Effect of Dietary Supplementation of Mannan Oligosaccharide on Gut Morphology of Pre-Weaning Calves

Calf raising is a costly and labor-intensive area of animal production.The gastro-intestinal tract of new born animals is specialized to a diet consisting of milk.However, milk supply to pre-weaning calves in Pakistan is limited because farmers primarily use calves to activate milk letdown and subsequently collect it for sale.It results in poor growth and high mortality rate in calves.The aim of this study was to investigate the effects of mannan oligosaccharides (MOS) inclusion in the diet of dairy-calves, focusing on their growth parameters and plasma indicators related to the development of rumen.For experimental study 20 Holstein calves aged 4-5 days were purchased from local dairy farm and were equally divided into 2 groups.The trial was conducted under standard management conditions for 56 days.From the first to the sixth week, the calves received milk twice a day in an amount of 10% of their body weight.During the week 7 and 8, milk allowance was reduced to 5.0% and 2.5% of the body weight, respectively.Non-significant differences (p>0.05) were noted in physical parameters of the small intestine (SI), including villus height, width, surface area, lamina propria thickness, crypt depth, and thickness of the tunica muscularis between control and MOS-treated groups.Similarly, nonsignificant difference (p>0.05) was found in intraepithelial lymphocytes count amongst control and treatment groups, although their numbers were persistently elevated in the MOS-group.In the jejunum, the number of acidic goblet cells was significantly higher (p < 0.05) in the MOS-supplied group than in the control group.This suggests that feeding MOS partially improved the intestinal morphology of preweaning calves.