Brown Swiss Cattle Research Articles

Determination of Haptoglobin, Serum Amyloid A, Some Other Acute Phase Proteins, and Biochemical Parameters in Cattle with Hydatid Cysts

The aim of this study is to determine some acute phase proteins and biochemical parameter levels in cattle infected with the hydatid cysts. In the study, a total of 30, Brown Swiss cattle including 15 infected with the hydatid cysts in the study group and 15 in the control group were used. Haptoglobin, serum amyloid A (SAA), ceruloplasmin, interleukin (IL)-6, total protein, albumin, aspartate amino transferase (AST), gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) activity, urea, creatinine, iron (Fe) levels were determined colorimetrically. When the animals infected with hydatid cysts and control group were compared, it was determined that haptoglobin, SAA, IL-6, AST, ALP, GGT activity, urea, creatinine levels and acute phase protein index values increased, while albumin levels decreased. In addition, it was determined that the ceruloplasmin and total protein levels increased, globulin, albumin/globulin and Fe levels decreased, but they were statistically insignificant. In conclusion, it was determined that there were significant changes in the biochemical parameters and increased haptoglobin and SAA synthesis in the animals infected with the hydatid cysts, and it is thought that these parameters may contribute to the pathogenesis and diagnosis of the disease.

Genome-wide association study for milking speed in Fleckvieh cattle

Milking speed is an important trait influencing udder health of dairy cows as well as labor efficiency. Yet, it has received little attention in genomic association studies. The main objective of this study was to determine regions and genes on the genome with a potential effect on milking speed in Fleckvieh (dual purpose Simmental) cattle. Genome-wide association studies were conducted using de-regressed breeding values of bulls as phenotypes. Six SNP on 4 autosomes were significantly associated with milking speed for additive effects. Significant regions on BTA4 and BTA19 correspond with findings for other dairy cattle breeds. Based on the observation of Fleckvieh breed managers, variation of milking speed in batches of daughters of some bulls is much higher than in daughter groups of other bulls. This difference in within family variation may be caused by transmission of alternative alleles of bulls being heterozygous for a gene affecting milking speed. To check on this, we considered standard deviation of yield deviations in milking speed of half-sib daughters as a new trait and performed GWAS for dominance effects. One signal on BTA5 passed the genome wide Bonferroni threshold that corresponded to the significant signal from standard GWAS on de-regressed breeding values. The key conclusion of this study is that several strong genomic signals were found for milking speed in Fleckvieh cattle and that the strongest of them are supported by similar findings in Brown Swiss and Holstein Friesian cattle. Milking speed is a complex trait whose sub-processes have not yet been elucidated in detail. Hence, it remains a challenge to link the associated regions on the genome with causal genes and their functions.

Effects of Different Seasons on Milk Quality: A Study on Two Cattle Breeds in Rainy and Drought Contexts

The primary focus of dairy farming in the central region of Peru centers on producers. However, there is limited information on how different altitudinal zones, particularly during rainy and dry seasons, affect milk production. The present study aimed to investigate the effects of the rainy and dry seasons on the physicochemical properties of milk from Brown Swiss and Holstein cattle. A total of sixty cows were selected for the study, comprising 30 Brown Swiss and 30 Holstein. The study was conducted across two distinct seasons, including rainy and dry seasons. All animals received the same semi-intensive management and were fed ryegrass and balanced feed. Each animal provided 500 ml of milk for analysis in the morning. The milk was transported at a temperature of 2 °C, where they were analyzed with the Lactoscan equipment to evaluate protein, lactose, fat, total solids, milk density, freezing point, salts, and pH. Significant differences were observed in the interaction between Brown Swiss and Holstein breeds across different seasons, including rainy and dry periods. Significant differences were observed in protein content, showing a positive effect in the interaction “rain: Brown” a value of 3.50 ± 0.36, while “rain: Holstein” showed 3.14 ± 0.05. Statistical differences were observed in the interactions for lactose content, with rain: Brown at 4.82% and dry: Holstein at 4.37%. Similarly, there were significant differences in fat content and total solids for rain interaction of rain: Holsten, and dry: Brown. Nevertheless, no differences were observed in terms of milk density, freezing point, salts, and pH. It is concluded that there was an influence of the interaction between breed physiology and seasonal conditions on milk composition. The results also highlight the impact of season-specific environmental factors on the quality of milk.

Genomic prediction of male fertility in Brown Swiss cattle

Bull fertility has been recognized as an important factor affecting dairy herd fertility. The objective of this study was to assess the feasibility of predicting male fertility in Brown Swiss cattle using genomic data. The data set consisted of 1,102 Italian Brown Swiss bulls with sire conception rate (SCR) records and genotype data for roughly 480k SNP. The analyses included the use of linear kernel-based regression models fitting all SNPs or incorporating markers with large effect. Predictive performance was evaluated in 5-fold cross-validation using the correlation between observed and predicted SCR values and mean squared error of prediction. The entire SNP set exhibited predictive correlations around 0.19. Interestingly, the inclusion of 2 markers with large effect yielded predictive correlations around 0.32. Overall, using linear kernel-based models fitting markers with large effect is a promising approach. Our findings could help Brown Swiss breeders make enhanced genome-guided management and selection decisions on male fertility.

Modification of the allelofund of the Brown Swiss cattle breed during its improvement

Modification of the allelofund of the Brown Swiss cattle breed during its improvement

The first results of the use of the gene pool of the Kalmyk breed on the brown stock of Brown Swiss cattle

The given investigation is devoted to a comparative assessment of the growth, meat productivity and efficiency of beef production by bulls of different genotypes. It was formed 3 groups of bull calves, 15 heads in eachon the 2nd-3rd days after birth: group firstis brown Swiss calves, the second is Kalmyk breed, the third is crossbreeds obtained from crossing Brown Swiss cows and Kalmyk bulls. It has been established that to the age of 18 months, the advantage of Kalmyk bulls and their crossbreeds in terms of live weight over purebred animals of the Brown Swiss breed averaged 16.3-28.2 kg (P>0.999). According to the average daily increase in live weight for the entire production cycle, animals of the Kalmyk breed favorably differed among the analyzed genotypes of young animals, the superiority of which over their peers of different origin varied within 29-61 g (P> 0.999). The difference between bulls of the Brown Swiss breed and crossbreds was 32 g (P>0.999) in favor of the latter. From bull-calves of the Kalmyk breed and their crosses, in contrast to those of the Brown Swiss breed, heavier carcasses were obtained - by 24.8 (P> 0.99) and 14.9 (P> 0.99) kg, slaughter yield is by 2.4 (P>0.99) and 1.4 abs.%, respectively. Representatives of the Kalmyk breed and crossbred peers differed in the highest yield of pulp, whose superiority over bulls of the improved breed was 12.0 (P>0.99) and 7.5 (P>0.99) kg, respectively. A higher level of profitability at the level of 34.6-37.9% was characterized by the descendants of bulls of the Kalmyk breed versus 26.7% in the group of brown Swiss breed.

Pedigree base of brown Swiss cattle breed in the Smolensk region

The current state by the end of 2020of the Brown Swiss breed of cattle in pedigree farms of the Smolensk region was studied. The average milk yield in herds for the last completed lactation is 4045 – 6626 kg of milk, the yield of milk fat and protein is 158 – 268 kg and 134 – 236 kg, respectively. In the best farm of the SPK “Druzhba”, the average milk yields of cows for the highest lactation exceed 7000 kg of milk, eight animals have record results of 10016 – 11720 kg. Cows are born from fathers of high breeding value. The average milk yield mothers of fathers in herds is 9767 – 12333 kg. The average age of cows according to the last completed lactation in the studied herds is 2.3 – 3.9 lactation. The age of the first fruitful insemination in the best farm is 16.5 months. From 87.8 to 98.3% of cows belong to lines of foreign origin.

Plasma pharmacokinetics of clorsulon following administration of a single subcutaneous or intravenous injection to cattle.

The benzenedisulfonamide derivative clorsulon is a potent fasciolicide which is marketed in fixed combination injectables, typically combined with the macrocyclic lactone ivermectin. In the presented pharmacokinetic study, the plasma profile of clorsulon in 32 healthy, young Brown Swiss cattle was administered a single intravenous dose at 3 mg/kg body weight or subcutaneously at 3, 6 or 12 mg/kg body weight (4 intact male and 4 female animals per treatment) as a 30% w/v clorsulon injection formulation. Serial blood samples were collected up to 24 days after administration to establish the pharmacokinetics, bioavailability and dose proportionality of clorsulon. Following a single intravenous injection of clorsulon at 3 mg/kg body weight, the area under the concentration versus time curve from the start of dose administration to the time of the last quantifiable concentration (AUClast ) was 4830 ± 941 day*ng/mL, and half-live was 2.37 ± 0.98 days. The back extrapolated concentration at time 0 was 38,500 ± 6070 ng/mL. The volume of distribution at steady state and clearance were 685 ± 107 mL/kg and 664 ± 127 mL/day/kg, respectively. In the groups dosed at 3, 6 or 12 mg/kg body weight by subcutaneous injection, clorsulon plasma concentrations rose to maximum within 0.5 day and decreased to the last sample point. For these groups, the maximum plasma clorsulon concentrations were 3100 ± 838, 5250 ± 1220 and 10,800 ± 1730 ng/mL, respectively, and the AUClast was 5330 ± 925, 9630 ± 1300 and 21,500 ± 3320 day*ng/mL, respectively. Half-lives, 2.01 ± 0.62, 3.84 ± 1.42 and 5.36 ± 0.60 days, respectively, increased significantly with dose, likely related to increasing dose volume. Clorsulon was well absorbed and fully bioavailable (103%-114%) after subcutaneous injection. No gender-related difference in systemic exposure was observed. Assessment of Cmax and AUClast demonstrated a proportional increase in systemic exposure to the clorsulon subcutaneous doses over the range of 3-12 mg/kg body weight.

MOCOS-associated renal syndrome in a Brown Swiss cattle.

A recessive form of MOCOS-associated xanthinuria type II is described in Tyrolean grey cattle. A similar case was identified in a 5-month-old Brown Swiss calf with hoof overgrowth, rough coat, urine sediment, and pneumonia. To characterize the disease phenotype, to evaluate its genetic etiology, and to determine the prevalence of the deleterious allele in the Brown Swiss population. An affected calf, its parents, and 65 441 Swiss dairy cattle. The affected animal was clinically examined and necropsied. Microarray genotyping was used to determine the genotypes and to assess the frequency of the MOCOS allele in a Brown Swiss control cohort. Ultrasonography revealed hyperechoic renal pyramids with multifocal distal shadowing and echogenic sediment in the urinary bladder. Necropsy revealed suppurative bronchopneumonia and urolithiasis. Histology revealed numerous nephroliths with multifocal chronic lymphohistiocytic interstitial infiltrates, fibrosis, tubular degeneration, chronic multifocal glomerulonephritis with sclerosis, and bilateral hydronephrosis. Dysplastic changes were observed in the corium of the claw and the cornea. Genetic testing identified the homozygous presence of a known MOCOS frameshift variant in the case. Both parents were heterozygous and the prevalence of carriers in genotyped Brown Swiss cattle was 1.4% (342/24337). The findings were consistent with the diagnosis of a recessive renal syndrome similar to xanthinuria type II described in Tyrolean grey cattle. The prevalence of the deleterious MOCOS allele is low in the Brown Swiss breed. However, mating of carriers should be avoided to prevent further losses.

WNT10B: A locus increasing risk of brachygnathia inferior in Brown Swiss cattle

Shortening of the mandible (brachygnathia inferior) is a congenital, often inherited and variably expressed craniofacial anomaly in domestic animals including cattle. Brachygnathia inferior can lead to poorer animal health and welfare and reduced growth, which ultimately affects productivity. Within the course of the systematic conformation scoring, cases with a frequency of about 0.1% were observed in the Brown Swiss cattle population of Switzerland. In contrast, this anomaly is almost unknown in the Original Braunvieh population, representing the breed of origin. Because none of the individually examined 46 living offspring of our study cohort of 145 affected cows showed the trait, we can most likely exclude a monogenic-dominant mode of inheritance. We hypothesized that either a monogenic recessive or a complex mode of inheritance was underlying. Through a genome-wide association study of 145 cases and 509 controls with imputed 624k SNP data, we identified a 4.5 Mb genomic region on bovine chromosome 5 significantly associated with this anomaly. This locus was fine-mapped using whole-genome sequencing data. A run of homozygosity analysis revealed a critical interval of 430 kb. A breed specific frameshift duplication in WNT10B (rs525007739; c.910dupC; p.Arg304ProfsTer14) located in this genomic region was found to be associated with a 21.5-fold increased risk of brachygnathia inferior in homozygous carriers. Consequently, we present for the first time a genetic locus associated with this well-known anomaly in cattle, which allows DNA-based selection of Brown Swiss animals at decreased risk for mandibular shortening. In addition, this study represents the first large animal model of a WNT10B-related inherited developmental disorder in a mammalian species.

Genome-wide genetic variation and population structure of native and cosmopolitan cattle breeds reared in Türkiye

This is the first comprehensive study to reveal genetic variation and population structure at genome level in six Anatolian (Anatolian Black, East Anatolian Red, South Anatolian Red, South Anatolian Yellow, Turkish Grey Steppe, and Zavot) and two cosmopolitan (Brown Swiss and Holstein Friesian) cattle breeds reared in Türkiye. Being 20 samples from each population, a total of 160 blood samples retrieved from representative herds were utilized to generate genomic libraries by ddRADseq method. Genomic libraries sequenced by Illumina HiSeq X Ten instrument revealed a total of 211,119 bi-allelic SNPs with high call rate. Compared to cosmopolitan cattle breeds, a higher genetic variation was observed in native Turkish cattle with an average of 0.380 observed heterozygosity. Genetic distances were comparatively low between native cattle breeds, whereas the highest genetic distance (0.064) was detected between South Anatolian Yellow and Brown Swiss. Population structure analyses showed that the native Turkish and cosmopolitan cattle breeds were clearly different from each other according to their phylogenetic origin. Besides, a high level of genetic admixture was detected among Anatolian Black, Turkish Grey Steppe, South Anatolian Red, and South Anatolian Yellow, whereas East Anatolian Red and Zavot were distinct from the other native and cosmopolitan cattle breeds. TreeMix algorithm under the assumption of one and two migration events revealed a migration route from Anatolian clade to Anatolian Black, while a second migration edge was drawn from Brown Swiss to East Anatolian Red. This study demonstrates the importance of national conservation studies in the native breeds whose population size has dramatically decreased. In addition, SNP arrays and next-generation sequencing platforms are recommended for future studies to reveal the genetic variation of other local Turkish livestock species to arrange effective conservation programs.

Identification of runs of homozygosity associated with male fertility in Italian Brown Swiss cattle.

Intensive selection for improved productivity has been accompanied by an increase in inbreeding rates and a reduction in genetic diversity. The increase in inbreeding tends to impact performance, especially fitness-related traits such as male fertility. Inbreeding can be monitored using runs of homozygosity (ROH), defined as contiguous lengths of homozygous genotypes observed in an individual's chromosome. The goal of this study was to evaluate the presence of ROH in Italian Brown Swiss cattle and assess its association with bull fertility. First, we evaluated the association between ROH and male fertility using 1,102 Italian Brown Swiss bulls with sire conception rate records and 572K SNPs spanning the entire genome. Second, we split the entire population into 100 high-fertility and 100 low-fertility bulls to investigate the potential enrichment of ROH segments in the low-fertility group. Finally, we mapped the significant ROH regions to the bovine genome to identify candidate genes associated with sperm biology and male fertility. Notably, there was a negative association between bull fertility and the amount of homozygosity. Four different ROH regions located in chromosomes 6, 10, 11, and 24 were significantly overrepresented in low-fertility bulls (Fisher's exact test, p-value <0.01). Remarkably, these four genomic regions harbor many genes such as WDR19, RPL9, LIAS, UBE2K, DPF3, 5S-rRNA, 7SK, U6, and WDR7 that are related to sperm biology and male fertility. Overall, our findings suggest that inbreeding and increased homozygosity have a negative impact on male fertility in Italian Brown Swiss cattle. The quantification of ROH can contribute to minimizing the inbreeding rate and avoid its negative effect on fitness-related traits, such as male fertility.

Associations Between IGF-II Gene Polymorphism and Milk Yield Characteristics In Brown Swiss Cattle

This study was carried out on 114 Brown Swiss cattle reared in intensive conditions at Ataturk University Food and Livestock Application and Research Center and at the private cattle farm found in Erzurum province. Genotypic structures were examined in terms of Insulin-like growth factor (IGF)-II gene locus and the distribution of genotypes and allele frequencies of the cattle concerning the genes were determined. The identified Insulin-like growth factor (IGF)-II genotypes were associated with milk yield traits such as actual milk yield, 305-day, and daily milk yield. Insulin-like growth factor (IGF)-II genotypes were determined by using the Polymerase Chain Reaction (PCR)- Restriction fragment length polymorphism (RFLP) method from blood samples taken from the cattle. The CC, CT, and TT genotype frequencies of the Insulin-like growth factor (IGF)-II gene found in the population were 41 (34%), 65 (54%), and 14 (12%), and the frequency of the C allele and the T allele was found to be 0.61 and to be 0.39. The general averages of actual true milk yield, 305-day and daily milk yield were 4317±272.9 kg, 5277±240.7 kg and 18±0.9 kg, respectively, while CC, CT and TT genotypes 4168±515.8, 3756±321.7 and 5382±600.3 kg, respectively. As a result, correctly identified IGF-II genotypes were detected by using the PCR-RFLP method in the blood samples obtained from Brown Swiss cattle. Genotype and allele frequencies determined for IGF-II gene polymorphism can be considered sufficient to demonstrate the genotype diversity of the race. According to the Hardy-Weinberg genetic equilibrium test, the distribution of genotype frequencies of the cattle was observed in equilibrium.

The size and composition of haplotype reference panels impact the accuracy of imputation from low-pass sequencing in cattle

BackgroundLow-pass sequencing followed by sequence variant genotype imputation is an alternative to the routine microarray-based genotyping in cattle. However, the impact of haplotype reference panels and their interplay with the coverage of low-pass whole-genome sequencing data have not been sufficiently explored in typical livestock settings where only a small number of reference samples is available.MethodsSequence variant genotyping accuracy was compared between two variant callers, GATK and DeepVariant, in 50 Brown Swiss cattle with sequencing coverages ranging from 4- to 63-fold. Haplotype reference panels of varying sizes and composition were built with DeepVariant based on 501 individuals from nine breeds. High-coverage sequence data for 24 Brown Swiss cattle were downsampled to between 0.01- and 4-fold to mimic low-pass sequencing. GLIMPSE was used to infer sequence variant genotypes from the low-pass sequencing data using different haplotype reference panels. The accuracy of the sequence variant genotypes that were inferred from low-pass sequencing data was compared with sequence variant genotypes called from high-coverage data.ResultsDeepVariant was used to establish bovine haplotype reference panels because it outperformed GATK in all evaluations. Within-breed haplotype reference panels were more accurate and efficient to impute sequence variant genotypes from low-pass sequencing than equally-sized multibreed haplotype reference panels for all target sample coverages and allele frequencies. F1 scores greater than 0.9, which indicate high harmonic means of recall and precision of called genotypes, were achieved with 0.25-fold sequencing coverage when large breed-specific haplotype reference panels (n = 150) were used. In absence of such large within-breed haplotype panels, variant genotyping accuracy from low-pass sequencing could be increased either by adding non-related samples to the haplotype reference panel or by increasing the coverage of the low-pass sequencing data. Sequence variant genotyping from low-pass sequencing was substantially less accurate when the reference panel lacked individuals from the target breed.ConclusionsVariant genotyping is more accurate with DeepVariant than GATK. DeepVariant is therefore suitable to establish bovine haplotype reference panels. Medium-sized breed-specific haplotype reference panels and large multibreed haplotype reference panels enable accurate imputation of low-pass sequencing data in a typical cattle breed.

Genome-wide association study for heat stress resistance in Brown Swiss cattle in Yucatan, Mexico

Global climate change has made heat stress tolerance an important trait to be considered in breeding programs to improve the resistance of productive animals to unfavorable environmental conditions. The aim of this study was to know the association between single nucleotide polymorphism (SNP) markers and heat stress resistance through a genome-wide association study (GWAS). Where 95 Brown Swiss dairy cows have measured body temperatures, respiratory frequencies, and genotypes. Seven SNP were detected with a statistically significant effect (P &lt; 0.01) on respiratory frequency under heat stress. The markers with the highest association are in the Bos taurus autosome 6 (BTA 6), e.g. the BovineHD0600010397 SNP located within the FAM13A gene, and the BovineHD0600012612 SNP located within the PI4K2B gene. The ARS-BFGL-NGS-102407 SNP that is located in BTA 4 is the SNP that presents the highest number of associations to genes. Most of the genes are involved in cellular processes that are present in the resistance of individuals to high and humid environmental temperatures. These results provide new insights into the genetics of heat stress tolerance in Brown Swiss cattle in Yucatan, Mexico.

Genomic regions underlying positive selection in local, Alpine cattle breeds.

We used genome-wide SNP data from 18 local cattle breeds from six countries of the Alpine region to characterize population structure and identify genomic regions underlying positive selection. The geographically close breeds Evolèner, Eringer, Valdostana Pezzata Nera, and Valdostana Castana were found to differ from all other Alpine breeds. In addition, three breeds, Simmental, and Original Braunvieh from Switzerland and Pinzgauer from Austria built three separate clusters. Of the 18 breeds studied, the intra-alpine Swiss breed Evolèner had the highest average inbreeding based on runs of homozygosity (FROH ) and the highest average genomic relationship within the breed. In contrast, Slovenian Cika cattle had the lowest average genomic inbreeding and the lowest average genomic relationship within the breed. We found selection signatures on chromosome 6 near known genes such as KIT and LCORL explaining variation in coat color and body size in cattle. The most prominent selection signatures were similar regardless of marker density and the breeds in the data set. In addition, using available high-density SNP data from 14 of the breeds we identified 47 genome regions as ROH islands. The proportion of homozygous animals was higher in all studied animals of local breeds than in Holstein and Brown Swiss cattle, the two most important commercial breeds in the Alpine region. We report ROH islands near genes related to thermoregulation, coat color, production, and stature. The results of this study serve as a basis for the search for causal variants underlying adaptation to the alpine environment and other specific characteristics selected during the evolution of local Alpine cattle breeds.

Analysis of reproduction indicators of brown Swiss cattle of the Smolensk region

In dairy cattle breeding, the breeding work is carried out mainly to increase the milk productivity of cows, which often leads to a decrease in the reproductive qualities of the breeding stock. Therefore, practicing breeders are faced with the task of studying and improving the qualities of animals associated with the reproduction of the herd. At the same time, in the conditions of a decrease in the number of livestock, the issue of preserving and improving the reproductive properties of animals is also put forward in the first position. For design breeding problems, it is necessary to have information about the genesis of reproduction. The conducted studies covering the period 2011-2020 reveal the dynamics of significant reproductive indicators – the age of the first fruitful insemination, the number of inseminations per fruitful one, as well as the open days in the first lactation of the breeding stock of the Swiss breed. In the process of its improvement, the age of the first fruitful insemination of animals decreased. The multiplicity of insemination and the associated open days in the first lactation do not have a stable nature of changes. To obtain more informative data on the level of organization of the biological system under study, the entropy – information analysis was used in the study. The age of the first fruitful insemination at the initial stages was poorly controlled, with an absolute organization (O) having values from 0.168 bits (H=3.292 bits) it was found however, during the selection process, the controllability of this system increases (O=0.873 bits; H=2.586 bits). The most controlled feature throughout all stages is the multiplicity of insemination (O = 0.401...1.147 bits; H=1.921 ...1.175 bits). The least controlled is the open days (O=0.136...0.604 bits; H=3.449...2.981 bits). The obtained results of the study contribute to the conduct of purposeful breeding of Brown Swiss cattle, taking into account the reproductive ability.

Diagnosis of lameness via data mining algorithm by using thermal camera and image processing method in Brown Swiss cows.

Lameness is one of the culling factors such as mastitis, low milk yield, and infertility that cause economic losses in herd management as they threaten animal health and welfare. The purpose of this study was to evaluate the early detection of lameness in Brown Swiss cattle by using a data mining algorithm by both integrating lameness scores and some image parameters such as Lab (CIE L*, a*, b*), HSB (hue, saturation, brightness), RGB (red, green, blue) by processing thermal images with ImageJ program. In the study, the variables obtained as a result of processing the skin surface temperatures and thermal images taken at the fetlock joint of 33 Brown Swiss cattle were used as independent variables. Also, healthy cows (lameness scores 1 and 2) and unhealthy cows (lameness scores 3, 4, and 5) used in the diagnosis of lameness were used as a binary response variable. Classification and regression tree (CART) was used as a data mining algorithm in the diagnosis of lameness. As a result, the CART algorithm correctly classified 12 of the 13 heads unhealthy cows according to locomotion scores. According to locomotion scores by using CART analysis in this study, independent variables that are used to classify healthy and unhealthy (lame) animals were determined as maximum temperature (Tmax), green (mean), L (max), and age (P<0.05). The cut-off values of these independent variables were predicted as 32.40, 149.14, 97.11, and 5.50 for Tmax, green (mean), L (max), and age, respectively. Also, the sensitivity, specificity, and area under the ROC curve (AUC) of the CART algorithm for locomotion scoring were found as 92.31%, 95%, and 93.7% respectively. The area under ROC curve (AUC) was found to be significant in the diagnosis of lameness (P<0.01). Results showed that the use of CART classification algorithm together with thermal camera and image processing methods is a usefull tool in the detection of lameness in the herds. It is recommended that more comprehensive studies by increasing the number of animals in the future would be more beneficial.

The relationships between Pit-1 gene polymorphism and some performance traits in simmental and brown swiss breeds

It was aimed to investigate the genotypic structures of the Pit-1 gene from genomic DNA samples taken from Simmental and Brown Swiss breeds and determine the distribution of genotype and allele frequencies of bovine breeds and to determine the relationships between the detected genotypes and some performance traits. Pit-1/HinfI gene polymorphisms were determined using the PCR-RFLP method from genomic DNA obtained from Brown Swiss and Simmental breed cattle used in the study. According to the Hardy-Weinberg genetic test, the distribution of genotype frequencies of the studied population was found to be in equilibrium (p˃0.05) in both breeds. Genotype frequencies of AA, AB, and BB alleles of the Pit-1 gene were determined as 5.73%, 36.42%, and 57.85%, respectively, for Simmental breed, while the genotype frequencies for Brown Swiss breed were determined as 9.43%, 42.86%, and 48.01%, respectively. The actual milk yield for Simmental breed was determined as 5953 ± 364.2, 5212 ± 993.4, 5507 ± 889.5 kg, the 305-day milk yield as 5953 ± 276.8, 5642 ± 782.7, 5427 ± 246.7 kg, the lactation period as 307 ± 47, 293 ± 29, 303 ± 22 days, the daily milk yield as 19.53 ± 6, 18.49 ± 8, 17.81 ± 2 kg for AA, AB, and BB genotypes, respectively. The actual milk yield for the Brown Swiss breed was determined as 3606 ± 253, 3558 ± 530, 3999 ± 099 kg, the 305-day milk yield as 4920 ± 217, 4462 ± 900, 4635 ± 870 kg, the lactation period as 222 ± 36, 240 ± 04, 258 ± 37 days, the daily milk yield as 17.62 ± 2, 15.49 ± 2, 16.04 ± 3 kg for AA, AB, and BB genotypes, respectively. In the statistical analyses, the relationships between the performance traits studied and Pit-1 genotypes in Simmental and Brown Swiss cattle were not prove to be significant statistically.

Genotype by environment interaction due to heat stress in Brown Swiss cattle

Due to its geographical position and a highly variable orography, Italy is characterized by several climatic areas and thus, by many different dairy cow farming systems. Brown Swiss cattle, in this context, are a very appreciated genetic resource for their adaptability and low metabolic requirement. The significant heterogeneity in farming systems may consist of genotype by environment (G × E) interactions with neglected changes in animals' rank position. The objective of this study was to investigate G × E for heat tolerance in Brown Swiss cattle for several production traits (milk, fat, and protein yield in kilograms; fat, protein, and cheese yield in percentage) and 2 derivate traits (fat-corrected milk and energy-corrected milk). We used the daily maximum temperature-humidity index (THI) range, calculated according to weather stations' data from 2008 to 2018 in Italy, and 202,776 test-day records from 23,396 Brown Swiss cows from 639 herds. Two different methodologies were applied to estimate the effect of the environmental variable (THI) on genetic parameters: (1) the reaction norm model, which uses a continuous random covariate to estimate the animal additive effect, and (2) the multitrait model, which splits each production pattern as a distinct and correlated trait according to the first (a thermal comfort condition), third (a moderate heat stress condition), and fifth (a severe heat stress condition) mean THI value quintile. The results from the reaction norm model showed a descending trend of the additive genetic effect until THI reached the value of 80. Then we recorded an increase with high extreme THI values (THI 90). Permanent environmental variance at increasing THI values revealed an opposite trend: The plot of heritability and the ratio of animal permanent environmental variance to phenotypic variance showed that when the environmental condition worsens, the additive genetic and permanent environmental component for production traits play a growing role. The negative additive genetic correlation between slope and linear random coefficient indicates no linear relationship between the production traits or under heat stress conditions, except for milk yield and protein yield. In tridimensional wireframe plots, the extreme margin decreases until a minimum of ∼0.90 of genetic correlation in the ECM trait, showing that the magnitude of G × E interaction is greater than the other traits. Genetic correlation values in Brown Swiss suggest the possibility of moderate changes in animals' estimated breeding value in heat stress conditions. Results indicated a moderate G × E interaction but significant variability in sire response related to their production level.