Lactoferrin is a milk protein that exhibits broad-spectrum antimicrobial properties. Previous studies indicated that supplemental lactoferrin may alter the microbial populations in the gut of nonruminants and increase preweaning weight gains in calves. In the present study, 40 Holstein calves were used to examine the effects of supplemental lactoferrin (0, 1, 2, or 3 g/d) on health, growth, and feed intake from 3 d of age to 2 wk postweaning. Lactoferrin was mixed and fed with a nonmedicated milk replacer. Calves were housed in individual pens and offered a textured, nonmedicated starter and water for ad libitum consumption. Body weight and heart girth were measuredweekly. Intakes of milk replacer and starter were determined daily. Fecal consistency was monitored three times per week. Calves were weaned when they met certain criteria based on body weight gain and starter intake. Preweaning fecal score responded quadratically, with the group fed 1 g/d of lactoferrin having the lowest score. Overall and preweaning number of days medicated responded in the same manner as fecal score. Preweaning average daily gain and gain-to-feed ratio increased linearly with lactoferrin supplementation, whereas postweaning gain-to-feed ratio decreased linearly with lactoferrin. Overall average daily heart girth gain increased linearly with lactoferrin. Body weight, weaning age, and dry matter intake were not different among treatments. Based on the observed improved gain-to-feed ratios, increased average daily gains, improved fecal scores, and reduced morbidity in preweaned calves, it appears that lactoferrin may be a beneficial supplement in the diets of neonatal calves prior to weaning.

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Can. J. Anim. Sci.65:613-618 (Sept. 1985) 6r3 Can. J. Anim. Sci. Downloaded from www.nrcresearchpress.com by 34.210.69.67 on 05/10/18For personal use only.

No abstract

Groups of 10 lambs were fed either a control diet or a diet consisting of 10% polyethylene at isoenergetic levels for 30 d to study the effect of dietary bulk on visceral organ mass and metabolism of mucosa from the jejunum and proximal colon. Fasting heat production was measured using an additional six lambs. Weights of the large intestine, stomach complex and lungs were greater in lambs fed the polyethylene diet than control lambs. Liver and small intestine weights were not affected by diet. Oxygen consumption rates of jejunal mucosa were not affected by diet while a trend existed for oxygen consumption rates of mucosa from the proximal colon to be increased due to feeding polyethylene. Na+,K+ ATPase activity of mucosa from both jejunum and colon was increased due to feeding polyethylene. Fasting heat production, oxygen consumption or carbon dioxide production did not differ with diet. Dietary bulk affects growth and metabolism of visceral organs but metabolic modifications appear different among tissues.