Genotype In Cases Research Articles

Investigation of the influence of milk protein genotype on the process of fermentation of milk curds by mesophilic lactic acid streptococci

The relevance of this study lies in the fact that the majority of commercial milk processed into fermented dairy products is a mixture of β-casein genotypes. The increasing use of A2 milk in the dairy industry necessitates the development of scientifically grounded technologies for the production of fermented products, as casein genotype modifications can affect the course of technological processes and require adjustments to production parameters. The study aimed to determine the impact of genetic modification of the β-casein protein in cow’s milk on the fermentation process of milk mixtures during the production of fermented dairy products. Research methods included chemical, physical, organoleptic, and microbiological methods (determination of the quality indicators of raw milk and fermented milk curds), and technological methods (determination of acid formation activity and viscosity). The initial characteristics of raw milk were investigated according to genotype, revealing no direct correlation. Changes in the physicochemical, microbiological, and organoleptic properties of fermented milk curds during biotechnological processing and storage were examined. Optimal technological process regimes were selected, and technological methods were chosen to minimise the influence of secondary factors on the experiment. A mixed culture preparation of mesophilic lactic acid lactococci, including L. Lactis ssp., was chosen as a starter culture. It was established that all 13 milk samples were suitable for biotechnological processing using mixed cultures of mesophilic lactic acid bacteria. As a result, it was concluded that the production of fermented dairy products from raw milk with the presented β-casein genetic modifications, A1A1, A1A2, and A2A2 – using L. lactis ssp. cultures – is possible using the classical technology and does not require adjustment of the technological conditions. The obtained results can be used in the dairy industry when developing technologies for fermented dairy products from A2 raw milk

Estimating the Effect of the Kappa Casein Genotype on Milk Coagulation Properties in Israeli Holstein Cows.

In Israel, about 26% of produced milk is used to produce hard cheeses and 29% for soft cheeses. Milk with preferred coagulation properties requires a shorter coagulation time and yields a higher curd firmness than milk with inferior coagulation properties. Studies have shown that milk from cows with the B allele of kappa casein (κ-CN) produces more cheese than milk from those with A and E alleles. There is evidence that milk from AE or EE genotype cows is unsuitable for cheese production. In the early 1990s, the proportion of the B allele in Israeli Holstein cattle was about 17%, similar to its prevalence in the Holstein population worldwide. In recent years, however, its proportion has increased to about 40%. We analyzed milk coagulation properties as a function of the cow's κ-CN genotype, including time in minutes until the beginning of coagulation and curd firmness after 60 min-measured in volts via an optigraph device and scored on a scale of 0-4 by a laboratory technician. Cow selection was based on their sire's genotype, so that there would be sufficient genotypes that include the rare E allele. A total of 359 cows were sampled from 15 farms: 64 with genotype AA, 142 with AB, 41 with AE, 65 with BB, and 47 with BE. Data were analyzed via the general linear model procedure of SAS. We found the following: (a) There were significant differences between genotypes for optigraph-measured curd firmness. In a multi-comparison test, the BB genotype gave the highest curd firmness, and AB and BE showed a significant advantage compared to AA and AE (9.4, 8.6, 8.4, 6.9, 6.8 V, respectively). Assuming a frequency of about 55% for the A allele, about 30% of the milk delivered to dairy plants comes from AA cows. (b) There was a significant difference between the genotypes in technician-observed curd firmness, with BB scoring significantly higher than AA and AE. (c) The optigraph-measured curd firmness was significantly higher for milk from primiparous cows as compared to milk from second, third, or fourth lactation cows (8.9, 7.8, 7.9, 7.7 V, respectively). The technician-observed curd firmness was significantly higher for primiparous vs. multiparous cows. There was a clear advantage in curd firmness for genotypes that included the B allele compared to those with AA and AE genotypes. We can increase the proportion of the B allele in the population by insemination of cows using bulls with the genotypes AB and BB. This factor should therefore be included in the selection index.

Retraction Note: Influence of the kappa casein genotype on the technological properties of cow milk of Simmental and Alatau breeds.

Retraction Note: Influence of the kappa casein genotype on the technological properties of cow milk of Simmental and Alatau breeds.

ФОРМИРОВАНИЕ ГЕНЕАЛОГИЧЕСКОЙ СТРУКТУРЫ ПОГОЛОВЬЯ БЫКОПРОИЗВОДЯЩИХ КОРОВ И ПЛЕМЕННЫХ БЫКОВ ГОЛШТИНСКОЙ ПОРОДЫ МОЛОЧНОГО СКОТА ОТЕЧЕСТВЕННОЙ СЕЛЕКЦИИ В ПЛЕМЕННЫХ СЕЛЬСКОХОЗЯЙСТВЕННЫХ ПРЕДПРИЯТИЯХ МИНСКОЙ ОБЛАСТИ С УЧЕТОМ ГЕНОТИПОВ ПО β -КАЗЕИНУ

For the first time in the Republic of Belarus, following the example of agricultural enterprises of the Minsk region, there has been formed the genealogical structure in herds of bull-producing cows and breeding bulls of the Holstein dairy cattle breed of domestic selection, considering the β -casein genotypes. It has been established that animals with the A2A2 β -casein genotype belong to all six planned genealogical complexes that make up the structure of the Holstein breed. The RUAE Minsk Pedigree Breeding Enterprise possesses a sufficient stock of sperm doses taken from breeding bulls with the A2A2 β -casein genotype to obtain replacement bulls of all complexes and develop selection herds with the desired genotype, producing A2 milk.

RETRACTED: Analysis of SOCS3 gene genotype in patients with acute cerebral infarction and its relationship with disease progression

This reseaech aimed to analyze the polymorphism of SOCS3 gene in patients with acute cerebral infarction (ACI), and to explore its relationship with disease progression. A total of 310 patients with ACI were categorized into mild stroke group and moderate to severe stroke group according to the National Institute of Stroke Scale (NIHSS) score at admission. Based on NIHSS scores at 7 days after admission, patients were further divided into advanced group and non-advanced group. According to the results of SOCS3 gene detection, three genotypes of rs8064821 were detected: CC, CA and AA. The distribution difference of the genotypes and their predictive possibility were reckoned. The distribution of SOCS3 genotype at rs8064821 in patients with ACI was CC (161 cases), CA (127 cases), and AA (22 cases), with frequencies of 51.93%, 40.97%, and 7.10%, respectively. Compared with mild group, the proportion of CC genotype was lower, while the proportion of CA and AA genotypes was higher in moderate-severe stroke group (P<0.01). Compared with non-advanced group, patients who advanced to neurological deficit had a lower proportion of CC genotype, and a higher proportion of CA and AA genotype (P<0.01). CA and AA genotypes were the main genotypes of SOCS3 in patients with ACI in northern Anhui of China. The disease was more severe in patients with CA and AA, who are more likely to develop neurological deficits.

Formation of economically useful traits in cows of ukrainian black-and-white dairy breed of different genotypes by kappa-casein

The influence of kappa casein genotype on the formation of economically useful traits of Ukrainian black-and-white dairy cattle has been studied. Genotyping of 25 heads of cattle of the Ukrainian black-and white dairy breed belonging to the Breeding Plant of the State Enterprise "Research Farm of the Institute of Agriculture of Northern East of NAAS" was carried out. Determination of polymorphism of the kappa-casein gene was performed in the genetic laboratory of the Bogomolets Institute of Physiology of NAS using molecular biological analysis of allele recognition by polymerase chain reaction (PCR) in real time. To assess the economically useful features used an electronic database of SUMS "Orsek". The content of milk components was determined in the laboratory of Sumy National Agrarian University on the equipment Ultrasonic milk analyzer Master Classic. It was found that the animals met the breed standard in almost all indicators of milk productivity. Between animals of different genotypes the difference on separate economically useful signs is revealed. However, in different periods and on different grounds, it varied greatly, and in some cases it was statistically significant. The genotype for kappa-casein did not have a significant effect on live weight in all study periods. Animals with the AA genotype predominated on this trait of animals of other genotypes. At the same time, animals of all studied genotypes in almost all age periods exceeded the breed standard. According to the results of the assessment of the reproductive capacity of animals, it was found that the youngest age of the first insemination is characteristic of animals with genotype AA, and the highest - with genotype BB. The age of first insemination in animals with genotype AA was less than the average for the herd. The live weight of these animals was the largest and was higher than the average for the herd. The average duration of the service period for the herd was 130 days. It was lowest in animals with homozygous BB genotype (P &lt;0.05). Accordingly, the duration of the period between calving and the value of the reproductive capacity were the lowest in homozygous (BB) animals (P &lt;0.05). The level of average milk yield of an animal with the desired genotype (BB) was lower than the average yield of animals with other studied genotypes. They were also inferior to the average indicator of the herd. The level of milk yield of animals of all genotypes was higher than the breed standard. It was found that the average fat content in the milk of animals of homozygous genotypes AA and BB slightly prevailed over animals with heterozygous genotype AB. Animals with the BB genotype (p &lt;0.05) were statistically significantly superior in protein content. Compliance with the breed standard in terms of fat content in milk is positive, and only homozygous (BB) animals met the standard in terms of protein content. In terms of dry matter content, dry nonfat milk residue, casein, animals with homozygous BB genotype were preferred. In terms of lactose content, animals with the AA genotype were preferred. It is proved that the formation of herds with BB genotype for kappa-casein will not have a negative impact on the economically useful characteristics of animals. Key words: genotype, kappa-casein, live weight, reproductive capacity, milk productivity.

Use of allele specific PCR to investigate the presence of β-casein polymorphism in Holstein-Friesian cows

Following the ?one health? principle, we have conducted optimization of a protocol for ?-casein genotyping in cattle in order to select cows with exclusively the A2A2 genotype. Gastrointestinal proteolysis of A1 ?-casein in humans releases beta-casomorphin 7, which is believed to cause a number of diseases/conditions (diabetes mellitus type 1, ischemic heart disease, atherosclerosis, sudden infant death syndrome, autism, schizophrenia, gastrointestinal discomfort, and prolonged gastrointestinal passage time). On the contrary, A2 ?-casein does not cause similar effects on human health, due to its different metabolism. DNA extraction was conducted from blood samples belonging to the laboratory archive of the Department of Biology, Faculty of Veterinary Medicine, University of Belgrade. Determination of genotypes was performed using the Allele Specific Polymerase Chain Reaction (AS-PCR) method. The amplification was preceded by determination of proper primer annealing temperature (65.50 ?C), in order to ensure optimal genotyping results. The results obtained indicated a higher frequency of the A2 allele (0.56) compared to the A1 allele (0.44). Furthermore, in 7 out of 35 tested samples, the A1A1 genotype (20.00%) was found, in 17 samples, the A1A2 genotype (48.60%) was found, and in 11 samples, the A2A2 genotype (31.40%) was found. The molecular methods used ensured reliable ?-casein genotyping that would enable selection of cows with the A2A2 ?-casein genotype, implying production of.

Identification of β Casein Genotypes in Indian Gir and Crossbred Exotic Cows from Mumbai Dairy Farms

Background: Collective evidence of polymorphic β-casein and associated health problems has led to the concern about milk consumption and cow breeding policies worldwide. This association has also engrossed the interest of dairy scientist and industry in evaluation of β casein genotype distribution. With increasing proportion of exotic and crossbred cows in India it is worth while to screen cattle for A1A2 β casein and enhance indigenous cow breeds. Methods: The present study intended to identify β casein genotypes in pure Indian Gir cows and crossbred Holstein and jersey cows from three local dairy farms. We analysed β casein genotypes by PCR-RFLP method in total 95 cows during the period of 2017-2019. Result: All the indigenous Gir cows had fixed A2 allele whereas crossbred Jersey and Holstein Frisian both had A1A2 as the most common genotype (frequency: 0.473 and 0.6 respectively) followed by A2A2 (Frequency 0.368 and 0.333 respectively) and A1A1 (Frequency 0.158 and 0.066 respectively). The results show that in this study group Gir, a native Indian breed has fixed A2 β casein variant whereas crossbred Jersey and Holstein Frisian have A1A2 as a most common genotype. Screening of cattle for â casein genotypes is vital to monitor the frequency of A1 beta casein in native Indian cow breeds.

Influence of the kappa casein genotype on the technological properties of cow milk of Simmental and Alatau breeds.

The main objective of dairy farming is to obtain highly productive animals that produce milk with high protein content and have good technological properties. Currently, with the development of molecular genetics and molecular biology, it is possible to identify genes directly or indirectly associated with the milk production of animals. The identification of variants of such genes that are preferable from the standpoint of selection will allow, apart from the conventional selection of animals, to perform selection at the level of deoxyribonucleic acid technologies, i.e. according to genotype. The paper includes the study of milk productivity indicators and physicochemical quality indicators of milk from cows of Simmental and Alatau breeds by loci of the kappa casein gene, and also determines the cheese suitability and technological properties of milk of cows of Simmental and Alatau breeds with different genotypic affiliations for kappa casein for the production of semi-hard cheeses. The determination of polymorphism by the kappa casein gene was carried out with the use of the polymerase chain reaction method for genotyping of the major milk proteins of kappa casein gene. In a comparative aspect, the interrelation of genotypes with milk productivity was studied, the frequencies of allelic polymorphism of cows of Simmental and Alatau breeds in the Republic of Kazakhstan were identified, the nature of milk productivity was determined for each genotype. Scientifically based data on the assessment of biological value, technological properties, cheese suitability of milk of cows of Simmental and Alatau breeds are obtained.

ANALYSIS OF COMPLEX GENOTYPES OF BETA- AND KAPPA CASEIN OF BULLS OF DAIRY BREEDS

Marker-dependent breeding is one of the most relevant areas for improving the dairy productivity of cattle. It allows the selection of parent forms at the gene level. The growing demands of the market for milk quality make it necessary to select dairy herds using genetic markers associated with qualitative characteristics of milk productivity. A topical issue in dairy cattle breeding today is the study of the relationship between hereditary factors that determine the types of proteins in milk. Casein is the main component of milk proteins and is represented by three fractions – alpha (CSN1S1), beta (CSN2) and kappa (CSN3). The content of individual casein fractions depends on the breed of cows. Genetic variants of beta-casein significantly affect human health, while kappa-casein is associated with the quality of milk and the greater suitability of milk for processing and cheese production.&#x0D; The aim of this work is to evaluate the genotype of sires approved for use in Ukrainian farms in 2020 based on beta- and kappa-casein genes.&#x0D; Materials and methods. The research was conducted by analyzing the catalog of bulls of dairy and dairy-meat breeds for breeding stock reproduction in 2020. Bulls were analyzed according to the genotype of beta – and kappa-casein of Holstein (n = 872), Simmental (n = 17), Montbellard (n = 3), (wro.synel.net; motbeliarde.org) Jersey (n = 59), Red Danish (n = 8), Red Norwegian (n = 7), Schwyz (n = 17), Aishir (n = 8) breeds, evaluated by offspring quality and genomic assessment. The website DairyBulls.com is used to analyze the results of the evaluation of bulls-producers on a set of characteristics. The research results were processed by mathematical statistics methods using the "Statistica-6.1" package in a Windows PC environment.&#x0D; It was found that the majority of bulls-producers approved for use were evaluated based on these genotypes. Depending on the breed, the number of bulls estimated by the studied characteristics ranged from 43 to 85%. Depending on the breed, from 2 to 16 different combinations of beta- and kappa-casein genotypes were identified. The frequency of occurrence of the desired complex genotype A2A2/BB, depending on the breed, was in the range of 0.0 to 75.0%. Holstein bulls of the desired A2A2/BB genotype were estimated to be superior to bulls of some other complex genotypes in terms of daughter milk yield, the amount of milk fat, milk protein, lifetime profit indices, cheese profit, and milk profit.&#x0D; Therefore, the use of sperm production of bulls with the A2A2/BB genotype will improve the economically useful characteristics of offspring, and will further increase the number of livestock with the desired complex genotype.&#x0D; Summary.&#x0D; 1. Taking into account the data of many domestic and foreign scientists who claim that the genotype of animals by the beta – and kappa-casein polymorphism affects the qualitative composition of milk, it is necessary to have in herds the necessary number of animals carrying the A2 allele of beta-casein and the B allele of the kappa-casein gene. The desired breeding parameters of the herd can be achieved by using bulls with BB genotypes for kappa-casein and A2A2 for beta-casein. Correction of the bulls-producers selection system can only be carried out if the breeding stock of the herd is genotyped according to the polymorphism of the beta-and kappa – casein genotypes. Holding this event will increase the protein content and will improve cheese suitability of milk of cattle of future generations.&#x0D; The use of bulls-producers without taking into account their genotypes for the casein fractions described above and the lack of polymorphism control of these genes among cows can lead to a decrease in the frequency of desired genotypes in the herd and a decrease in the technological qualities of milk as raw materials.&#x0D; 2. The created database of bulls-producers approved for use in Ukraine, evaluated by the beta-and kappa – casein genotypes, allows us to establish a positive perspective on the possibility of forming staffed herds of animals with the desired complex A2A2/BB genotype in Ukraine.&#x0D; 3. It was found that bulls of dairy breeds have different frequencies of beta – and kappa casein alleles. The part of bulls-producers of the desired complex genotype A2A2/BB of Holstein breed is 8.49%, Holstein Red-pockmarked – 2.94%, Schwyz – 75%, Jersey – 13.79%, Red Danish – 12.5%, Red Norwegian – 20.0%, Montbellard – 25%. Among animals of Simmental and Aishir breeds – bulls with the desired complex genotype A2A2/BB were not detected.&#x0D; 4. Bulls of the desired complex genotype A2A2/BB according to the indicators of milk yield of daughters, the amount of milk fat, milk protein, indices of lifetime profit, profit for cheese, profit for milk were dominated bulls with separate complex genotypes CSN2-CSN3

Associations between maternal milk protein genotypes with preweaning calf growth traits in beef cattle.

The objectives of this study were to investigate milk casein polymorphisms in dams and to determine the impacts of maternal casein genotypes on growth traits of their sucking calves. Milk samples from 433 dams of the breeds German Angus (GA) and German Simmental (GS) were typed at the milk protein loci α s1-casein (αs1-CN), β-casein (β-CN), α s2-casein (αs2-CN), and κ-casein (κ-CN) via isoelectric focusing. Associations between casein genotypes in maternal milk with growth traits of their 1,872 calves were analyzed until the age of weaning using linear mixed models, considering either genotypes of individual casein loci (model 1) or composite α s1-β-α s2-κ-CN genotypes within the casein cluster (model 2). Besides environmental effects such as sex, age of the dam, and calving year-season, genetic effects (breed group and maternal and paternal effects) were considered in statistical models. The composite casein genotype BBǀA2A2ǀAAǀAB (order of genes on bovine chromosome 6: α s1-ǀβ-ǀα s2-ǀκ-CN) was associated with greater average daily weight gains (ADG) and heavier age-adjusted weaning weights (WW) of calves (P < 0.05). The effects of composite genotypes on birth weight of calves were similar (P > 0.05; model 2). With regard to individual casein loci, greater ADG and WW were observed for calves from dams with the genotypes κ-CN BB and α s1-CN BB, respectively (P < 0.05; model 1). Age-adjusted WW was largest for calves from dams carrying the κ-CN genotype BB (215 kg) compared with calves representing the maternal AB and AA genotypes (both 204 kg). Results from the present study suggested selectable casein genotypes due to their nutritional value of milk (value in terms of offspring performances), offering new perspectives for breeding strategies in beef cattle to improve preweaning calf performance.

The effect of selection on casein genetic polymorphisms and haplotypes in Italian Holstein cattle

Milk protein genes are known to be highly polymorphic. Several studies have shown the influence of milk proteins genetic variants and casein haplotypes on milk nutritional and technological properties. From 1990, the analysis of caseins polymorphism gained new attention due to the concern about possible negative effects of CSN2*A1 on human health. As a consequence, the CSN2*A2 variant gained interest and milk produced by with A2A2 β-casein cows is now available in different countries. Aim of the present paper was to analyse how casein variants’ and haplotypes’ frequencies changed in the Italian Holstein breed, due to the health ‘claims’ about CSN2*A2, and the possible effects on milk technological properties. Data were compared also with Italian Jersey cattle. A total of 223,655 Holstein and of 622 Jersey were genotyped using Illumina beadchips and data of 62 SNP in the casein cluster were analysed to reconstruct casein genotypes and haplotypes. The results demonstrate that although the selection towards β-casein A2 is not so effective in Italy, an increase of the frequency of this allele to the disadvantage of A1 and B alleles, included in the most favourable genotypes and haplotypes for cheese making, is occurring and should not be forced. Indeed, although a selection for the favourable κ-casein B allele, and against the unfavourable E allele, is occurring and is limiting the general loss of haplotypes associated with good technological properties, the sharp decrease of the favourable B-B and I-B β- κ-haplotypes, is an alert of the risk of losing useful biodiversity. Highlights After the concern about the β-caseinA1 variant on human health, a selection favoring the A2 allele was carried out in different countries. In Italy milk is mostly destined to cheese-making and even without a direct selection for theβ-casein A2 caseins allelic frequencies are changing. Genotyping data should be used to monitor and maybe contrast the reduction of variants associated with milk favorable technological properties.

REALIZATION OF PARENTAL INDICES OF COW PRODUCTIVITY IN DIFFERENT MILKING BREEDS AT BREEDING FARM "AGROFIRMA "PAKHMA"

Combination of genotypes of main types’ genetic markers causes milk productivity in cattle. The article studies correlation between kappa casein genotypes (C3N3), beta-lactoglobulin (LGB), their complexes and milk production indices in cows bred under equal conditions at a breeding farm. The calculation of parental milk yield and fat indices between the three breeds showed a significant difference (P&gt;0,999) of PCI of Ayrshire and Holstein cattle breed milk yield - 3395 kg, PCI of fat - 0,22%; between Holstein and Yaroslavl cattle breeds - 3200 kg, PCI offat - 0,16%. A significant difference of realization indices of protein between all three breeds was not stated. The highest realization ofparental milk yield index was stated - between Ayrshire and Yaroslavl cattle breeds- 113%, Holstein cattle breed - 88%. As for the fat and protein indices, all three cattle breeds showed a high realization of PCI from 98% to 109%. However, Holstein cattle breed showed the highest percentage: protein - 101%, fat - 109%. A significant difference of PCI realization of milk productivity in CSN3 and LGB genotypes was not stated. It was also stated that there is a tendency of high level parental indices realization when there is a higher number of B-allele variants in genotypes of cows.

Goat Milk with Different Alpha-s1 Casein Genotype (CSN1S1) Fermented by Selected Lactobacillus paracasei as Potential Functional Food

The characteristics of fermented milk are affected by the type of milk used and the microorganisms involved in the fermentation process. Goat milk has been widely suggested as a possible alternative to cow milk in allergic subjects, because of the high genetic variability in alpha-s1 casein (CSN1S1) content, which is associated with different technological and nutritional properties of milk. The aim of the study was to evaluate the suitability of goat milk with low and high CSN1S1 to produce fermented milk. In addition, the performance as starter of selected Lactobacillus paracasei FS109 strain compared to no-selected L. paracasei strains was investigated. Initially, the selected L. paracasei FS109 strain was tested for adhesion ability to HT-29 and Caco-2 cells and immunomodulation effect. Then, the strain was used to produce fermented milk from goat milk with a low and high casein CSN1S1 genotype. The results indicated that greater acidifying activity was obtained for L. paracasei FS109 after 24 h of fermentation than the other two strains tested independently by the CSN1S1 genotype. L. paracasei FS109 grew well during fermentation, reaching a higher value (&gt;8.5 log CFU/mL). Interestingly, the same strain maintained a high viable population (about 9 log CFU/mL) during the 30-day cold storage of the product. The present study shows for the first time the suitability of the goat milk with low CSN1S1 genotypes to produce fermented milk and highlight the importance of strain selection in determination of technological and beneficial traits. Combining goat milk with low CSN1S1 and selected strains could be a strategy of improving traditional and functional fermented milk market.

Polymorphism of k-casein and β-lactoglobuline in Simmental cattle in Serbia

The objective of this study was to determine the frequency of the ?-casein and ?-lactoglobulin genotypes in the Simmental cattle in Serbia and compare it with the frequency according to the Hardy-Weinberg equilibrium law. Blood samples were taken from a total of 157 cows of the Simmental breed in Toplica and Rasina districts. Of the 157 cows included in this study, the AA ?-casein genotype was found in 53 cows, which makes a frequency of 33.80%, the genotype in 81 cows or 51.60% and the BB genotype in 23 cows or 14.60%. The allelic frequency A was 59.60%, while allele B had a frequency of 40.40%. In regard to the frequency of genotypes and ?-lactoglobulin alleles for the total studied population of cows obtained for AA, and BB genotypes for ?-lactoglobulin, was 33.10%, 49.70% and 17.20%, respectively, which means that 52 animals had genotype AA, 78 genotype and 27 genotype BB. The frequency of alleles A and B resulting from the incidence of genotypes was 58.00% for allele A and 42.00% for allele B. The specified frequencies for both protein fractions statistically differed significantly from the frequency according to the Hardy-Weinberg equilibrium law, which confirmed the absence of equilibrium in the examined population.

Evaluation of bovine beta casein polymorphism in two dairy farms located in northern Italy.

Bovine beta casein A1 is one of the most common variants in dairy cattle breeds; it is considered a risk factor in milk intolerance and in other important human diseases, because of the bioactive peptide beta casomorphin-7 (BCM7) produced by raw or processed A1-milk, but not by A2-milk, during digestion. The aim of this study was to perform a cheap and rapid method to investigate beta casein polymorphism in copious animals. The study included 2 dairy farms with a totally of 1230 cows. Beta casein genotypes were estimated evaluating Exon 7 region of bovine beta casein gene (CSN2) by sequences analysis. In the population included in the study 5 variants (A1, A2, B, F, I) and 13 genotypes (A1A1, A1A2, A1B, A1F, A1I, A2A2, A2B, A2F, A2I, BB, BF, BI, FI) were detected. The method showed high sensibility and specificity, resulted low-cost and few time consuming.

Molecular Characterization of Genetic Variability among Sudanese Baggara Cattle within Kappa Casein Csn3 Gene (Exon V)

The present work was conducted to detect possible genetic variants of kappa casein (CSN3) gene in Western Baggara cattle in Sudan. This gene is associated with higher fat, protein, and has a significant influence on milk processing properties in comparison to other casein variants. 70 blood samples were collected from Western Baggara cattle in three areas (Hai Elgabal, Bulbul and Umdamm). Genomic DNA was extracted from the whole blood using guanidine chloroform method. A 495 bp fragment containing exon V of kappa casein gene was amplified by PCR using specific set of primers. The amplified PCR product was digested by Hinf1; the bands were visualized under UV-light to observe the polymorphic locus by the size change of DNA fragments. The results revealed that the restriction analysis produced two fragments of 424 and 71 bp indicating the presence of kappa casein BB genotype (monomorphic) in all population. The present study is the first report on kappa casein genotype of Baggara cattle in South Darfur State, Sudan, which elucidated uniform and homozygous population for kappa casein B allele.

Effects of milk protein polymorphism and composition, casein micelle size and salt distribution on the milk coagulation properties in Norwegian Red cattle

Effects of milk protein polymorphism and composition, casein micelle size and salts distribution on the coagulation properties of milk from 99 Norwegian Red cattle (NRF) were studied. Genetic variants of αS1-casein (CN), β-CN, κ-CN and β-lactoglobulin (LG) affected rennet coagulation properties of milk. Significant effects of κ-CN and the composite genotype αS1-β-κ-CN were observed on acid coagulation properties. Relative concentrations of milk proteins were significantly affected by individual casein genotypes and the composite genotype of αS1-β-κ-CN while, the relative concentration of β-LG was only affected by β-LG genotypes. The salts distribution in milk and the concentration of milk proteins affected both rennet and acid coagulation properties. Milk protein genotypes associated with better rennet coagulation, impaired the acid coagulation properties. However, αS1-β-κ-CN BB-A1A2-BE and BB-A2A2-BB were associated with poor rennet and acid coagulation properties. Breeding programs should focus on decreasing these genotypes in NRF cattle.

Including α s1 casein gene information in genomic evaluations of French dairy goats.

BackgroundGenomic best linear unbiased prediction methods assume that all markers explain the same fraction of the genetic variance and do not account effectively for genes with major effects such as the αs1casein polymorphism in dairy goats. In this study, we investigated methods to include the available αs1casein genotype effect in genomic evaluations of French dairy goats.MethodsFirst, the αs1casein genotype was included as a fixed effect in genomic evaluation models based only on bucks that were genotyped at the αs1casein locus. Less than 1 % of the females with phenotypes were genotyped at the αs1casein gene. Thus, to incorporate these female phenotypes in the genomic evaluation, two methods that allowed for this large number of missing αs1casein genotypes were investigated. Probabilities for each possible αs1casein genotype were first estimated for each female of unknown genotype based on iterative peeling equations. The second method is based on a multiallelic gene content approach. For each model tested, we used three datasets each divided into a training and a validation set: (1) two-breed population (Alpine + Saanen), (2) Alpine population, and (3) Saanen population.ResultsThe αs1casein genotype had a significant effect on milk yield, fat content and protein content. Including an αs1casein effect in genetic and genomic evaluations based only on male known αs1casein genotypes improved accuracies (from 6 to 27 %). In genomic evaluations based on all female phenotypes, the gene content approach performed better than the other tested methods but the improvement in accuracy was only slightly better (from 1 to 14 %) than that of a genomic model without the αs1casein effect.ConclusionsIncluding the αs1casein effect in a genomic evaluation model for French dairy goats is possible and useful to improve accuracy. Difficulties in predicting the genotypes for ungenotyped animals limited the improvement in accuracy of the obtained estimated breeding values.

Goat casein genotypes are associated with milk production traits in the Sarda breed.

The aim of the current work was to analyze, in the Sarda breed goat, genetic polymorphism within the casein genes and to assess their influence on milk traits. Genetic variants at the CSN1S1, CSN2, CSN1S2 and CSN3 gene loci were investigated using PCR-based methods, cloning and sequencing. Strong alleles prevailed at the CSN1S1 gene locus and defective alleles also were revealed. Null alleles were evidenced at each calcium-sensitive gene locus. At the CSN3 gene locus, we observed a prevalence of the CSN3 A and B alleles; the occurrence of rare alleles such as CSN3 B'', C, C', D, E and M; and the CSN3 S allele (GenBank KF644565) described here for the first time in Capra hircus. Statistical analysis showed that all genes, except CSN3, significantly influenced milk traits. The CSN1S1 BB and AB genotypes were associated with the highest percentages of protein (4.41 and 4.40 respectively) and fat (5.26 and 5.34 respectively) (P<0.001). A relevant finding was that CSN2 and CSN1S2 genotypes affected milk protein content and yield. The polymorphism of the CSN2 gene affected milk protein percentage with the highest values recorded in the CSN2 AA goats (4.35, at P<0.001). The CSN1S2 AC goats provided the highest fat (51.02g/day) and protein (41.42g/day) (P<0.01) production. This information can be incorporated into selection schemes for the Sarda breed goat.