Brahman Cattle Research Articles

Genotype of Brahman and Brahman Cross Cattle based on SNP in Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3) gene sequences

Priyadi DA, Panjono, Bintara S, Hartatik T. 2017. The genotype of Brahman and Brahman Cross Cattle based on SNP in Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3) gene sequences. Biodiversitas 18: 795-800. The IGFBP-3 gene is a potential marker of cattle growth, which is related to the functions that influence the growth, energy metabolism, reproduction and immunity. The genome was isolated from whole blood samples of 10 Brahman cattle and 16 Brahman Cross cattle. Cattle IGFBP-3 gene that targeted in this study was located in the part of intron 2, exon 3 and part of intron 3. The gene targets were amplified using specific primers by Polymerase Chain Reaction (PCR) technique, resulting 563 bp amplification product. As data comparison to reveal the SNP, the GenBank sequences (n = 14) from various breed and countries were used. The objective of this study was to reveal the SNP on the Brahman and Brahman Cross IGFBP-3 gene. The results obtained 3 genotypes from one SNP that spread in the sample population. The SNP was located in intron 2 at position 3,930 (Gïƒ A). The Polymorphism could be recognized by PvuII restriction enzymes. There was not enough evidence to associate the SNP with the phenotype (at pre-weaning age) of Brahman and Brahman Cross cattle. There was a genetic diversity in the population studied. Knowledgeable SNP could be used as genetic markers for further research on Brahman and Brahman Cross cattle.

PROSPEK USAHA PENGGEMUKAN SAPI BRAHMA DI KABUPATEN OKU TIMUR

The purpose of this study is to: (1) To know the cost of production, acceptance and income of brahman cattle fattening in Eastern OKU, (2) To know the added value of brahman cattle fattening in East OKU, (3) Feasibility of brahman cattle fattening business in East OKU Regency. The research was conducted in OKU Timur Regency, with purposive determination of the research location with the consideration that there are still a few businessmen of cattle fattening who choose to fatten brahman cow, whereas the brahman cattle fattening in OKU Timur Regency has good prospect. This is because demand brahman cows from year to year continues to increase, in addition to the brushed cattle brewing process is quite easy and in a relatively long time has gained profits. This research has been conducted in March 2015 until May 2015 on the brahman cattle fattening that already existed in East OKU Regency. This study found that the average cost of production for brahman cattle fattening business is Rp. 79.438.224, - / PP, with a flat fee of Rp. 3,588,335, - / PP, and variable cost of Rp. 75.849.889, - / PP. Receipt is Rp. 123.333.333, - / PP then obtained revenue of Rp. 43.895.109, - / PP (Rp 7,315,852, - / Month). The added value of brahman cattle fattening business in Kabupaten OKU Timur is Rp. 59.305.278, - / tail (Rp 118.610.555, - / PP or Rp 19.768.426, - / Month). Brahman cattle fattening business in East OKU district can be said to be profitable and feasible to do. This is because the brackish cattle fattening business obtained NPV value at the bank interest rate of 18% (Rp 85.691.855, -) with the value of Net B / C of 1.89 and the value of IRR 32.16% which means feasible or effort can be done Because advantageous. So, brahman cattle fattening in Regency OKU East have good prospect to be developed.

Using ultrasound to derive new reproductive traits in tropical beef breeds: implications for genetic evaluation

Key components of female fertility in tropically adapted beef breeds are age at puberty and interval from calving to conception. Presence of an ovarian corpus luteum or stage of pregnancy were recorded using trans-rectal ultrasonography in 4649 heifers and 2925 first-lactation cows in seven herds of either Brahman, Droughtmaster or Santa Gertrudis tropical beef cattle breeds in northern Australia. The traits derived from a single ultrasonographic examination were incidence of corpus luteum at ~600 days of age in heifers, and weeks pregnant 5 weeks post-mating in heifers at ~2.5 years of age and in first-lactation cows at either 2.5 or 3.5 years of age. At 600 days of age, the bodyweight of heifers averaged 340 kg and 40% had a corpus luteum. At 2.5 years of age bodyweight of heifers averaged 452 kg and 80% were pregnant. First-lactation cows averaged 473 kg and 64% were pregnant. Considerable between-herd variation in traits reflected differences in climate and management at each site. However, estimates of heritability of incidence of corpus luteum at 600 days (0.18–0.32) and weeks pregnant in lactating cows (0.11–0.20) suggested that a significant proportion of the variation was due to additive gene action. Small to moderate genetic correlations with other economically important traits and the range in estimated breeding values indicate substantial opportunity for genetic improvement of the traits. The study provided evidence to accept the hypothesis that strategically timed ultrasound examinations can be adopted to derive useful traits for genetic evaluation.

Detection of Allelic and Genotypic Frequencies of Polymorphisms Associated with Meat Quality in the Mediterranean Baladi Cattle

Baladi, (B taurus; DAGRIS) a native cattle breed found throughout the entire Southern Mediterranean basin, is known for its high disease resistance and hardiness. Baladi cows in Israel and Southern Mediterranean basin are endangered due to the introduction of larger and more productive European breeds in these regions. In order to promote conservation initiatives of Baladi by stakeholders, the yet unexplored production traits, over their well accepted adaptation to the harsh Mediterranean conditions, were sought in the current study. Aiming at locating the genetic potential of Baladi for meat quality, the allelic and genotypic frequencies of four polymorphisms in CAST, CAPN1, DGAT1, and FASN genes, previously reported to be associated with meat quality traits, were compared to four cattle breeds. The other four breeds included Limousine, Holstein, Simmental and Brahman cattle, which represent beef, dairy, dual-purpose and indicine bovine members, respectively. Relative to the four bovine members, Baladi cattle exhibited high frequencies of the increasing alleles and genotypes in all four SNPs associated with meat tenderness or fat deposition. These findings, along with future phenotyping and genomic profiling of meat quality related markers, and the well-established adaptability to the challenging Mediterranean pasture conditions, may promote conservation initiatives of Baladi cattle by stakeholders.

"Waktu dan Kemerahan Vulva Saat Inseminasi Buatan Merupakan Faktor Penentu Angka Kebuntingan Sapi di Sumatera Barat (TIME AND REDDISH SIGN OF VULVA DURINGARTIFICIAL INSEMINATION AS A DETERMINANT FACTORS ON CONCEPTION RATE OF COW IN WEST SUMATERA) "

An experiment was conducted to evaluate determinant factors on conception rate of local and crossbreedcow at West Sumatera. There were 162 cows of four AI center at parity-0 to 4TH parity (P-4), inseminatedusing frozen semen of four different bulls (simental,brahman, limousine and Bali cattle). All fed similarityat four AI centers and location to observation of sign of estrus in high land and low land in West Sumatera.All data were analyzed using analyzed of variance in Randomized Block Design (RBD) in factorial as afactor A was time of inseminated; parity;sign of vulva,breed and two location as a replication. Resultsofthis study showed that there were no interaction between time of insemination, breed, parity and thereddish sign of vulva (P>0.05) on conception rate. On the contrary,there were significantly different(P>0.05) on conception rate by time of insemination. The highest conception rate wasfound at the end ofestrus 13–18 h (68.91%),local cow (71.82%), P-3 (67.19%) and reddish sign of vulva (74.25%). It wasconcluded that the effects,both inseminationtime and reddish sign of vulva might be the important factorto get the highest conception rate of the cows.

Genome-wide association study for birth, weaning and yearling weight in Colombian Brahman cattle.

Genotypic and phenotypic data of 1,562 animals were analyzed to find genomic regions that potentially influence the birth weight (BW), weaning weight at seven months of age (WW) and yearling weight (YW) of Colombian Brahman cattle, with genotyping conducted using Illumina Bead chip array with 74,669 SNPs. A Single Step Genomic BLUP (ssGBLP), approach was used to estimate the proportion of variance explained by each marker. Multiple regions scattered across the genome were found to influence weights at different ages, also dependent on the trait component (direct or maternal). The most interesting regions were connected to previously identified QTLs and genes, such as ADAMTSL3, CAPN2, CAPN2, FABP6, ZEB2 influencing growth and weight traits. The identified regions will contribute to the development and refinement of genomic selection programs for Zebu Brahman cattle in Colombia.

Multiple-trait genomewide mapping and gene network analysis for scrotal circumference growth curves in Brahman cattle

Multiple-trait genomewide mapping and gene network analysis for scrotal circumference growth curves in Brahman cattle

Establishing the Relationship Between Mineral Content and Palatability Attributes of Ribeye Steaks from Savannah-Fed Brahman-Influenced Cattle

ObjectivesCombination of eating qualities of beef plays an important role in beef consumer satisfaction; however, it is not well-understood how those eating attributes could be influenced by individual mineral components. The objective of this study was to examine the multivariate relationships between mineral profile and palatability attributes determined by consumers of Venezuelan Brahman-influenced cattle (Brahman).Materials and MethodsSteers and bulls (n = 33) of Brahman cattle were raised under similar extensive and feeding conditions (native grass pasture) and slaughtered at 19 and 24 mo of age (MOA). Ribeye steaks (2.54-cm thick) were removed from the longissimus thoracis muscle (posterior end) from the right side of each carcass at 48 h post-mortem. All samples were vacuum-packaged and immediately frozen at -30°C for Warner-Bratzler shear force (WBSF), mineral content (ash, Na, K, Mg, P, Ca, Cu, Mn, Zn, Fe; mg/100 g fresh tissue) and consumer sensory evaluation (n = 137; 9-point hedonic scale for overall, flavor liking, flavor intensity and tenderness liking). Principal component analysis was performed to identify the influence of the measured attributes.ResultsCorrelations coefficients did not reveal strong relationship among the variables measured. The total variance was distributed into 15 principal components (PC). The factor analysis showed that the first five PC with eigenvalues greater than 1 explained 67.24% of the standardized variance; PC1 explained 21.28%, PC2 16.82%, PC3 12.88%, PC4 8.68%, and PC5 7.59% of the total variance. The set of variables for the first PC included mineral components mainly Na, K, Mg, Ca, Cu, Mn, and Fe (based on the largest loading values). Next, PC2 was related to overall liking, tenderness liking, flavor liking, Ca and Zn. Principal component 3 had a large loading for ash, Na, P, Mn, WBSF, and flavor intensity. The fourth PC had ash and Fe; while PC5 K, Ca, WBSF and tenderness liking, flavor liking, and flavor intensity. Results obtained after plotting the first two PC showed segregation of ribeye steaks from animals slaughtered at 19 MOA and 24MOA (regardless of sex classes); younger animals tended to have more Ca, P, Fe, Mn, Mg, Cu, and less Na and K; and their samples had more desirables scores in overall liking, tenderness liking, flavor liking than older ones. In the second plotting (PC1 × PC3), WBSF and P were located in the positive side of PC1 along with 19MOA Brahman steaks; while ash, Zn, Na, and K on the PC1 negative side along with 24MOA Brahman steaks and closely associated with flavor intensity. Further results plotting (PC1 × PC4; PC1 × PC5) reaffirmed and showed a closely association between minerals and treatments previously mentioned.ConclusionThese results indicate sensory attributes are weak to moderate influenced by individual mineral content in beef. Content of individual minerals can affect the degree of liking more than overall ash content. Additionally, Ca, P, Fe, Mn, Mg, Cu content were positively associated to overall liking, tenderness liking, and flavor liking; in contrast ash, Zn, Na, and K were negative associated to such sensory attributes; but not to flavor intensity.

Study of the optimum haplotype length to build genomic relationship matrices.

Background As genomic data becomes more abundant, genomic prediction is more routinely used to estimate breeding values. In genomic prediction, the relationship matrix ({mathbf{A}}), which is traditionally used in genetic evaluations is replaced by the genomic relationship matrix ({mathbf{G}}). This paper considers alternative ways of building relationship matrices either using single markers or haplotypes of different lengths. We compared the prediction accuracies and log-likelihoods when using these alternative relationship matrices and the traditional {mathbf{G}} matrix, for real and simulated data.MethodsFor real data, we built relationship matrices using 50k genotype data for a population of Brahman cattle to analyze three traits: scrotal circumference (SC), age at puberty (AGECL) and weight at first corpus luteum (WTCL). Haplotypes were phased with hsphase and imputed with BEAGLE. The relationship matrices were built using three methods based on haplotypes of different lengths. The log-likelihood was considered to define the optimum haplotype lengths for each trait and each haplotype-based relationship matrix.ResultsBased on simulated data, we showed that the inverse of {mathbf{G}} matrix and the inverse of the haplotype relationship matrices for methods using one-single nucleotide polymorphism (SNP) phased haplotypes provided coefficients of determination (R2) close to 1, although the estimated genetic variances differed across methods. Using real data and multiple SNPs in the haplotype segments to build the relationship matrices provided better results than the {mathbf{G}} matrix based on one-SNP haplotypes. However, the optimal haplotype length to achieve the highest log-likelihood depended on the method used and the trait. The optimal haplotype length (7 to 8 SNPs) was similar for SC and AGECL. One of the haplotype-based methods achieved the largest increase in log-likelihood for SC, i.e. from −1330 when using {mathbf{G}} to −1325 when using haplotypes with eight SNPs.ConclusionsBuilding the relationship matrix by using haplotypes that comprise multiple SNPs will increase the accuracy of estimated breeding values. However, the optimum haplotype length that shows the correct relationship among individuals for each trait can be derived from the data.

Direct and maternal genetic effects on growth, reproduction, and ultrasound traits in zebu Brahman cattle in Colombia.

Covariance components and genetic parameters were estimated for birth weight (BiW); adjusted weights at 4, 7, 12, and 18 mo; and ADG between 0 and 4 mo, between 4 and 7 mo, between 7 and 12 mo, and between 12 and 18 mo. Additionally, reproductive traits, calving interval, and age at first calving were analyzed, together with traits measured by ultrasound: loin eye area, deep fat mean, back fat, and rump fat. Analyses were performed using an animal model, considering the fixed effects of the farm ( = 37), year and month of birth, sex, calving number (1 to 7), season (dry and rainy seasons), region (North Coast, Andean Region, and Oriental Savannas), and conception (natural mating or AI), whereas the age of the cows at calving was considered a polynomial covariate with linear and quadratic effects. Three different models were used to find the one with the best fit for each trait: a single-trait model with an additive direct genetic effect, a single-trait model with additive direct and maternal genetic effects, and finally, a multitrait model with an additive direct genetic effect. For the growth traits, the heritability was between 0.24 and 0.47, with the lowest value for weight at 7 mo and the greatest value for BiW, and the maternal heritability was found to be between 0.15 and 0.21 but did not decrease later on. The correlation between direct and maternal effects was high and negative (-0.59 to -0.76). With ultrasound traits, a model with only direct effects was used. The heritability was between 0.13 and 0.28 for back fat and loin eye area, respectively. The heritabilities for deep fat mean and rump fat were similar, being 0.19 and 0.21, respectively. The reproductive traits showed high residual variance. In particular, the heritability of calving interval was low (0.06). The results showed that the growth traits have an important genetic component, which is a favorable indicator for obtaining improvement progress in the zebu Brahman breed for beef production in tropical regions of Colombia. The maternal effects influenced the weight performance from 4 to 18 mo and should be taken into account in genetic analyses. In general, the direct heritability of medium magnitude estimated for growth and traits measured by ultrasound suggests that individual selection for these traits will be effective.

Adiposity, lipogenesis, and fatty acid composition of subcutaneous and intramuscular adipose tissues of Brahman and Angus crossbred cattle1

The objective of this study was to demonstrate differences in aspects of adipose tissue cellularity, lipid metabolism, and fatty and cholesterol composition in Angus and Brahman crossbred cattle. We hypothesized that in vitro measures of lipogenesis would be greater in three-fourths Angus progeny than in three-fourths Brahman progeny, especially in intramuscular (i.m.) adipose tissue. Progeny ( = 227) were fed a standard, corn-based diet for approximately 150 d before slaughter. Breed was considered to be the effect of interest and was forced into the model. There were 9 breed groups including all 4 kinds of three-fourths Angus calves: Angus bulls Angus-sired F cows ( = 32), Angus bulls Brahman-sired F cows ( = 20), Brahman-sired F bulls Angus cows ( = 24), and Angus-sired F bulls Angus cows ( = 20). There were all 4 kinds of three-fourths Brahman calves: Brahman bulls Brahman-sired F cows ( = 21), Brahman bulls Angus-sired F cows ( = 43), Brahman-sired F bulls Brahman cows ( = 26), and Angus-sired F bulls Brahman cows ( = 13). Additionally, F calves (one-half Brahman and one-half Angus) were produced only from Brahman-sired F bulls Angus-sired F cows ( = 28). Contrasts were calculated when breed was an important fixed effect, using the random effect family(breed) as the error term. Most contrasts were nonsignificant ( > 0.10). Those that were significant ( < 0.05) included cholesterol concentration of subcutaneous (s.c.) adipose tissue (three-fourths Angus > F, three-fourths Brahman > F, and three-fourths crossbred progeny combined > F), s.c. adipocyte volume (three-fourths Angus > F and three-fourths bloods combined > F), lipogenesis from acetate in s.c. adipose tissue (three-fourths Brahman calves from Brahman dams > three-fourths Brahman calves from F dams), and percentage 18:3-3 in s.c. adipose tissue (three-fourths Brahman calves from Brahman-sired F dams < three-fourths Brahman calves from Angus-sired F dams). Intramuscular adipocyte volume ( < 0.001) was less in three-fourths Brahman cattle than in three-fourths Angus cattle. Additionally, several differences were observed in i.m. adipose tissue that were consistent with this being a less-developed adipose tissue in three-fourths Brahman cattle than in three-fourths Angus cattle.

Effect of restricted suckling on the onset of follicular dynamics and body condition score in Brahman cattle raised under tropical conditions

With the aim of evaluating the effect of restricted suckling on the onset of follicular dynamics and body condition, multiparous Bos indicus cows were distributed in two groups. One group (RS=36) was subjected to a scheme of restricted suckling starting at 21days postpartum. Calves were allowed to suckle once per day for a period of two h whilst the control group (C=18) remained with their dams at all times. At calving, body condition score, back fat thickness and body weight had similar values (p>0.05) for both groups. By day 85 postpartum both groups had recorded losses in body weight. The cows in the continuous group formed a greater (p<0.05) number of follicles of class size <6mm in both periods before and after synchronization. The proportion of cows showing estrus and ovulation before 45days, was not different (p>0.05). The number of cows that exhibited estrus after 45days, was greater (p<0.05) in RS than C group, 72.2% and 55.5%, respectively. Same situation (p<0.05) occurred in cows that ovulated, 88.8 and 66.7%, for groups RS and C, respectively. The subset in the intensive observations showed that the size of the bigger follicle was larger (p<0.05) for RS cows than C cows from 36h after CIDR withdrawal. At 57h, the size of the biggest follicle recorded was not different between groups (p>0.05). A regime of restricted suckling favors the earlier growth of follicles and the prompt restoration of ovarian activity.

Association of polymorphisms in growth hormone and leptin candidate genes with live weight traits of Brahman cattle.

Polymorphisms in candidate genes can produce significant and favorable changes in the phenotype, and therefore are useful for the identification of the best combination of favorable variants for marker-assisted selection. In the present study, an assessment to evaluate the effect of 11 single nucleotide polymorphisms (SNPs) in candidate genes on live weight traits of registered Brahman cattle was performed. Data from purebred bulls were used in this assessment. The dataset included birth (BW), weaning (WW), and yearling (YW) weights. A panel of 11 SNP markers, selected by their formerly reported or apparent direct and indirect association with live weight traits, was included in an assessment previously confirming their minimum allele frequency (<0.05). Live weights were adjusted BW (aBW), WW (aWW), and YW (aYW) using a generalized linear model, which included the fixed effects of herd and season of birth and the random effect of the sire and year of birth. An SNP in a growth hormone gene (GH4.1) was significantly related to aWW (P = 0.035) with an estimate substitution effect of 3.97 kg (P = 0.0210). In addition, a leptin SNP (LEPg.978) was significantly associated with aYW (P = 0.003) with an estimate substitution effect of 9.57 kg (P = 0.0007). The results suggest that markers GH4.1 and LEPg.978 can be considered as candidate loci for assisted genetic improvement programs in Mexican Brahman cattle.

Single nucleotide polymorphisms associated with carcass traits in a population of Brahman and Brahman-influenced steers.

Brahman cattle are important in tropical regions due to their ability to tolerate excessive heat and parasites. However, Brahman cattle exhibit lower carcass quality characteristics when compared to Bos taurus breeds. The objective of this study was to evaluate potential associations between single nucleotide polymorphisms (SNPs) in six candidate genes for carcass quality and composition traits in a population of Brahman and Brahman-influenced steers. Steers were evaluated through the American Brahman Breeders Association carcass evaluation project in Gonzales, Texas. Carcass traits measured included hot carcass weight, ribeye area, marbling score, yield grade, quality grade, dressing percent, and Warner-Bratzler shear force score. Six previously described candidate genes were chosen for SNP analysis based on their previous association with growth and carcass traits. Candidate genes utilized in the current study included calpastatin (CAST), calpain (CAPN3), thyroglobulin (TG), growth hormone, insulin growth factor 1, and adiponectin. Six unique SNPs from three candidate genes (TG, CAST, and CAPN3) were significantly associated (P < 0.001) with carcass quality traits (marbling score and quality grade). A genotypic effect was observed for all significant SNPs, with differing levels of performance observed for animals inheriting different genotypes. Although multiple SNPs in the current study were significantly (P < 0.001) associated with growth and carcass traits, they should be validated in larger populations prior to implementation in selection strategies.

Effects of tea seed saponin supplementation on physiological changes associated with blood methane concentration in tropical Brahman cattle

A 59-day experiment compared the effects of increasing tea seed (Camellia sinensis L.) saponin (TSS) supplementation on dry matter intake (DMI), liveweight (LW), rumen fermentation, methanogenesis, blood biochemistry and animal tolerance. Six, 10, 15, 20, 25 and 30 g of powder TSS were dissolved during 5, 7, 4, 3, 3 and 2 days, respectively, and infused into the rumen of four rumen-cannulated Brahman steers (234 ± 13.6 kg LW; least-squares means ± s.e.m.) or mixed in the basal diet [BD: 0.15 Rhodes grass (Chloris gayana) hay plus a high-grain feed (0.85)] of two non-cannulated (253 ± 19.3 kg) steers. Overall, DMI was not affected, by the sequential infusion of TSS (5.3 ± 0.15 kg) or addition to the BD (5.4 ± 0.18 kg), but relative to all diets, 6 g of TSS supplementation reduced DMI (P &lt; 0.05), while the administration above 30 g of the supplement was associated with significantly (P &lt; 0.001) reduced DMI, scours and bloat disorders. Clinical symptoms disappeared 8 days after withdrawal of the supplement. LW increased with time (P &lt; 0.05) and the final LW was similar for cannulated (258 ± 13.6 kg) and non-cannulated (276 ± 19.3 kg) steers. Saponin supplementation reduced total volatile fatty acid (VFA) concentration (P &lt; 0.05), modified pattern of individual molar VFA concentrations and moderately increased ruminal pH (P &lt; 0.05). Cannulated and non-cannulated steers fed the BD had similar daily (g) methane or yield (CH4 g/kg DMI) emissions while in respiratory chambers. However, compared with cannulated (8.0 ± 1.20 ng/mL) animals, the addition of 30 g of TSS in the BD increased (P &lt; 0.01) blood CH4 concentration in non-cannulated (15.6 ± 1.74 ng/mL) animals. Diets supplemented with 30 g of TSS were associated with higher chloride (P &lt; 0.01) and alkaline phosphatase (P &lt; 0.05) blood concentrations, and lower serum concentrations of potassium and urea nitrogen (P &lt; 0.01), iron and total lipase (P &lt; 0.05), than was the BD. It was concluded that higher levels of TSS supplement may evoke physiological changes in the animal. However, the potential CH4 mitigation effect of this form of saponin in tropical cattle needs further investigation, alongside the derived response of the rumen microbial ecology to the tested range of supplementation.

Investigation into Possible Differences in Salmonella Prevalence in the Peripheral Lymph Nodes of Cattle Derived from Distinct Production Systems and of Different Breed Types

Previous research demonstrated significant variation in the prevalence of Salmonella in peripheral lymph nodes (LNs) of feedlot cattle and cull cows, with greater prevalence in feedlot cattle. Therefore, we performed experiments to investigate whether these differences in Salmonella prevalence in subiliac LNs are due to, or influenced by, breed, which in many respects is a proxy for the production system in which the animal is derived. Holstein steers are a by-product of dairy systems, and beef steers are an intended product of commercial beef operations. For the first experiment, Holstein and beef steers originating from the same feedlot and harvested on the same day were sampled. Of the 467 Holstein and 462 beef cattle LNs collected, 62.1% of Holstein and 59.7% of beef cattle samples harbored Salmonella (P = 0.46; qualitative culture), with 51.2 and 48.9% of samples containing quantifiable concentrations (P = 0.49), respectively. The concentration of Salmonella within the LN followed a decreasing trend over the collection period (May to October), averaging 1.4 log CFU/g of LN for both Holstein and beef cattle samples (P = 0.78). In a second experiment, we compared 100% Brahman cattle to their beef cattle counterparts, as we hypothesized that the resistance of Brahman cattle to insects may reduce Salmonella transmission via biting insects. Of the 42 Brahman and 31 beef cattle LNs collected, the concentration of Salmonella within the LN averaged 3.0 log CFU/g for Brahman cattle and 2.9 log CFU/ g for beef cattle samples (P = 0.30). Using qualitative culture, we recovered Salmonella from 100% of LNs from Brahman cattle and 97% of beef cattle samples (P = 0.25). Results of this research indicate that the differences observed are not due to breed and are likely a function of age, immune function, or other factors yet to be identified. Understanding which cattle are more likely to harbor Salmonella within LNs will aid in targeting both pre- and postharvest intervention strategies.

Accuracy of genomic selection for age at puberty in a multi-breed population of tropically adapted beef cattle.

Genomic selection is becoming a standard tool in livestock breeding programs, particularly for traits that are hard to measure. Accuracy of genomic selection can be improved by increasing the quantity and quality of data and potentially by improving analytical methods. Adding genotypes and phenotypes from additional breeds or crosses often improves the accuracy of genomic predictions but requires specific methodology. A model was developed to incorporate breed composition estimated from genotypes into genomic selection models. This method was applied to age at puberty data in female beef cattle (as estimated from age at first observation of a corpus luteum) from a mix of Brahman and Tropical Composite beef cattle. In this dataset, the new model incorporating breed composition did not increase the accuracy of genomic selection. However, the breeding values exhibited slightly less bias (as assessed by deviation of regression of phenotype on genomic breeding values from the expected value of 1). Adding additional Brahman animals to the Tropical Composite analysis increased the accuracy of genomic predictions and did not affect the accuracy of the Brahman predictions.

Multi-Trait GWAS and New Candidate Genes Annotation for Growth Curve Parameters in Brahman Cattle.

Understanding the genetic architecture of beef cattle growth cannot be limited simply to the genome-wide association study (GWAS) for body weight at any specific ages, but should be extended to a more general purpose by considering the whole growth trajectory over time using a growth curve approach. For such an approach, the parameters that are used to describe growth curves were treated as phenotypes under a GWAS model. Data from 1,255 Brahman cattle that were weighed at birth, 6, 12, 15, 18, and 24 months of age were analyzed. Parameter estimates, such as mature weight (A) and maturity rate (K) from nonlinear models are utilized as substitutes for the original body weights for the GWAS analysis. We chose the best nonlinear model to describe the weight-age data, and the estimated parameters were used as phenotypes in a multi-trait GWAS. Our aims were to identify and characterize associated SNP markers to indicate SNP-derived candidate genes and annotate their function as related to growth processes in beef cattle. The Brody model presented the best goodness of fit, and the heritability values for the parameter estimates for mature weight (A) and maturity rate (K) were 0.23 and 0.32, respectively, proving that these traits can be a feasible alternative when the objective is to change the shape of growth curves within genetic improvement programs. The genetic correlation between A and K was -0.84, indicating that animals with lower mature body weights reached that weight at younger ages. One hundred and sixty seven (167) and two hundred and sixty two (262) significant SNPs were associated with A and K, respectively. The annotated genes closest to the most significant SNPs for A had direct biological functions related to muscle development (RAB28), myogenic induction (BTG1), fetal growth (IL2), and body weights (APEX2); K genes were functionally associated with body weight, body height, average daily gain (TMEM18), and skeletal muscle development (SMN1). Candidate genes emerging from this GWAS may inform the search for causative mutations that could underpin genomic breeding for improved growth rates.

Kinetics of pro-inflammatory cytokines, interleukin-10, and virus neutralising antibodies during acute ephemeral fever virus infections in Brahman cattle

While fever and inflammation are hallmark features of bovine ephemeral fever (BEF), the cytokine networks that underlie the acute phase of the disease have not been empirically defined in cattle. This study characterised the plasma kinetics of proinflammatory cytokines (IL-1β, IL-6, TNF-α) and IL-10 during acute BEF and elucidated on the relationship between the onset of the virus neutralizing antibody response and resolution of viraemia in natural BEF virus (BEFV) infections in cattle. Plasma from three BEFV-infected and three uninfected cattle was tested for the study cytokines by a cELISA, viraemia monitored by qRT-PCR, and virus neutralizing antibody titres determined using a standard protocol. Unlike the negative controls, plasma concentrations of IL-1β, TNF-α, IL-6, and IL-10 were consistently increased in the three virus-infected animals. Two of the infected heifers were recumbent and pyrexic on the first day of monitoring and increased cytokine production was already in progress by the time viraemia was detected in all the three infected animals. In all the virus-infected heifers, IL-1β was the most strongly expressed cytokine, IL-6 and IL-10 manifested intermediate plasma concentrations while TNF-α was the least expressed and demonstrated bi-phasic peaks three and five days after the onset of pyrexia. In two of the BEFV-infected heifers, viraemia resolved on the day of seroconversion while in the other infected animal, viral RNA was detectable up to three days after seroconversion. The present data document variable increase in plasma IL-1β, IL-6, TNF-α, and IL-10 during natural BEFV infections and the fact that upregulation of all but TNF-α precedes seroconversion. In addition to virus neutralising antibodies, it is likely that cytokine-mediated cellular mechanisms may be required for resolution of viraemia in BEF. Considering the anti-inflammatory properties of IL-10, its upregulation may potentially antagonise the fever response in BEFV-infected cattle.

Estimates of genetic parameters for growth traits in Brahman cattle using random regression and multitrait models.

Random regression models (RRM) and multitrait models (MTM) were used to estimate genetic parameters for growth traits in Brazilian Brahman cattle and to compare the estimated breeding values obtained by these 2 methodologies. For RRM, 78,641 weight records taken between 60 and 550 d of age from 16,204 cattle were analyzed, and for MTM, the analysis consisted of 17,385 weight records taken at the same ages from 12,925 cattle. All models included the fixed effects of contemporary group and the additive genetic, maternal genetic, and animal permanent environmental effects and the quadratic effect of age at calving (AAC) as covariate. For RRM, the AAC was nested in the animal's age class. The best RRM considered cubic polynomials and the residual variance heterogeneity (5 levels). For MTM, the weights were adjusted for standard ages. For RRM, additive heritability estimates ranged from 0.42 to 0.75, and for MTM, the estimates ranged from 0.44 to 0.72 for both models at 60, 120, 205, 365, and 550 d of age. The maximum maternal heritability estimate (0.08) was at 140 d for RRM, but for MTM, it was highest at weaning (0.09). The magnitude of the genetic correlations was generally from moderate to high. The RRM adequately modeled changes in variance or covariance with age, and provided there was sufficient number of samples, increased accuracy in the estimation of the genetic parameters can be expected. Correlation of bull classifications were different in both methods and at all the ages evaluated, especially at high selection intensities, which could affect the response to selection.