Effects of different energy intakes before and after calving on food intake, performance and blood hormones and metabolites in dairy cows

Abstract

An experiment with 25 dairy cows was performed to investigate the effects of different energy intakes on food intake, performance and blood hormone and metabolite levels during the last 70 days of pregnancy and the first 125 days after parturition. Compared with animals fed ad libitum before parturition, cows fed only according to requirements during the same time showed no decrease of food intake at calving. Cows fed at a restricted level also showed a faster increase in food intake, a smaller energy deficiency at the onset of lactation and a smaller weight loss after parturition. Peak milk yield was also lower, but the peak was maintained for a longer period, and during the first 2 months of lactation these cows had higher concentrations of glucose and lactic acid, and lower concentrations of non-esterified fatty acids and ketone bodies in the blood. Weight losses, and decrease of milk production during the 1st weeks of lactation were higher in cows fed only 0-75 of requirements during the first 60 days of lactation than in animals whose energy intake was planned to cover energy requirements, and during the first 2 months of lactation levels of unesterified fatty acids, ketone bodies and urea were higher, whereas levels of insulin, thyroxine and triiodothyronine were lower. Endocrine and metabolic changes seen during early lactation suggested improved glucose homeostasis, diminished fat mobilization and ketogenesis in cows .given reduced amounts of energy during the dry period compared to animals fed ad libitum. To prevent the development of acetonaemia an adequate energy supply during the first part of lactation is, however, of greater importance.

Metabolic response of early-lactating cows exposed to transport and high altitude grazing conditions

“…This explains reduced thyroid hormone levels during energy deficiency (Kunz et al, 1985;Ronge et al, 1988) but also increased levels at low ambient temperatures, as was found in the case of T 3 by Aceves et al (1987). Considering that ambient temperature was considerably lower at high altitude than at lowland (Christen et al, 1996), the effect of cold exposure on heat production (Sano et al, 1995) obviously exceeded the decrease in heat production expected in the state of deficient energy supply (Ortigues and Vermorel, 1996).…”

“…Concentrations of both metabolites were elevated directly from the start of alpine sojourn, although already at lowland plasma NEFA levels had indicated a catabolic situation as is characteristic for early-lactating cows (Kunz et al, 1985). The initial increase lasted for 2 (NEFA; only experiment 2) to 3 weeks (BHB).…”

Effects of live weight adjusted feeding strategy on plasma indicators of energy balance in Holstein cows managed for extended lactation

“…The same pattern was found for cows fed ad libitum before parturition and then fed restrictively according to requirements after calving (Kunz et al, 1985). These cows had higher concentrations of NEFA after parturition than cows fed the same restricted diet before and after parturition and indicated an increase in ketone bodies (Kunz et al, 1985).…”

Metabolic changes in early lactation and impaired reproductive performance in dairy cows

“…They also reach their maximum dry matter intake, that usually occurs between 12 to 16 weeks post partum [23], later in lactation [40]. Also, a less pronounced depression of feed intake around parturition has been related to restricted feeding in the dry period and lower BCS of dry cows [39,59]. This means that high BCS during the dry period, results on average in a more severe and probably also longer lasting cNEB in these cows and should therefore regarded as risk factor for non adaptation.…”