Metabolic and Lactational Responses during Recombinant Bovine Tumor Necrosis Factor-α Treatment in Lactating Cows

Abstract

This study examined the effects of recombinant bovine tumor necrosis factor-alpha (rbTNF) administration on metabolic and hormonal responses and lactational performance in dairy cows. Twelve lactating Holstein cows were injected subcutaneously with rbTNF (2.5 microg per kg per d) or saline (3 ml per head per d) at 1200 h daily for 7 d (d 0-6) and used in a crossover design. The rbTNF treatment induced increases in plasma haptoglobin, nonesterified fatty acid, cortisol, and growth hormone levels compared with the control levels. The rbTNF-treated cows had lower triiodothyronine and insulin-like growth factor-1 concentrations than control cows. In a somatoliberin challenge on d 6, the somatotropin response to somatoliberin (0.25 microg/kg) was smaller in the rbTNF group than in the control. The rbTNF treatment also produced increases of the nitrite plus nitrate concentration in plasma and milk during the period between d 1 and 7. Milk yield was reduced by rbTNF administration from d 1 to 8. The percentage of milk fat was increased on d 1-7 by rbTNF treatment, but milk protein content in the rbTNF group was decreased on d 5 and 7 as compared with that in the control group. These results support the possibility that tumor necrosis factor-alpha is responsible for the changes in hormone secretion, milk production and composition, and inflammatory parameters observed during coliform mastitis.

Temporal gene expression profiling of liver from periparturient dairy cows reveals complex adaptive mechanisms in hepatic function

“…It is well established in humans that IL-1␤ has appetite-depressing effects, whereas plasma concentrations of TNF-␣ are associated with increased energy expenditure (41). Recombinant bovine TNF-␣ administration to lactating cows increased serum haptoglobin, NEFA, cortisol, growth hormone, and nitric oxide and decreased feed intake (25). Some of these conditions closely resemble responses that we and others have observed during the periparturient period (17), as well as in response to endotoxin administration (46).…”

Chemerin is a novel regulator of lactogenesis in bovine mammary epithelial cells

“…As TNF-a has a proinflammatory effect and impairs insulin sensitivity, its role in metabolic disease is well understood [31]. In the lactating cow, TNF-a plays an important role in the immune response in mastitis and has a negative effect on milk yield [32,33]. Given CCRL2 acts in the immune response through chemerin signaling [34,35], upregulation of CCRL2 by TNF-a may facilitate chemotaxis of immune cells in the mammary gland in case of inflammation; meanwhile, suppression of CMKLR1 expression by TNF-a might be related to the negative effect of TNF-a on lactation.…”

Serum amyloid A and TNF? in serum and milk during experimental endotoxin mastitis

“…TNFα not being found in serum may indicate that in cattle the systemic SAA production is not induced by TNFα but by some other cytokines, although the intradermal injection of recombinant bovine TNFα has been reported to cause some increase in the APP, namely haptoglobin [14,33]. IL-6 increases in the serum after LPS stimulation or E. coli mastitis [19,27], and it has been shown to be a potent inducer of hepatic production of SAA [2].…”