The Use of an Automated System (GreenFeed) to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals.

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during storage. These processes are the major sources of greenhouse gas (GHG) emissions from animal production systems. Techniques for measuring enteric CH4 vary from direct measurements (respiration chambers, which are highly accurate, but with limited applicability) to various indirect methods (sniffers, laser technology, which are practical, but with variable accuracy). The sulfur hexafluoride (SF6) tracer gas method is commonly used to measure enteric CH4 production by animal scientists and more recently, application of an Automated Head-Chamber System (AHCS) (GreenFeed, C-Lock, Inc., Rapid City, SD), which is the focus of this experiment, has been growing. AHCS is an automated system to monitor CH4 and carbon dioxide (CO2) mass fluxes from the breath of ruminant animals. In a typical AHCS operation, small quantities of baiting feed are dispensed to individual animals to lure them to AHCS multiple times daily. As the animal visits AHCS, a fan system pulls air past the animal's muzzle into an intake manifold, and through an air collection pipe where continuous airflow rates are measured. A sub-sample of air is pumped out of the pipe into non-dispersive infra-red sensors for continuous measurement of CH4 and CO2 concentrations. Field comparisons of AHCS to respiration chambers or SF6 have demonstrated that AHCS produces repeatable and accurate CH4 emission results, provided that animal visits to AHCS are sufficient so emission estimates are representative of the diurnal rhythm of rumen gas production. Here, we demonstrate the use of AHCS to measure CO2 and CH4 fluxes from dairy cows given a control diet or a diet supplemented with technical-grade cashew nut shell liquid.

An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production.

A quarter of all anthropogenic methane emissions in the United States are from enteric fermentation, primarily from ruminant livestock. This study was undertaken to test the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission in lactating Holstein cows. An experiment was conducted using 48 cows in a randomized block design with a 2-wk covariate period and a 12-wk data collection period. Feed intake, milk production, and fiber digestibility were not affected by the inhibitor. Milk protein and lactose yields were increased by 3NOP. Rumen methane emission was linearly decreased by 3NOP, averaging about 30% lower than the control. Methane emission per unit of feed dry matter intake or per unit of energy-corrected milk were also about 30% less for the 3NOP-treated cows. On average, the body weight gain of 3NOP-treated cows was 80% greater than control cows during the 12-wk experiment. The experiment demonstrated that the methane inhibitor 3NOP, applied at 40 to 80 mg/kg feed dry matter, decreased methane emissions from high-producing dairy cows by 30% and increased body weight gain without negatively affecting feed intake or milk production and composition. The inhibitory effect persisted over 12 wk of treatment, thus offering an effective methane mitigation practice for the livestock industries.

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.