Ultrasonography of the reticulum, rumen, omasum, and abomasum in 10 calves before, during, and after ingestion of milk

Abstract

The reticulum, rumen, omasum, and abomasum were assessed via ultrasonography before, during, and 15, 30, and 120 minutes after feeding milk to 10 healthy calves. The ultrasonographic examinations were conducted using a 5.0 MHz linear transducer. Loops were recorded on video for further evaluation. The reticulum could be visualised before feeding in seven calves. Its appearance and pattern of contractions were similar to those in adult cattle, although the amplitude (1.7 ± 0.75 cm) and velocity (2.7 ± 1.34 cm/s) of the first contraction were smaller than in adult cattle. The reticulum could not be visualised in any of the calves during feeding as it was displaced cranially and laterally and therefore being obscured by the lungs as the abomasum expanded with the ingested milk. 2 hours post ingestion it remained obscured in 5 individual and was visualized again the other 5. The position and size of the entire rumen including the dorsal and ventral sacs and the ruminal contents were assessed. There were no changes in the ultrasonographic appearance of the rumen during or after feeding. Except for its smaller size, the ultrasonographic appearance of the omasum of calves was similar to that of adult cattle. Milk flow through the omasum could not be seen in any of the calves, and there were no changes in the appearance of the omasum during and after feeding. The abomasum was seen to the left and right of the ventral midline before feeding in all calves; it occupied considerably more space on the left than the right. The flow of milk into the abomasum and milk clotting, which occurred 15 minutes after feeding, could be seen in all calves. The milk clots started to slowly disintegrate 30 minutes after the start of feeding, and by 2 hours post feeding, this process was greatly advanced but remained incomplete. Ultrasonography is an ideal tool for the evaluation of the reticulum, rumen, omasum, and abomasum before, during, and after the ingestion of milk in calves.

Ultrasonographic examination of the oesophageal groove reflex in young calves under various feeding conditions

“…The ultrasonographic findings of the reticulum and abomasum before feeding were the same as those described previously (Gautschi, 2010;Braun and Gautschi, 2012;Krüger, 2012; and the position and size of the organs corresponded to results of computed tomographic examinations (Schnetzler, 2012;Braun et al, 2014). The flow of milk into the abomasum during feeding was readily confirmed ultrasonographically (Gautschi, 2010;Braun and Gautschi, 2012;Krüger, 2012;; the stomach usually filled from cranial to caudal and the content was homogeneous and echoic.…”

“…The ultrasonographic findings of the reticulum, anterior blind sac of the rumen, rumen and abomasum before, during and after feeding were the same as those published earlier (Braun and Gautschi, 2012; and are only presented collectively here; they were described in detail elsewhere (Brammertz, 2014). The reticulum appeared as an empty crescent-shaped structure with an echoic wall before feeding.…”

“…2). Based on earlier studies (Braun and Gautschi, 2012;, functioning of the reflex was confirmed ultrasonographically when milk was seen entering the abomasum during feeding. For feedings, a 10-litre bucket with a rubber nipple was used.…”

“…Ultrasonographic examination of the reticulum, rumen, anterior blind sac of the rumen and abomasum was carried out as described earlier (Gautschi, 2010;Braun and Gautschi, 2012) in the standing calf using a 5.0-MHz convex transducer. The position, size and content of these organs were assessed before, during and after feeding milk.…”

“…This reflex causes the two lips of the groove to contract and rotate to form a tube while the reticulo-omasal orifice relaxes (Kaske, 2005). Ultrasonography is a non-invasive and straightforward technique for indirectly monitoring the oesophageal groove reflex; a functional reflex is confirmed ultrasonographically when milk is seen entering into the abomasum during feeding (Wittek et al, 2005;Braun and Gautschi, 2012;. Complete or partial failure of the oesophageal groove reflex can result from unnatural housing and feeding conditions (Kaske, 2005) or from neonatal disorders such as diarrhoea (Dirksen, 2006).…”