Technical note: Infusion, sampling, and vacuum-assisted collection devices for use in ruminally cannulated calves

Abstract

Calves can be ruminally cannulated at young ages, but equipment size limitations preclude use of an infusion and sampling device in these small animals. Likewise, a procedure to easily evacuate rumen contents in young calves has not been described. Overcoming these technical complications related to assessment of ruminal passage kinetics, nutrient digestion, and volatile fatty acid absorption would aid in future studies advancing our knowledge of dairy calf nutrition. The first objective was to design and fabricate 2 devices (one device for infusion and sampling, and another for vacuum-assisted collection) suitable for use in young ruminally cannulated dairy calves. The second objective was to test the utility of these tools when performing procedures commonly used in ruminant nutrition research. A single weaned 62-d-old ruminally cannulated calf was used to evaluate the ability to infuse a solution of LiCoEDTA and sample rumen contents through the cannula cap over a period of 2 h to assess the rumen liquid passage rate (procedure 1). The device was capable of infusing the LiCoEDTA and sampling the rumen fluid, as evidenced by the presence of elevated Co concentrations in the sampled rumen fluid. Using the fluid samples obtained, liquid passage rate within the calf was estimated to be 40.2% of ruminal fluid/h. The second procedure tested the vacuum-assisted collection device and consisted of evacuating and weighing the rumen contents, which is considered a key preparatory step in washed reticulorumen technique experiments that aim to measure nutrient absorption. In agreement with existing literature, evacuated rumen contents represented approximately 4% of the calf's body weight. In conclusion, custom-built devices for infusion, sampling, and vacuum-assisted collection were efficacious when tested in a 62-d-old ruminally cannulated calf fed a diet of 100% texturized starter (18% crude protein, as-fed). Fellow scientists may employ and further modify these techniques to suit their needs when assessing passage kinetics, nutrient digestion, and volatile fatty acid absorption in calves.

Effect of heat-treated canola meal and glycerol inclusion on performance and gastrointestinal development of Holstein calves

“…According to Hall et al (2015), SCFA concentration might not be the most reliable measure of fermentation, as it does not account for the ruminal volume, ruminal dilution, or absorption rates. The ruminal dilution rate may be particularly important in young calves (Yohe et al, 2018) considering that we observed increased digesta weight in the abomasum, duodenum, jejunum, and cecum, and increased tissue mass of the jejunum and colon when calves were supplemented with glycerol without differences in ruminal tissue weight. We suspect that glycerol might promote faster digesta passage through the GIT because glycerol increased starter intake, did not affect ruminal digesta weight, and increased digesta weight in regions of the GIT distal to the rumen.…”

Form of calf diet and the rumen. II: Impact on volatile fatty acid absorption

“…On the final day of the trial, each calf underwent a washed rumen procedure adapted from Storm et al (2011). The procedure involved evacuating the rumen using a vacuum-assisted collection device, washing the rumen with warm tap water and warm wash buffer (Table 2), and then filling the rumen with an experimental VFA buffer (Table 2) as described in Yohe et al (2018). For this, starting at 0 h the experimental VFA buffer was introduced (Table 2), the primer dose of LiCoEDTA (40 mL at 15 mg/mL) was given, an initial baseline sample of rumen fluid was collected, and then continuous LiCoEDTA infusion (0.158 mg/mL) was administered through the rumen cannula.…”

“…We then collected rumen fluid samples over the next 6 h to assess liquid passage rate (LiCoEDTA) and VFA absorption. The sampling procedure is described in detail by Yohe et al (2018), but briefly, in this study we obtained a total of 19 samples of rumen fluid (~5 to 10 mL per sample) using a 60 mL syringe, drawing fluid from the custom-made sampling device over the 6 h infusion/sampling period (starting with time 0) for VFA analysis and cobalt determination. The initial 5 to 10 mL drawn up by syringe were discarded (sample line dead volume).…”