Effect of curd suppression in a milk replacer on physiological parameters in calves. II. Selected blood profiles

Abstract

Fourteen Holstein calves, two to four days of age, were randomly divided into two groups to determine the effect of abomasal curd suppression on selected blood profiles. Calves received a milk replacer in which casein coagulation either was normal (CM), or was prevented by the precipitation of Ca++ with an oxalic acid - sodium hydroxide buffer (NCM). Jugular blood samples were taken before the morning feeding (0 h), as well as at 1, 2, 4 and 6 h postfeeding. Fasting (0 h) plasma free essential amino acid (EAA) concentration tended to be higher for the CM treatment than for the NCM treatment, while the contrary was observed for postprandial values up to 6 h post-feeding. Plasma EAA concentration increased significantly during the fIrst hour post-feeding for the NCM treatment, whereas values remained fairly constant for the CM treatment. Plasma triglyceride concentration was signifIcantly higher for the CM treatment at 0, 4 and 6 h post-feeding, while it was higher for the NCM treatment at 1 h post-feeding. The fasting plasma glucose concentration was similar for both treatments. Plasma glucose was significantly higher for the CM treatment at 2 h post-feeding, but the contrary was observed thereafter. For the CM treatment, the plasma glucose profile almost mirrored the triglyceride profile. It was concluded that profiles of plasma free EAA and triglycerides may be reliable indicators of in vivo curd-forming ability of a given milk replacer, and that abomasal curd suppression may have a detrimental effect on amino acid and caloric homeostasis.

Veertien Holsteinkalwers, tussen twee- en vier-dae-ouderdom, is ewekansig in twee groepe verdeel om die invloed van voorkoming van stolselvorming in die abomasum op geselekteerde bloedprofiele te bepaal. Een melksurrogaat is geformuleer en kaselenkoagulering is in die een behandeling (NCM) voorkom deur presipitering van Ca++ met 'n oksaalsuur-natriumhidroksiedbuffer. Die ander groep kalwers (CM) het onbehandelde (koaguleerbare) melksurrogaat ontvang. Bloedmonsters is voor die oggendvoeding (0 h), asook I, 2, 4 en 6 h na voeding geneem. Vastende (0 h)
plasmavrye essensiele-aminosuur(EAA)-konsentrasie het geneig om hoer te wees vir die CM-behandeling as vir die NCM-behandeling, terwyl die teenoorgestelde waargeneen is vir die periode tot 6 h na voeding. Met die NCMbehandeling het die plasma-EAA-konsentrasie betekenisvol toegeneem gedurende die eerste uur na voeding, terwyl dit redelik konstant gebly het met die CM-behandeling.  Plasmatrigliseriedkonsentrasie was betekenisvol hoer vir die CMbehandeling
by 0, 4 en 6 h na voeding as vir die NCM-behandeling, terwyl die teenoorgestelde 1 h na voeding waargeneem is. Vastende plasmaglukosekonsentrasie was dieselfde vir albei behandelings. Een uur na voeding het die plasmaglukosewaardes geneig om hoer te wees vir die CM-behandeling en 2 h na voeding was dit betekenisvol hoer
as vir die NCM-behandeling. Die teenoorgestelde is 4 en 6 h na voeding  waargeneem. Vir die CM-behandeling was die plasmaglukoseprofiel feitlik die omgekeerde van die trigliseriedprofiel. Die gevolgtrekking is gemaak dat plasmavrye EAA- en trigliseriedprofiele moontlik betroubare indikators van in vivo  stollingsvermoe van 'n gegewe melkvervanger kan wees, en dat voorkoming van abomasale stolselvorming moontlik 'n nadelige invloed op die handhawing van aminosuur- en kaloriese homeostase kan he.

Keywords: Blood profiles, calves, casein curd formation, milk replacers, plasma free amino acids, plasma glucose, plasma triglycerides.