Xylazine administered in a low dose to cows preceding lateral recumbency for claw trimming decreased hormonal and metabolic stress responses, but augmented the respiratory depressive effect of lateral recumbency reflected by a decreased Pao and increased Paco(2).

The objective was to evaluate the analgesic efficacy of pre- and postoperative administration of meloxicam on the postsurgical convalescence period of lame dairy cows undergoing resection of the coffin joint. In a blinded, placebo-controlled, explorative clinical trial, 19 lame German Holstein-Friesian cows weighing 536 ± 98 kg (mean ± SD) and aged 5.7 ± 2.8 yr were included. All cows suffered from unilateral lameness due to septic arthritis of the coffin joint. Lame cows were randomly allocated to either the meloxicam group (n=9) or the control group (n=10) and received an intravenous injection of meloxicam (0.5mg/kg of BW) or an equal volume of saline immediately before surgery (d 0) and once daily from d 1 to 4. All cows received a retrograde intravenous local anesthesia (20 mL of procaine 2%) before the surgical intervention. Heart rate, respiratory rate, body temperature, plasma concentrations of cortisol, as well as production parameters (milk yield and feed intake) were evaluated from d 0 to 7. The gait of the animals was assessed daily by lameness scores and by monitoring the cows' activity by means of pedometers attached to both hind legs. Possible adverse effects on abomasal mucosal integrity were monitored by fecal occult blood tests and blood cell counts from d 0 to 7 and on d 14. Under meloxicam treatment plasma cortisol levels, lameness scores, and body temperature were significantly reduced compared with controls. While being treated with meloxicam, the time cows were standing per day was significantly longer compared with controls. In the healthy limb significantly more steps were registered in meloxicam-treated cows than in controls. Feed intake and milk yield were not significantly affected by meloxicam. No group differences were found in number of positive tests for fecal occult blood or blood cell counts. In conclusion, repeated meloxicam application demonstrated effective analgesia in the postsurgical period after resection of septically infected coffin joints in dairy cows without indications of evoking adverse effects on abomasal integrity.

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Dairy cattle will mobilize large amounts of body fat during early lactation as an effect of decreased lipogenesis and increased lipolysis. Regulation of lipid metabolism involves fatty acid synthesis from acetate and β-adrenergic-stimulated phosphorylation of hormone-sensitive lipase (HSL) and perilipin in adipocytes. Although basic mechanisms of mobilizing fat storage in transition cows are understood, we lack a sufficiently detailed understanding to declare the exact regulatory network of these in a broad range of dairy cattle. The objective of the present study was to quantify 1) protein abundance of fatty acid synthase (FAS), 2) extent of phosphorylation of HSL and perilipin in vivo, and 3) β-adrenergic stimulated lipolytic response of adipose tissues in vitro at different stages of the periparturient period. We fed 20 German Holstein cows an energy-dense or an energetically adequate diet prepartum and 0 or 24 g/d nicotinic acid (NA) supplementation. Biopsy samples of subcutaneous and retroperitoneal adipose tissue were obtained at d 42 prepartum (d -42) and at d 1, 21, and 100 postpartum (d +1, d +21, d +100, respectively). To assess β-adrenergic response, tissue samples were incubated with 1 μ isoproterenol for 90 min at 37°C. The NEFA and glycerol release, as well as HSL and perilipin phosphorylation, was measured as indicators of in vitro stimulated lipolysis. In addition, protein expression of FAS and extent of HSL and perilipin phosphorylation were measured in fresh, nonincubated samples. There was no effect of dietary energy density or NA on the observed variables. The extent of HSL and perilipin phosphorylation under isoproterenol stimulation was strongly correlated with the release of NEFA and glycerol, consistent with the functional link between β-adrenergic-stimulated protein phosphorylation and lipolysis. In the nonincubated samples, FAS protein expression was decreased at d +1 and d +21, whereas HSL and perilipin phosphorylation increased from d -42 to d +1 and remained at an increased level throughout the first 100 d of lactation. In vitro lipolytic response was significant in prepartum samples at times when in vivo lipolysis was only minimally activated by phosphorylation. These data extend our understanding of the complex nature of control of lipolysis and lipogenesis in dairy cows and could be useful to the ongoing development of systems biology models of metabolism to help improve our quantitative knowledge of the cow.