Effect of orally administered duodenal fluid susceptibility of newborn calves to an Escherichia coli challenge

Heat-treated colostrum and reduced morbidity in preweaned dairy calves: results of a randomized trial and examination of mechanisms of effectiveness

A randomized controlled clinical trial was conducted using 1,071 newborn calves from 6 commercial dairy farms in Minnesota and Wisconsin, with the primary objective being to describe the effects of feeding heat-treated colostrum on serum immunoglobulin G concentration and health in the preweaning period. A secondary objective was to complete a path analysis to identify intermediate factors that may explain how feeding heat-treated colostrum reduced the risk for illness. On each farm, colostrum was collected each day, pooled, and divided into 2 aliquots; then, one aliquot was heat-treated in a commercial batch pasteurizer at 60°C for 60 min. Samples of fresh and heat-treated colostrum were collected for standard microbial culture (total plate count and total coliform count, cfu/mL) and for measurement of immunoglobulin G concentrations (mg/mL). Newborn calves were removed from the dam, generally within 30 to 60 min of birth, and systematically assigned to be fed 3.8L of either fresh (FR, n=518) or heat-treated colostrum (HT, n=553) within 2h of birth. Venous blood samples were collected from calves between 1 and 7d of age for measurement of serum IgG concentrations (mg/mL). All treatment and mortality events were recorded by farm staff between birth and weaning. Regression models found that serum IgG concentrations were significantly higher in calves fed HT colostrum (18.0 ± 1.5 mg/mL) compared with calves fed FR colostrum (15.4 ± 1.5 mg/ml). Survival analysis using Cox proportional hazards regression indicated a significant increase in risk for a treatment event (any cause) in calves fed FR colostrum (36.5%, hazard ratio=1.25) compared with calves fed HT colostrum (30.9%). In addition, we observed a significant increase in risk for treatment for scours in calves fed FR colostrum (20.7%, hazard ratio=1.32) compared with calves fed HT colostrum (16.5%). Path analysis suggested that calves fed HT colostrum were at lower risk for illness because the heat-treatment process caused a significant reduction in colostrum total coliform count, which was associated with a reduced risk for illness as a function of improved serum IgG concentrations.

Problems of calf rearing in connection with their mortality and optimal growth: A review

Protection of calves against enteric and respiratory disorders is dependent on the passive immunity that the calf has received, its innate resistance to infection, the burden of infection in the environment and the nutrition of the calf. Superimposed on these, are the effects of management and physical environment.

The plane of nutrition required for dairy heifers during rearing depends on the age at first calving, and for meat animals depends on the carcass weight and fat deposition required at a particular slaughter date in relation to time of birth.

Effect of purified immunoglobulins or pooled colostrum on performance of rearing calves

Fifty Belgian white-blue male calves, purchased from the market at about 10 days of age, were divided into three groups. The basic diet was the same for all calves, and consisted of a restricted amount of commercial milk replacer containing 50 ppm zinc bacitracin and 20 pm virginiamycin, calf starter and grass hay. Weaning occurred when daily starter intake over 7 consecutive days averaged 0.5 kg. Maximum starter intake was restricted to 3 kg day^-1, and grass hay was fed ad libitum. The experiment lasted 20 weeks. Group 1 (control) received the basic diet. Groups 2 and 3 were supplemented with either 2 g purified immunoglobulins (Ig) or 25-ml pooled colostrum (CO) twice daily, via the milk replacer as used in Group 1. Neither Ig nor CO exerted a positive effect on growth rate and feed efficiency. Six calves died: two, one and three in Groups 1, 2 and 3, respectively. Their serum IG content was significantly lower than that of the surviving animals. Mechanisms explaining the lack of any protective effect are discussed. It is supposed that the main reason was due to the gap between the CO feeding at birth and the onset of the administration of Ig or CO at the start of the experiment. At that time, 31 of the 50 calves excreted rota-and/or coronaviruses.

Influence of administered indigenous microorganisms on uptake of [iodine-125] gamma-globulin in vivo by intestinal segments of neonatal calves

Ten calves less than 14 h of age (average 8.6 h) were anaesthetized, and the intestine was ligated into segments 10 cm in length at 3-cm intervals beginning 1.8 m anterior of the ileocecal junction and proceeding proximally. Seven treatments were assigned in random order to segments in three successive sections of the small intestine. Segments received 1 ml of viable bacteria of intestinal origin, autoclaved bacteria of intestinal origin, or sterile microbiological broth at zero time; then after 4 h they were injected with iodine-125 labeled gamma-globulin. After an additional 1.5 h, the experiment was ended and uptake assayed. Two treatments measured anaerobic microbial growth after 4 h incubation with 1 ml of either sterile broth or live bacteria culture. Residual [iodine-125] gamma-globulin was measured in segments receiving 1 ml of sterile broth or live bacteria culture with 5.5-h incubation followed by 15-s exposure to labeled gamma-globulin. Uptake was lowest in segments receiving live bacteria as compared to segments receiving sterile inocula. Number of bacteria per gram of tissue was correlated negatively with uptake. Low corticosteroids in serum were associated with low uptake of gamma-globulin.

Symposium: disease prevention in calves. Factors affecting susceptibility of calves to disease

Enteric and respiratory disorders are the main hazards to successful calf rearing. The many interrelated factors in the etiology of these disorders are reviewed, and an attempt has been to classify the factors into those of a microbiological, immunological, nutritional, genetic, physical, or psychological nature. No one would dispute that enteric and respiratory disorders are the two main hazards to calf health, but many would argue about the relative importance of specific pathogens and other predisposing factors in the etiology of these disorders.

Effect of orally administered duodenal fluid on serum proteins in neonatal calves

This study was to determine if orally administered duodenal fluid, as a source of intestinal microorganisms, would influence absorption of gamma-globulin of colostrum in newborn calves. Duodenal fluid was obtained 2 h postfeeding from a cannulated milk-fed calf. Twenty-seven male and female Holstein calves obtained within 6 h of birth were assigned randomly to one of three treatments: 1) colostrum alone, 2) 200 ml duodenal fluid immediately followed by colostrum, and 3) 200 ml duodenal fluid followed 3 h later by colostrum. Pooled colostrum was fed at 10% of body weight in two daily feedings. Total protein, albumin, alpha-globulin, beta-globulin, and gamma-globulin of blood serum were determined prior to colostrum consumption, and again 24 and 48 h after administration of duodenal fluid. Total proteins, beta-globulin, and gamma-globulin of serum increased with age in all calves. Inocula interference with absorption was indicated by depressed values of serum in calves of treatment 3 as compared to treatment 1 calves for protein (5.28 to 6.28 g/dl), beta-globulin (.67 to .87 g/dl), and gamma-globulin (.76 to 1.33 g/dl). Protein was also lower in calves of treatment 3 (6.05 g/dl) compared to uninoculated calves (6.28 g/dl). Malabsorption of colostral proteins may be related to early establishment of large numbers of intestinal microorganisms in the newborn calf.