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Background: The assessment of genetic diversity, population structure, as well as within and across breed relationships using DNA markers is essential to develop conservation and genetic improvement programs. Objective: To assess the genetic diversity and population structure of Criollo Lechero Tropical (CLT) and Romosinuano (ROMO) cattle breeds in Mexico and compare them with other Criollo and Spanish breeds. Methods: The study included CLT and ROMO genotypes from the 65k Axiom©BovMDv3 array. Genomic data of Criollo and Spanish breeds were retrieved from a repository. Genetic diversity across breeds was evaluated by pairwise Wright's FST, principal components, and structure analysis. Results: Observed and expected heterozygosity, inbreeding coefficient, and effective population size (Ne) were 0.31, 0.30, -0.018 and 56 in CLT, and 0.32, 0.31, -0.023 and 99 in ROMO, respectively. Wright's FST indicated that both breeds are related to American Criollo and some Spanish cattle. ROMO cattle showed more significant Spanish ancestry than CLT. Conclusions: This study presents novel evidence indicating that, although the Ne of these breeds is small, they are still diverse and can be used as genetic reservoirs in conservation programs. [ABSTRACT FROM AUTHOR]

Objetivo. Establecer el efecto de las medidas morfométricas y productivas sobre los parámetros reproductivos: número de partos e intervalo entre partos en hembras Romosinuano (ROMO) y Costeño con Cuernos (CCC) bajo las condiciones agroclimáticas del Caribe húmedo colombiano. Materiales y métodos. Se utilizaron 408 vacas entre las razas ROMO (250) y CCC (158) se tomaron las medidas morfométricas de: amplitud del isquion (ADI), amplitud de cadera (ADC), altura del sacro (ADS), altura de la cruz (ADLC), así como el peso vivo, peso primer parto (PPP), peso último parto (PUP), condición corporal (CC), y los parámetros reproductivos como el número de partos e intervalos entre partos (IEP). Las diferencias entre los parámetros morfométricos y reproductivos por raza se establecieron por análisis de varianza. Las relaciones entre las variables morfométricas y reproductivas se analizaron a través correlaciones canónicas. Resultados. El análisis de varianza mostró diferencias estadísticamente significativas (p

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Se realizó un estudio descriptivo de corte transversal para determinar la prevalencia y factores epidemiológicos asociados con las enfermedades virales del Complejo Respiratorio Bovino (CRB) en razas criollas del Centro de Investigación Turipaná - AGROSAVIA (Colombia). Se evaluaron 403 bovinos de la raza Romosinuano y 445 Costeño con Cuernos (CCC). A través de la técnica de ELISA indirecta se determinó la presencia de anticuerpos para diarrea viral bovina (DVB), rinotraqueitis infecciosa bovina (IBR), parainfluenza-3 (PI3) y virus sincitial respiratorio bovino (BRSV). Se obtuvieron las prevalencias y se evaluó la asociación entre los agentes virales y entre estos con las variables sexo, edad, tipo de hato y raza; la prueba de Ji-cuadrada se aplicó con un nivel de significancia del 5% y el efecto de la asociación fue determinado por la razón de probabilidades (OR). se constituyó un modelo de regresión logística para explicar la enfermedad más prevalente. Las prevalencias medias en las dos razas fueron: DVB (33.02 %), BRSV (18.51 %), IBR (12.85 %) y PI3 (11.20 %); sin embargo, individualmente, la raza CCC presentó mayor prevalencia para todas las enfermedades. El modelo de regresión mostró una asociación entre DVB, IBR y PI3, las variables sexo, edad, hembras con más de 1 año de edad y la raza CCC. Para abordar las enfermedades del CRB, se recomiendan acciones con énfasis en el control y prevención de DVB y estudios más profundos para entender la dinámica y co-endemicidad de la DVB, IBR, BRSV y PI3 en las razas estudiadas.

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Romosinuano (Romo) and Costeño con cuernos (CCC) are Bos taurus criollo breeds (adapted to the conditions of the tropics) that presented higher plasmatic Progesterone (P4) concentration during the luteal phase compared to non-adapted genotypes. The central hypothesis was that these P4 concentrations could modulate the uterine receptivity. Blood and endometrial biopsy samples were obtained on days 0, 5, 10, 15, and 20 of the estrous cycle (day 0 = estrus) of animals of different genotypes [Romo (n = 14), CCC (n = 14), and Crossbreed Brahman × Holstein (Cross, n = 13)]. Tissue-samples were used for morphometry and immunohistochemistry analyses. Data analyses were performed with Proc Mixed of SAS. The criollo breeds have higher P4 concentrations on days 5 and 15, higher values of superficial glandular area (all days) and density (days 0, 5, 10, and 15) than Cross cows (P < 0.05). ESR1 and PGR immunostaining were higher on days 0, 5, and 15 and on days 0 and 15, respectively for CCC and Romo when compared to Cross (P < 0.05). In conclusion, tropical adapted bovine breeds possess more receptive to embryo uterine environment than non-adapted breeds. This is mediated by a higher serum progesterone concentration, a strong P4 signaling, and greater developed uterine-gland morphology.

Background: Romosinuano cattle breed in Mexico has endured isolation and it is necessary to characterize it in order to facilitate sustainable genetic management. Objective: To assess the evolution of the structure and genetic diversity of the Romosinuano breed in Mexico, through pedigree analysis. Methods: Pedigree data was obtained from Asociación Mexicana de Criadores de Ganado Romosinuano y Lechero Tropical (AMCROLET). The ENDOG program (4.8 version) was used to analyze two datasets, one that includes upgrading from F1 animals (UP) and the other with only straight-bred cattle (SP). For both datasets, three reference populations were defined: 1998-2003 (RP1), 2004-2009 (RP2), and 2010-2017 (RP3). The pedigree included 3,432 animals in UP and 1,518 in SP. Demographic parameters were: Generation interval (GI), equivalent number of generations (EG), pedigree completeness index (PCI), and gene flow among herds. Genetic parameters were: Inbreeding (F) and average relatedness (AR) coefficients, effective population size (Nec), effective number of founders and ancestors, and number of founder genome equivalents. Results: The GI varied from 6.10 to 6.54 for UP, and from 6.47 to 7.16 yr for SP. The EG of the UP and SP improved >63% from RP1 to RP3. The PCI increased over time. No nucleus or isolated herds were found. For RP3, F and AR reached 2.08 and 5.12% in the UP, and 2.55 and 5.94% in the SP. For RP3, Nec was 57 in the UP and 45 in the SP. Genetic diversity losses were attributed mainly (>66%) to genetic drift, except for RP3 in the SP (44%). Conclusions: A reduction of the genetic diversity has been occurring after the Romosinuano breed association was established in Mexico, and this is mainly due to random loss of genes. [ABSTRACT FROM AUTHOR]

The ultimate goal of genetic selection is to improve genetic progress by increasing favorable alleles in the population. However, with selection, homozygosity, and potentially harmful recessive alleles can accumulate, deteriorating genetic variability and hampering continued genetic progress. Such potential adverse side effects of selection are of particular interest in populations with a small effective population size like the Romosinuano beef cattle in Mexico. The objective of this study was to evaluate the genetic background and inbreeding depression in Mexican Romosinuano cattle using pedigree and genomic information. Inbreeding was estimated using pedigree (FPED) and genomic information based on the genomic relationship matrix (FGRM) and runs of homozygosity (FROH) of different length classes. Linkage disequilibrium (LD) was evaluated using the correlation between pairs of loci, and the effective population size (Ne) was calculated based on LD and pedigree information. The pedigree file consisted of 4875 animals born between 1950 and 2019, of which 71 had genotypes. LD decreased with the increase in distance between markers, and Ne estimated using genomic information decreased from 610 to 72 animals (from 109 to 1 generation ago), the Ne estimated using pedigree information was 86.44. The reduction in effective population size implies the existence of genetic bottlenecks and the decline of genetic diversity due to the intensive use of few individuals as parents of the next generations. The number of runs of homozygosity per animal ranged between 18 and 102 segments with an average of 55. The shortest and longest segments were 1.0 and 36.0 Mb long, respectively, reflecting ancient and recent inbreeding. The average inbreeding was 2.98 ± 2.81, 2.98 ± 4.01, and 7.28 ± 3.68% for FPED, FGRM, and FROH, respectively. The correlation between FPED and FGRM was −0.25, and the correlations among FPED and FROH of different length classes were low (from 0.16 to 0.31). The correlations between FGRM and FROH of different length classes were moderate (from 0.44 to 0.58), indicating better agreement. A 1% increase in population inbreeding decreased birth weight by 0.103 kg and weaning weight by 0.685 kg. A strategy such as optimum genetic contributions to maximize selection response and manage the long-term genetic variability and inbreeding could lead to more sustainable breeding programs for the Mexican Romosinuano beef cattle breed.

Background: Ticks have a negative effect on dairy and beef cattle production systems around the world, with the concomitant risk they represent for the transmission of some important infectious diseases. Colombian cattle breeds are distributed across different agroecological regions and are exposed to different environmental challenges. In humid and warmer climates such as those from the tropics, tick burden and heat stress are important factors that can compromise livestock performance. The aim of this study was to characterize tick burden in four Colombian cattle breeds and evaluate the relationship between heat stress and tick burden in Bos taurus cattle under tropical conditions. Tick counting was conducted in 1332 cattle from Romosinuano (ROMO), Costeño con Cuernos (CCC), San Martinero (SM) and Blanco Orejinegro (BON) breeds, located in the Caribbean, Orinoquia and Andean regions. Vital signs and environmental variables were taken to calculate an adaptability index (AI) and a temperature humidity index (THI). An AI < 2 indicates maximum adaptability while an AI ≥ 2 indicates a state of lower adaptability. In beef cattle, productivity starts to be affected by heat stress when environmental conditions allow an estimation of a THI > 75. Results: Results showed a differing distribution of ticks on the body of individuals that varied according to the agroecological region. There was a significant effect of breed, sex, family, age and live weight on cattle tick burden. The lowest tick burden was observed in the ROMO breed (12.8 ± 2.6), while the highest tick burden was observed in CCC (31.8 ± 2.3), which were located in the same agroecological region. SM and ROMO animals with an AI > 2 had a higher tick burden than their counterparts that had an AI < 2. Conclusions: Cattle breed, sex, age and live weight affect the tick burden in Bos taurus Colombian cattle breeds. The tick burden is higher in cattle with lower adaptability to heat stress. Moreover, it decreases as heat stress levels increase in a tropical environment. The interaction between tick burden and environmental heat stress can be affected by characteristics of the agroecological region itself, the breed and the genetic resistance of the individual tick, as well as the thermal adaptability of cattle. [ABSTRACT FROM AUTHOR]

Romosinuano (Romo) and Costeño con cuernos (CCC) are Bos taurus criollo breeds (adapted to the conditions of the tropics) that presented higher plasmatic Progesterone (P4) concentration during the luteal phase compared to non-adapted genotypes. The central hypothesis was that these P4 concentrations could modulate the uterine receptivity. Blood and endometrial biopsy samples were obtained on days 0, 5, 10, 15, and 20 of the estrous cycle (day 0 = estrus) of animals of different genotypes [Romo (n = 14), CCC (n = 14), and Crossbreed Brahman × Holstein (Cross, n = 13)]. Tissue-samples were used for morphometry and immunohistochemistry analyses. Data analyses were performed with Proc Mixed of SAS. The criollo breeds have higher P4 concentrations on days 5 and 15, higher values of superficial glandular area (all days) and density (days 0, 5, 10, and 15) than Cross cows (P < 0.05). ESR1 and PGR immunostaining were higher on days 0, 5, and 15 and on days 0 and 15, respectively for CCC and Romo when compared to Cross (P < 0.05). In conclusion, tropical adapted bovine breeds possess more receptive to embryo uterine environment than non-adapted breeds. This is mediated by a higher serum progesterone concentration, a strong P4 signaling, and greater developed uterine-gland morphology. [ABSTRACT FROM AUTHOR]

Earlier work has shown that young tropically adapted cattle do not gain weight as rapidly as temperately adapted cattle during the winter in Oklahoma. The objective for this study was to determine whether efficiency of gains was also affected in tropically adapted cattle and whether efficiency was consistent over different seasons. Over 3 yr, 240 straightbred and crossbred steers (F1 and 3-way crosses) of Angus, Brahman, or Romosinuano breeding, born in Brooksville, FL, were transported to El Reno, OK in October and fed in 2 phases to determine performance, individual intake, and efficiency. Phase 1 (WIN) began in November after a 28-d recovery from shipping stress and phase 2 (SS) began in March, 28 d following completion of WIN each year. The diet for WIN was a grower diet (14% CP, 1.10 Mcal NEg/kg) and that for the SS was a feedlot diet (12.8% CP; 1.33 Mcal NEg/kg). After a 14-d adjustment to diet and facilities, intake trials were conducted over a period of 56 to 162 d for determination of intake and gain for efficiency. Body weights were recorded at approximately 14-d intervals, and initial BW, median BW, and ADG were determined from individual animal regressions of BW on days on feed. Individual daily DMI was then regressed by phase on median BW and ADG, and residuals of regression were recorded as residual feed intake (RFI). Similarly, daily gain was regressed by phase on median BW and DMI, and errors of regression were recorded as residual gain (RADG). Gain to feed (G:F) was also calculated. The statistical model to evaluate ADG, DMI, and efficiency included fixed effects of dam age (3 to 4, 5, 6 to 10, and >10 yr), harvest group (3 per year), age on test, and a nested term DT (ST × XB), where DT is the proportion tropical breeding of dam (0, 0.5, or 1), ST is the proportion tropical breeding of sire (1 or 0), and XB whether the calf was straightbred or crossbred. Year of record, sire (ST × XB), and pen were random effects. Preweaning ADG and BW increased (P < 0.05) with level of genetic tropical influence, but during the WIN, ADG and efficiency estimated by G:F and RADG declined (P < 0.05). Tropical influence had little effect on RFI during the WIN, or on most traits during SS. In general, during SS, crossbred steers gained faster and were more efficient by G:F and RADG (P < 0.05) than straightbred steers. Simple correlations, both Pearson and Spearman, between RFI in WIN and RFI in SS were 0.51 (P < 0.001), whereas that for RADG was 0.17 (P < 0.01). [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate circulating concentrations of plasma cortisol and measures of temperament at weaning in calves (steers and heifers) and at transport in steers. Calves (n = 993) were produced from a 3-breed diallel mating design that included calves from 3 consecutive years. Breed types of calves were straightbred Angus (A), Brahman (B), and Romosinuano (R) and all F1 crossbred combinations (AB, BA, AR, RA, BR, and RB). At weaning (d 0) and at 24 and 72 h after weaning, blood was sampled from calves and the plasma was stored for later cortisol assay. Additionally, at each of these times, temperament was assessed as chute score, exit velocity, and pen score. About 1 mo later, steer calves (n = 471) were sampled before shipment, at arrival, and at 24 h, 72 h, 2 wk, and 4 wk after shipment (2,025 km; Brooksville, FL, to El Reno, OK). At each of these sampling times, blood was collected and plasma was stored for subsequent cortisol assay and temperament was assessed by measurement of exit velocity. At both weaning and transport, plasma concentrations of cortisol did not significantly differ (P > 0.05) among straightbreds or among crossbreds. Significant (P < 0.05) positive genetic effects were observed for plasma concentration of cortisol at weaning (heterosis for BA and direct Romosinuano effect) and transport (heterosis for RA, BR, and BA; direct Romosinuano effect; and maternal Angus effect). Assessment of temperament using the objective measurement of exit velocity or the subjective measures of chute score or pen score (1 [lowest] to 5 [highest excitability] scale, based on behavior in chute and behavior in pen with human observer, respectively) generally provided similar results: Brahman was higher than Brahman crosses, which were higher than Angus, Romosinuano, and their reciprocal crosses. For exit velocity, however, Brahman did not differ from Brahman crosses and Angus did not differ from Romosinuano or Brahman crosses. At transport, sire breed and dam breed affected exit velocity of steers, with higher (P < 0.05) estimates for Brahman than for Romosinuano or Angus. These data suggest that weaned calves and shipped steers of various breed types show a similar response to stressors in cortisol concentration. In contrast, in assessing temperament or behavioral response to humans, Romosinuano and Angus had better temperaments and were less excitable than Brahman. [ABSTRACT FROM AUTHOR]

This study was initiated to evaluate performance and patterns of cow traits and blood metabolites of 3 breeds of cows grazing bahiagrass (Paspalum notatum Flügge) pastures in central Florida. Purebred cows (n = 411) of either Angus (Bos taurus), Brahman (Bos indicus), or Romosinuano (Bos taurus) breeding, rotationally grazed (moved twice weekly) bahiagrass pastures year-round, and received bahiagrass hay supplemented with molasses and soyhulls or legume hay supplemented with unfortified molasses from October to June each production year. At monthly intervals, all cows were weighed, measured at the hip (HH), scored for BCS, and blood samples collected by jugular puncture from 10 cows per cow breed/block group for plasma urea N (PUN), glucose and non-esterified fatty acids (NEFA). Data were analyzed on cows that calved with a statistical model that included fixed effects of year, cowage, cow breed, month, block, supplement group (n = 2, but not presented), and whether the cow weaned a calf the previous year. Cow was a repeated observation over mo. Three-way interactions involving monthly patterns for cowage x year, year x lactation status the previous year, cowage × cow breed, year × cow breed, and cow breed × lactation status the previous year were significant (P < 0.001) for BW and BCS. The interaction for cowage × month was also significant (P < 0.05) for glucose, and cow breed × month was important (P < 0.01) for PUN, glucose, and NEFA. Important differences included: 1) greater BW and BCS for older cows compared to 3-yr old cows; 2) greater BW and BCS before calving for cows that did not lactate the previous year; 3) PUN levels were above 11 mg/dl except for February, August and September, and was generally greater in tropically adapted breeds; 4) GLU was greatest in Brahman, lowest in Angus, and intermediate in Romosinuano cows; and 5) plasma levels of NEFA escalated at calving and then declined, but Brahman cows maintained greater (P < 0.05) levels from calving until weaning than the other breeds. Cows that lactated the previous year had less NEFA than those that did not lactate. Brahman cows were less fertile than Bos taurus breeds, and weaned heavier calves. [ABSTRACT FROM AUTHOR]

comercial bajo condiciones de manejo eficiente de pasturas y de suplementación estratégica durantela época seca. Materiales y métodos: Se evaluó la producción de carne de novillos F1 romo x cebúy cebú en pastoreo rotacional de pasto angleton bajo condiciones del Valle del Sinú, departamentode Córdoba. El experimento tuvo una duración de 289 días que incluyó un período completo desequía. Durante la época de lluvia, los animales se suplementaron con un kilo de semilla de algodónpor día, y en la época seca, además del pastoreo, se suministró, en promedio, 10 kilos de ensilajede maíz balanceado con .02% de urea-sulfato de amonio y suplementado con un kilo de semilla dealgodón más medio kilo de salvado de arroz. Resultados. En la pastura se estimó la producción demateria seca, la composición química y la digestibilidad In Situ de la materia seca. La carga fue de4 animales por hectárea los cuales se pesaron cada 24 días. La ganancia promedia diaria fue de0.660 y 0.728 kilos/animal/día, respectivamente para los F1 y cebú, sin diferencia estadística(p>0.05). Conclusión. La producción de carne por hectárea año fue de 963.6 y 1062.8 kilogramos,para F1 y cebú respectivamente. El valor de producción de un kilo de carne fue de US$ 0.38 paralos F1 y US$ 0.34 para los cebú, lo que demustra una buena rentabilidad

Objetivo. Estudiar los factores ambientales y genéticos que influyen sobre la edad al primer parto dehembras romosinuano. Materiales y métodos. Fueron estudiados 932 datos de la edad al primer partode hembras de la raza Romosinuano, nacidas en el Centro de Investigación Turipaná de CORPOICA,Cereté, Colombia, en el período de 1980 a 2001. Para el estudio de los factores ambientales se utilizóel análisis de varianza mediante modelos lineales utilizando el procedimiento GLM de SAS (1995).Resultados. La edad al primer parto fue de 1162.3±4.2 días, con un coeficiente de variación del 11.19%.El análisis de varianza reveló que el año y mes de nacimiento fueron causas estadísticamente significativasde variación de la edad al primer parto. La heredabilidad, calculada por la correlación intraclase entremedias hermanas paternas fue de 0.16±0.08. Conclusión. El año y mes de nacimiento influyeron en laedad al primer parto de hembras romosinuano, pero la heredabilidad de la edad al primer parto y elsexo de la cría no se constituyen en características importantes a tener en cuenta.

Se analizaron 1877 datos de pesos de terneros al nacimiento de la raza Romosinuano, desde el año de1980 hasta el 2001. El peso medio al nacimiento, para ambos sexos, fue de 30,65 Kg. Los machospesaron en promedio 31,46 Kg., y las hembras 29,8 kg. El año de nacimiento, el número de partos y elsexo, influyeron significativamente sobre el peso al nacimiento de los terneros (P < 0,0001). Lasheredabilidades estimadas para el efecto directo y materno fueron: 0,17 ± 0,06 y 0,087 ± 0,03,respectivamente.

Con el objetivo de caracterizar y determinar algunos factores que podrían ser de gran utilidad a la hora detomar decisiones en una empresa ganadera, se consideraron mediciones cuantitativas como la alzada yamplitud de isquiones, y cualitativas como la condición corporal, ángulo de anca, aplomos, ubre y pezones.Se realizaron análisis de varianza para las variables en cada estado fisiológico (hembras de levante, vacasparidas, vacas paridas preñadas, vacas horras y vacas horras preñadas) y se consideraron los efectos de laedad del animal (regresión lineal y cuadrática) y grupo genético del animal. Las hembras jóvenes (9 a 12meses) tuvieron un peso promedio de 172.0 Kg., y las vacas adultas un promedio de peso entre 415 a 445Kg. En el peso, el efecto de grupo genético, fue altamente significativo en las vacas horras, donde losgrupos genéticos con mayor peso fueron el Cebú y cruce BON x Cebú. Para los otros estados fisiológicosno se encontraron diferencias estadísticas. Para las hembras de levante, las BxC/CxB (n= 100) presentaronmenor condición corporal frente a los CCO/BRH (n= 28), RxC/CxR (n= 50) y 3/4Cx1/4A (n= 15). En lasvacas horras el grupo genético CCO/BRH (n= 328) fue el que presentó la mejor condición corporal. Lasvacas horras preñadas mostraron diferencias entre los grupos genéticos CCO/BRH (n= 273) y AxC/CxA(n= 332). En las vacas paridas, el grupo genético 3/4Cx1/4A (n= 91) obtuvo un promedio superior a losotros grupos analizados. El grupo genético 3/4Cx1/4A presenta los mejores registros en cuanto a cualidadesfísicas en las vacas adultas, lo que confirma su potencial productivo para las zonas groecológicas similaresa las del presente estudio.

The slick hair coat (SLICK) is a dominantly inherited trait typically associated with tropically adapted cattle that are from Criollo descent through Spanish colonization of cattle into the New World. The trait is of interest relative to climate change, due to its association with improved thermo-tolerance and subsequent increased productivity. Previous studies localized the SLICK locus to a 4 cM region on chromosome (Chr) 20 and identified signatures of selection in this region derived from Senepol cattle. The current study compares three slick-haired Criollo-derived breeds including Senepol, Carora, and Romosinuano and three additional slick-haired cross-bred lineages to non-slick ancestral breeds. Genome-wide association (GWA), haplotype analysis, signatures of selection, runs of homozygosity, and identity by state (IBS) calculations were used to identify a 0.8Mb (37.7-38.5Mb) consensus region for the SLICK locus on Chr 20 in which contains SKP2 and SPEF2 as possible candidate genes. Three specific haplotype patterns are identified in slick individuals, all with zero frequency in non-slick individuals. Admixture analysis identified common genetic patterns between the three slick breeds at the SLICK locus. Principle component analysis and admixture results show Senepol and Romosinuano sharing a higher degree of genetic similarity to one another with a much lesser degree of similarity to Carora. Variation in GWA, haplotype analysis, and IBS calculations with accompanying population structure information supports potentially two mutations, one common to Senepol and Romosinuano and another in Carora, effecting genes contained within our refined location for the SLICK locus.

The use of Brahman in cow-calf production offers some adaptation to the harsh characteristics of endophyte-infected tall fescue. Criollo breeds, such as the Romosinuano, may have similar adaptation. The objectives were to estimate genetic effects in Romosinuano, Angus, and crossbred cows for their weights, weights of their calves, and ratios (calf weight:cow weight and cow weight change:calf weight gain) across lactation and to assess the influence of forage on traits and estimates. Cows (n = 91) were bred to Charolais bulls after their second parity. Calves (n = 214) were born from 2006 to 2009. Cows and calves were weighed in early (April and June), mid- (July), and late lactation (August and October). Animal was a random effect in analyses of calf data; sire was random in analyses of cow records and ratios. Fixed effects investigated included calf age, calf sex, cow age-year combinations, sire breed of cow, dam breed of cow, and interactions. Subsequent analyses evaluated the effect of forage grazed: endophyte-free or endophyte-infected tall fescue. Estimates of maternal heterosis for calf weight ranged from 9.3 ± 4.3 to 15.4 ± 5.7 kg from mid-lactation through weaning (P < 0.05). Romosinuano direct effects (of the cow) were -6.8 ± 3.0 and -8.9 ± 4.2 kg for weights recorded in April and June. Calf weights and weight gains from birth were greater (P < 0.05) for calves of cows grazing endophyte-free tall fescue except in mid-summer. Cow weight change from April to each time was negative for Angus cows and lower (P < 0.05) than other groups. Cows grazing endophyte-free tall fescue were heavier (P < 0.05) at all times but had more weight loss in late lactation. Angus cows had the lowest (P < 0.05) ratios (negative) of cow weight change:calf weight gain, indicating an energy-deficit condition. Cows grazing endophyte-free tall fescue had more negative (P < 0.05) values for this trait but not in early lactation (P < 0.05). Estimates of heterosis ranged from 12.8 ± 9.5 to 28.6 ± 9.4 kg for cow weight, 7.9 ± 3.0 to 15.8 ± 5.0 kg for cow weight change, and 0.07 ± 0.03 to 0.27 ± 0.1 for cow weight change:calf weight gain. Direct Romosinuano effects ranged from 14.8 ± 4.2 to 49.8 ± 7.7 kg for cow weight change and 0.2 ± 0.04 to 0.51 ± 0.14 for cow weight change:calf weight gain. The adaptive ability of Romosinuano in temperate fescue regions may be favorable with respect to relative cow and calf weight but may be a consequence of lower milk-producing ability. [ABSTRACT FROM AUTHOR]

El objetivo de esta investigación fue evaluar el efecto de un biopreparado a base de una levadura nativa con características probióticas, sobre los parámetros de ganancia de peso diario y producción de leche en ganado bovino. Se utilizaron lotes de 30 vacas de raza romosinuano (Córdoba-Colombia), de las cuales 15 fueron testigo y 15 de prueba; el experimento se realizó con 3 repeticiones, un régimen alimenticio de pastoreo y se suministró el biopreparado (concentración de levadura, 3X108ufc/mL) una vez al día durante dos meses. Los resultados demostraron que no hubo diferencias estadísticamente significativas en la ganancia de peso, mientras que si se observó diferencias para la producción de leche con un α (0.05) utilizando el test de T para muestras independientes. El biopreparado demostró un efecto positivo sobre la ganancia de leche en ganado de doble propósito de la región de Córdoba El objetivo de esta investigación fue evaluar el efecto de un biopreparado a base de una levadura nativa con características probióticas, sobre los parámetros de ganancia de peso diario y producción de leche en ganado bovino. Se utilizaron lotes de 30 vacas de raza romosinuano (Córdoba-Colombia), de las cuales 15 fueron testigo y 15 de prueba; el experimento se realizó con 3 repeticiones, un régimen alimenticio de pastoreo y se suministró el biopreparado (concentración de levadura, 3X108 ufc/mL) una vez al día durante dos meses. Los resultados demostraron que no hubo diferencias estadísticamente significativas en la ganancia de peso, mientras que si se observó diferencias para la producción de leche con un α (0.05) utilizando el test de T para muestras independientes. El biopreparado demostró un efecto positivo sobre la ganancia de leche en ganado de doble propósito de la región de Córdoba

The objectives of this work were to compare the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman in subtropical Florida and to estimate heterosis for size traits of their calves, their own weight, and maternal efficiency traits. Cows (n = 404) were born from 2002 to 2005. After their first exposure to bulls as young cows, crossbred cows were bred to bulls of the third breed, and straightbred cows were bred in to bulls of the other 2 breeds. Calves were spring-born from 2005 through 2011. Evaluated calf (n = 1,254) traits included birth weight and weight, ADG, BCS, and hip height at weaning. Cow weight (n = 1,389) was recorded at weaning. Maternal efficiency traits evaluated included weaning weight per 100 kg cow weight, weaning weight per calving interval, and weaning weight per cow exposed to breeding (n = 1,442). Fixed effects and their interactions were investigated included sire and dam breed of cow, sire breed of calf, cow age, year, calf gender, and weaning age as a linear covariate (calf traits at weaning). Direct and maternal additive genetic effects were random in models for calf traits; only direct additive effects were modeled for cow traits. Cows sired by Angus bulls from outside the research herd had calves that were heavier at birth and weaning and greater ADG, BCS, and hip height (P < 0.05). Estimates of heterosis for weaning weight, BCS, and ADG ranged from 1.3 to 13.2% for all pairs of breeds (P < 0.05). Estimates of heterosis for birth weight (3.2 to 8.2%) and hip height (2.3%) were significant for Romosinuano-Angus and Brahman-Angus. Heterosis for cow weight was 65 ± 8 kg for Brahman-Angus (P < 0.001), and estimates for other pairs of breeds were approximately one-half that value. Heterosis for weaning weight/100 kg cow weight was 3.4 ± 0.75 kg for Romosinuano-Angus. Heterosis estimates for weaning weight/calving interval (P < 0.001) ranged from 0.08 ± 0.01 to 0.12 ± 0.01. Heterosis for weaning weight/cow exposed were 31.6 7.7, 36.9 ± 7.4, and 59.1 ± 7.5 kg for Romosinuano-Angus, Romosinuano-Brahman, and Brahman-Angus, respectively (P < 0.001). Most aspects of Romosinuano crossbred maternal performance were acceptable; maternal performance of Brahman-Angus cows excelled. [ABSTRACT FROM AUTHOR]

The objectives of this work were to compare reproduction and parturition traits of the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman, to estimate heterosis and direct and maternal genetic breed effects, and to describe calf loss, cow removals from the project, the occurrence of calving difficulty, inadequate calf vigor at birth, and udder problems by cow breed groups. Cows (n = 404) were bom from 2002 to 2005. After their first exposure to bulls as young cows, in all subsequent breeding seasons crossbred cows were bred to bulls of the third breed, and straightbred cows were bred to bulls of the other two breeds. Calving records (n = 1,484) from 2005 to 2011 were used to create calving and weaning rate and calving interval (excluding the interval between 2 and 3 yr of age). Final models for these traits included sire breed-dam breed interaction, cow age within year, and random animal effects. Heterosis estimates for Romosinuano-Brahman calving and weaning rate were 0.06 ± 0.02 and 0.07 ± 0.03 (P < 0.05); those for Brahman-Angus were twice as large (0.13 ± 0.03 and 0.14 ± 0.03, respectively; P < 0.001). Estimates of Brahman direct effects on calving and weaning rate were -0.12 ± 0.04 and -0.14 ± 0.05 (P < 0.05); however, Angus direct effects were beneficial for both traits (0.1 ± 0.05, P < 0.05). The effect of heterosis was to reduce calving interval by -49.2 ± 9.9 and -37.2 ± 9.7 d for Romosinuano-Brahman and Brahman-Angus, respectively (P < 0.001). Romosinuano and Fj cows sired by Romosinuano and out of Angus dams had the most occurrences of difficult births as a proportion of cows that calved (0.028 and 0.025, P = 0.04). Angus-sired crossbred cows and Brahman cows had the most occurrences of udder problems as a proportion of lac-tating cows (0.14 to 0.21, P < 0.04). There were more Brahman-sired cows that died or were culled as a proportion of those cows that began the project (0.1 to 0.28, P < 0.02) than cows in the other breed groups. Romosinuano-Brahman and Romosinuano-Angus cow performance was acceptable, but for most traits, those pairs of breeds had lower heterosis than Brahman-Angus. [ABSTRACT FROM AUTHOR]

En un hato de conservación del ganado criollo colombiano Romosinuano se estimaron los valores genéticos (Diferencias Esperadas de Progenie, DEP) de los caracteres de crecimiento (peso al nacimiento, al destete y a los 16 meses en terneros, y pesos al parto y al destete de su cría en vacas), así como de los rasgos reproductivos en hembras (edad al primer parto e intervalos entre partos). Las DEP diferenciales entre los toros de mayor y menor potencial genético para los pesos al nacer, al destete y a los 16 meses fueron respectivamente de +4,07, +29,30 y +36,04 kg. Las DEP de las vacas para los pesos al parto y al destete del ternero fueron de +36,04 y +43,23 kg. Para la edad al primer parto y el intervalo entre partos las DEP fueron de –89,35 y –30,10 días, respectivamente. Sin embargo, la variabilidad genética de estos caracteres se ha mantenido, ya que los coeficientes de regresión (r2) fueron cercanos a cero. Se estimó la capacidad más probable de producción (CMPP) de cada vaca y luego se estableció una correlación lineal entre el valor genético (DEP) y la CMPP para los pesos al nacer y al destete, las cuales fueron altas (r = +0,91 y +0,79). El intervalo entre generaciones calculado para el hato fue de 4,96 años: 3,92 y 6,99 años para machos y hembras, respectivamente.

Se analizaron 932 registros de la edad al primer parto en hembras de la raza criolla Romosinuano nacidas entre los años 1980 y 2001 en el núcleo de conservación del Centro de Investigación Turipaná de Corpoica en Cereté (Córdoba). La edad promedio al primer parto fue de 1.162,297 ± 4,26 días (cv= 11,19%). Para el estudio de los factores ambientales se utilizó el análisis de varianza mediante modelos lineales del procedimiento Proc Glm del programa estadístico SAS®. El análisis de varianza reveló que el año y el mes de nacimiento fueron causas de variación estadísticamente significativas respecto de la edad al primer parto. La heredabilidad de este rasgo, calculada por la correlación intraclase entre medias hermanas paternas, fue de 0,16 ± 0,08. Con relación al intervalo entre partos, la media estimada fue de 433,60 ± 3,69 días, con una desviación estándar de 139,18 días (cv= 32,10%); el respectivo análisis estadístico fue realizado a través del método de mínimos cuadrados del algoritmo Proc Glm de SAS®. El análisis de varianza señaló que el año y el mes de nacimiento, así como el número de partos, constituyeron causas de variación estadísticamente significativas del intervalo entre partos en hembras Romosinuano. La heredabilidad de esta característica, estimada mediante los componenetes de varianza del programa Mtdfreml fue de 0,05 ± 0,04. La eficiencia reproductiva promedio fue del 85,11%, con una desviación estándar de 17,65% y variaciones individuales que oscilaron entre 117,74 % y 32,19%.

Mediante el procedimiento general de modelos lineales (Proc Glm) del paquete estadístico SAS®, fueron analizados 1.877 registros de pesos al nacimiento, al destete y a los 16 meses de edad de terneros de la raza criolla colombiana Romosinuano nacidos en el Centro de Investigación Turipaná de Corpoica en Cereté (Córdoba) entre los años 1980 y 2001. Los pesos promedio al nacimiento, al destete y a los 16 meses de edad fueron en su orden de 30,65 ± 3,79 kg; 182,77 ± 29,35 kg y 247,18 ± 33,81 kg. Los efectos del año de nacimiento y el sexo del ternero fueron significativos (P< 0,01) para los tres momentos de pesaje. Por su parte, el efecto del número de partos de la vaca fue significativo (P

Abstract: The response of the immune and stress systems have been assessed in response to a lipopolysaccharide (LPS) challenge, yet the role of metabolism in mediating energy requirements during the acute phase response has not been sufficiently studied. This study tested heat-tolerant (Romosinuano [RO]) and heat-sensitive (Angus [ANG]) Bos taurus breeds at different ambient temperatures (Ta) to determine differential metabolic responses to LPS challenge. Twenty-one heifers (ANG: n = 11, 306 ± 26 kg BW; RO: n = 10, 313 ± 32 kg BW) were housed in stanchions in 4 temperature-controlled chambers. Initially, Ta in all 4 chambers was cycling at thermoneutrality (TN; 18.5°C–23.5°C) for a 1-wk adjustment period, followed by an increase in 2 chambers to cycling heat stress (HS; 24°C–38°C) for 2 wk. Five ANG and 5 RO heifers were housed at TN, whereas 6 ANG and 5 RO heifers were housed at HS. On day 19, heifers were fitted with jugular catheters. On day 20, heifers were challenged with LPS (0.5 μg/kg BW; 0 h), and blood samples were collected from −2 to 8 h and at 24 h relative to LPS challenge. Serum was analyzed for glucose, insulin, and NEFA concentrations. In addition, feed intake was measured 3 d before and on the day of the challenge. Feed intake decreased over time (P < 0.001) and was decreased in heifers housed at HS compared with heifers housed at TN (P = 0.013). Glucose concentrations before LPS challenge were greater in RO (P = 0.01) than in ANG heifers and greater in TN-housed heifers (P = 0.02) than in HS heifers. Glucose after LPS challenge initially increased before decreasing below baseline concentrations (P < 0.01) in all heifers. In addition, there was a breed by Ta interaction (P < 0.004), such that HS decreased glucose concentrations in ANG heifers compared with ANG heifers housed at TN (P < 0.001), whereas HS did not affect glucose concentrations after LPS challenge in RO heifers (P = 0.941). Nonesterified fatty acid concentrations before LPS challenge were not affected by breed (P = 0.37) or Ta (P = 0.60). Although NEFA concentration after LPS challenge was unaffected by Ta (P = 0.78), there tended to be a breed by Ta interaction (P = 0.07) such that, when housed at HS, RO heifers had greater serum NEFA concentrations after LPS challenge than ANG heifers (P = 0.009). Insulin concentration before LPS challenge was greater in RO heifers than in ANG heifers (P < 0.01). Insulin after LPS challenge increased (P < 0.01), with RO heifers producing a greater insulin response than ANG heifers (P < 0.01). These data suggest that HS decreases the metabolic response of heat-sensitive ANG heifers in response to LPS challenge, thus providing physiological evidence that may explain differences observed in the acute phase response between heat-sensitive ANG and heat-tolerant RO cattle breeds. [Copyright &y& Elsevier]

Abstract: The difference in the acute phase response of a heat-tolerant and a heat-sensitive Bos taurus breed to a lipopolysaccharide (LPS) challenge when housed at different air temperatures (Ta) was studied. Angus (ANG; heat-sensitive; n = 11; 306 ± 26 kg BW) and Romosinuano (RO; heat-tolerant; n = 10; 313 ± 32 kg BW) heifers were transported from the USDA Agricultural Research Service SubTropical Agricultural Research Station in Florida to the Brody Environmental Chambers at the University of Missouri, Columbia. Heifers were housed in stanchions in 4 temperature-controlled environmental chambers. Initially, Ta in the 4 chambers was cycling at thermoneutrality (TN; 18.5°C–23.5°C) for a 1-wk adjustment period, followed by an increase in 2 of the 4 chambers to cycling heat stress (HS; 24°C–38°C) for 2 wk. On day 19, heifers were fitted with jugular catheters and rectal temperature (RT) recording devices. On day 20, heifers were challenged with LPS (0.5 μg/kg BW; 0 h), sickness behavior scores (SBSs) were recorded, and blood samples were collected at 0.5-h intervals from −2 to 8 h and again at 24 h relative to LPS challenge at 0 h. Serum was isolated and stored at −80°C until analyzed for cortisol and cytokine concentrations. A breed by Ta interaction (P < 0.001) was observed for RT such that the post-LPS average RT in RO heifers housed at TN was lower than the RT of all other treatment groups (P < 0.001), whereas ANG heifers housed at HS had greater post-LPS average RT than all other treatment groups (P < 0.001). In response to LPS, HS increased SBS after LPS in RO heifers compared to RO heifers housed at TN (P < 0.001), whereas HS decreased SBS after LPS in ANG heifers compared to ANG heifers housed at TN (P = 0.014). The cortisol response to LPS was greater in TN than in HS heifers (P < 0.01) and was also greater in RO than in ANG heifers (P = 0.03). A breed by Ta interaction (P < 0.01) was observed for tumor necrosis factor-α (TNF-α) concentration such that HS increased post-LPS serum concentrations of TNF-α in ANG heifers compared to ANG heifers housed at TN (P = 0.041), whereas HS decreased post-LPS concentrations of TNF-α in RO heifers compared to RO heifers housed at TN (P = 0.008). A tendency (P < 0.06) was observed for a breed by Ta interaction for IL-6 concentrations such that RO heifers had greater post-LPS concentrations of IL-6 than ANG heifers when housed at HS (P = 0.020). A breed by Ta interaction was observed for interferon-γ (IFN-γ; P < 0.01) concentrations such that HS decreased post-LPS concentrations of IFN-γ in ANG heifers compared to ANG heifers housed at TN (P < 0.001), and HS increased post-LPS concentrations of IFN-γ in RO heifers compared to RO heifers housed at TN (P = 0.017). These data indicate differences in the acute phase response between the heat-tolerant RO and heat-sensitive ANG heifers under different Ta which may aid in elucidating differences in productivity, disease resistance, and longevity among cattle breeds. [Copyright &y& Elsevier]

Objetivo. Estudiar los factores ambientales y genéticos que influyeron sobre el intervalo entre partos de hembras romosinuano. Materiales y métodos. Se analizaron retrospectivamente 1.911 registros los intervalos entre partos de las vacas de la raza Romosinuano del Centro de Investigaciones Turipaná de CORPOICA, Cereté, Córdoba, desde el año de 1980 hasta el año 2003. Para el estudio de los factores ambientales se utilizó el método de los cuadrados mínimos mediante el procedimiento PROC GLM de SAS. Resultados. La media estimada para el intervalo entre partos fue de 433,60 ± 3,69 días, con una desviación estándar de 139,18 días y un coeficiente de variación de 32,10%. La heredabilidad estimada a través de los componentes de varianza del método MTDFREML fue de 0,05 ± 0,04. Conclusión. El análisis de varianza reveló que el año, el mes de nacimiento y el número de partos, fueron causas estadísticamente significativas de variación del intervalo entre partos.

Se estimaron los parámetros genéticos para características de crecimiento en un núcleo de bovinos de la raza criolla Romosinuano que forman parte del Programa de Conservación del Centro de Investigación Turipaná, localizado en el Valle del Sinú (Córdoba, Colombia). Fue utilizado un modelo animal univariado para las características productivas de ‘peso al nacimiento’ (PN), ‘peso al destete’ (PD, ajustado a los 270 días), ‘peso a los 16 meses’ (P16m), ‘ganancia diaria de peso al destete’ (GPD) y ‘ganancia diaria de peso a los 16 meses’ (GP16m). Se obtuvieron valores de heredabilidad total medios (0,28; 0,43 y 0,38 para PN, PD, P16m, respectivamente); así mismo, se obtuvo un valor medio para GPD (0,42) y un valor bajo para GP16m (0,20). Los valores de heredabilidad directa siempre fueron mayores que los valores de heredabilidad materna y la correlación entre efectos directos y maternos presentó valores negativos consistentemente. Los valores genéticos anuales promedio para los efectos directos presentaron siempre una tendencia creciente a diferencia de los efectos maternos que mostraron una tendencia decreciente, con excepción del PN. Los resultados muestran valores de heredabilidad aceptables para los parámetros mencionados, mientras la tendencia indica un progreso genético leve pese a ser un núcleo de conservación cuyo objeto es preservar la variabilidad genética.

The objective of this investigation was to evaluate the effect of biopreparado with a native yeast with probiotic characteristics, on the parameters of gain of daily weight and milk production in bovine cattle. Lots of 30 cows of romosinuano race were used (Cordoba-Colombia), of which 15 were witness and 15 of test; the experiment was realised with 3 repetitions, a nutritional regime of pasturing and the biopreparado one (inoculate 3X108 ufc/mL) to the day was provided once during two months. The results demonstrated that there were statistically no significant differences in the gain of weight, whereas if were observed differences for the milk production with α (0,05) having used the test of T for independent samples. The biopreparado one demonstrated a positive effect on the milk gain in cattle of double intention of the region of Cordoba. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this study were to characterize rectal temperature and coat score under subtropical North American summer conditions for straightbred and crossbred Romosinuano, Brahman, and Angus cattle, to estimate heterosis and breed direct and maternal effects in a subset of those, and to estimate heritability and genetic correlation of these traits. Records of cows (n=612 cows; 1861 total records) and calves (n=1588) from summer days in subtropical Florida, USA, were evaluated using animal models. Records of cows and calves from 2 management groups were analyzed separately. In the first management group, cows were all straightbred as were their calves; most of these cows were dams of cows in the other management group. Cows in that second management group were produced from all possible matings of Romosinuano, Brahman, and Angus bulls and cows; breed groups were 3 straightbred groups and 3 groups of F1 cows (reciprocal crosses combined). Calves of these cows were 3-breed crosses (all F1 cows were mated to bulls of the 3rd breed) and F1 crosses (straightbred cows were bred in approximately equal numbers to bulls of the other 2 breeds). Angus straightbred and crossbred cows and calves had the highest rectal temperature and coat score (subjective score where larger numbers indicated greater quantity of hair on the coat) means in all 4 analyses. In the second management group (straightbred and crossbred cows raising crossbred calves), Romosinuano straightbreds and F1 Romosinuano–Brahman cows had the lowest (P<0.001) rectal temperature and coat score means. Heterosis for rectal temperature was −0.2±0.05 and −0.24±0.05°C for Romosinuano–Angus and Brahman–Angus, respectively (P<0.001). Heterosis for coat score was −1.4±0.2, −0.9±0.2, and −2±0.2 for Brahman–Angus, Romosinuano–Brahman, and Romosinuano–Angus, respectively (P<0.001). Direct effects of Romosinuano and Brahman reduced rectal temperature and coat score; direct effects of Angus increased both. Estimates of heritability were 0.19±0.03 and 0.27±0.04 for rectal temperature and coat score, respectively. Permanent environmental effects as proportions of phenotypic variance were 0.03±0.02 and 0.17±0.04 for rectal temperature and coat score, respectively. The estimate of genetic correlation of these traits was 0.24±0.09. With respect to these traits, Romosinuano may offer benefits of tropical adaptation at least to the extent of Brahman under Florida summer conditions. [Copyright &y& Elsevier]

The article focuses on a study to determine heterosis and breed genetic effects for carcass quantity, quality and palatability traits of steers produced from striaghtbred and crossbred of Romosinuano, Brahman and Angus bulls and cows. It informs that Romosinuano steers had some quality and palatability advantage relative to Brahman but did not provide a clear superior alternative to Brahman for U.S. producers. It discusses the results which states that Romosinuano-Angus estimates was smallest.

Beef cows in the subtropical USA must be adapted to the stressors of the environment, typically supplied by using Brahman (Br) breeding. Calves produced in the region, however, are usually grown and finished in more temperate regions, and have a perceived reputation for poor ADG and feed efficiency during finishing. Compromised fertility and carcass quality often associated with the Br have increased interest in tropically adapted Bos taurus breed types. The objective of this study was to evaluate 3 breeds [An = Angus (Bos taunts, temperate); Br (B. indicus, tropical); and Ro = Romosinuano (B. taurus, tropical)] and all possible crosses during various segments of post-weaning growth, and for feed efficiency during the finishing phase. Steer calves (n = 473) born over 3 yr were weaned in late September, backgrounded for at least 21 d (BKG), shipped 2,025 km to El Reno, OK, in October, fed a preconditioning diet for 28 d (RCV), grazed wheat (Triticum aestivum L.) pasture from November to May (WHT), finished on a conventional feedlot diet (FIN), and serially harvested after approximately 95, 125, and 150 d on feed. Body weight and ADG during each segment were tested using a mixed model that included calf age at weaning, year (Y), breed of sire (SB), breed of dam (DB), and interactions. In addition, winter treatment (continuous wheat or reduced grazing of wheat with supplement) was included for the wheat and feedlot phases. Sire within SB × SB [and pen (barn × year) for feedlot phase] were considered random. The SB × DB interaction was significant for all traits (P < 0.01 ) except exit velocity taken at weaning and ADG during FIN, but both traits were affected by 3-way interactions with Y or harvest group. Tropically-adapted purebred steers had greater (P < 0.01) ADG than AnAn through weaning and BKG in FL but the reverse was true during the RCV and WHT segments. Similar, but less pronounced results were noted for F, steers with 100% tropical influence compared with those with only 50%. Heterosis was numerically greater for most traits for An × Br (11 to 64%) compared with An × Ro and Br × Ro (3 to 42%), which were similar. In a subset of the steers (n = 261), G:F was not influenced by level of tropical breeding, but tropically adapted steers were more efficient (P < 0.05) by residual feed intake. No heterosis was evident. These data show that in temperate zones, winter is the period when productivity of tropically adapted cattle is compromised. [ABSTRACT FROM AUTHOR]

The objective was to identify single nucleotide polymorphisms (SNP) associated to fertility in cows raised under a subtropical environment. Re-sequencing of nine genes associated to GH-IGF endocrine pathway, which are located in bovine chromosomes 5, 16 and 20, identified 73 SNP useful for associative genetic studies; however, only seven resulted as polymorphic and unique to the Romosinuano breed. Then, DNA samples were extracted from 129 beef heifers and used to determine genotypes corresponding to each SNP. Mixed model analysis identified one SNP from the PAPP-A2 gene (C/T, rs110490898) as predictor (P<0.05) of reproductive performance. The allele T was the most favorable allele (P<0.05), because it was associated with lower age at first calving (-37.1 ± 14.4 d) and age at second calving (-65.43 ± 30.8 d). In the contrast analysis, the linear term resulted as significant and quadratic term as non significant, which suggested an additive effect of the alleles. These results provide evidence to support the PAPP-A2 gene as a candidate gene associated to reproductive performance in heifers and first-calf cows from the Romosinuano breed, raised under a subtropical environment. [ABSTRACT FROM AUTHOR]

El objetivo fue identificar polimorfismos de un solo nucleótido (SNP) asociados a la fertilidad en hembras bovinas criadas en subtropico. La re-secuenciación de nueve genes relacionados al eje endocrino GH-IGF, localizados en los cromosomas 5, 16 y 20 del bovino, identificó 73 SNP útiles para estudios genéticos asociativos; sin embargo, sólo siete resultaron polimórficos y exclusivos de la raza Romosinuano. Muestras de ADN se extrajeron de 129 vaquillas Romosinuano y usadas para determinar los genotipos correspondientes a cada SNP. Un análisis de modelos mixtos identificó únicamente a un polimorfismo del gen PAPP-A2 (C/T, rs110490898) como predictor (P<0.05) del comportamiento reproductivo. El alelo T fue el más favorable (P<0.05) ya que éste se asoció a una reducción tanto en la edad al primer parto (-37.1 ± 14.4 días), como en la edad al segundo parto (-65.43 ± 30.8 días). En el análisis de contrastes el término lineal resultó significativo (P<0.05), pero no el quadrático, lo cual sugiere un efecto aditivo de los alelos. Los resultados proporcionan evidencia para proponer al gen PAPP-A2, como candidato asociado al comportamiento reproductivo en vaquillas y vacas primerizas de la raza Romosinuano. [ABSTRACT FROM AUTHOR]

Abstract: Our primary objective of this experiment was to evaluate potential genetic differences between two diverse Bos taurus breeds [Angus (AG) and Romosinuano (RO)] in response to an endotoxin challenge. Eighteen steers (n = 9 steers/breed; 299.4 ± 5.2 kg BW) were acclimated to environmentally controlled chambers maintained at thermoneutrality (19.7 °C) and then fitted with indwelling jugular catheters and rectal temperature (RT) recording devices 1 d before the endotoxin challenge. The next day, blood samples were collected at 30-min intervals from −2 to 8 h, and RT was measured continuously at 1-min intervals throughout the study. At time 0, all steers received an intravenous bolus injection of lipopolysaccharide (LPS; 2.5 μg/kg BW). Serum samples were stored at −80 °C until analyzed for cortisol, proinflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and interferon gamma (IFN-γ)], and acute phase proteins (serum amyloid A, acid soluble protein, ceruloplasmin, and α-acid glycoprotein). Rectal temperatures increased in both breeds within 1 h after LPS, with RO producing a greater increase in RT than AG steers (P < 0.001). Serum cortisol and TNF-α increased (P < 0.01) in both breeds within 1 h after the LPS challenge. For cortisol, an overall breed effect (P < 0.02) was detected, such that AG steers had a higher cortisol response than RO steers. A breed × time interaction (P < 0.01) was observed for TNF-α, such that the response was delayed and extended in the RO steers compared with the AG steers. At 2 and 2.5 h after LPS, TNF-α concentrations were greater (P < 0.03) in RO steers than in AG steers. For IL-1β, a breed × time interaction (P < 0.04) was also observed. At 3 h after LPS, IL-1β concentrations were greater (P < 0.01) in RO steers than in AG steers. Serum IL-6 and IFN-γ increased (P < 0.01) in a similar manner in both groups after the LPS challenge. These data show differences in the innate immune response between two diverse Bos taurus breeds which may provide insight about differences observed in productivity, heat tolerance, disease resistance, and longevity among cattle breeds. [Copyright &y& Elsevier]

The objectives of this work were to estimate genetic effects for age and size at estimated time of first conception, and temperament in straightbred and crossbred heifers (n = 554) produced from Romosinuano, Brahman, and Angus cattle, and to evaluate first-parturition performance of heifers, including calf birth weight, occurrence of calving difficulty, occurrence of poor vigor in their newborn calves, and calf mortality. At approximately 7 mo of age, weaned heifers were pastured with Mashona or Tuli bulls until confirmed pregnant. Body weight, hip height, exit velocity (m/s), and chute temperament score (1 calm, no movement; 5 = continuous movement, struggling) were recorded at 28-d intervals until heifers averaged 19 mo of age. Age at first conception was estimated as age at calving minus 285 d. Regression analyses were used to estimate BW and hip height at age of first conception. Brahman heifers were older, heavier, and had greater hip height than other straightbred groups (P < 0.05) and most crossbred groups. Brahman and reciprocal Brahman-Angus heifers had greater (P < 0.05) exit velocity than Romosinuano and Angus heifers. Brahman sire and dam breed chute temperament scores were greater (P < 0.05) than those of all other breed groups. Estimates of heterosis for age at first conception were -53.7 ± 9.5 (-11%), -56 ± 10.1 (-11%), and -92.9 ± 11 d (- 18%) for Romosinuano-Brahman, Romosinuano-Angus, and Brahman-Angus, respectively (P < 0.01). Heterosis was detected (P < 0.04) for Romosinuano-Brahman for BW (12 ± 4.3 kg, 3.7%) and hip height (1.3 ± 0.6 cm, 1%) at first conception. Maternal heterosis for calf birth weight was 3.6 ± 0.5 (12%) and 2.4 ± 0.6 kg (8.6%) for Romosinuano-Angus and Brahman-Angus. In Romosinuano-Brahman and Brahman-Angus, heterosis for exit velocity was 0.23 ± 0.09 (10%) and 0.5 ± 0.1 m/s (21%). The direct breed effect of Romosinuano was to reduce age (-58.2 ± 18.9 d), BW (-57.6 ± 10.5 kg), and hip height (-2.6 ± 1.1 cm) at the time of first conception (P < 0.01), and the direct Brahman effects (P < 0.001) were large and numerically positive for these traits (169.8 ± 20.8 d, 93.3 ± 11.6 kg, and 14 ± 1.2 cm). Use of Romosinuano in crossbreeding programs with Brahman may be useful for decreasing the age at first conception. The larger birth weights of calves born to Romosinuano-Angus cross heifers would not be desirable in southern cow-calf operations. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the fatty acid (FA) composition of intramuscular fat from the LM of 3 divergent breeds of cattle: Angus (AN, n = 9), Brahman (BR, n = 7), and Romosinuano (RM, n = 11). Cattle were blocked by breed and finished 129 d before slaughter in one year and 157 d in the next year. Longissimus muscle samples were collected from each carcass between the 10th and 13th ribs, trimmed of external fat, frozen in liquid nitrogen, homogenized, and used for fat extraction, using a modified Folch procedure. Extracted fat was analyzed for FA by using a GLC system with an HP-88 capillary column. Fatty acid composition was expressed using both a normalized percentage (%) and gravimetric calculation (mg/g of fresh muscle tissue) in relation to degree of saturation, which was determined using a saturation index (ratio of total SFA to total unsaturated FA). Crude fat determination revealed that LM from AN purebred cattle had the greatest amount of intramuscular fat (7.08%; P = 0.001). Although intramuscular fat of LM from RM contained a reduced percentage of total SFA (P = 0.002) compared with AN, it had the greatest percentage of total PUFA (P < 0.001 and P = 0.020). The percentages of total MUFA were similar among the 3 breeds (P = 0.675). The gravimetric calculation, a measure of actual FA concentration, showed significantly greater concentrations of SFA (26.67 mg/g), MUFA (26.50 mg/g), and PUFA (2.37 mg/g) in LM from AN cattle, as compared with LM from BR and RM cattle (P < 0.001). Interestingly, BR purebreds had the least PUFA concentration (1.49 mg/g; P < 0.001) in the LM, although their intramuscular fat content was similar to that of RM (P = 0.924). Regardless of breed, the MUFA proportion was always the greatest (47.58%; P ⩽ 0.005), whereas PUFA was the least contributor to FA composition (1.49 to 2.37 mg/g and 4.36 to 8.78%; P < 0.001). Beef LM fatty acid composition was characterized by palmitic and oleic acids being the most abundant FA (P < 0.001). These results suggested a genetic variation in FA synthesis and deposition among breeds that influenced both marbling and its composition. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this study were to develop an accurate and precise method for cholesterol quantification in meat samples based on modifications made to an existing procedure (AOAC Official Method 994.10), and to apply this modified method to evaluate cholesterol levels in longissimus muscles (LM) from Angus (AN, n=5), Brahman (BR, n=4), and Romosinuano (RM, n=9) breeds. Validation of this method was performed using a meat homogenate (Standard Reference Material 1546) from National Institute of Standards and Technology (NIST), and LM samples from the three breeds with fat contents ranging from 2.4% to 9.3%. The results indicated that the modified method was accurate with cholesterol recovery exceeding 95%. The method was also found to be precise with an average coefficient of variation of 3.12%. The modification reduced 90% of chemicals used and eliminated time-consuming steps that hindered high throughput application of the traditional method. The application of this method to quantify cholesterol contents of LM samples revealed differences among the three breeds evaluated. The Angus LM with a higher fat content (50% higher) was associated with a significantly higher cholesterol concentration (70.25mg/100g) as compared to LM from Brahman and Romosinuano purebreds (64.77 and 65.76mg/100g; P=0.005 and 0.006, respectively). Cholesterol concentration was found to be correlated with the i.m. fat content of LM muscle from the three breeds (r=0.90, P<0.001). Cholesterol concentrations of LM determined in this study were comparable to those reported in the USDA National Nutrient Database for Standard Reference for separable lean from Choice rib-eye steaks. This modified method was reliable and should be evaluated for adoption as an appropriate method for cholesterol quantification in meat samples. [Copyright &y& Elsevier]

The objective herein was to estimate heterosis and breed effects in purebred and crossbred Romosinuano, Brahman, and Angus calves on acute phase protein response to weaning and transportation. Calves (n = 1,032) were weaned in September of 2002, 2003, and 2004 at approximately 7 mo of age. Approximately 28 d after weaning, steer calves (n = 482) were transported 1,800 km (20 h) to Oklahoma. Concentrations of 3 acute phase proteins (ceruloplasmin, fibrinogen, and haptoglobin) were measured in blood samples. Calves (steers and heifers) were sampled at weaning, and 24 and 72 h postweaning. For separate analyses, steers sent to Oklahoma were sampled before shipment, upon arrival, and 24 and 72 h after arrival. Combinations of the following fixed effects were investigated: sire breed, dam breed, sampling time, birth location, calf sex (weaning only), year, cow age, and interactions. Effects of special interest were sire breed × dam breed as an indication of breed group of calf, and the interaction of sire and dam breeds with sampling time. Weaning age and BW were investigated as linear and quadratic covariates. Sire of calf within sire breed was a random term. The correlation structure of repeated measures was determined by comparison of information criterion values for different structures within each analysis. In general, plasma acute phase protein concentrations in weaned calves increased with sampling time. Concentrations in the transported steers increased through sampling at 24 h after arrival, and were lower at 72 h. Significant estimates of heterosis were detected for Brahman-Angus haptoglobin concentrations at weaning (0.38 ± 0.14 mg/dL × 100; 44%), and for Romosinuano-Angus fibrinogen concentrations at weaning (11.4 ± 5.5 mg/dL; 10%) and in transported steers (22.5 ± 8.4 mg/dL; 20%). The direct effect of Romosinuano was to increase (P < 0.004) ceruloplasmin concentrations of weaned calves (4.1 ± 0.9 mg/dL) and of transported steers (3.9 ± 1.3 mg/dL). The direct effect of Angus was to lower ceruloplasmin concentrations in weaned calves (-3.9 ± 1.2; P = 0.001). Significant maternal effects were detected at weaning for ceruloplasmin concentrations in Romosinuano (-1.4 ± 0.5 mg/dL) and Angus (1.6 ± 0.7 mg/dL) and fibrinogen concentrations in Brahman calves (-17.7 ± 8.8 mg/dL). These data imply that acute phase protein concentrations in response to weaning and transportation are impacted by cattle breed. [ABSTRACT FROM AUTHOR]

The objectives of this work were to evaluate birth and weaning traits, to estimate genetic effects, including heterosis and direct and maternal breed effects, and to evaluate calving difficulty, calf vigor at birth, and calf mortality of Romosinuano as purebreds and as crosses with Brahman and Angus. Calves (n = 1,348) were spring-born from 2002 through 2005 and weaned in the fall of each year at about 7 mo of age. Traits evaluated included birth and weaning weight, ADG, BCS, and weaning hip height. Models used to analyze these traits included the fixed effects of year, sire and dam breeds, management unit, calf sex, cow age, and source of Angus sire (within or outside of the research herd). Calf age in days was investigated as a covariate for weaning traits. Sire within sire breed and dam within dam breed were random effects. Estimates of Romosinuano-Brahman and Romosinuano-Angus heterosis (P < 0.05) were 2.6 ± 0.3 (8.6%) and 1.4 ± 0.3 kg (4.7%) for birth weight, 20.5 ± 1.5 (9.5%) and 14.6 ± 1.4 kg (7.4%) for weaning weight, 79.2 ± 6.1 (9.8%) and 55.1 ± 6.0 g (7.5%) for ADG, 0.16 ± 0.03 (2.7%) and 0.07 ± 0.03 (1.2%) for BCS, and 2.77 ± 0.32 cm (2.4%) and 1.87 ± 0.32 cm (1.7%) for hip height. Heterosis for Brahman-Angus was greater (P < 0.05) than all Romosinuano estimates except those for Romosinuano-Brahman and Romosinuano-Angus BCS. Romosinuano direct effects were negative and lowest of the breeds, except for the Angus estimate for hip height. Romosinuano maternal effects were the largest of the 3 breeds for birth weight and hip height but intermediate to the other breeds for weaning weight and ADG. A large proportion of Brahman-sired calves from Angus dams (0.09 ± 0.03; n = 11) was born in difficult births and died before 4 d of age. Brahman and Angus purebreds and Romosinuano-sired calves from Brahman dams also had large proportions of calves that died before weaning (0.09 or greater). Results indicated that Romosinuano may be used as a source of adaptation to subtropical environments and still incorporate substantial crossbred advantage for weaning traits, although not to the extent of crosses of Brahman and Angus. [ABSTRACT FROM AUTHOR]

Presents abstracts of several studies on dairy production and management and the environment. "Minimum Dry Period Length to Maximize Performance," by M. T. Kuhn, J. L. Hutchison and H. D. Norman; "Effect of Photoperiod on Milk Production in Lactating Dairy Cows," by M. J. VanBaale, D. V. Armstrong, R. M. Mattingly and J. B. Fiscalini; "Reasons and Timing of Cows Leaving Dairy Herds in Florida and Georgia," by B. L. Butler and A. de Vries.

Presents abstracts of several articles on meat science and muscle biology. "Effect of Feeding Program and Sex on Productive Performance and Carcass Quality of Iberian Crossbred Pigs," by D. G. Valencia, R. Lázaro, M. Nieto and G. G. Mateos; "Early Postmortem pH Influences Proteolysis of Cytoskeletal Proteins During Aging in Porcine Longissimus Muscle," by S. M. Lonergan and E. Huff-Lonergan; "The Use of Creatine as a Means of Improving the Belly/Bacon Quality of Market Barrows Fed 4.5 g/ton Paylean," by C. A. Stahl, M. S. Carlson, T. B. Schmidt, G. Rentfrow, E. K. Burger and E. P. Berg; "Effects of Sedated-Harvest on Channel Catfish Fillet Color, pH, and Drip-Loss," by B. G. Bosworth and D. J. Gregory.

Presents abstracts of several studies on animal breeding and genetics. "The Impact of Herd Opportunity and Milk Recording Periods in Estimating Lifetime Net Income," by E. Yook, R. E. Pearson and B. G. Cassell; "Joint Genetic Evaluation of Male and Female Fertility Using Longitudinal Binary Responses," by R. Rekaya and T. Averil; "Contribution of Inbreeding and Recessive Defects to Early Embryo Loss," by P. M. VanRaden and R. H. Miller; "Effects of Climate and Photoperiod on Feed Intake of Beef Bulls During Feedlot Performance Tests," by G. T. Tabler Jr., A. H. Brown Jr., Z. B. Johnson, E. E. Gbur Jr., I. L. Berry, D. W. Kellogg and K. C. Thompson.

Presents abstracts of several studies on dairy production and management and the environment. "Minimum Dry Period Length to Maximize Performance," by M. T. Kuhn, J. L. Hutchison and H. D. Norman; "Effect of Photoperiod on Milk Production in Lactating Dairy Cows," by M. J. VanBaale, D. V. Armstrong, R. M. Mattingly and J. B. Fiscalini; "Reasons and Timing of Cows Leaving Dairy Herds in Florida and Georgia," by B. L. Butler and A. de Vries.

Presents abstracts of several articles on meat science and muscle biology. "Effect of Feeding Program and Sex on Productive Performance and Carcass Quality of Iberian Crossbred Pigs," by D. G. Valencia, R. Lázaro, M. Nieto and G. G. Mateos; "Early Postmortem pH Influences Proteolysis of Cytoskeletal Proteins During Aging in Porcine Longissimus Muscle," by S. M. Lonergan and E. Huff-Lonergan; "The Use of Creatine as a Means of Improving the Belly/Bacon Quality of Market Barrows Fed 4.5 g/ton Paylean," by C. A. Stahl, M. S. Carlson, T. B. Schmidt, G. Rentfrow, E. K. Burger and E. P. Berg; "Effects of Sedated-Harvest on Channel Catfish Fillet Color, pH, and Drip-Loss," by B. G. Bosworth and D. J. Gregory.

Presents abstracts of several studies on animal breeding and genetics. "The Impact of Herd Opportunity and Milk Recording Periods in Estimating Lifetime Net Income," by E. Yook, R. E. Pearson and B. G. Cassell; "Joint Genetic Evaluation of Male and Female Fertility Using Longitudinal Binary Responses," by R. Rekaya and T. Averil; "Contribution of Inbreeding and Recessive Defects to Early Embryo Loss," by P. M. VanRaden and R. H. Miller; "Effects of Climate and Photoperiod on Feed Intake of Beef Bulls During Feedlot Performance Tests," by G. T. Tabler Jr., A. H. Brown Jr., Z. B. Johnson, E. E. Gbur Jr., I. L. Berry, D. W. Kellogg and K. C. Thompson.