Health Status Of Calves Research Articles

Effects of Feeding Milk Replacer Ad Libitum or in Restricted Amounts for the First Five Weeks of Life on the Growth, Metabolic Adaptation, and Immune Status of Newborn Calves.

The pre-weaning period is critical for calf health and growth, and intensive milk feeding programs may assist postnatal development by improving body growth and organ maturation. The aim of the present work was to study the effects of ad libitum milk replacer (MR) feeding on the growth, metabolic adaptation, health, and immune status of newborn calves. Twenty-eight newborn Holstein and Holstein x Charolais crossbred calves were fed ad libitum (ADLIB) or in restricted amounts (6 liters per day; RES) during the first five weeks of life. The MR intake in the ADLIB treatment was gradually reduced at weeks 6 and 7, and all calves then received 6 liters of MR per day until day 60. Blood samples were collected to measure the plasma concentrations of metabolites, insulin, insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBP), immunoglobulins, and acute phase proteins. The expression of mRNA associated with both the somatotropic axis and gluconeogenic enzymes was measured in the liver on day 60. Intensive feeding improved MR intake and growth in ADLIB without influencing concentrate intake. Carcass weight, perirenal fat, and muscle mass were greater in ADLIB. Plasma concentrations of glucose, triglycerides, insulin, and IGF-I were greater, whereas plasma concentrations of β-hydroxybutyrate, total protein, albumin, urea, IGFBP-2 and -4, and fibrinogen were lower at distinct time points in ADLIB. The hepatic mRNA expression of cytosolic phosphoenolpyruvate carboxykinase was greater in ADLIB. Most metabolic and endocrine differences occurred during the MR feeding period, but a slightly greater concentrate intake was associated with increased plasma IGF-I and insulin at the end of the study. The immune and health status of the calves were not affected by MR feeding. However, increased plasma fibrinogen in the RES group suggested differences in the acute phase response.

The use of probiotics in cattle feeding: The health status of calves

The use of probiotics in cattle feeding: The health status of calves

Impacts of self- and cross-sucking on cattle health and performance.

Background:Improvement of dairy farms economics requires intensification, automatic milking, and artificial rearing methods. The ability to express normal behavior is one of the five freedoms to achieve animal welfare, whereas the display of abnormal behaviors is considered as an indicator of poor welfare. Cross-sucking is defined as sucking any body parts of pen-mate calves, whereas inter-sucking in cows is defined as sucking the udder or udder area. Previous studies showed that self- and cross-sucking during the calf-hood period could be a causal factor of milk sucking in adulthood.Aim:To investigate the effects of cross-sucking among calves and inter-sucking in cows on animal health status and performance.Materials and Methods:Gathering information from customized questionnaires, the study of the breeding records, recording of self- and cross-sucking behaviors, and health status of calves till weaning, and dairy cows before milking were performed in two governmental farms under the same managemental conditions in Sohag and Qena governorates.Results:Cross-sucking appeared in calves at the 2nd week of age followed by abscesses at ears and navels that were observed within cross-sucker calves. Milk sucking was higher in primiparous than multiparous cows during the second lactation period, as primiparous cows start to suck mostly around the 4th month of milking. Mastitis and elongation of the front teats were observed in sucker cows. Suffered animals had body condition scoring 3.5 or less. Interestingly, most of the cows displaying self-sucking were sucking another cow and were experienced self- or cross-sucking in their calf-hood. The use of pronged nose-rings was ineffective in preventing milk sucking and all cows were ultimately culled at the end of the season.Conclusion:The results of this study demonstrate the health problems of abnormal oral behaviors in terms of developed ears and navels abscesses in cross-sucker calves, and mastitis and teat deformities in milk-sucker cows. Furthermore, indexes that lead to oral satisfaction should be taken in priorities of farm managers to effectively reduce or prevent cross-sucking in calves. Culling of cows and heifers suffering from sucking would be the ultimate uneconomic alternative in case of persistent suckers.

Impact of early castration and health status on the performance of Holstein-Friesian and beef crossbred calves

Abstract Introduction: This article presents the analysis of the correlation between the category and health status of calves and the results of their rearing and levels of selected blood parameters. Material and Methods: The study included 105 Polish Holstein-Friesian and beef (Limousine, Charolaise and Hereford) crossbred calves. Young bulls were purchased at the age of two to four weeks. The animals underwent quarantine, were dehorned, and 46 young bulls were castrated. The germ horns were removed by burning out. Castration was carried out with a bloodless method using a rubber band. The calves were kept in groups and fed a milk replacer administered via teats from automated milk-feeding stations. After the period of milk feeding, the calves were fed grass silage ad libitum and a concentrate at 2.5 kg/animal/day. The calves were weighed every two weeks. Blood for analyses was sampled at 43 d of age. Results: After the rearing period finished at the age of six months, young bulls and steers had similar body weights (176.17 and 176.55 kg) and approximate average daily weight gains from birth (0.756 and 0.767 g/day). The healthy calves at six months of age weighed 180.47 kg, whereas the animals which at least once suffered from some diseases during rearing were lighter by approx. 30 kg (P ≤ 0.01). A statistically significant (P ≤ 0.01) difference was found for the count of red blood cells and white blood cells. In comparison with healthy individuals, the diseased animals had less RBC (8.33 and 9.42 1012/L respectively) and more WBC (27.03 and 12.26 109/L respectively). Conclusion: Castration of young bulls did not have any impact on the results of rearing and health status of the calves. The magnitude of the analysed parameters depended on the health status of the calves. Thus RBC and WBC parameters may be used to predict the health status of calves during rearing.

Colostrum and milk pasteurization improve health status and decrease mortality in neonatal calves receiving appropriate colostrum ingestion

The objective of the study was to evaluate if on-farm heat treatment of colostrum and bulk tank milk can improve calf health status and morbidity and mortality rates during the first 21d of life in neonatal Holstein calves receiving appropriate colostrum ingestion. A total of 587 calves were randomly assigned to 2 groups of males and females over 18mo. The nonpasteurized group (n=287, 143 males and 144 females) was fed frozen (−20°C) colostrum (6–8L during the first 12h of life) that was previously reheated up to 40°C. They were also fed refrigerated (4°C) raw milk from the bulk tank that was also reheated up to 40°C (1.8L every 12h). The pasteurized group (n=300, 150 males and 150 females) was also fed colostrum and milk, but both were pasteurized before freezing. Blood samples were drawn from all calves to obtain serum at 2 to 5d of life. Serum total protein (g/dL) was determined using a commercially available refractometer. Colostrum and milk underwent routine bacteriological analysis to determine total plate counts (cfu/mL) and total coliform counts (cfu/mL). All the calves underwent clinical examination every 24h during the first 21d of life. Every day, calves were clinically diagnosed either as being healthy or suffering from respiratory disease, neonatal calf diarrhea, or suffering other diseases. On-farm heat treatment for colostrum and milk reduced total plate counts and total coliform counts between 1 and 2 log10. Pasteurization of colostrum and milk significantly decreased the morbidity and mortality (5.2 and 2.8%) in comparison with calves receiving nonpasteurized colostrum and milk (15.0 and 6.5%), respectively, during the first 21d of life, even in animals receiving appropriate colostrum ingestion.

Effect of infrared lamps to ameliorate morbidity and mortality in Murrah calves

The present study was conducted out to evaluate the effect of Infrared lamps to ameliorate morbidity and mortality in Murrah calves. Ten newborn Murrah calves were randomly divided into two groups (G 1 and G 2 ) of five each. The calves of G 1 were provided with no additional protection; however the calves of G 2 were protected against the cold weather by using the Infrared lamps. The health status of calves was monitored daily both in the morning and evening. The blood samples collected within six hours of birth and then at fortnightly interval were analyzed for total leukocyte count (TLC, thousands/µl) and differential leukocyte count (DLC). The physiological parameters i.e. respiration rate (RR, breaths/min), heart rate (HR, beats/min) and rectal temperature (RT, °F) were recorded at weekly interval. The health performance was better in calves of G 2 as compared to G 1 . The calves in G 1 showed comparatively higher values of TLC and neutrophils and the differences were found significant (P<0.05) on 15 th day for TLC and 45 th day for neutrophils. The values of lymphocytes were significantly (P<0.05) lower in calves of G 1 than G 2 on 45 th day. The physiological parameters did not varied significantly between the groups except for RT which was found significantly (P<0.01) lower on 56 th day in calves of G 1 than G 2 . On the basis of the results, it could be concluded that the Infrared lamps were efficient in providing favourable microclimate and hence can be effectively used in calf shed to protect newborn calves from adverse conditions of winter.

Molecular screening of pathogenic Escherichia coli strains isolated from dairy neonatal calves in Cordoba province, Argentina

The aim of this study was to perform a current molecular characterization of bovine pathogenic Escherichia coli strains isolated from random samplings in Argentinean dairy farms. Rectal swabs were obtained from 395 (63.7%) healthy and 225 (36.3%) diarrheic calves, belonging to 45 dairy farms in Cordoba Province, Argentina. E. coli isolates were examined for virulence genes (f5, f41, f17, sta, stb, lt, eae, vt) using PCR and the prevalence of E. coli virulence profiles was spatially described in terms of spatial distribution. A total of 30.1% isolates were found to be positive for at least one of the virulence genes. Depending on the different gene combinations present, 11 virulence profiles were found. Most of the isolates analyzed had a single gene, and no combination of fimbrial and enterotoxin gene was predominant. There was no association between the frequency and distribution of E. coli virulence genes and calf health status. Most of the virulence profiles were compatible with ETEC strains and showed a homogeneous distribution over the sampled area. A clustering pattern for E. coli virulence profiles could not be recognized. This work provides updated information on the molecular characterization of pathogenic E. coli strains from dairy herds in Cordoba, Argentina. These findings would be important to formulate prevention programs and effective therapies for diarrhea in calves caused by E. coli.

Effect of Infrared Lamps to Ameliorate Morbidity and Mortality in Vrindavani Calves

The present study was carried out to determine the effect of Infrared lamps to ameliorate morbidity and mortality in Vrindavani calves. Ten newborn calves were randomly divided into two groups (G1 and G2) of five each. The calves of G1 were provided with no additional protection; however calves of G2 were protected against cold weather by using the Infrared lamps. The health status of calves was monitored daily both in the morning and evening. The blood samples collected within six hours of birth and then at fortnightly interval were analyzed for total leukocyte count (TLC, thousands/μl) and differential leukocyte count (DLC). The physiological parameters i.e. respiration rate (RR, breaths/min), heart rate (HR, beats/min) and rectal temperature (RT,°F) were recorded at weekly interval. The health performance was better in calves of G2 as compared to G1. The calves in G1 showed comparatively higher values of TLC and neutrophils and the differences were found significant (P<0.05) on 15th day for TLC and 15th and 45th day for neutrophils. The values of lymphocytes were found significantly (P<0.05) lower in calves of G1 than G2 on 15th and 45th day.The physiological parameters did not varied significantly between the groups except for RT which was most of the times significantly (P<0.05) lower in calves of G1 than G2. On the basis of the results, it could be concluded that the Infrared lamps are efficient in providing favourable microclimate and hence can be effectively used in calf shed to protect newborn calves from adverse conditions of winter.

Respiratory Diseases of Calves on Dairy Cow Farm

Intensive cattle breeding involves a whole series of technological processes, which should allowcontinued production and optimal use of production capacities. In those conditions new born calves must adapt todifferent environmental factors, including diet and housing conditions. Diseases of digestive and respiratory organsare the most common health problems in calves during the first months of their life. In this paper, we provide anoverview of respiratory diseases of calves on a dairy farm. We monitored health status of calves on a dairy cow farm.Calves show clinical picture of respiratory diseases. In microbiological laboratory wide range of bacteria was isolatedfrom calve lungs and nasal swabs. During one calendar year, the following bacteria were isolated from calve lungs:Pasteurella multocida, Mannheimia haemolytica, Pasteurella spp. Histophilus somni, Haemophilus spp, Trueperella(Arcanobacterium) pyogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella Enteritidis,Salmonella Typhimurium. The total of 61 calves was diagnosed with respiratory diseases (34 male and 27 femalecalves). Number of dead male calves is 24 (16 male calves and 8 female calves). Calves with respiratory diseases wereapproximately 71.62 days old. Dead calves with pathomorphological changes on their lungs were approximately 77.25days old. Diseases of calves on farms usually have multifactorial etiology, and the most important health disorders incalves on our farms were respiratory diseases. The occurrence of respiratory diseases is highly significant unfavorableresult of microclimate conditions, hygienic accommodation and inadequate technological processes.

Does iodine supplementation of the prepartum dairy cow diet affect serum immunoglobulin G concentration, iodine, and health status of the calf?

Absorption of adequate IgG from colostrum is critical to provide the newborn calf with adequate immunological protection and resistance to disease. Excessive iodine supplementation of the prepartum ewe reduces IgG absorption of her offspring; it is possible that excessive iodine supplementation of the prepartum dairy cow may similarly impair the ability of the calf to acquire immunological protection. The objectives of this study were to determine whether the iodine status, health status, and ability of calves to absorb IgG from colostrum were affected by prepartum iodine supplementation strategies of their dams. Dairy cows (n=127) received one of the following levels of iodine supplementation precalving: 15mg of iodine/kg of dietary dry matter (DM) (HI); no additional iodine supplementation (MI); 5mg/kg of dietary DM (SI); and 15mg of iodine/kg of DM for the first 3.5wk of the precalving period and no additional supplementation for the second 3.5wk (HMI). Calves were assigned to 1 of 6 experimental treatments, based on the prepartum iodine supplementation treatment of their dam and the precalving treatment group of the cows from which the colostrum fed was obtained: (1) HI_HI: born to HI dams, fed HI colostrum (i.e., colostrum produced by cows in the HI group); (2) MI_MI: born to MI dams, fed MI colostrum; (3) SI_SI: born to SI dams, fed SI colostrum; (4) HI_MI: born to HI dams, fed MI colostrum; (5) MI_HI: born to MI dams, fed HI colostrum; and (6) HMI_HMI: born to HMI dams, fed HMI colostrum. Concentration of calf serum IgG and plasma inorganic iodine (PII) was measured at 0 and 24h of age. Apparent efficiency of absorption for IgG was determined. Health scores were assigned to calves twice weekly and all episodes of disease were recorded. Cow experimental treatment group affected calf PII at 0h of age; the PII of calves born to HI dams (987.2µg/L) was greater than that of calves born to MI dams (510.1µg/L), SI (585.2µg/L), and HMI dams (692.9µg/L). Calf experimental treatment group affected calf PII at 24h of age; the PII of HI_HI (1,259.2µg/L) and HI_MI (1,177.8µg/L) calves was greater than MI_MI (240.7µg/L), SI_SI (302.2µg/L), HMI_HMI (320.7µg/L), and MI_HI (216.3µg/L) calves. No effect of experimental treatment was observed on the concentration of IgG measured in calf serum at 24h of age, or on apparent efficiency of absorption. Experimental treatment had no effect on the likelihood of a calf being assigned a worse nasal, eye and ear, cough, or fecal score within the study period, nor did it affect the probability of a calf receiving treatment for a disease a greater number of times. Prepartum iodine supplementation of cows at 15mg/kg of DM increased the iodine levels in their calves at birth and 24h of age, but did not affect their ability to absorb IgG from colostrum. Supplementation with iodine above the minimum requirements established by the National Research Council was unnecessary to ensure appropriate iodine levels in calves at birth.

Effect of Feeding Selenium-Fertilized Alfalfa Hay on Performance of Weaned Beef Calves

Selenium (Se) is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB) Se concentrations in mature beef cows. Our current objective was to test whether feeding Se-fertilized forage increases WB-Se concentrations and performance in weaned beef calves. Recently weaned beef calves (n = 60) were blocked by body weight, randomly assigned to 4 groups, and fed an alfalfa hay based diet for 7 wk, which was harvested from fields fertilized with sodium-selenate at a rate of 0, 22.5, 45.0, or 89.9 g Se/ha. Blood samples were collected weekly and analyzed for WB-Se concentrations. Body weight and health status of calves were monitored during the 7-wk feeding trial. Increasing application rates of Se fertilizer resulted in increased alfalfa hay Se content for that cutting of alfalfa (0.07, 0.95, 1.55, 3.26 mg Se/kg dry matter for Se application rates of 0, 22.5, 45.0, or 89.9 g Se/ha, respectively). Feeding Se-fertilized alfalfa hay during the 7-wk preconditioning period increased WB-Se concentrations (P Linear<0.001) and body weights (P Linear = 0.002) depending upon the Se-application rate. Based upon our results we suggest that soil-Se fertilization is a potential management tool to improve Se-status and performance in weaned calves in areas with low soil-Se concentrations.

Optimization of rearing dairy breed calves according to organic principles / Optymalizacja odchowu cieląt ras mlecznych według wymogów ekologicznych

Abstract The aim of the study was to determine the degree to which different whole milk feeding systems according to ecological standards affect the results of rearing, some blood biochemical and haematological parameters, and health status of Polish Holstein-Friesian calves. The experiment was conducted from birth to 150 days of age with 32 calves (16 heifer and 16 bull calves), assigned to four analogous groups (8 animals: 4 ♀ and 4 ♂ per group). In group I, calves suckled colostrum (ad libitum) and mother’s milk from 5 to 90 days of age (twice daily for 30 minutes); in group II, they suckled colostrum (ad libitum), mother’s milk from 5 to 42 days of age (twice daily for 30 minutes), and received milk from nipple buckets (6 l twice daily) from 43 to 90 days of age; in groups III and IV calves received from nipple buckets a limited amount of colostrum (4.5-6 l/day) and milk (on average 5.82 and 4.82 l/day, respectively). Feeding limited whole milk from nipple buckets to the calves did not cause significant differences in haematological blood indices, serum concentrations of glucose and IgG, and health status of calves compared to those suckling their mothers. Calves which remained with their mothers during colostrum feeding were characterized by a significantly lower concentration of serum cortisol at 2 days of age compared to calves that received colostrum from nipple buckets. Compared to the calves suckling their mothers (group I), the use of economical milk feeding system (III and IV groups) reduced rearing costs and increased the amount of milk intended for sale by 700-760 l/cow.

The efficiency of propolis in post-colostral dairy calves

Abstract. The study aimed at an assessment of a possibility of calves’ health status improvement in neonatal period by preventive application of 10 % ethanol extract of propolis (EEP). An influence of EEP on selected biochemical and haematological parameters of blood, body weight gains and diarrhoea symptoms intensity was determined. Propolis contains a range of biologically active compounds and exhibits numerous beneficial properties. Ethanolic extract is a form of propolis that is usually used in prevention. Forty five calves were used in the experiment. The assessment of clinical symptoms of diarrhoea, dehydration and vitality was conducted and calves (without symptoms of diarrhoea) were divided into 3 groups (15 calves in each): control, and two experimental (2 and 4 ml of EEP/day). The results of the study point that EEP may be a useful mean improving health status of calves. After an application of propolis in a dose of 4 ml/day higher daily gains were noted when compared to the control calves. Although no obvious influence of EEP on haematological parameters was noted, the positive influence on erythropoiesis and Fe content was observed. Higher EEP dose caused a significant decrease in lactic acid (LA) level. No influence on macroelements and electrolytes in blood serum was noted.

Detection of Corona virus antigen by ELISA from diarrhoeic cow calves in Mathura, India

Neonatal diarrhoea is one of the most important conditions of calves, associated with morbidity and mortalities. Diarrhoeal diseases have an adverse effect on calf health status, survival and productive performances. Corona virus is one of the etiological agents responsible for calf diarrhea worldwide. However there is paucity of literature stating the disease status in India. The present study was carried out to determine the prevalence of corona virus infection among cow calves in Mathura and adjacent regions. During the present study 63 diarrhoeic stool samples collected from cow calves were screened for corona virus. Of the 63 diarrhoeic samples 3 samples (4.76%) were found to be positive for corona virus by ELISA.

Indicators of passive immunity and health status of calves

The aim of this study was the determination of immunoglobulin (IgG, IgM, IgA), total serum protein content and activity of enzyme GGT in sera of 71 dairy calves up to the age of four weeks. We investigated to which extent the sera profiles correlated with total immunoglobulin level in the administered colostrum. The results were related to the health status of the calves. One of the goals of the study was also to asses the applicability of these indicators of colostrum supplied in Slovenian herds. In the serum samples the concentration of IgG, IgA, IgM, TSP and activity of GGT were measured. In colostrum samples the total Ig level was estimated. The correlations between the colostral Ig content and the concentration of IgG, TSP and activity of GGT were significant up to the 4th week of age. Only on the base of the values of the investigated parameters no direct conclusion about the foreseen health status of calves is possible. The investigated indicators are suitable to assess colostrum supply in calves at least up to the 3rd week of age. Indirect indicators such as TSP and GGT are more reliable to ascertain if the colostrum was absorbed as for estimation of immunoglobulin levels in the calf's serum.

Vitamin E supplementation of newly arrived feedlot calves1,2

Seven hundred fifteen crossbred (primarily British) calves purchased in southern Oklahoma and northern Texas auction barns were received at the Willard Sparks Beef Research Center, Stillwater, OK, and used to study effects of duration (days) of vitamin E feeding during a 42-d receiving period on animal performance, health, and serum cholesterol and vitamin E concentrations. Upon arrival, calves were blocked by load (seven loads), sorted by BW (light, n = 4 pens per load; and heavy, n = 4 pens per load), and assigned randomly to one of four dietary treatments (n = 2 pens per load; 14 pens per treatment). Experimental diets were formulated to provide 2,000 IU.calf(-1).d(-1) of supplemental vitamin E (dl-alpha-tocopherol acetate) for 0 (CON), 7 (E7), 14 (E14), or 28 (E28) d. Vitamin E was delivered in a pelleted supplement that was added to the basal diet in decreasing concentrations as DMI increased (2.0 kg of DMI = 6%; 4.0 kg of DMI = 4%; and 6.0 kg of DMI = 2%). Serum samples were collected on d 0, 14, 28, and 42 for determination of cholesterol, alpha-tocopherol (d 0, 28, and 42), and antibody (IgG) concentrations. Duration of vitamin E supplementation did not affect ADG (0.98 kg/d; P = 0.56) or G:F (0.189; P = 0.87). Serum cholesterol concentrations decreased (day effect; P < 0.001) for all treatments from d 0 (average = 127 mg/100 mL) to 14 (average = 62 mg/100 mL). Serum alpha-tocopherol decreased (day effect; P < 0.001) from d 0 (5.2 microg/mL) to 28 (1.8 microg/mL); however, on d 28, a greater (P < 0.001) serum alpha-tocopherol concentration was observed for E28 (3.4 microg/mL) calves than for CON (1.1 microg/mL), E7 (1.2 microg/mL), or E14 (1.5 microg/mL) calves. Respiratory disease was diagnosed in 64.6% of calves in this study. Medical costs were less (P = 0.08) for calves fed vitamin E for 28 d (4.88 dollars/calf) than for calves fed the control diet (6.29 dollars/calf). Carcass characteristics were not affected (P = 0.19 to 0.88) by dietary treatments. Supplemental vitamin E formulated for 2,000 IU.calf(-1).d(-1) had little influence on performance and overall health status of calves under our experimental conditions; however, the increased serum concentrations of alpha-tocopherol when vitamin E was fed for 28 d suggests that any potential effects of vitamin E on health status might be time-dependent.

Associations between passive immunity and morbidity and mortality in dairy heifers in Florida, USA

A prospective cohort study was undertaken to determine calf-level factors that affected calf health status between birth and 6 months of age. A convenience sample of approximately 3300 female Holstein calves born in 1991 on two large Florida dairy farms was used for the study. Data collected on each calf at birth included farm of origin, weight, height at the pelvis, birth date, and serum total protein (a measure of colostral immunoglobulin absorption). Birth season was dichotomized into summer and winter using meteorological data collected by University of Florida Agricultural Research Stations. Health data including date of initial treatment and number of treatments were collected for the diseases diarrhea, omphalitis, septicemia and pneumonia. All calves were followed for 6 months. Cumulative incidences of mortality and occurrence of diarrhea, omphalitis, septicemia and pneumonia were 0.12, 0.35, 0.11, 0.24 and 0.21, respectively. Serum total protein (TP) was a significant risk factor for mortality. The association of TP and mortality was quadratic and showed a dramatic decrease in mortality as TP increased from 4.0 to 5.0 g/dl, a small improvement from 5.0 to 6.0 g/dl and virtually no improvement in mortality rates as TP increased over 6.0 g/dl. The hazard mortality ratio was constant from birth to six months, indicating that the increased risk of mortality associated with low levels of TP was evident through six months of age. No interactions between TP, farm, season, or birth weight were found in these analyses. Serum total protein concentration was a significant risk factor for the occurrences, age of onset and severity of septicemia and pneumonia. The association between TP and septicemia was linear and an interaction with birth season was found. The association between TP and pneumonia was quadratic, and in contrast to the TP-and-septicemia relationship, the morbidity hazard ratio for pneumonia was not constant over the time measured; that is, colostral immunity protected the calf from developing pneumonia early in life, but this effect disappeared as the calf got older. Total protein was not a significant risk factor for diarrhea or omphalitis.

Proliferation of peripheral blood lymphocytes of feeder calves in response to chromium

The effects of supplemental chromium (Cr) in the diet, or by direct addition to the culture medium on proliferation of bovine peripheral blood lymphocytes (PBL) was evaluated with and without addition of the mitogen concanavalin A (con A). Twenty-four stressed steer calves were randomized (three animals per pen) to the following treatments: control diet (high quality corn silage) and control diet supplemented with 0.14 ppm chelated Cr. The PBL blastogenic activity was accessed using 0, 2 and 10 ug/ml con A on d 0, 7, 14, 21, 28, 35, and 49 following arrival of calves from sales barns. Blastogenic activity was measured by uptake of methyl- 3H-thymidine. The PBL from calves fed dietary Cr showed increased (P<0.05) blastogenic activity following incubation with culture medium containing the higher concentration (10 ug/ml con A) of mitogen. An interaction between Cr and health status of calves occurred with or without mitogen (P<0.05). Morbid animals had lower PBL blastogenic responses but supplemental Cr increased (P<0.05) this response of morbid animals. However, supplemental Cr had no effect on response of healthy animals. When soluble chelated Cr was directly added to the culture medium at 0, .045, .45 and 4.5 ppm, Cr enhanced (P<0.05) blastogenic activity at both concentrations of mitogen, as well as without mitogen stimulation. In addition, using PBL from eight animals fed the control diet from d 0 to 120, chelated Cr and CrCl 3 were directly added in the PBL culture medium at 0, 0.0045, 0.045, 0.45 and 4.5 ppm, and the same enhanced blastogenic activity was observed. However, chelated Cr showed greater (P<0.10) enhancement of PBL activity at 0.045 to 0.45 ppm and CrCl 3 at 0.0045 ppm concentration (P<0.05). These results confirmed previous indications that Cr can effect certain aspects of cell mediated immunity, which may contribute to the morbidity reduction of calves fed supplemental Cr.

Plasma 1,25-dihydroxyvitamin D, insulin-like growth factor-1, calcium, magnesium and phosphorus concentrations in pregnant beef cows and calves from a herd with a known history of congenital joint laxity and dwarfism

An investigation was undertaken to ascertain the possibility of a relationship between calcium, inorganic phosphorus, magnesium, 1,25-dihydroxy-vitamin D [1,25(OH) 2D], and insulin-like growth factor-1 ( IGF-1) concentrations in blood plasma and occurrence of congenital joint laxity and dwarfism ( CJLD) in young cattle. Pregnant cows were fed hay (30 cows) or grass silage (122 cows) during winter months (October 15 to calving in March). Blood samples were taken from cows on seven occasions during the experiment and 48 hours after calving, and from calves at birth, and at seven, 14 and 56 days old. Five per cent of calves born (six of 122) to cows fed grass silage and none born to cows fed hay were affected by CJLD. The diet and health status of calves were not significantly (P>0·05) associated with the plasma concentration of 1,25(OH) 2D. The plasma calcium concentration declined with age of the calves (P<0·05) but was not affected by the occurrence of CJLD. Plasma phosphorus and magnesium concentrations in calves born to cows fed silage were higher (P<0·05) than in those born to cows fed hay. At birth and seven days old, plasma phosphorus concentrations were higher (P<0·05) in CJLD-affected calves than in healthy calves but the plasma concentration of IGF-1 was not different (P>0–05). It was concluded that the high plasma phosphorus concentrations in CJLD-affected calves and their dams could be related to the aetiology of the CJLD condition in calves.

Leukocyte function and health status of calves supplemented with vitamins A and E (1991)

Forty-four Holstein calves were fed milk replacers with varied concentrations of vitamins A and E from 3 to 45 d of age to determine their effects on concentrations of plasma vitamin A (retinol and retinyl palmitate) and vitamin E (αtocopherol), lymphocyte and neutrophil functions, and health of calves. Plasma α-tocopherol was unaffected by increased vitamin A supplementation. Fecal scores, and eye and nose membrane responses were improved with increased vitamin A and lower vitamin E concentration, whereas the same treatment tended to reduce neutrophil cytotoxic and bactericidal activity by 6 wk of age. Increased supplemental vitamin E tended to enhance neutrophil functions. However, age appeared to have an effect on response to both vitamins.