Anatomical Study of the Cardiac Veins and their Tributaries in Bovines (Bos indicus) in Comparison with Humans and Other Animal Species / Estudio Anatómico de las Venas Cardiacas y sus Tributarias en Bovinos (Bos indicus) en Comparación con Humanos y Otras Especies Animales

SUMMARY: In bovines, anatomical observations of the coronary vascular tree describe qualitative characteristics. The objective of this study was to morphometrically characterize the coronary veins and their tributaries in cattle. An arcuate application with 2.0 silk was performed around the ostium of the coronary sinus of 28 bovine hearts and a number 14 catheter was placed, through which semi- synthetic polyester resin and mineral blue color was perfused. In 22 hearts (78.6 %) the great cardiac vein was originated at the cardiac apex. The configuration of the arteriovenous trigone was mainly closed inferior and superior types (50 %). The caliber of the great cardiac vein at the level of the atrioventricular sulcus was 6.7 +/- 1.2 mm. The origin of the left marginal vein was observed in the lower third of the left cardiac margin (53.6 %), its distal caliber was 4.1 +/- 0.8 mm and its drainage was at the level of the great cardiac vein. The middle cardiac vein originated from the cardiac apex in 78.6 % of the samples, emptied mainly into the coronary sinus (82.1 %) and its distal caliber was 4.7 +/- 0.9 mm. Anastomoses occurred in 28.6 % of the hearts, being found in most cases between the middle cardiac vein and the great cardiac vein (50 %), which was significant compared to other anastomoses (p<0.001). The length of the coronary sinus was 42.2 +/- 5.1 mm, its distal caliber was 13.8 +/- 2 mm, and its shape was cylindrical. Myocardial bridges were found in 3 hearts (10.7 %) mainly in the lower third of the middle cardiac vein (66.6 %). Most of the main coronary veins drained into the coronary sinus, with some cases with atypical outlets and the presence of a high percentage of anastomosis that serves to improve cardiac venous drainage in case of venous compression or obstruction.

En bovinos, las observaciones anatómicas de árbol vascular coronario describen características cualitativas. El objetivo de este estudio fue caracterizar morfométricamente las venas coronarias y sus tributarias en bovinos. Se realizó una aplicatura arciforme con seda 2.0 alrededor del ostium del seno coronario de 28 corazones de bovino y se colocó un catéter número 14, a través del cual se perfundió resina de poliéster semisintética y color azul mineral. La vena cardiaca magna se originó en 22 corazones (78,6 %) en el ápex cardiaco. La configuración del trígono arteriovenoso fue principalmente cerrado inferior y superior (50 %). El calibre de la vena cardiaca magna a nivel del surco atrioventricular fue 6,7 +/- 1,2 mm. El origen de la vena marginal izquierda se observó en el tercio inferior del margen izquierdo cardiaco (53,6 %), su calibre distal fue 4,1 +/- 0,8 mm y su desembocadura fue a nivel de la vena cardiaca magna. La vena cardiaca media se originó en el ápex cardiaco en el 78,6 % de las muestras, desembocó principalmente en el seno coronario (82.1 %) y su calibre distal fue 4,7 +/- 0,9 mm. Se presentó anastomosis en el 28,6 % de los corazones, encontrándose en la mayoría de los casos entre la vena cardiaca media y la vena cardiaca magna (50 %), lo cual fue significativo en comparación con otras anastomosis (p<0,001). La longitud del seno coronario fue 42,2 +/- 5,1 mm, su calibre distal fue 13,8 +/- 2 mm y su forma fue cilíndrica. Se encontró puentes miocárdicos en 3 corazones (10,7 %) y en el tercio inferior de la vena cardiaca media (66,6 %). La mayoría de las venas coronarias principales desembocan en el seno coronario, con algunos casos con desembocaduras atípicas y la presencia de un alto porcentaje de anastomosis que sirve para mejorar el drenaje venoso cardiaco en caso de compresión u obstrucción venosa.

Comparative morphological and computed tomographical measurements of the orbit in cattle and pig eyes / Mediciones morfológicas y tomográficas computarizadas comparativas de la órbita en ojos de bovinos y porcinos

SUMMARY: Understanding species intraocular parameters using computed tomography (CT) scanning is initial and crucial step in ophthalmology. There is a lack of studies that have specialized in estimating the cattle and pig eyes using CT scans. Therefore, this study aimed to describe the anatomical and computed tomography features of cattle and pig eyes and its internal structures. Animal heads that not suffer from any diseases related to the eye were disarticulated. CT scan was performed. Moreover, 10 % fixed buffered formalin Specimens were used for the anatomical description of the eye and the optic nerve in particular. The values of length, width of the lens and globe, radio density of the optic nerve, lens, the anterior chamber, the vitreous chamber, and orbital dimensions were measured. Statistically, all parameters of cattle optic nerve increased significantly than that of the pig except for radiodensity, and angle of the optic nerve. Furthermore, all intraocular parameters of cattle increased significantly than that of the pig except the radiodensity of aqueous and vitreous humor. There was no significant difference between species in the opening angle of the orbit. This study's findings represent a first step toward developing CT reference values for cattle and pigs intraocular structural assessments.

Comprender los parámetros intraoculares de especies mediante la tomografía computarizada es un paso inicial y crítico en oftalmología. Faltan estudios enfocados en la estimación de ojos de bovinos y porcinos mediante tomografías computarizadas. Por tanto, este estudio tuvo como objetivo describir las características anatómicas y de tomografía computarizada de los bulbos oculares de bovinos y porcinos y sus estructuras internas. Se desarticularon cabezas de animales que no padecieran alguna enfermedad relacionada con el ojo. Se realizó una tomografía computarizada. Se fijaron las muestras en formalina tamponada al 10 % para la descripción anatómica del bulbo ocular y del nervio óptico en particular. Se midieron los valores de longitud del bulbo ocular, ancho del lente y la radio densidad del nervio óptico, lente, cámara anterior, cámara vítrea y dimensiones orbitarias. Estadísticamente, todos los parámetros del nervio óptico del ganado aumentaron significativamente con respecto al del cerdo, excepto la radio densidad y el ángulo del nervio óptico. Además, todos los parámetros intraoculares del ganado bovino aumentaron significativamente respecto a los del cerdo, excepto la radio densidad del humor acuoso y cuerpo vítreo. No hubo diferencia significativa entre especies en el ángulo de apertura de la órbita. Los hallazgos de este estudio representan un primer paso hacia el desarrollo de valores de referencia de tomografía computarizada para evaluaciones estructurales intraoculares de ganado vacuno y porcino.

Development of an interactive multidisciplinary platform for the bovine neuroanatomy study / Desarrollo de una plataforma interactiva multidisciplinar para el estudio de la neuroanatomía bovina

SUMMARY: The anatomy study is part of the basic cycle of disciplines that composes Veterinary Medicine college curriculum, and its comprehension is essential for other courses subject understanding. However, the current student's profile, the reduced time frame of superior education programs, and the multidisciplinary approach nowadays have made anatomy teaching method outdated and ineffective. Addressing the problem we developed an interactive and multidisciplinary platform based on the blended learning methodology, which could serve as a valuable tool for bovine neuroanatomy comprehension. To produce a new study tool, photos from bovine specimens fixed in formaldehyde, platinated brain pieces sectioned in a metameric order, as well as histological slides of the bovine central nervous system were used. These materials were applied to photos and schemes production, that were correlated with image exams correlation, as well as written content and videotaped classes. The obtained content was compiled into a digital platform, that can serve as an effective additional method to bovine central nervous system study. Furthermore, our results serve as a guide for the development of other blended learning methodologies in veterinary medicine and anatomy teaching. The platform provides a great tool for those who wish to accomplish a better understanding of bovine neuroanatomy and its clinical, surgical and image diagnosis correlations.

El estudio de la anatomía forma parte del ciclo básico de disciplinas que componen el currículo de la facultad de Medicina Veterinaria, y su comprensión es fundamental para el entendimiento de las materias de otros cursos. Sin embargo, el perfil del estudiante actual, la reducción de los tiempos de los programas de educación superior y el enfoque multidisciplinario actual han hecho que el método de enseñanza de la anatomía sea obsoleto e ineficaz. Abordando el problema desarrollamos una plataforma interactiva y multidisciplinar basada en la metodología blended learning, que podría servir como una valiosa herramienta para la comprensión de la neuroanatomía bovina. Para producir una nueva herramienta de estudio, se utilizaron fotografías de especímenes bovinos fijados en formaldehído, piezas de cerebro plastinadas y seccionadas en un orden metamérico, así como láminas histológicas del sistema nervioso central bovino. Estos materiales se utilizaron en la producción de fotos y esquemas, que se correlacionaron con exámenes de imágenes, así como contenido escrito y clases grabadas en video. El contenido obtenido se compiló en una plataforma digital, que puede servir como un método adicional y eficaz para el estudio del sistema nervioso central bovino. Además, nuestros resultados sirven como guía para el desarrollo de otras metodologías de aprendizaje semipresencial en la enseñanza de la medicina veterinaria y la anatomía. La plataforma proporciona una gran herramienta para aquellos que deseen lograr una mejor comprensión de la neuroanatomía bovina y sus correlaciones clínicas, quirúrgicas y de diagnóstico por imágenes.

Copy number variation of bovine DYNC1I2 gene is associated with body conformation traits in chinese beef cattle.

Previous, studies have shown that the dynein transporter compound has a role in diseases such as intellectual disability and cerebral malformations. However, the study of CNV in DYNC1I2 gene has not been reported. Q-PCR and data association analysis were used for DYNC1I2 gene copy in this study. In this study, blood samples were collected from five breeds of Chinese cattle (Qingchuan cattle, Xianan cattle, Yunling cattle, Pinan cattle and Guyuan cattle) for DYNC1I2 gene CNV type detection. SPSS 20.0 software and method of ANOVA were used to analyzed the association between types of CNV and growth traits. Results reveal that the distribution of different copy number types in different cattle breeds is different. Association analysis indicate that CNV of DYNC1I2 gene showed a positive effect in cattle growth: in XN cattle, individuals with deletion types showed better performance on height at hip cross (P < 0.05); individuals with duplication types have better performance on body length (P < 0.05) in PN cattle; individuals with deletion types was significantly correlated with chest width and Hucklebone width (P < 0.05) in QC cattle; individuals with duplication types in Yunling cattle were better than the normal types, and there was a significant correlation between copy number variant and chest depth (P < 0.05). The results showed that CNV markers closely related to cattle production traits were detected at DNA level, which could be used as an important candidate molecular marker for marker-assisted selection of growth traits in Chinese cattle, and provided a new research basis for genetics and breeding of Chinese beef cattle.

Individual dairy cow identification based on lightweight convolutional neural network.

In actual farms, individual livestock identification technology relies on large models with slow recognition speeds, which seriously restricts its practical application. In this study, we use deep learning to recognize the features of individual cows. Alexnet is used as a skeleton network for a lightweight convolutional neural network that can recognise individual cows in images with complex backgrounds. The model is improved for multiple multiscale convolutions of Alexnet using the short-circuit connected BasicBlock to fit the desired values and avoid gradient disappearance or explosion. An improved inception module and attention mechanism are added to extract features at multiple scales to enhance the detection of feature points. In experiments, side-view images of 13 cows were collected. The proposed method achieved 97.95% accuracy in cow identification with a single training time of only 6 s, which is one-sixth that of the original Alexnet. To verify the validity of the model, the dataset and experimental parameters were kept constant and compared with the results of Vgg16, Resnet50, Mobilnet V2 and GoogLenet. The proposed model ensured high accuracy while having the smallest parameter size of 6.51 MB, which is 1.3 times less than that of the Mobilnet V2 network, which is famous for its light weight. This method overcomes the defects of traditional methods, which require artificial extraction of features, are often not robust enough, have slow recognition speeds, and require large numbers of parameters in the recognition model. The proposed method works with images with complex backgrounds, making it suitable for actual farming environments. It also provides a reference for the identification of individual cows in images with complex backgrounds.

Bias, dispersion, and accuracy of genomic predictions for feedlot and carcase traits in Australian Angus steers.

BACKGROUND: Improving feedlot performance, carcase weight and quality is a primary goal of the beef industry worldwide. Here, we used data from 3408 Australian Angus steers from seven years of birth (YOB) cohorts (2011-2017) with a minimal level of sire linkage and that were genotyped for 45,152 SNPs. Phenotypic records included two feedlot and five carcase traits, namely average daily gain (ADG), average daily dry matter intake (DMI), carcase weight (CWT), carcase eye muscle area (EMA), carcase Meat Standard Australia marbling score (MBL), carcase ossification score (OSS) and carcase subcutaneous rib fat depth (RIB). Using a 7-way cross-validation based on YOB cohorts, we tested the quality of genomic predictions using the linear regression (LR) method compared to the traditional method (Pearson's correlation between the genomic estimated breeding value (GEBV) and its associated adjusted phenotype divided by the square root of heritability); explored the factors, such as heritability, validation cohort, and phenotype that affect estimates of accuracy, bias, and dispersion calculated with the LR method; and suggested a novel interpretation for translating differences in accuracy into phenotypic differences, based on GEBV quartiles (Q1Q4). RESULTS: Heritability (h2) estimates were generally moderate to high (from 0.29 for ADG to 0.53 for CWT). We found a strong correlation (0.73, P-value < 0.001) between accuracies using the traditional method and those using the LR method, although the LR method was less affected by random variation within and across years and showed a better ability to discriminate between extreme GEBV quartiles. We confirmed that bias of GEBV was not significantly affected by h2, validation cohort or trait. Similarly, validation cohort was not a significant source of variation for any of the GEBV quality metrics. Finally, we observed that the phenotypic differences were larger for higher accuracies. CONCLUSIONS: Our estimates of h2 and GEBV quality metrics suggest a potential for accurate genomic selection of Australian Angus for feedlot performance and carcase traits. In addition, the Q1Q4 measure presented here easily translates into possible gains of genomic selection in terms of phenotypic differences and thus provides a more tangible output for commercial beef cattle producers.

Characteristics of pulmonary microvascular structure in postnatal yaks.

Yaks are typical plateau-adapted animals, however the microvascular changes and characteristics in their lungs after birth are still unclear. Pulmonary microvasculature characteristics and changes across age groups were analysed using morphological observation and molecular biology detection in yaks aged 1, 30 and 180 days old in addition to adults. Results: Our experiments demonstrated that yaks have fully developed pulmonary alveolar at birth but that interalveolar thickness increased with age. Immunofluorescence observations showed that microvessel density within the interalveolar septum in the yak gradually increased with age. In addition, transmission electron microscopy (TEM) results showed that the blood-air barrier of 1-day old and 30-days old yaks was significantly thicker than that observed at 180-days old and in adults (P < 0.05), which was caused by the thinning of the membrane of alveolar epithelial cells. Furthermore, Vegfa and Epas1 expression levels in 30-day old yaks were the highest in comparison to the other age groups (P < 0.05), whilst levels in adult yaks were the lowest (P < 0.05). The gradual increase in lung microvessel density can effectively satisfy the oxygen requirements of ageing yaks. In addition, these results suggest that the key period of yak lung development is from 30 to 180 days.

Hyaluronan and Collagen Are Prominent Extracellular Matrix Components in Bovine and Porcine Ovaries.

The extracellular matrix (ECM) is a major component of the ovarian stroma. Collagen and hyaluronan (HA) are critical ovarian stromal ECM molecules that undergo age-dependent changes in the mouse and human. How these matrix components are regulated and organized in other mammalian species with reproductive characteristics similar to women such as cows and pigs, has not been systematically investigated. Therefore, we performed histological, molecular, and biochemical analyses to characterize collagen and HA in these animals. Bovine ovaries had more collagen than porcine ovaries when assessed biochemically, and this was associated with species-specific differences in collagen gene transcripts: Col3a1 was predominant in cow ovaries while Col1a1 was predominant in pig ovaries. We also observed more HA in the porcine vs. bovine ovary. HA was distributed across three molecular weight ranges (<100 kDa, 100-300 kDa, and >300 kDa) in ovarian tissue and follicular fluid, with tissue having more >300 kDa HA than the other two ranges. Transcripts for HA synthesis and degradation enzymes, Has3 and Hyal2, respectively, were predominant in cow ovaries, whereas Has2, Kiaa1199, and Tmem2 tended to be predominant in pig ovaries. Together, our findings have implications for the composition, organization, and regulation of the ovarian ECM in large mammalian species, including humans.

Genome-wide association study of trypanosome prevalence and morphometric traits in purebred and crossbred Baoulé cattle of Burkina Faso.

In this study, single-SNP GWAS analyses were conducted to find regions affecting tolerance against trypanosomosis and morphometrics traits in purebred and crossbred Baoulé cattle of Burkina Faso. The trypanosomosis status (positive and negative) and a wide set of morphological traits were recorded for purebred Baoulé and crossbred Zebu x Baoulé cattle, and genotyped with the Illumina Bovine SNP50 BeadChip. After quality control, 36,203 SNPs and 619 animals including 343 purebred Baoulé and 279 crossbreds were used for the GWAS analyses. Several important genes were found that can influence morphological parameters. Although there were no genes identified with a reported strong connection to size traits, many of them were previously identified in various growth-related studies. A re-occurring theme for the genes residing in the regions identified by the most significant SNPs was pleiotropic effect on growth of the body and the cardiovascular system. Regarding trypanosomosis tolerance, two potentially important regions were identified in purebred Baoulé on chromosomes 16 and 24, containing the CFH, CRBN, TRNT1 and, IL5RA genes, and one additional genomic region in Baoulé, x Zebu crossbreds on chromosome 5, containing MGAT4C and NTS. Almost all of these regions and genes were previously related to the trait of interest, while the CRBN gene was to our knowledge presented in the context of trypanosomiasis tolerance for the first time.

Use of multivariate analysis as a tool in the morphological characterization of the main indigenous bovine ecotypes in northeastern Algeria.

Sustainability in livestock farming requires monitoring of autochthonous breeds which are well adapted to the local environment. The morphometric measurements seem to be the first approach which can provide useful information on the suitability of animal genetic resources for selection. In this work, thirteen morphometric variables were used for the phenotypic characterization of 130 adult autochthones cattle randomly selected from 30 local farms in Guelma. There were cases from four commonly accepted and traditional ecotypes: Guelmois, Cheurfa, Sétifien and Fawn. The results showed several and significant positive correlations between the different variables. Correlations were analyzed using Varimax orthogonal rotation PCA and three factors were extracted, which explain more than 75% of the total variation in the four ecotypes. Stepwise discriminant analysis showed that 6 of the 13 variables had discriminatory power to define the phenotypic profile of the ecotypes. Canonical discriminant analysis indicated that the Sétifien ecotype is separate from the other three ecotypes. Mahalanobis distances were significant between the different ecotypes except for the distance between the Guelmois and Fawn ecotypes. The cross-validation procedure assigned 91.42% of the Sétifien animals to their genetic group, while the percentages of animals assigned to the Cheurfa, Guelmois and Fawn ecotypes were 80.00%, 65.71% and 53.33% respectively. The multivariate approach has proven to be effective in differentiating the four ecotypes, with clear morphological differences from the Sétifien ecotype that may benefit from a genetic improvement program for more sustainable genetic resources preservation.

Anatomical organization of the lateral cervical nucleus in Artiodactyls.

The presence of the lateral cervical nucleus (LCN) in different mammals, including humans, has been established in a number of anatomical research works. The LCN receives its afferent inputs from the spinocervical tract, and conveys this somatosensory information to the various brain areas, especially the thalamus. In the present study, the organization of the calf and pig LCN was examined through the use of thionine staining and immunohistochemical methods combined with morphometrical analyses. Specifically, the localization of calbindin-D28k (CB-D28k) and neuronal nitric oxide synthase (nNOS) in the LCN was investigated using the immunoperoxidase method. Calf and pig LCN appear as a clearly defined column of gray matter located in the three cranial segments of the cervical spinal cord. Thionine staining shows that polygonal neurons represent the main cell type in both species. The calf and pig LCN contained CB-D28k-immunoreactive (IR) neurons of varying sizes. Large neurons are probably involved in the generation of the cervicothalamic pathway. Small CB-D28k-IR neurons, on the other hand, could act as local interneurons. The immunoreactivity for nNOS was found to be mainly located in thin neuronal processes that could represent the terminal axonal portion of nNOS-IR found in laminae III e IV. This evidence suggests that nitric oxide (NO) could modulate the synaptic activity of the glutamatergic spinocervical tracts. These findings suggest that the LCN of Artiodactyls might play an important role in the transmission of somatosensory information from the spinal cord to the higher centers of the brain.

Relationship between thermal environment and morphophysiological, performance and carcass traits of Brahman bulls raised on tropical pasture: A canonical approach to a set of indicators.

The purpose of this study was to understand and discuss the relationships of the thermal environment, morphophysiological response, performance, and carcass traits of Brahman bulls from weaning at 18 months exposed to grazing conditions based on the physiological and evolutionary rationale behind the different proposals for the thermal adaptation of zebu cattle. Fifty-three uncastrated and clinically healthy bulls with birth and weaning weight of 34.0 ± 3.32 kg and 215.5 ± 44.75 kg, respectively, were evaluated. Fifteen canonical correlations were estimated, but only six were significant: thermal environment × thermoregulatory responses (rc = 0.4635; P = 0.0413); thermal environment × performance (rc = 0.4338; P = 0.0218); thermoregulatory responses × performance (rc = 0.5119; P = 0.0071); hair coat characteristics × performance (rc = 0.4939; P = 0.0273); hormone × carcass traits (rc = 0.5408; P = 0.0698); and performance × carcass traits (rc = 0.9644; P < 0.0001). Thermal environment, thermoregulatory responses and hair coat morphology influence of 18.81%, 21.49% and 24.40%, respectively, were found in the performance. We also concluded that (i) rectal temperature (RT) is a homoeothermic indicator; (ii) sweating rate (SR) is an important heat dissipation mechanism to explain the adaptation of zebu animals in the tropics and is related to weight at 550 days (W550); (iii) coat morphology, especially length (HL), diameter (HD) and hair density (ND) are related to animal performance; and (iv) hormonal profile, mainly T4, influences the carcass traits (yield, weight, subcutaneous fat and marble meat).

Hepatic ultrasonography in three breeds of healthy calves: Nellore, Curraleiro Pe-duro and Pantaneiro.

An ultrasonography was performed in 21 healthy male calves of Nellore (n = 8), Curraleiro Pe-duro (n = 7) and Pantaneiro (n = 6) breeds, between 8 and 12 months, with the objective to display information about size, position and ultrasonographic parenchymal patterns of the liver, in addition to the topography of the gallbladder, right kidney and major vessels. The measurements used were dorsal margin distance (DMD) and ventral margin distance (VMD) of the liver, viewable extension (VE) of the liver, the caudal vena cava (CVC), width (CVCW) and depth (CVCD) and the portal vein (PV), width (PVW) and depth (PVD). The measures DMD, VMD and VE were similar, and the organ's longest visible extension was in 11th ICS. CVC was more frequently observed in the 11th and 10th ICS, despite being visible from the 12th to the 9th ICS in Nellore and still 8th ICS in Curraleiro Pe-duro and Pantaneiro. CVCD was lower in the 10th and 9th ICS in Nellore. The PV presented higher observation frequency in the 10th ICS. The measures PVD and PVW were higher in Nellore in the 11th, 10th and 9th ICS. To our knowledge, this report is the first to document ultrasonographic findings in three healthy calves. Considering the three breeds, the results show no differences in the ultrasonographic features as regard to the measurements and visualization of the position, size and vasculature of the liver and there was no additional information about the topography of the gallbladder and the right kidney.

Short communication: Molecular markers for epithelial cells across gastrointestinal tissues and fecal RNA in preweaning dairy calves.

The objective of this study was to compare the transcription of gene markers for gastrointestinal (GI) epithelial cells, including fatty acid binding protein 2 (FABP2) and cytokeratin 8 (KRT8), and tight junction complex genes (TJP1, CLDN1, CLDN4) in fecal RNA against several GI tract tissue sections in dairy calves. Eight healthy Jersey calves were euthanized at 5 wk of age, and postmortem samples were collected from rumen, duodenum, jejunum, ileum, large intestine, cecum, and feces for total RNA isolation. Tissues and fecal samples were immediately frozen in liquid nitrogen until RNA isolation. A real-time quantitative PCR analysis was performed using a single standard curve composited of equal amounts of all samples, including cDNA from fecal and GI tract tissues. The mRNA expression of the tight junctions TJP1, CLDN1, and CLDN4 was greater in fecal RNA compared with lower GI tract tissues (i.e., duodenum, jejunum, ileum, large intestine, and cecum). Similar to fecal RNA, rumen tissue had greater expression of tight junctions CLDN1 and CLDN4 than lower GI tract tissues. Similarly, rumen tissue had greater expression of TPJ1 than all lower GI tract tissues except duodenum. The expression of TJP1 and CLDN4 was greater in fecal RNA than in rumen tissue; in contrast, CLDN1 mRNA expression was greater in rumen tissue than in the fecal RNA. The expression of FABP2 was greater in duodenum in comparison to all tissue except ileum. The mRNA expression of FABP2 in fecal samples was similar to jejunum and ileum. The expression of KRT8 in fecal samples was similar to duodenum, large intestine, and cecum. The fecal RNA had a greater expression of KRT8 in comparison to jejunum and ileum. The rumen tissue had the lowest mRNA expression of KRT8. The expression levels of FABP2, KRT8, and tight junction genes observed in fecal transcripts suggest that a considerable amount of RNA derived from GI tract epithelial cells can be detected in fecal RNA, which is in agreement with previous data in neonatal dairy calves and other biological models including humans, rodents, and primates. The greater expression of tight junctions in fecal RNA in comparison to sections of the low GI remains to be understood, and due to the importance of tight junctions in GI physiology, further clarification of this effect is warranted. The similarities in mRNA expression of FABP2 and KRT8 between fecal RNA and intestinal sections add up to the accumulating evidence that fecal RNA can be used to investigate molecular alterations in the GI tract of neonatal dairy calves. Further research in this area should include high-throughput transcriptomic analysis via RNA-seq to uncover novel molecular markers for specific sections of the GI tract of neonates.

Major quantitative trait loci influencing milk production and conformation traits in Guernsey dairy cattle detected on Bos taurus autosome 19.

The goal of this study was to identify potential quantitative trait loci (QTL) for 27 production, fitness, and conformation traits of Guernsey cattle through genome-wide association (GWA) analyses, with extra emphasis on BTA19, where major QTL were observed for several traits. Animals' de-regressed predicted transmitting abilities (PTA) from the December 2018 traditional US evaluation were used as phenotypes. All of the Guernsey cattle included in the QTL analyses were predictor animals in the reference population, ranging from 1,077 to 1,685 animals for different traits. Single-trait GWA analyses were carried out by a mixed-model approach for all 27 traits using imputed high-density genotypes. A major QTL was detected on BTA19, influencing several milk production traits, conformation traits, and livability of Guernsey cattle, and the most significant SNP lie in the region of 26.2 to 28.3 Mb. The myosin heavy chain 10 (MYH10) gene residing within this region was found to be highly associated with milk production and body conformation traits of dairy cattle. After the initial GWA analyses, which suggested that many significant SNP are in linkage with one another, conditional analyses were used for fine mapping. The top significant SNP on BTA19 were fixed as covariables in the model, one at a time, until no more significant SNP were detected on BTA19. After this fine-mapping approach was applied, only 1 significant SNP was detected on BTA19 for most traits, but multiple, independent significant SNP were found for protein yield, dairy form, and stature. In addition, the haplotype that hosts the major QTL on BTA19 was traced to a US Guernsey born in 1954. The haplotype is common in the breed, indicating a long-term influence of this QTL on the US Guernsey population.

Heifer management characterization in dairy herds from the west of Buenos Aires, Argentina / Caracterização da gestão de novilhas em rebanhos leiteiros do oeste de Buenos Aires, Argentina

The replacement program in a dairy farm represents the second or third largest cost in a dairy operation. This study aimed to characterize and typify the practices related to the dairy heifer replacement program and describe the growth, development, and health parameters during this period in commercial dairy herds in Trenque Lauquen. A cross-sectional observational study was carried out, including 54 randomly selected dairy farms that were visited once to collect data about facilities and management through a semi-structured survey. Cluster and principal coordinates analysis were applied to classify the farms based on all variables collected, grouped in four main areas: pre-fresh cows, colostrum management, pre-weaning calf 's management, and personnel. Additionally, growth, development, and health status were also recorded and described for calves and breeding heifers. Two similar-sized farm clusters were identified with differences in management and facilities in different areas of calves rearing. In one cluster there was a greater proportion of farms having a pre-fresh group, implementing appropriate health (colostrum, vaccination) and feeding management. Also, differences in personnel and technical support were relevant. The estimated body gain was 452 and 774 g/d for calves younger or older than 60 d of age, respectively. The age and weight farm averages in breeding heifers were 21.0 mo (range: 16.7-27.5) and 416.3 kg (range: 336.7-519.3), respectively. Diarrhea and respiratory affections were the major problems in pre-weaning calves and heifer rearing, respectively. The median mortality was 7.3, 7.6, and 2.9% at the calving, pre-weaning, and heifer rearing period, respectively. The results showed an improvement opportunity for producers, the design of precise and high impact programs that could lead to an improved replacement program.(AU)

Nos rebanhos leiteiros, o programa de reposição representa o segundo ou o terceiro maior custo da atividade de produção de leite. O objetivo do presente trabalho foi caracterizar e tipificar as práticas relacionadas ao programa de reposição de novilhas leiteiras e descrever o crescimento, desenvolvimento e parâmetros de saúde durante este período em rebanhos leiteiros comerciais localizados em Trenque Lauquen, oeste de Buenos Aires, Argentina. Foi realizado um estudo observacional transversal incluindo 54 fazendas de produção de leite selecionadas ao acaso e visitadas uma única vez para a colheita de dados relacionados a instalações e manejo empregando-se um questionário semi-estruturado. Foi efetuada a análise dos agrupamentos e das coordenadas principais para classificar as fazendas com base em todas as variáveis colhidas e agrupadas em quatro principais áreas: vacas pré-parto, manejo de colostro, manejo pré-desmame de bezerros e recursos humanos. Os dados referentes ao crescimento, desenvolvimento e estado de saúde dos animais também foram registrados e descritos para bezerros e novilhas. Dois grupos de fazendas de tamanho semelhante foram identificados com diferenças no manejo e instalações em distintas áreas de recria de bezerros. Em um grupo houve uma maior proporção de fazendas que tinham um grupo de vacas pré-parto, com implementação de adequado manejo de saúde (colostro, vacinações) e manejo alimentar. Também foram relevantes as diferenças em termos de pessoal e suporte técnico. O ganho de peso estimado foi de 452 e 774 gramas por dia, respectivamente, para os bezerros jovens e os com idade superior a 60 dias. As médias das fazendas da idade e do peso das novilhas de reprodução foram, respectivamente, 21,0 meses (variação de 16,7 a 27,5) e 416,3 kg (variação de 336,7 a 519,3). A diarreia e as afecções respiratórias foram os maiores problemas de saúde, respectivamente, nos bezerros em pré-desmama e novilhas em recria. A média de mortalidade foi de 7,3; 7,6 e 2,9%, respectivamente, ao parto, na pré-desmama e durante a recria de novilhas. Os resultados obtidos demonstraram a existência de oportunidades de melhoria para os produtores, com o delineamento de programas precisos e de alto impacto que poderão propiciar um programa de reposição aprimorado.(AU)

Preliminar histological study of the thymus in regularly slaughtered Chianina beef cattle to improve methods for the detection of illicit treatments.

Chianina is an Italian cattle breed appreciated for its meat and resilience skills. No standard values are present in literature regarding Chianina thymic involution. A possible early physiological involution has been reported during the Italian National Residue Plan screening tests. The aim of this work was to perform an anatomo­histopathological study of the thymus in Chianina cattle to improve knowledge about thymic involution in this breed. Forty Chianina bulls (16­24 months old), never treated with corticosteroids and regularly slaughtered in the Umbria region (Italy), were enrolled. Animals aged 19­21 months which received score 3 thymic atrophy had a prevalence of 0.15 (CI 95%: 0.02­0.45%), while the prevalence was 0.29 (CI 95%: 0.10­0.56%) among animals aged 22­24 months. The thymus/carcass weight and thymic cortex/medulla ratio resulted close to those reported in cattle experimentally challenged with corticosteroids. Results suggest that the Chianina breed could be characterized by a physiological premature involution of the thymus gland in comparison to other breeds. These results represent a starting point to increase the reliability of the National Residue Plan histological screening test.

Genetic relationships of calving difficulty with birth measurements and carcass traits in Japanese Black cattle.

The objectives of this study were to compare the genetic parameters for calving difficulty (CD), which were treated as both a calf trait (CD_calf) and as a dam trait (CD_dam), and to clarify genetic relationships of these CDs with body size traits of calves at birth and carcass traits. In total, the CD records and calf body measurements of 2,258 Japanese Black cattle heifers were used in this study, in addition to the carcass records of 4,300 feedlot steers and heifers. Direct heritability of CD_calf (0.44) was higher than maternal heritability of CD_calf (0.30), as well as CD_dam heritability (0.25). Direct genetic correlations between CD_calf and calf body size were moderate to strongly positive (0.64 to 0.81). The correlations between EBVs of CDs and carcass weight were also positive (0.30 to 0.64). These positive relationships showed that genetically improving CD (reducing dystocia) could produce smaller calves and carcasses. In contrast, the correlations between CDs and beef marbling score were weak, suggesting that improving CD would not influence meat quality traits. Fitting an animal model to CD_calf could be more preferred to fitting the model to CD_dam, because the former could separate the genetic effects of dams and calves.

Comparative scanning electron microscope analysis of the enamel of permanent human, bovine and porcine teeth.

BACKGROUND: Bovine and porcine teeth are often used in in vitro experiments as substitutes of human teeth. OBJECTIVES: The aim of the present study was to perform a comparative analysis of enamel morphology of permanent human, bovine and porcine teeth under the scanning electron microscope. METHODS: As many as 10 human, 10 bovine, and 10 porcine teeth were studied. All the teeth were sectioned and the halves were randomly divided into 2 groups according to the examined tissue (vestibular enamel at the mid-height of the dental crown and in the cervical area). Human and bovine enamel was etched for 15 sec and porcine enamel for 30 sec. The scanning electron microscope analysis was performed. The length and width of enamel prisms were determined with the "Met-Ilo" 1.1 computer program. RESULTS: All enamel samples revealed the same etching pattern-Silverstone's type 2. Bovine enamel showed a similar porosity and the amount of interprismatic enamel compared to human enamel while the amount and width of interprismatic enamel bands in porcine enamel were evidently greater. The shape of the porcine prisms was visually similar to human prisms, although dimensions were significantly different. However, bovine prisms differed in form and appeared to be distinctly elongated. CONCLUSIONS: Reported findings indicate that the results of experimental studies carried out on bovine and porcine enamel should not be compared with the results obtained on human enamel.