Research Note: Postnatal Development of Electrolyte Transport in Calf Rumen as Affected by Weaning Time

Abstract

In a previous study we found a positive correlation between early weaning in calves and morphological parameters which were indicative of ruminal development, i.e. the length and width of the papillae. The objective of the present study was to determine to what extent this observation could be reflected by modulations of absorptive and secretory functions of the rumen mucosa. For this purpose the short-circuit currents (Isc) as a measure of electrogenic net ion fluxes and the transepithelial conductances (G(T)) as a measure of the overall tissue permeability were measured in vitro applying the Ussing-chamber technique. Simultaneously, the unidirectional flux rates of sodium and chloride across rumen wall epithelia were determined in the absence of electrochemical gradients. Under these conditions, significant positive net flux rates (Jnet) clearly indicate active mechanisms for electrolyte absorption. For the experiments 12 male Holstein calves 7 d of age were assigned to three groups of 4 animals each: milk group (I, slaughtered after 6 weeks of age), late weaning group (II, slaughtered after 9 weeks of age) and early weaning group (II, weaned after 6 weeks of age and slaughtered after 9 weeks of age). Whereas G(T) values remained unaffected by different age and feeding, Isc values were significantly affected by early weaning but were not influenced by age. Irrespective of weaning time active absorption of Na+ tended to be higher by about 60% in 9 weeks old animals. Active absorption of chloride was significantly increased in milk fed 9 weeke old calves and this effect was further stimulated by early weaning. In conclusion, the data show an increasing active Na+ absorption with age in calf rumen that could not be influenced by early weaning. Similarly, active Cl- absorption was initially increased during postnatal development and this effect could be stimulated further by early weaning.

Short communication: Transport of 2-hydroxy-4-methyl-thio-butanoic isopropyl ester by rumen epithelium in vitro

“…The I sc and G t values varied between 0.2 and 0.5 μEq/cm 2 per hour and 5.5 and 7.0 mS/cm 2 , respectively. These results are comparable with data from other studies using ruminal epithelia from sheep and goats (Schröder et al, 1997(Schröder et al, , 1999 and from calves and cattle (Sehested et al, 1999;Breves et al, 2002) for transport measurements as well as characterization of short-chain fatty acid metabolism. At the conclusion of the incubations, the remaining ruminal and serosal solutions (13 mL) were collected and kept at −20°C until analysis, as were rumen epithelial samples.…”

Differences in monocarboxylic acid transporter type 1 expression in rumen epithelium of newborn calves due to age and milk or milk replacer feeding

“…() noticed 14 times higher MCT1 protein abundance in 2‐week‐old goats as compared to kids being 1 day old. However, to which extent development of absorptive functions of the rumen epithelium is regulated ontogenetically and to which extent it is determined by nutritional factors are still debatable (Breves et al., ; Lane et al., ). Indisputably, those two factors are related, but, unfortunately, confounded.…”

“…Furthermore, a significant correlation between solid feed intake, SCFA concentration in the rumen and MCT1 protein expression, both in the dorsal and ventral sac of the rumen was shown, supporting an importance of solid feed intake for forestomachs development. On the other hand, some functional features of the rumen epithelium may develop independently of solid feed intake (Breves et al., ; Lane et al., ; Pfannkuche et al., ), and they may be affected by the type of liquid feed (milk or milk replacer) or amount of liquid feed consumed (Górka et al., ; Naeem et al., ).…”

“…In ruminants, solid feed intake and solid feed composition are considered as the main factors affecting rumen epithelium functions, both in adult and newborn animals (Baldwin et al, 2004;Penner et al, 2011). In newborn animals, solid feed intake enhances rumen papillae growth and some functional features of the rumen epithelium (Baldwin, 2000;Breves et al, 2002). This is especially apparent when solid feed rich in starch and simple sugars easily fermented in the rumen are offered (Lesmeister and Heinrichs, 2005;Laarman et al, 2012).…”

Diet induced ruminal papillae development in neonatal calves not correlating with rumen butyrate

“…SCFA are chemical stimuli for the development of rumen epithelium, promoting its structural development and absorption activity (Kauffold et al, 1977;Jesse et al, 1995;Zitnan et al, 1998;Lesmeister and Heinrichs, 2004 In a previous study we demonstrated a positive correlation between early weaning and progress of the morphological development of the rumen epithelium, as characterized by the number of papillae as well as their length and width (Zitnan et al, 1999). A recent report indicates similar ontogenic and physiological effects on sodium and chloride transport in the developing calf rumen epithelium (Breves et al, 2002). Increased sodium and chloride transport by the developing rumen epithelium could reflect an increase in the SCFA absorptive capacity by the rumen epithelium (Sehested et al, 1999).…”