Extended colostrum feeding for 2 weeks improves growth performance and reduces the susceptibility to diarrhea and pneumonia in neonatal Holstein dairy calves.

The objective of this study was to determine the effect of partial replacement of whole milk with colostrum on the growth performance and health status of Holstein dairy calves. Neonatal heifer calves (n = 144; 2 d of age; 39.3 ± 0.82 kg of body weight, BW; mean ± SE) were assigned randomly to 3 groups with partial replacement of pasteurized whole milk with pasteurized colostrum at 0 (C0; 0 kg/d of colostrum + 5 kg/d of whole milk), 350 g (C350; 0.350 kg/d of colostrum + 4.650 kg/d of whole milk), or 700 g (C700; 0.700 kg/d of colostrum + 4.300 kg/d of whole milk) for 14 d; there were no refusals of liquid feed. From d 15 onward, the calves were fed with 5 kg/d of pasteurized whole milk, weaned on d 61, and monitored until d 81 of life. Throughout the study, the calves had free access to fresh clean water and calf starter. Partial replacement of whole milk with colostrum increased liquid feed dry matter intake (DMI) but decreased milk DMI; however, intakes of starter DMI, total DMI, metabolizable energy, crude protein, and ether extract were not affected by treatments. Overall, the C700 calves recorded greater weaning weight, final BW, heart girth change, feed efficiency, and average daily gain (ADG). The calves fed milk had a higher chance of having rectal temperature ≥39.4°C and general appearance score ≥2 compared with those receiving colostrum in their milk. Diarrhea was more prevalent in C0 versus C700 calves. The occurrence of pneumonia tended to be higher in milk-fed calves compared with C350 and C700 animals. Colostrum feeding resulted in fewer days with a rectal temperature ≥39.4°C, general appearance ≥2, diarrhea, and pneumonia. We computed Cliff's delta (effect sizes) of the extended colostrum feeding (C350 vs. C0, C700 vs. C0, and C700 vs. C350) on starter and milk DMI, ADG, BW, and feed efficiency. In C350 calves, the effect sizes (Cliff's delta) for milk DMI, ADG, BW, and feed efficiency were positive and small, but negative in C700 calves. Compared with C350 treatment, C700 treatment resulted in greater final BW with moderate effect size. Positive and moderate effects of feeding colostrum (C700 vs. C0) were observed on postweaning ADG and final BW. The findings showed that the inclusion of 700 g of colostrum in 5 kg of milk may be beneficial to the growth and health of dairy calves.

Impact of elimination diets on nutrition and growth in children with multiple food allergies.

PURPOSE OF REVIEW: Growth and nutritional intake of children with cows' milk allergy and other food allergens has been thoroughly investigated in recent years across many different countries and age groups. An impaired growth in atopic children should not be attributed only to a high number of allergens and foods to be avoided, but to a general condition of 'sub-inflammation', which unfavorably affects the absorption and utilization of fuel and substrates. Atopic study participants may represent a good target for personalized nutrition and in this review we sought to outline many of the issues that should be taken into account when dietitians advise patients regarding food avoidance and expected effects on growth. RECENT FINDINGS: The dietary management of food allergy requires appropriate dietary choices to maintain adequate growth, starting with special formulas in infancy. An emerging area of research is the fussy eating related to the exclusion of cow's milk and other foods during infancy and the long-term effects on eating habits and food preferences. SUMMARY: Study participants with either mono or polyallergic diseases should ideally undergo the definition of their allergic and metabolic characteristics, to precisely adjust dietary interventions on an individual basis to support the genetic potential of growth and prevent unfavorable outcomes.

Environmental risk factors for type 1 diabetes.

The incidence of type 1 diabetes has risen considerably in the past 30 years due to changes in the environment that have been only partially identified. In this Series paper, we critically discuss candidate triggers of islet autoimmunity and factors thought to promote progression from autoimmunity to overt type 1 diabetes. We revisit previously proposed hypotheses to explain the growth in the incidence of type 1 diabetes in light of current data. Finally, we suggest a unified model in which immune tolerance to ß cells can be broken by several environmental exposures that induce generation of hybrid peptides acting as neoautoantigens.

Effect of vaccination against gonadotrophin-releasing factor on growth performance, carcass, meat and fat quality of male Duroc pigs for dry-cured ham production.

The aim of this study was to compare production, carcass and meat quality parameters, boar taint compounds and fat composition of green and dry-cured hams, between immunocastrated (IM), surgically castrated (CM) and female (FE) Duroc purebred pigs (n=75, 138.7±8.27kg). Liveweight and fat and muscle thicknesses were measured and average daily gain was calculated during growth. Carcass, meat and fat quality parameters were measured. Immunocastrated grew faster than CM or FE after the second dose of vaccine. IM had the lowest dressing percentage but similar % of ham and carcass lean to FE and CM. The effect of the immunocastration on carcass fatness depended on the location, did not affect fat and meat quality and reduced skatole and androstenone levels. Both in green and dry-cured ham, immunocastration slightly altered FA composition. Thus, Duroc pigs vaccinated with Improvac are suitable for the production of high quality dry-cured ham.

Sclerostin antibody treatment enhances bone strength but does not prevent growth retardation in young mice treated with dexamethasone.

OBJECTIVE: Exposure to supraphysiologic levels of glucocorticoid drugs is known to have detrimental effects on bone formation and linear growth. Patients with sclerosteosis lack the bone regulatory protein sclerostin, have excessive bone formation, and are typically above average in height. This study was undertaken to characterize the effects of a monoclonal antibody to sclerostin (Scl-AbI) in mice exposed to dexamethasone (DEX). METHODS: Young mice were concomitantly treated with DEX (or vehicle control) and Scl-AbI antibody (or isotype-matched control antibody [Ctrl-Ab]) in 2 independent studies. Linear growth, the volume and strength of the bones, and the levels of bone turnover markers were analyzed. RESULTS: In DEX-treated mice, Scl-AbI had no significant effect on linear growth when compared to control treatment (Ctrl-Ab). However, in mice treated with DEX and Scl-ABI, a significant increase in trabecular bone at the femoral metaphysis (bone volume/total volume +117% versus Ctrl-Ab-treated mice) and in the width and volume of the cortical bone at the femoral diaphysis (+24% and +20%, respectively, versus Ctrl-Ab-treated mice) was noted. Scl-AbI treatment also improved mechanical strength (as assessed by 4-point bending studies) at the femoral diaphysis in DEX-treated mice (maximum load +60% and ultimate strength +47% in Scl-AbI-treated mice versus Ctrl-Ab-treated mice). Elevated osteocalcin levels were not detected in DEX-treated mice that received Scl-AbI, although levels of type 5b tartrate-resistant acid phosphatase were significantly lower than those observed in mice receiving DEX and Ctrl-Ab. CONCLUSION: Scl-AbI treatment does not prevent the detrimental effects of DEX on linear growth, but the antibody does increase both cortical and trabecular bone and improves bone mechanical properties in DEX-treated mice.

Rnf8 deficiency impairs class switch recombination, spermatogenesis, and genomic integrity and predisposes for cancer.

Signaling and repair of DNA double-strand breaks (DSBs) are critical for preventing immunodeficiency and cancer. These DNA breaks result from exogenous and endogenous DNA insults but are also programmed to occur during physiological processes such as meiosis and immunoglobulin heavy chain (IgH) class switch recombination (CSR). Recent studies reported that the E3 ligase RNF8 plays important roles in propagating DNA DSB signals and thereby facilitating the recruitment of various DNA damage response proteins, such as 53BP1 and BRCA1, to sites of damage. Using mouse models for Rnf8 mutation, we report that Rnf8 deficiency leads to impaired spermatogenesis and increased sensitivity to ionizing radiation both in vitro and in vivo. We also demonstrate the existence of alternative Rnf8-independent mechanisms that respond to irradiation and accounts for the partial recruitment of 53bp1 to sites of DNA damage in activated Rnf8(-/-) B cells. Remarkably, IgH CSR is impaired in a gene dose-dependent manner in Rnf8 mutant mice, revealing that these mice are immunodeficient. In addition, Rnf8(-/-) mice exhibit increased genomic instability and elevated risks for tumorigenesis indicating that Rnf8 is a novel tumor suppressor. These data unravel the in vivo pleiotropic effects of Rnf8.

Corticosteroids usage in pediatric liver transplantation: To be or not to be!

The theoretical risks of early SW, <3 months post-LT, and complete elimination (steroid-free LT) lie in mainly three areas, namely the risks of AGR, CGR, and the development of d-AIH that has been described in SW post-LT in children. These should be balanced against the benefits of early SW mainly manifested as effects on growth post-LT. In this paper, we focused on the clinical trials that included CS therapy risks and benefits in pediatric LT. Focusing mainly on CGR and d-AIH as risks, and the beneficial effects on growth post-LT with either low-dose CS, SW, or steroid-free regimens. Main conclusions from comparing a large number of studies are: early SW or elimination from immunosuppression protocols was neither harmful to the patient nor to the graft survival rate in the short term, the overall impression is that steroids negatively affect growth in LT recipients when used in high doses and prolonged course, and that development of d-AIH is not associated with CS therapy with evidence that chronic low dose steroids post-LT have no preventative role against d-AIH.

Children developing type 1 diabetes before 6 years of age have increased linear growth independent of HLA genotypes.

AIMS/HYPOTHESIS: High birthweight and increased childhood growth are risk factors for type 1 diabetes. Relative birthweight is associated with HLA genotypes that confer a high risk of diabetes. Our aims were to test whether young children prior to clinical onset of type 1 diabetes have increased: (1) birthweight or birth length standard deviation scores (SDS); (2) height development SDS; or (3) BMI SDS during first 18 months of life and whether these parameters are related to HLA genotypes or mid-parental height (MPH). METHODS: Birthweight, birth length, weight and height were obtained from 58 type 1 diabetes children and 155 controls matched for HLA or not in the Diabetes Prediction in Skåne study. RESULTS: Birth length SDS corrected for MPH was increased in children developing diabetes compared with all (p < 0.048) and with non-HLA- (p < 0.050) but not with HLA-matched controls. Children developing diabetes had increased height gain at 0 to 18 months of age (p < 0.005). Diabetic children were significantly taller from 6 to 18 months of age when correcting for MPH compared with non-HLA-matched as well as HLA-matched controls, but BMI was not increased. CONCLUSIONS/INTERPRETATION: Birth length SDS was associated with diabetes risk HLA. When corrected for MPH, children developing diabetes were taller at birth than non-HLA- but not taller than HLA-matched controls. Diabetic children had increased MPH-corrected height up to 18 months of age compared with both HLA- and non-HLA-matched controls. High-risk HLA affects prenatal growth, but other factors may explain the increased postnatal linear growth in children developing diabetes.

Brothers and reduction of the birth weight of later-born siblings.

It has been speculated whether maternal immune responses against male-specific minor histocompatibility (H-Y) antigens affect pregnancies negatively. This study explores, on a population level, whether previous births of boys compared with girls are associated with a decrease in birth weight of later-born siblings. The population was identified in the Danish Birth Registry and consisted of all Danish women who gave birth to their first-born singleton from 1980 to 1998. The women were followed until 2004, and their subsequent births were recorded. A total of 545,839 second- to fourth-born children were identified. The authors used linear regression to analyze the association between sex of preceding children and birth weight of subsequent siblings. Brothers compared with sisters reduced the birth weight of later-born siblings. One or two brothers, respectively, reduced the mean birth weight of later-born boys by 29 g (p = 0.0001) and 38 g (p = 0.0001) and later-born girls by 17 g (p = 0.0001) and 21 g (p = 0.0001) compared with later-born siblings with no brothers. Part of this association was due to a shorter gestation among later-born siblings with brothers. An explanation for these results could be maternal immune reactions directed against the H-Y antigens initiated during pregnancies with boys. The findings might add to the understanding of both normal and pathologic pregnancies.

Long-term effect of early protein malnutrition on growth curve, hematological parameters and macrophage function of rats.

To evaluate the long-term effect of mild-early maternal protein malnutrition on weight gain, hematological parameters and macrophage function in rats at adult age, we compared rats whose dams were fed diets containing either 9.5% (low protein-LPD) or 23% protein (normal-NPD) for the first 12 d of lactation. At 80 d of age, the functions of spreading, phagocytosis and killing Candida albicans were determined in resident peritoneal macrophages, whereas leukocytes and red blood cells were counted in peripheral blood. The number of resident peritoneal macrophages from LPD was the same as from NPD, but the ability of spreading and phagocytosing opsonised yeast was impaired. Besides, they were not able to block the germ tube formation or kill C. albicans to the same extent as in the control group. The low protein diet produced a significant reduction in the pups' growth and in hematological parameters although no difference was found in leukocyte counts. Taken together the data suggest that protein malnutrition during early lactation induces permanent alterations in macrophage function, body composition and hematological status, which are not restored completely even after a normal protein diet is supplied.

Ontogeny of the allergic inflammatory response.

The ability to produce allergic responses begins early in fetal life along with the development of other elements of the immune system. Among the most interesting questions related to the development of allergic disease are whether the fetus in utero commonly is exposed to sufficient allergen to induce IgE production and how much the mother's immune responses affect the developing fetal immune system. After birth, it seems that many factors, including the frequency and severity of infections and the timing and intensity of allergen and animal exposures, continue to influence immune development.

Phenotypic selection for residual feed intake and its effect on humoral immune responses in growing layer hens.

According to the resource allocation theory, animals have to make a trade-off between resource-demanding life traits to obtain maximal fitness. Artificial selection toward efficient producing farm animals, however, may have created animals that have an impaired ability to divert resources to maintenance processes, such as responding to immune challenges. Residual feed intake (RFI), defined as the difference between observed feed intake (FI) and expected feed intake based on metabolic BW and growth, was used as a measure for feed efficiency. Individual BW and FI of 352 pullets were recorded weekly from 4 until 14 wk of age to estimate RFI. The top 50 efficient R- and the top 50 nonefficient R+ birds were selected. BW and BW gain in both groups were similar. FI and RFI, however, were significantly higher in R+ birds. Thirty animals out of every group were randomly allocated to 1 of 3 treatments: immunization with keyhole limpet hemocyanin (KLH), Mycobacterium butyricum, or heat-inactivated Salmonella enteritidis bacteria. Antibody titers against KLH, M. butyricum, or Salmonella lipopolysaccharide did not differ between R+ and R- birds. The antibody titer against Salmonella protein was higher in R+ birds. We concluded that a population of chickens from a commercial breed shows considerable variation in RFI. Specific antibody production against KLH, M. butyricum, and S. enteritidis lipopolysaccharide, however, is not influenced by efficiency in terms of RFI. R+ animals may have a higher level of nonantigen specific antibodies, as indicated by the higher antibody response to Salmonella protein.

Growth retardation and dyslymphopoiesis accompanied by G2/M arrest in APEX2-null mice.

APEX2/APE2 is a secondary mammalian apurinic/apyrimidinic endonuclease that associates with proliferating cell nuclear antigen (PCNA), and the progression of S phase of the cell cycle is accompanied by its expression. To determine the biologic significance of APEX2, we established APEX2-null mice. These mice were about 80% the size of their wild-type littermates and exhibited a moderate dyshematopoiesis and a relatively severe defect in lymphopoiesis. A significant accumulation of both thymocytes and mitogen-stimulated splenocytes in G(2)/M phase was seen in APEX2-null mice compared with the wild type, indicating that APEX2 is required for proper cell cycle progression of proliferating lymphocytes. Although APEX2-null mice exhibited an attenuated immune response against ovalbumin in comparison with wild-type mice, they produced both antiovalbumin immunoglobulin M (IgM) and IgG, indicating that class switch recombination can occur even in the absence of APEX2.

Hot-water extract from mycelia of Cordyceps sinensis as a substitute for antibiotic growth promoters.

Broiler chicks were orally dosed with a hot-water extract of mycelia from Cordyceps sinensis (CS-HW) to assess possible substitution of Avilamycin as an antibiotic growth promoter (AGP). The growth performance (body weight gain and survivability) and the health index (the microflora in the small intestines and the antibody titer to Newcastle disease virus) of chicks were significantly improved in the CS-HW (600 mg/kg diet) and the Avilamycin (20 mg/kg diet) fed group in comparison with the control group (p < 0.05). The Avilamycin-fed group and the CS-HW-fed group had similar growth performances but the latter gave a better microbial flora in the small intestines. These results indicate that CS-HW enhances the physiological activity in chicks and can be used as a substitute for AGPs.

Complement: more than a 'guard' against invading pathogens?

Recent studies have indicated that complement proteins might exert novel functions that are distinct from their well-established inflammatory role, by modulating cellular responses and cell-cell interactions that are crucial to early development and cell differentiation. Accumulating evidence suggests that complement might have important roles in diverse biologic processes, ranging from early hematopoiesis to skeletal and vascular development and normal reproduction. Furthermore, it is now becoming evident that complement-regulated pathways interact with other signaling networks and influence the outcome of complex developmental programs, such as limb regeneration in lower vertebrates and organ regeneration in mammals. These findings highlight a previously under-appreciated role of complement and might have important implications in the context of normal development by helping to elucidate the rather obscure role of innate immunity in such cell modulatory pathways.

The effect of plasma human immunodeficiency virus RNA and CD4(+) T lymphocytes on growth measurements of hemophilic boys and adolescents.

OBJECTIVE: The investigation examined the associations of plasma human immunodeficiency virus (HIV) RNA and CD4(+) T lymphocytes with height, weight, skeletal maturation, testosterone levels, and height velocity for hemophilic children and adolescents with HIV infection in the Hemophilia Growth and Development Study. STUDY DESIGN: Two hundred seven participants were evaluated over 7 years. RESULTS: A threefold increment in baseline plasma HIV RNA was associated with a 0.98-cm decrease in height and a 1.67-kg decrease in weight; 100-cells/microL decrements in baseline CD4(+) were associated with a 2.51-cm decrease in height and a 3.83-kg decrease in weight. Participants with high plasma HIV RNA (>3125 copies/mL) experienced significant delay in achieving maximum height velocity and lower maximum velocity compared with those with low viral load. The high CD4(+) (>243)/low plasma HIV RNA group had earlier age at maximum height velocity compared with the other 3 groups and higher maximum height velocity compared with the low CD4(+)/high plasma HIV RNA and low CD4(+)/low plasma HIV RNA groups. Decrements in CD4(+) were associated with decreases in bone age and testosterone level. CONCLUSIONS: CD4(+) and HIV RNA were important in predicting growth outcomes.

Association between steatorrhea, growth, and immunologic status in children with perinatally acquired HIV infection.

OBJECTIVE: To examine the prevalence of steatorrhea and exocrine pancreatic insufficiency (EPI) and their association with growth and immune status variables in children with perinatally acquired human immunodeficiency virus (HIV) infection. DESIGN: Cross-sectional study. SETTING: Tertiary care HIV subspecialty practice. PARTICIPANTS: Children with perinatally acquired HIV infection. Exclusion criteria included being younger than 1 year and receiving mineral oil as a medication. METHODS: Weight, height, and upper arm anthropometric variables were measured. Spot stool samples were analyzed for steatorrhea using the Sudan III qualitative test and for EPI using fecal elastase-1 enzyme assay. Hormone-stimulated pancreatic function testing and 72-hour stool and dietary fat sample collection were performed when fecal elastase-1 enzyme was in the range of EPI, defined as less than 200 microgram/g. HIV RNA viral load, CD4 status, type of antiretroviral therapy, and biochemical evidence of hepatobiliary disease were measured within 3 months of stool sample collection. z Scores were computed for height, weight, triceps skinfold, and upper arm muscle area. RESULTS: We enrolled 44 patients (23 girls [52%]) with a mean +/- SD age of 7.4 +/- 3.1 years. None had hepatobiliary disease. The prevalence of steatorrhea was 39% (95% confidence interval, 23%-56%). The prevalence of EPI was 0% (95% confidence interval, 0%-9%). There were no associations between steatorrhea and EPI, growth, HIV RNA viral load, CD4 status, or type of antiretroviral therapy. Older children had decreased z scores for height (r = -0.42; P =.006). CONCLUSIONS: The clinical significance of steatorrhea in children with HIV infection is unclear. Furthermore, its evaluation should focus on nonpancreas-based conditions. Continual close monitoring of growth is essential in children with HIV infection.

Growth hormone administration can improve growth in glucocorticoid-injected rats without affecting the lymphocytopenic effect of the glucocorticoid.

Long-term glucocorticoid therapy as it is found in children with kidney transplants results in retarded longitudinal growth. The aim of the present study was to evaluate if growth hormone could improve longitudinal growth in glucocorticoid-injected experimental animals without affecting the immuno-suppressive effect of the glucocorticoid. 117 female Wistar rats were injected from the ages of 2-5 months with either saline, growth hormone (5 mg/kg/day), or glucocorticoid (methylprednisolone 1,3,6 or 9 mg/kg/day), alone or in combination with growth hormone (5 mg/kg/day). Body weight, nose-tail length and length of the lower extremity were measured continuously during the study. After death, femoral and tibial lengths, growth at the proximal, epiphyseal growth plate, muscle mass and immunological parameters were examined. Glucocorticoid administration dose-dependently decreased weight gain and growth (nose-tail length, growth of the lower extremity), lengths of femur and tibia, growth at the proximal, epiphyseal growth plate and muscle mass. Glucocorticoid administration decreased spleen and thymus weight as well as the white blood cell count (WBC count), mainly due to a decrease in lymphocyte number. For all glucocorticoid doses examined, growth hormone increased weight gain and growth (nose-tail length, growth of the lower extremity), lengths of femur and tibia, and muscle mass. The effects of growth hormone were, however, dose-dependently decreased by glucocorticoid administration. Growth hormone injection alone increased the WBC count due to an increase in the number of lymphocytes and monocytes. When the two hormones were administered concomitantly, growth hormone did not, however, reverse the lymphocytopenic effect induced by glucocorticoid administration. In conclusion, growth hormone can increase longitudinal growth and increase muscle mass in glucocorticoid-injected rats, if a glucocorticoid preparation of a short half-life is used. Growth hormone does not reverse the lymphocytopenic effect of glucocorticoid injections.

Expression of growth hormone receptor by peripheral blood lymphocytes in children: evaluation in clinical conditions of impaired growth.

OBJECTIVE: It is widely accepted that the haematopoietic system is a target of growth hormone action and that GH may act as a lymphokine. The expression of GH receptors (GHR) on human peripheral blood lymphocytes (PBL) has been reported previously in adult donors by dual fluorochrome flow cytometry. The aim of this study was to apply the cytofluorimetric method to the analysis of GHR expression on PBL in various human conditions characterized by different patterns of growth due to age or physiopathological conditions. SUBJECTS AND DESIGN: PBL from 38 normal (control) subjects (7 newborns, 18 prepubertal children, 13 adults) were studied in order to provide age-related physiological data. Twenty-two short children (18 with idiopathic short stature, 4 with Ullrich-Turner syndrome) were studied to determine the expression of GHR in conditions of impaired longitudinal growth which may or may not require GH treatment. METHODS: Analysis was performed using a fluorescein isothiocyanate (FITC)-conjugated antibody specific for the GHR (mAb263) and phycoerythrin (PE)-anti CD2 (T and natural killer cells) or PE-anti CD2 (B cells) in dual fluorochrome flow cytometric assays. Results were expressed as mean fluorescent intensity (MFI). RESULTS: Adult CD2+ coils exhibited a significantly higher GHR expression (MFI 347 +/- 40) than that expressed in children and newborns (MFI 285 +/- 36 and 299 +/- 41, respectively, P < 0.001). A significantly increased expression of GHR on CD2+ cells was also found in short children (MFI 330 +/- 42 vs 285 42- 36, respectively; P < 0.002), whereas Ullrich-Turner syndrome patients did not show any difference from their age and gender matched controls (254 +/- 52 and 288 +/- 40, respectively). A negative relationship was found between GHR expression on CD2+ cells and height-SDS (r - 0.54, P < 0.0001) or BMI (r - 0.4, P < 0.015) in controls and short children, independent of their GH secretory status. Expression of GHR and CD20+ cells was higher than that expressed on CD2+ cells in all subjects. No appreciable differences were found in the MFI levels of GHR expression on CD20+ cells either among the different age group controls or between short children or Ullrich-Turner syndrome patients. A significant downregulation of expression was shown in CD20+ (P < 0.008) but not CD2+ cells after 6 months of GH treatment in 6 short children who had a poor response to GH provocative tests. CONCLUSIONS: GH receptor expression on immune cells in non-syndromic short children appears to be inversely related to the linear growth expression and BMI of the subjects, contrary to findings with hepatic derived serum GHBP. This finding may reflect alternate exon usage in lymphoid cells, and indicates that GH has a distinctive role in the immune system.

Lack of association of bovine MHC class I alleles with carcass and reproductive traits.

The present study was carried out to examine whether a relationship between bovine major histocompatibility complex (BoLA) class I alleles and carcass traits or reproductive performance exists in Braunvieh and Fleckvieh AI (artificial insemination) bulls. The influence of BoLA class I (BoLA-A) alleles on deregressed breeding values for net growth rate, carcass index and thigh volume was assessed in Braunvieh crosses and Fleckvieh bulls with a gene substitution model. The reproductive traits: non-return rate and interval between first and last insemination of daughters (female fertility), as well as non-return rate of inseminated cows (male fertility), were only investigated in Fleckvieh animals. No influence of the BoLA-A region on the traits evaluated could be demonstrated. An improper, i.e. less restrictive analysis would have led to spurious results.