Β-lactoglobulin Research Articles

Developing a synbiotic biotherapy to prevent allergic responses to food

Abstract Over the past generation, the prevalence of food allergies has risen dramatically, but the development of treatments has lagged. The commensal gut microbiome is critically involved in regulating allergic responses to food. Our laboratory has described a humanized model of cow’s milk allergy (CMA) in which germ-free mice are colonized with feces from healthy or CMA infants and sensitized to the cow’s milk allergen b-lactoglobulin (BLG). The healthy infant microbiota and specifically a single Clostridial species, Anaerostipes caccae, protect against the development of anaphylaxis, while the CMA microbiota does not induce this protection. We isolated a novel sub-strain of A. caccae (A. caccae_lahuc) from the feces of a healthy infant, sequenced its genome, and characterized its growth on various substrates in vitro. A. caccae_lahuc produces high concentrations of butyrate, a key immunoregulatory molecule in the gut which we hypothesize is critical to its protective impact. A. caccae_lahuc engrafts readily into the dysbiotic CMA microbiota, but co-delivery with lactulose is required for measurable butyrate production in vivo. Lactulose undergoes primary degradation by bacteria in the CMA feces which release small metabolites that A. caccae_lahuc can ferment into butyrate. Preliminary data show that this novel synbiotic biotherapy (A. caccae_lahuc + lactulose) prevents allergic responses to BLG in CMA-colonized mice as measured by serum mMCPT-1 and core body temperature upon challenge, and type 2 cytokine production in BLG-stimulated splenocytes. Further exploration into the mechanisms behind this therapeutic effect will contribute toward the larger goal of developing bacterial biotherapeutics against food allergies.

Hydrodynamics of Rising Air Bubbles in Mixture of Proteins with Non-Ionic Surfactants to Declare their Interaction at the Air-Water Interface

Evaluation of behaviour of adsorbed layers of protein-surfactant mixture at the air-water interfaces have recently received great attention due to their wide applications in food and pharmaceutical industries. In this research, qualitative study of surface activity of two kinds of proteins, Beta- Lactoglobulin (BLG) and Beta-Casein (BCS), nonioinic surfactant of C10DMPO, and the mixtures of them in different concentrations at the air-water interface is investigated using rising bubble method. The similarity between measured local velocity profiles can be due to the fact that all mentioned materials are surface-active one and could create the Marangoni effect and develop a dynamic adsorption layer. As there is no significant interaction between the protein and surfactant molecules, stable complex structures cannot be formed in the protein-C10DMPO mixture. The mixture velocity profile is more similar to that of the surfactant which is a result of replacement of protein molecules or complexes with free surfactant at the bubble interface. It is found that the mixture of non-ionic surfactant with BCS has a bit synergetic effect while for its mixture with BLG, a negative synergy is observed which is resulted from the shape of protein.

Safety of Beta-lactoglobulin as a Novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on beta‐lactoglobulin (BLG) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF (≥ 90% w/w dry matter protein) consists of BLG as primary component (≥ 90% of total protein), which is equivalent to BLG present in bovine milk and whey protein isolate (WPI). The NF is produced from bovine whey by crystallisation under acidic or neutral conditions. The NF is proposed to be used as a food ingredient in isotonic and sport drinks, whey powder and milk‐based drinks and similar products, and in food for special medical purposes as defined in Regulation (EU) No 609/2013. The target population is the general population. The highest daily intake of the NF was estimated for children of 3 to < 10 years of age as 667 mg/kg body weight (bw) per day. The NF presents proximate composition and content of essential amino acids similar to those in WPI. The Panel notes that the highest mean and highest 95th percentile daily protein intakes from the NF are below the protein population reference intakes for all population groups. Although a tolerable upper intake level has not been derived for protein, the protein intake from the NF may nevertheless further contribute to an already high dietary protein intake in Europe. The exposure to the reported minerals does not raise concerns. The Panel considers that the consumption of the NF is not nutritionally disadvantageous. No genotoxic concerns were identified from the standard in vitro test battery. No adverse effects were observed in the subchronic toxicity study, up to the highest dose tested, i.e. 1,000 mg NF/kg bw per day. The Panel concludes that the NF is safe under the proposed conditions of use.

Beta-Lactoglobulin as a Model Food Protein: How to Promote, Prevent, and Exploit Its Unfolding Processes.

Bovine milk beta-lactoglobulin (BLG) is a small whey protein that is a common ingredient in many foods. Many of the properties of BLG relevant to the food industry are related to its unfolding processes induced by physical or chemical treatments. Unfolding occurs through a number of individual steps, generating transient intermediates through reversible and irreversible modifications. The rate of formation of these intermediates and of their further evolution into different structures often dictates the outcome of a given process. This report addresses the main structural features of the BLG unfolding intermediates under conditions that may facilitate or impair their formation in response to chemical or physical denaturing agents. In consideration of the short lifespan of the transient species generated upon unfolding, this review also discusses how various methodological approaches may be adapted in exploring the process-dependent structural modifications of BLG from a kinetic and/or a thermodynamic standpoint. Some of the conceptual and methodological approaches presented and discussed in this review can provide hints for improving the understanding of transient conformers formation by proteins present in other food systems, as well as when other physical or chemical denaturing agents are acting on proteins much different from BLG in complex food systems.

Determination of specific and non-specific protein-protein interactions for beta-lactoglobulin by analytical ultracentrifugation and membrane osmometry experiments.

Protein-protein interactions are essential for the understanding of biological processes. Specific protein aggregation is an important aspect for many biological systems. In particular, electrostatic interactions play the key role for protein-protein interactions, as many amino acids have pH-dependent charge states. Moreover, protein dissociation is directly related to the solution pH, ionic strength, temperature and protein concentration. The subtle interplay between different specific and non-specific interactions is demonstrated for beta-lactoglobulin (BLG) with a focus on low salt concentrations, thus mimicking technically relevant processing conditions. BLG is a well-characterized model system, proven to attain its monomer-dimer equilibrium strongly dependent upon the pH of the solution. In this manuscript, we present a unique combination of analytical ultracentrifugation and membrane osmometry experiments, which quantifies specific and non-specific interactions, i.e. in terms of the dimer dissociation constants and the second osmotic virial coefficient, at pH 3 and 7 and sodium chloride concentrations of 10 mM and 100 mM. This provides direct insight to protein-protein interactions for a system with a concentration-dependent monomer-dimer equilibrium. Moreover, using a coarse-grained extended DLVO model in combination with molecular dynamics simulations, we quantify non-specific monomer-monomer, monomer-dimer and dimer-dimer interactions as well as the binding free energy of BLG dimerization from theoretical calculations. The experimentally determined interactions are shown to be mainly governed by electrostatic interactions and further agree with free energy calculations. Our experimental protocol aims to determine non-specific and specific interactions for a dynamically interacting system and provides an understanding of protein-protein interactions for BLG at low salt concentrations.

Micronutritional supplementation with a holoBLG-based FSMP (food for special medical purposes)-lozenge alleviates allergic symptoms in BALB/c mice: Imitating the protective farm effect.

Previously, the protective farm effect was imitated using the whey protein beta-lactoglobulin (BLG) that is spiked with iron-flavonoid complexes. Here, we formulated for clinical translation a lozenge as food for special medical purposes (FSMP) using catechin-iron complexes as ligands for BLG. The lozenge was tested in vitro and in a therapeutical BALB/c mice model. Binding of iron-catechin into BLG was confirmed by spectroscopy and docking calculations. Serum IgE binding of children allergic or tolerating milk was assessed to loaded (holo-) versus empty (apo-) BLG and for human mast cell degranulation. BLG and Betv1 double-sensitized mice were orally treated with the holoBLG or placebo lozenge, and immunologically analysed after systemic allergen challenge. Human PBMCs of pollen allergic subjects were flow cytometrically assessed after stimulation with apoBLG or holoBLG using catechin-iron complexes as ligands. One major IgE and T cell epitope were masked by catechin-iron complexes, which impaired IgE binding of milk-allergic children and degranulation of mast cells. In mice, only supplementation with the holoBLG lozenge reduced clinical reactivity to BLG and Betv1, promoted Tregs, and suppressed antigen presentation. In allergic subjects, stimulation of PBMCs with holoBLG led to a significant increase of intracellular iron in circulating CD14+ cells with significantly lower expression of HLADR and CD86 compared to their stimulation with apoBLG. The FSMP lozenge targeted antigen presenting cells and dampened immune activation in human immune cells and allergic mice in an antigen-non-specific manner, thereby conferring immune resilience against allergic symptoms.

Meta-Analysis of Gene Polymorphism of Beta-Lactoglobulin Gene in Indian Dairy Cows.

The aim of the present paper was to summarize the gene polymorphisms of beta-lactoglobulin (BLG) gene and its effects on milk yield in 1840 genotyped Indian dairy cows reported in 17 published studies. The meta-analysis was undertaken using gene frequencies of individual studies under random effects model, whereas for association analysis of genotypes with milk yield, standardized mean differences (SMDs) along with 95% confidence interval (CI) were obtained under four genetic models such as additive (AA vs. BB), dominant (AA+AB vs. BB), completely over dominant (AA+BB vs. AB) and recessive (AA vs. AB+BB). The heterogeneity index (I2) was used to determine heterogeneity between studies. The results of meta-analysis suggested that the pooled allelic frequency of allele A was subsidiary as 0.29 (95% CI 0.24, 0.33, I2 = 88.54%) in targeted population, and also, it was non-significantly (P > 0.05) different between Bos indicus (0.28) and Bos taurus/cross cows (0.30). Egger's test indicated no risk of publication bias (P > 0.05). The results also revealed that BLG gene variants have non-significant (P > 0.05) association with milk yield under all genetic models. Although positive effects of SMDs under some models were observed, however, they failed to meet statistical significance (P > 0.05) due to high heterogeneity between studies which lead to conclusion of only uncertain influences of SNP genotypes with milk yield. It was concludedthat BLG markers may not be beneficial for improving milk yield in Indian dairy cows. However, it is suggested that the revalidation of the present results should be done by using more number of studies.

Emulsifiers modulate the extent of gastric lipolysis during the dynamic in vitro digestion of submicron chia oil/water emulsions with limited impact on the final extent of intestinal lipolysis

Consumer demands for healthier foods are constantly on the rise and results in the diversification of sources such as vegetable oils. Chia oil is a relevant source of α-linolenic acid. One of the targeted applications is the inclusion of chia oil in emulsified form in beverages where it is necessary to obtain stable submicron emulsions, acting as carrier of nutrients such as lipids. In the present work, high-pressure homogenization was employed to produce emulsions (10% chia oil) with small oil droplets (300 nm), formulated with different emulsifiers (beta-lactoglobulin (BLG), lecithin and Tween 80). These emulsions were submitted to a dynamic in vitro digestion (DIDGI) to better understand the main mechanisms involved in the process of lipolysis, in order to design systems that may allow the modulation of the digestive action of lipases, thus ensuring the maximum bioaccessibility of the lipids. This device mimics part of the transient biochemical conditions as well as the flow of foods through the different compartments occurring in the real digestion. Significant differences were observed in the lipolysis during the gastric phase. BLGemulsions reached a lipolysis degree of 30%. Lecithin-stabilized emulsions behave similarly to BLG ones during the first 90 min but lipolysis levelled off further ∼20%. Finally, Tween-80-stabilized emulsions remained almost undigested (around 2%). No significant differences were noticed in duodenum and distal small intestine, irrespective of the emulsifier employed. After digestion, the fatty acid bioaccessibility was higher with BLG as emulsifier.

Peptide Characterization and Functional Stability of a Partially Hydrolyzed Whey-Based Formula over Time.

Human clinical trials have shown that a specific partially hydrolyzed 100% whey-based infant formula (pHF-W) reduces AD risk in the first yeast of life. Meta-analyses with a specific pHF-W (pHF-W1) confirm a protective effect while other meta-analyses pooling different pHF-W show conflicting results. Here we investigated the molecular composition and functional properties of the specific pHF-W1 as well as the stability of its manufacturing process over time. This specific pHF-W1 was compared with other pHF-Ws. We used size exclusion chromatography to characterize the peptide molecular weight (MW), a rat basophil degranulation assay to assess the relative level of beta-lactoglobulin (BLG) allergenicity and a preclinical model of oral tolerance induction to test prevention of allergic sensitization. To analyze the exact peptide sequences before and after an HLA binding assay, a mass cytometry approach was used. Peptide size allergenicity and oral tolerance induction were conserved across pHF-W1 batches of production and time. The median MW of the 37 samples of pHF-W1 tested was 800 ± 400 Da. Further oral tolerance induction was observed using 10 different batches of the pHF-W1 with a mean reduction of BLG-specific IgE levels of 0.76 log (95% CI = −0.95; −0.57). When comparing pHF-W1 with three other formulas (pHF-W2 3 and 4), peptide size was not necessarily associated with allergenicity reduction in vitro nor oral tolerance induction in vivo as measured by specific IgE level (p < 0.05 for pHF-W1 and 2 and p = 0.271 and p = 0.189 for pHF-W3 and 4 respectively). Peptide composition showed a limited overlap between the formulas tested ranging from 11.7% to 24.2%. Furthermore nine regions in the BLG sequence were identified as binding HLA-DR. In conclusion, not all pHF-Ws tested have the same peptide size distribution decreased allergenicity and ability to induce oral tolerance. Specific peptides are released during the different processes used by different infant formula producers.

Limited Lactosylation of Beta-Lactoglobulin from Cow's Milk Exerts Strong Influence on Antigenicity and Degranulation of Mast Cells.

Background: beta-lactoglobulin (BLG) is one of the major cow’s milk proteins and the most abundant allergen in whey. Heating is a common technologic treatment applied during milk transformational processes. Maillardation of BLG in the presence of reducing sugars and elevated temperatures may influence its antigenicity and allergenicity. Primary objective: to analyze and identify lactosylation sites by capillary electrophoresis mass spectrometry (CE-MS). Secondary objective: to assess the effect of lactosylated BLG on antigenicity and degranulation of mast cells. Methods: BLG was lactosylated at pH 7, a water activity (aw) of 0.43, and a temperature of 65 °C using a molar ratio BLG:lactose of 1:1 by incubating for 0, 3, 8, 16 or 24 h. For the determination of the effect on antibody-binding capacity of lactosylated BLG, an ELISA was performed. For the assessment of degranulation of the cell-line RBL-hεIa-2B12 transfected with the human α-chain, Fcε receptor type 1 (FcεRI) was used. Results: BLG showed saturated lactosylation between 8 and 16 incubation hours in our experimental setup. Initial stage lactosylation sites L1 (N-terminus)—K47, K60, K75, K77, K91, K138 and K141—have been identified using CE-MS. Lactosylated BLG showed a significant reduction of both the IgG binding (p = 0.0001) as well as degranulation of anti-BLG IgE-sensitized RBL-hεIa-2B12 cells (p < 0.0001). Conclusions and clinical relevance: this study shows that lactosylation of BLG decreases both the antigenicity and degranulation of mast cells and can therefore be a promising approach for reducing allergenicity of cow’s milk allergens provided that the process is well-controlled.

Analysis of peptides in a sheep beta lactoglobulin hydrolysate as a model to evaluate the effect of peptide amino acid sequence on bioactivity

Fungal protease FPII was found to hydrolyse sheep β-lactoglobulin (β-Lg), and the hydrolysate exhibited substantial antioxidant and ACE inhibition bioactivities. From analysis of the peptide sequences in the hydrolysate in relation to bioactivity, synthetic peptides corresponding to four regions of sequence in β-Lg (LAFNPTQLEGQCHV, DTDYKKYLLF, LDAQSAPLRVY and VEELKPTPE) were analysed for bioactivity. Additional synthetic peptides were designed to examine the bioactivity of different parts of the above four sequences, and the effect of amino acid substitutions on bioactivity. The results show that parts of the peptide sequences contribute differently to bioactivity and substitution of amino acids has a substantial effect on antioxidant and ACE inhibition activities.

Targeted micronutrition for allergic patients—possible applications of a food for special medical purposes

SummaryA novel and recently launched food for special medical purposes was discussed by a multidisciplinary expert panel as an option for allergic patients. The newly developed lozenge contains the whey protein beta-lactoglobulin (BLG) as well as the micronutrients iron, zinc and vitamin A. BLG loaded with ligands (holo-BLG) is discussed as one factor of the allergy-protective farm effect in numerous scientific studies. Further studies reveal that holo-BLG shuttles its ligands specifically to immune cells, where it balances the specific nutrient demand and can thus lead to immune resilience. Based on the scientific background, the experts see a broad range of possible applications for holo-BLG in the form of a lozenge, for example in patients suffering from multiple allergies, with sensitisation to rare allergens (including occupational allergens), tree pollen-associated food allergies or in general difficult treatment situations (e.g. allergies to animal dander or refusal of allergen immunotherapy). The expert panel describes the holo-BLG lozenge as an innovative and additional option for allergic patients.

Assessing the degradation of ancient milk proteins\xa0through site-specific deamidation patterns

The origins, prevalence and nature of dairying have been long debated by archaeologists. Within the last decade, new advances in high-resolution mass spectrometry have allowed for the direct detection of milk proteins from archaeological remains, including ceramic residues, dental calculus, and preserved dairy products. Proteins recovered from archaeological remains are susceptible to post-excavation and laboratory contamination, a particular concern for ancient dairying studies as milk proteins such as beta-lactoglobulin (BLG) and caseins are potential laboratory contaminants. Here, we examine how site-specific rates of deamidation (i.e., deamidation occurring in specific positions in the protein chain) can be used to elucidate patterns of peptide degradation, and authenticate ancient milk proteins. First, we characterize site-specific deamidation patterns in modern milk products and experimental samples, confirming that deamidation occurs primarily at low half-time sites. We then compare this to previously published palaeoproteomic data from six studies reporting ancient milk peptides. We confirm that site-specific deamidation rates, on average, are more advanced in BLG recovered from ancient dental calculus and pottery residues. Nevertheless, deamidation rates displayed a high degree of variability, making it challenging to authenticate samples with relatively few milk peptides. We demonstrate that site-specific deamidation is a useful tool for identifying modern contamination but highlight the need for multiple lines of evidence to authenticate ancient protein data.

Identification of Goats’ and Cows’ Milk Protein Profile in Banyumas Regency by Sodium Dedocyl Sulphate Gel Electrophoresis (Sds-Page)

Protein is one of the nutrient components in milk that is related to product quality. The components of milk protein are divided into casein alpha-s1, beta, alpha-s2, kappa, and whey fractions such as alpha lactalbumin and beta lactoglobulin. There are no existing data of milk protein fraction in dairy cow and goats in Banyumas Regency. This study aimed to determine the profile in form of protein fractions of cow and goat milk in Banyumas. Milk sample from fifty cows and thirty dairy goats was taken by random sampling in some areas. The milk protein profile was identified by the technique of sodium dodecyl sulphate gel electrophoresis (SDS-PAGE) and protein quantity prediction by software. The data obtained were analyzed statistically by Mann-Whitney between cows and goats. The results were significantly different (p&lt;0.05) between cows and goats in molecular weight of protein alpha-S1 casein (29.66 vs 33.37 kDa), alpha-S2 (27.76 vs 29.49 kDa), beta (24 , 48 vs 25.59 kDa) and beta lactoglobulin (15.75 vs 15.97 kDa). The quantity of casein alpha-S1 (7.88 vs 4.16 g/l), alpha-S2 (1.31 vs. 4.02 g/l), beta (8.74 vs 14.24 g/l), kappa (2.41 vs. 4.28 g/l) and alpha lactalbumin (0.91 vs 0.7 g / l) was significantly different (p &lt;0.05) between cow's and goat's milk, respectively. In conclusion, milk protein profile of cows and goats in Banyumas Regency is different.

One Health in allergology: A concept that connects humans, animals, plants, and the environment.

One Health is "a collaborative effort of multiple disciplines - working locally, nationally, and globally - to attain optimal health for people, animals, and the environment", the so-called One Health triad1 (Fig. 1).Historically, aspects of One Healthwere already discussed in the fourth century by Hippocrates, who realized that a clean environment is very important for human health1 . More recently, Rudolf Virchow (1821-1902) coined the term "zoonosis" in 1880and fathered modern One Healthin the sense of OneMedicine by strongly supporting the view of human and animal health being linked to each other.1.

Bovine Holo-Beta-Lactoglobulin Cross-Protects Against Pollen Allergies in an Innate Manner in BALB/c Mice: Potential Model for the Farm Effect.

The lipocalin beta-lactoglobulin (BLG) is a major protein compound in cow’s milk, and we detected it in cattle stable dust. BLG may be a novel player in the farm protective effect against atopic sensitization and hayfever. In previous studies, we demonstrated that only the ligand-filled holo-form of BLG prevented sensitization to itself. Here, we investigated whether holo-BLG could, in an innate manner, also protect against allergic sensitization to unrelated birch pollen allergens using a murine model. BALB/c mice were nasally pretreated four times in biweekly intervals with holo-BLG containing quercetin–iron complexes as ligands, with empty apo-BLG, or were sham-treated. Subsequently, mice were intraperitoneally sensitized two times with apo-BLG or with the unrelated birch pollen allergen apo-Bet v 1, adjuvanted with aluminum hydroxide. After subsequent systemic challenge with BLG or Bet v 1, body temperature drop was monitored by anaphylaxis imaging. Specific antibodies in serum and cytokines of BLG- and Bet v 1-stimulated splenocytes were analyzed by ELISA. Additionally, human peripheral blood mononuclear cells of pollen allergic subjects were stimulated with apo- versus holo-BLG before assessment by FACS. Prophylactic treatment with the holo-BLG resulted in protection against allergic sensitization and clinical reactivity also to Bet v 1 in an unspecific manner. Pretreatment with holo-BLG resulted in significantly lower BLG-as well as Bet v 1-specific antibodies and impaired antigen-presentation with significantly lower numbers of CD11c+MHCII+ cells expressing CD86. Pretreatment with holo-BLG also reduced the release of Th2-associated cytokines from Splenocytes in BLG-sensitized mice. Similarly, in vitro stimulation of PBMCs from birch pollen allergic subjects with holo-BLG resulted in a relative decrease of CD3+CD4+ and CD4+CRTh2 cells, but not of CD4+CD25+CD127− Treg cells, compared to apo-BLG stimulation. In conclusion, prophylactic treatment with holo-BLG protected against allergy in an antigen-specific and -unspecific manner by decreasing antigen presentation, specific antibody production and abrogating a Th2-response. Holo-BLG therefore promotes immune resilience against pollen allergens in an innate manner and may thereby contribute to the farm protective effect against atopic sensitization.

Properties of hydrolyzed α-lactalbumin, β-lactoglobulin and bovine serum albumin by the alcalase and its immunemodulation activity in Raw 264.7 cell

Properties of hydrolyzed α-lactalbumin, β-lactoglobulin and bovine serum albumin by the alcalase and its immunemodulation activity in Raw 264.7 cell

Effect of BLG gene variants on milk-related traits in small ruminants: a meta-analysis

This study aimed to investigate the effect of A and B alleles of beta-lactoglobulin (BLG) gene on milk-related traits in small ruminants by using data reported in 26 potential articles. Records from 9439 genotyped sheep and goats were analysed by utilising four genetic models, including dominant (AA + AB vs BB), recessive (AA vs AB + BB), additive (AA vs BB), and co-dominant (AA + BB vs AB). The effect size of each genotype on daily milk yield, fat percentage, and protein percentage was measured as a standardised mean difference (SMD). The fixed-effects or random-effects model was used to analyse data based on the results of the heterogeneity test. The results showed that B allele of BLG gene positively, but slightly increased the fat percentage of milk in combined data of sheep and goat under dominant (SMD = 0.207, p = .018), recessive (SMD = 0.190, p = .000) and additive (SMD = 0.699, p = .003) genetic models. Also, a statistically significant effect of B allele on daily milk yield of goat was found under dominant (SMD = 0.208, p = .001) and co-dominant (SMD = −0.149, p = .002) models. There was no association between studied alleles and milk protein percentage in sheep and goat. Results of publication bias tests showed a lack of bias and sensitivity analyses suggested additive model as the best one and animals with BB genotype showed highest performance in milk fat production with a SMD equal to 0.699. Highlights Meta-analyses results indicated a small to medium association between BLG variants and daily milk yield in goats The B allele of BLG gene positively affect milk fat percentage in small ruminants The sensitivity analysis suggested additive genetic models for analysing data of fat percentage in small ruminants, based on the absence of outlier studies No association between BLG variants and milk protein was found

EFFECT OF PROLACTIN (PRL) AND BETA-LACTOGLOBULIN (BLG) GENES ON INDICATORS OF DAIRY PERFORMANCE IN COWS OF RED BELARUSIAN BREED GROUP

Studies show that according to the prolactin gene (PRL), the highest milk yield was determined in the first-calf heifers with the PRLAB genotype by 2.5%, and in cows of the second and third lactations – with the PRLAA genotype by 0.8-7.0%. In terms of fat and milk protein content, animals with the PRLAB genotype had higher rate than those with the PRLAA genotype by 0.1-0.2 pp, the second and especially third lactation animals having the most noticeable changes. For the beta-lactoglobulin (BLG) gene, animals with the BLGBB genotype had the higher rate of milk yield for 305 days of lactation, as well as the amount of milk fat and lactoprotein. With an increase in the lactation ordinal number, the difference in these indices between the BLGAB and BLGAA herdmates increased.

EFFECT OF PROLACTIN (PRL) AND BETA-LACTOGLOBULIN (BLG) GENES ON DAIRY PERFORMANCE INDICATORS IN THE HIGHLY HOLSTEINIZED BELARUSIAN BLACK-AND-WHITE BREED

The study show that for the prolactin gene (PRL), the highest milk yield for the period of 305 days of lactation was in first-calvers, cows of the second and third lactations having the PRLAB genotype. They were superior to their homozygotic herd mates on the PRLA allele by 1.2-10.7%, and on the PRLB allele by 4.2-9.4%. In terms of butterfat percentage, animals with the PRLBB genotype had higher rates, and in terms of milk protein content, animals with the PRLAB and PRLAA genotypes had higher rates. In terms of the amount of fat and protein in milk in first-calvers, homozygous individuals with the PRLAA genotype had higher rates, and in second and third lactation cows, heterozygous individuals with the PRLAB genotype had higher rates. For the beta-lactoglobulin (BLG) gene, the higher quantitative indicators for milk yield within 305 days of lactation, as well as for the content of milk fat and protein were in first-calvers with the BLGAA genotype, for the second and third lactation – animals with the BLGAB genotype.