Effects of energy and protein status on reproductive parameters and presence of subclinical ketosis in Brown Swiss cows postpartum

This study aimed to determine protein and energy metabolites in postpartum Brown Swiss cows and their effect on the presence of subclinical ketosis and reproductive parameters. One hundred cows from four farms in the Mantaro Valley (Junín, Perú) were grouped according to parity (1, 2, 3 and 4). The variables of the metabolic profile (total proteins, blood urea nitrogen [BUN], glucose, βhydroxybutyrate [B-HB]), milk production and body condition were estimated between 7 to 60 days postpartum in 7-day intervals. Likewise, the calving-first heat interval and the pregnancy rate at first service were recorded. The determination of subclinical ketosis was based on a semi-quantitative analysis by levels of B-HB in milk (µmol/l) using a commercial kit. BUN levels ranged between 11.74 and 15.92 mg/dl, being higher in fourth parity cows (p<0.05). The averages of total protein (6.54-7.90 g/dl) were homogeneous between calvings. The glucose values presented an inverse response, being lower in cows of third and fourth parity compared to cows of first and second parity (p<0.05). Similarly, the highest levels of milk production were observed in third parity cows (14.41 ± 5.42 l/d) and fourth parity (15.43 ± 4.36 l/d) with respect to first and second calvers (p<0.05). Body condition was lower in cows with subclinical ketosis. The calving - first heat interval and the pregnancy rate at first service were lower in cows with subclinical ketosis (p<0.05).

Single Nucleotide Polymorphisms in the Bovine TLR2 Extracellular Domain Contribute to Breed and Species-Specific Innate Immune Functionality

Recent evidence suggests that several cattle breeds may be more resistant to infection with the zoonotic pathogen Mycobacterium bovis. Our data presented here suggests that the response to mycobacterial antigens varies in macrophages generated from Brown Swiss (BS) and Holstein Friesian (HF) cattle, two breeds belonging to the Bos taurus family. Whole genome sequencing of the Brown Swiss genome identified several potential candidate genes, in particular Toll-like Receptor-2 (TLR2), a pattern recognition receptor (PRR) that has previously been described to be involved in mycobacterial recognition. Further investigation revealed single nucleotide polymorphisms (SNP) in TLR2 that were identified between DNA isolated from cells of BS and HF cows. Interestingly, one specific SNP, H326Q, showed a different genotype frequency in two cattle subspecies, Bos (B.) taurus and Bos indicus. Cloning of the TLR2 gene and subsequent gene-reporter and chemokine assays revealed that this SNP, present in BS and Bos indicus breeds, resulted in a significantly higher response to mycobacterial antigens as well as tri-acylated lipopeptide ligands in general. Comparing wild-type and H326Q containing TLR2 responses, wild-type bovine TLR2 response showed clear, diminished mycobacterial antigen responses compared to human TLR2, however bovine TLR2 responses containing H326Q were found to be partially recovered compared to human TLR2. The creation of human:bovine TLR2 chimeras increased the response to mycobacterial antigens compared to the full-length bovine TLR2, but significantly reduced the response compared to the full-length human TLR2. Thus, our data, not only present evidence that TLR2 is a major PRR in the mammalian species-specific response to mycobacterial antigens, but furthermore, that there are clear differences between the response seen in different cattle breeds, which may contribute to their enhanced or reduced susceptibility to mycobacterial infection.

MILK PRODUCTIVITY AND TRUENESS TO TYPE OF BROWN SWISS COWS OF THE SMOLENSK REGION

Изучена молочная продуктивность коров бурой швицкой породы и определена ее производственная типичность в условиях Смоленской области. Исследования показали, что в породе преобладают животные молочного (36%) и низкомолочного (31%) типов, при этом высокомолочные коровы составляют 26% от всего поголовья. Рассчитанные усредненные значения коэффициента производственной типичности (КПТ) и индекса производственной типичности (ИПТ) находятся в пределах 3,00—3,99 ед., то есть изучаемых животных возможно отнести к классу молочных. Отмечено снижение значений результатов типичности от 1-ой к 3-ей лактации на 0,04—0,03 ед. (Р≤0,001).Экстерьер коров в зависимости от производственного типа имеет, в основном, недостоверную разницу между значениями промеров, но позволяет определить их соответствие типу. Следует отметить значительную разницу у коров всех лактаций глубины груди — 8,4—10,0 см (Р≤0,001), косой длины туловища — 5,6—8,2 см (P≤0,001). Интенсивность удоя в первую и вторую фазы лактации в зависимости от производственного типа увеличивается от 1-й к 3-й лактации. У коров всех производственных типов происходит снижение коэффициента устойчивости от 1-й к 3-й лактации и составляет 0,9—13,3%. Результаты коэффициента молочности постепенно увеличиваются от 1-й лактации к 3-й, кроме группы высокомолочных коров. Полученные данные обеспечат достоверность отбора лучших животных для дальнейшей селекции, повысят точность определения производственного типа, ускорят проведение оценки, поскольку для установления направления продуктивности животных целесообразно ее проводить по окончании 1-й лактации путем расчета КПТ и ИПТ. Итог — получение стад соответствующего направления продуктивности в зависимости от пожеланий собственника. The milk productivity of Brown Swiss cattle was studied and its trueness to type assessment was carried in the Smolensk region. The survey of the breed was showed that it is dominated by animals of the milk (36%) and low-milk (31%) types, while high-milk ones make up 26%. The observed average values of the trueness to type coefficient (TTC) and the index trueness to type of (ITT) are in the range of 3.00—3.99 points, that is, the studied animals may be classified as milk. There was a decrease the results to type from 1 to 3 lactation by 0.04—0.03 points (P≤0.001). The exterior of cows, depending on the production type, has mainly an unreliable difference between the values of body measurements, but what it allows to determine their compliance with the trueness to type. It should be noted a significant difference in the chest depth in all lactation 8.4—10.0 cm (P≤0.001), the oblique body length 5.6—8.2 cm (P≤0.001). The rate of production in the first and second phases of lactation, depending of the trueness to type, increases from 1 to 3 lactation. In all cow’s trueness to types, the coefficient of lactation stability decreases from the first to the third lactation and is 0.9 - 13.3%. The results of the milk yield coefficient gradually increase from 1 lactation to 3, except for the group of high-milk cows. The obtained results will ensure the reliability of the selection of the best animals for further breeding, increase the accuracy of determining the trueness to type, step up the assessment, since it is advisable to conduct it after the end of the first lactation by calculating the TTC and ITT to determine the direction of animal productivity. The result is the receipt of herds of the appropriate direction of productivity, depending on the wishes of the owner.

The relationships between leptin gene polymorphism and some performance traits in Simmental and Brown Swiss cattle

This study was carried out to determine the genotype and allele frequencies and association between the Leptin gene Sau3AI polymorphism and some performance characteristics in Simmental (n=60) and Brown Swiss (n=62) breed cattle raised in the province of Erzurum, Turkey. In the study, leptin/Sau3AI gene polymorphisms in DNA isolated from blood samples obtained from Simmental and Brown Swiss cattle were determined using PCR-RFLP method. As genotype frequencies of leptin/Sau3AI gene in the population, in Brown Swiss cattle, 88,7% with genotype AA, 9,7% with AB and 1,6% with BB genotypes were determined, Simmental breed cattle, 78,3% with genotype AA, 16,7% with AB and with 5,0% BB genotypes were determined. AA genotype frequencies were the highest in the population, and those with BB genotypes had the lowest frequency in both breeds. When the population was examined in terms of allele frequencies, the A allele was 0,87 and B allele was 0,13 in the Simmental cattle, and the A allele was 0,94 and B allele was 0,06 in the Brown Swiss breed. According to Hardy-Weinberg genetic balance test, the distribution of genotype frequencies was balanced (P>0.05) in the Brown Swiss breed but not in the Simmental breed in the population studied. As a result of the analysis performed in the Simmental breed, the general averages were found to be 5422,4 ± 1901,74 kg for actual milk yield, 5626,6 ± 1475,85 kg for 305-day milk yield, 298,7 ± 84,80 days for lactation duration and 18,5 ± 4,84 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on the actual milk yield during lactation, lactation duration and daily milk yield was significant. As a result of the analysis made in the Brown Swiss breed, the general averages were 3917,8 ± 1584,38 kg for actual milk yield, 4614,3 ± 982,62 kg for 305 days milk yield, 254.9 ± 99.88 days for lactation duration and 16,0 ± 3,82 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on performance characteristics was insignificant in Simmental and Brown Swiss cattle.

A 1-bp deletion in bovine QRICH2 causes low sperm count and immotile sperm with multiple morphological abnormalities

Background: Semen quality and male fertility are monitored in artificial insemination bulls to ensure high insemination success rates. Only ejaculates that fulfill minimum quality requirements are processed and eventually used for artificial inseminations. We examined 70,990 ejaculates from 1343 Brown Swiss bulls to identify bulls from which all ejaculates were rejected due to low semen quality. This procedure identified a bull that produced twelve ejaculates with an aberrantly low number of sperm (0.2±0.2 x 109 sperm per ml) which were mostly immotile due to multiple morphological abnormalities. Results: The genome of the bull was sequenced at 12-fold coverage to investigate a suspected genetic cause. Comparing the sequence variant genotypes of the bull with those from 397 fertile bulls revealed a 1-bp deletion in the coding sequence of QRICH2 encoding glutamine rich 2 as a compelling candidate causal variant. The 1-bp deletion causes a frameshift in translation and induces a premature termination codon (ENSBTAP00000018337.1:p.Cys1644AlafsTer52). The analysis of testis transcriptomes from 76 bulls showed that the transcript with the premature termination codon is subjected to nonsense-mediated mRNA decay. The 1-bp deletion resides on a 675 kb haplotype spanning 181 SNPs from the Illumina BovineHD Bead chip. The haplotype segregates at a frequency of 5% in the Brown Swiss cattle population. This analysis also identified another bull that carried the 1-bp deletion in the homozygous state. Semen analyses from the second bull confirmed low sperm concentration and immotile sperm with multiple morphological abnormalities primarily affecting the sperm flagellum and, to a lesser extent, the sperm head. Conclusions: A recessive loss-of-function allele of bovine QRICH2 likely causes low sperm concentration and immotile sperm with multiple morphological abnormalities. Routine sperm analyses unambiguously identify homozygous bulls. A direct gene test can be implemented to monitor the frequency of the undesired allele in cattle populations.

Reproductive Performance and Culling Rate of Purebred Holstein Cows and Their Crosses With Fleckvieh and Brown Swiss Cows Under Subtropical Conditions

This study aimed to elucidate the reproductive performance of purebred Holstein (HO) cows with their crosses with Fleckvieh (FV) and Brown Swiss (BS) cows under subtropical conditions. A total of 677 cows [487 HO, 104 HO × FV (HFV); 50% FV and 50% HO and 86 HO × BS (HB); 50% BS and 50% HO] were enrolled in this study. Pure HO cows had significantly greater service per conception (S/C; 3.69), days open (147.9 days), and calving interval (449.6 days), than the HFV (2.89, 116.7, and 407.4 days, respectively) and HB (3.07, 134.3, and 434.2 days, respectively) crossbred cows. At day 28, the conception percentage was significantly greater among HFV crossbred cows vs. pure HO cows [crude odds ratios (COR) = 2.16], but embryonic loss, abortion percentage, calving difficulty, and retained placenta percentage were similar (p &gt; 0.05) among pure HO cows and their crosses. HFV crossbreds had significantly lower incidence of endometritis (COR = 0.70, p = 0.035), mastitis (COR = 0.69, p = 0.015), and ketosis (COR = 0.53, p = 0.004) vs. other cows. HB and pure HO cows had a similar incidence of mastitis, lameness, and ketosis (COR = 0.76, 0.75, and 0.81; p = 0.223, 0.468, and 0.492, respectively). HFV crossbred cows had a lower risk of culling rate than HB crossbred cows. In summary, HFV cows demonstrated the best reproductive performance in terms of S/C, days open, calving interval, conception at 28 days, mastitis percentage, ketosis percentage, and endometritis.

Meeting the physiological requirements for energy and nutrients to manifest the genetic potential of dairy cattle

The paper presents the results of the scientific and economic experiment for the evaluation of the influence of the energy supplement included in the diet of lactating cows of the Brown Swiss breed. During the research period, all animals were kept in the same conditions, corresponding to zootechnical standards. They were divided into two groups differentiated only by the feed ration. The cows of the first (control) group were given rations typical for the farm corresponding to the feeding norms of dry and lactating cows. For the cows of the second group in the dry period (14 days before calving) the feeding ration was changed with a change in structure towards an increase in the proportion of concentrated feed, and immediately after calving, they received an energy feed supplement to maintain the physiological status of dairy cows after calving. Only clinically healthy animals participated in the experiment. It was revealed that the inclusion of the energy feed supplement in the diet of lactating cows in the experimental groups during lactation led to an increase in the productivity of livestock as compared with those in the control group.

Efecto de marcadores genéticos moleculares en genes inducibles por hipoxia de bovinos criollos y Brown Swiss criados en los Andes de Perú

Los genomas de 41 bovinos de cinco razas existentes en la base de datos del SRA-NCBI, fueron usados para identificar 17 polimorfismos de nucleótido simple (PNSs), los cuales generan mutaciones no sinónimas en 10 genes inducibles por hipoxia. De ese total, solo tres PNSs ubicados en las posiciones c.1081G>C, c.2089G>A y c.2101G>A de los exones 7 y 12 del gen EPAS1 tuvieron frecuencias alélicas diferentes entre bovinos cárnicos y lecheros (p<0.05). Basados en los resultados del análisis bioinformático de los genomas, se eligieron regiones exónicas de los genes EPAS1, NOS2, EPO y VEGFA, que fueron estudiadas en 60 muestras de ADN de bovinos criollos y Brown Swiss criados en la región altoandina (3213-4309 msnm). Los bovinos fueron agrupados por su concentración de hemoglobina (Hb) en Brown Swiss con Hb alta (BSHbA) (n=13), Brown Swiss con Hb baja (BSHbB) (n=11), criollos con Hb alta (CRHbA) (n=13) y criollos con Hb baja (CRHbB) (n=12); además se tuvo un grupo de Brown Swiss con mal de altura (BSMA) (n=11). Los amplicones generados fueron secuenciados con la metodología Sanger, identificándose 10 PNSs. No se encontraron asociaciones entre estos PNSs y los grupos considerados. Únicamente un PNS ubicado en la posición intrόnica Cr.19: 19403681T>C del gen NOS2 tuvo frecuencia diferente entre bovinos criollos y Brown Swiss (p<0.05); además dicho PNS se encontró ligado a otros dos que están ubicados en el exón 12 del mismo gen.