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Supplementation of seaweeds improves the immune status of milk-fed Holstein calves.

M. B. Samarasinghe

Abstract:

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Supplementation of seaweeds improves the immune status of milk-fed Holstein calves.
M. B. Samarasinghe*, M. Vestergaard, J. Sehested, T. Larsen, L. E. Hern�ndez-Castellano. Department of Animal Science, Aarhus University, Foulum Tjele, Denmark.

Seaweeds are used as functional feed ingredients as they contain a variety of complex polysaccharides, vitamins, chelated minerals and antioxidants, which are known to promote immune status, hence health and growth of humans and livestock. This experiment aimed to study the systemic immune status of calves fed milk supplemented with either Ulva lactuca, Ascophyllum nodosum, or Laminaria saccharina. Forty Holstein calves in 10 blocks of 4 with birth BW 41 � 4 kg and plasma BRIX% ≥ 8.7% 2 d after birth were used. Calves were fed 4 L of cow milk twice a day (8 L/day). From d 2 until d 28, calves in the control group (CTRL, n = 10) received milk without seaweed. Experimental calves received milk supplemented with either Ulva lactuca (SW1, n = 10), Ascophyllum nodosum (SW2, n = 10) or Laminaria saccharina (SW3, n = 10). Dried and ground seaweeds were offered in a concentration of 25 g/4 L of milk. Blood samples were collected from the jugular vein on d 2, 4, 7, 14, 21, and 28 after birth. Plasma concentrations of immunoglobulins, serum amyloid A (SAA) and tumor necrosis factor α (TNF-α) were analyzed by ELISA, fibrinogen (Fib) by immune reaction and turbidimetry, and total protein, albumin and haptoglobin by spectrophotometric methods. The statistical model included the effect of treatment, sampling day, and their interaction, block and calf. Autoregressive covariance structure was applied for repeated measurements. No differences in ADG were detected between the groups (0.9 � 0.03 kg/day) during this study. However, plasma concentrations of Fib (P = 0.05) and SAA (P = 0.04) were significantly different between treatment groups and there was a tendency for TNF-α (P = 0.07). At d 14, Fib was significantly higher in calves fed with SW1 (5.7 � 0.5 g/L) and SW2 (5.4 � 0.5 g/L) compared with the CTRL group (3.9 � 0.5 g/L). In addition, plasma SAA was significantly higher in SW2 (181 � 31 mg/L) and SW3 (214 � 31 mg/L) calves than in CTRL calves (103 � 31 mg/L) at d 14. These results indicate that milk supplementation with seaweeds improves the systemic immune status in milk-fed calves.

Keywords: seaweed, immunity, calf.