Factors Affecting Lipid Output and Flow of Thoracic Duct Lymph in Newborn Calves

Abstract

The factors affecting lipid absorption in unanaesthetized calves less than 24 hr old have been studied by comparing the output of lipid in the thoracic duct lymph of calves fed one of the following diets: (1) colostrum, in which the colostral fat was replaced with milk fat globules; (2) milk; (3) colostral whey containing milk fat globules; (4) isotonic saline containing milk fat globules. The animals were fed after they had recovered sufficiently from the operation to stand and suck from a nipple feeder.In calves fed diets 1 and 2 the maximum output of lipid in lymph occurred 12 and 6 hr after feeding respectively. In contrast, lipid absorption in calves fed the casein-free diets 3 and 4 was rapid, the maximum output of lipid in lymph occurring at 2-3 hr. It is apparent from these results that newborn calves are capable of absorbing large quantities of lipid and that the delayed absorption associated with colostrum and milk feeding was a function of casein concentration.The lipid in all diets was absorbed with equal efficiency. It was evident from a comparison of the rate and efficiency of lipid absorption in calves fed diets 3 and 4 that factors in colostrum known to be associated with enhanced protein absorption do not significantly influence lipid absorption.Immediately prior to feeding, lymph flow had reached comparatively stable values of 536±5·4 ml/hr (mean ± S.E.) for 13 calves. Flow increased almost twofold within the first 2-3 hr after feeding colostrum and remained elevated for a further 3-4 hr. This occurred in the absence of significant lipid absorption but it was associated with an increase of up to threefold in globulin concentration of lymph. In contrast there was little change in flow over the first 4 hr after feeding milk, although lymph flow increased up to 1· 5-fold at 5-6 hr, corresponding with the peak of lipid absorption.

Concurrent studies of the flow of digesta in the duodenum and of exocrine pancreatic secretion of calves

“…In our experiments, failure of the diet to clot due to the inclusion of non-milk proteins results in the abomasal outflow of large amounts of lipid in the early post-prandial period, so that lipid outflow and the TG:'non-polar' lipid values were related. The peak flow of esterified fatty acids in the thoracic duct of young calves given fatty whey with little coagulable protein has been shown to occur 3 h earlier than when whole milk was given (Gooden et al 1971). In addition, Gibney & Walker (1977) found for preruminant lambs that digestibilities of the fatty acids of coconut oil were lower (especially the longer-chain acids) when soya-bean-protein-based diets rather than milk-protein-based diets were fed.…”

ADSA Foundation Scholar Award: New frontiers in calf and heifer nutrition—From conception to puberty

“…Colostrum has a high fat content [5.7-6.4% vs. 4.3% in whole milk (WM); Dunn et al, 2017;Fischer-Tlustos et al, 2020] that is readily absorbed (Gooden et al, 1971) to support thermoregulation and the rapid metabolism of a newborn calf (Vermorel et al, 1983). Colostrum also contains a distinct fatty acid (FA) profile compared with WM, with higher levels of polyunsaturated and n-3 FA, and lower concentrations of saturated short-chain FA (Contarini et al, 2014;McGrath et al, 2016;O'Callaghan et al, 2020).…”

Effects of colostrum management on transfer of passive immunity and the potential role of colostral bioactive components on neonatal calf development and metabolism

“…Colostral fat is readily absorbed by the small intestine in neonatal calves (Fig. 1B) in a manner similar to that of mature ruminants (Gooden et al, 1971). The post-absorptive effect of specific colostral FA on neonatal calf development is generally understudied and mainly focused on ω-FA (Garcia et al, 2014(Garcia et al, , 2016Coleman et al, 2018;Opgenorth et al, 2020;Ricks et al, 2020).…”