen. Já o tratamento com calor úmido e a associação tanino-calor, mostraram efeito contrário, promovendo aumento da degradabilidaderuminal dessas frações. A adição de tanino condensado e/ ou tratamento com autoclave diminuíram a digestibilidade da MS e da PB.

Nutritional value of ten earless corn hybrids used for silage / Valor nutricional de diez híbridos de maíz sin mazorca utilizados para ensilaje / Valor nutritivo de dez híbridos de milho sem espiga utilizados para silagem

Background: corn plant silage is characterized by its high nutritional value and high energy content. However, it is important to determine corn silage characteristics that affect its nutritional value, such as the cell wall constituents. Objective: the objective of this experiment was to evaluate the chemical-bromatological composition and apparent digestibility of 10 corn hybrids (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistachio and Buxxil). Methods: the hybrids were planted at INRA (Unité of Génétique Amélioration des Plantes Fourragères, Lusignan, France) in an area of 150 m2. The experiment was conducted in triplicate. All evaluations were conducted in whole corn plants without ears. Results: the DK265bm3 hybrids presented the best values for enzymatic solubility and cell wall digestibility; it was associated with reduced cell wall KL and esterified p-coumaric acid content compared with the other hybrids. The corn hybrids were evaluated before ensilage using Near Infrared Spectrometry, and a significant difference for chemical composition was found among treatments. Conclusion: DK265bm3 showed superior digestibility of DM, OM, cellulose, NDF and IVDMD compared to the other hybrids.

Antecedentes: el ensilaje de maíz se caracteriza por su alto contenido nutricional y energético. No obstante, la determinación de las características del ensilaje de maíz que afectan su valor nutritivo, como los constituyentes de la pared de la planta, son de suma importancia. Objetivo: el objetivo del presente trabajo fue evaluar la composición química y digestibilidad de 10 híbridos de maíz (DK265bm3, DK265, HS5, SA6, HTV2, HTV27, Anjou285, Mexxal, pistacho y Buxxil). Métodos: los híbridos fueron plantados en el INRA (Unité of Génétique Amélioration des Plantes Fourragères, Lusignan, France) en 150 metros cuadrados, el experimento se realizó por triplicado. Todas las evaluaciones se llevaron a cabo en plantas enteras sin mazorcas. Resultados: el híbrido DK265bm3 mostró mejores valores de solubilidad y digestibilidad enzimática de la pared celular, y esto se asoció con una reducción de la pared celular y el contenido de ácido p-cumárico esterificado en comparación con otros híbridos. Los híbridos de maíz fueron evaluados antes del ensilaje con Espectrometría de Infrarrojo Cercano, y se encontraron diferencias entre los tratamientos para la composición química. Conclusión: el DK265bm3 mostró mayores valores de digestibilidad de la materia seca, orgánica, celulosa, fibra detergente neutra y digestibilidad in vitro de la materia seca, en comparación con los otros híbridos.

Antecedentes: a silagem de milho é caracterizada pelo seu alto valor nutricional e energético. No entanto, a determinação das características da silagem de milho que afetam seu valor nutricional, como os constituintes da parede vegetal são de suma importância. Objetivo: avaliar a composição químico-bromatológica e a digestibilidade aparente de 10 híbridos de milho (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistachio e Buxxil). Métodos: os híbridos foram plantados no INRA (Unité of Génétique Amélioration des Plantes Fourragères, Lusignan, France) em 150 m² de área; o experimento foi conduzido em triplicata. Todas as avaliações foram conduzidas nas plantas inteiras sem espigas. Resultados: o híbrido DK265bm3 apresentou os melhores valores de solubilidade enzimática e digestibilidade da parede celular, e isto foi associado a redução da parede celular e do conteúdo de ácido p-coumárico esterificado comparado com os outros híbridos. Os híbridos de Milho foram avaliados antes da ensilagem usando o Espectometria de infravermelho próximo, e foi verificada a diferença entre os tratamentos para composição química. Conclusões: o hibrido de milho DK265bm3 mostrou valores superiores de digestibilidade da matéria seca, matéria orgânica, celulose, fibra em detergente neutro e digestibilidade in vitro da matéria seca, comparado aos outros híbridos.