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Les éleveurs de vaches allaitantes en système spécialisé sont conduits à agrandir leur surface et accroître les effectifs de leur troupeau, en permanence, car le nombre d’UGB par travailleur est un des facteurs les plus déterminants du revenu. Les exploitants du RICA (OTEX 42) avaient, en 1992, 37 vaches allaitantes en moyenne française et 46 pour la seule région de Bourgogne. L’augmentation continue des effectifs de vaches par exploitation ne se fait-elle pas au détriment des performances techniques et économiques du cheptel ? La concentration d’animaux comporte des risques, certaines opérations d’élevage, notamment les vêlages et les soins aux jeunes veaux, ne sont pas mécanisables et demeurent contraignantes pour l’éleveur. En outre, la rentabilité relativement faible des bovins allaitants limite les capacités d’investissements des exploitants. L’article analyse le fonctionnement d’exploitations ayant de grands troupeaux charolais dans le Centre de la France (plus de 50 vêlages annuels par travailleur). Une présentation des performances zootechniques et des résultats économiques obtenus sur 13 années par 10 grands troupeaux est faite en comparaison avec ceux d’un échantillon Témoin de 37 exploitations suivies sur la même période et la même zone. Elle met en évidence une absence de dégradation des performances dans les grands troupeaux. Ce maintien des performances n’est pas acquis d’avance, il exige de nombreuses conditions : une grande technicité des éleveurs qui doivent savoir tirer parti des particularités de conduite des vaches allaitantes, des bâtiments adaptés, notamment des stabulations libres et des dispositifs d’aide à la surveillance des vêlages, une croissance en continu des troupeaux, réalisée essentiellement par croît interne avec l’élevage d’un nombre largement suffisant de génisses. L’adaptation des techniques est à faire en permanence. Mais l’effort principal est la capitalisation : celle-ci exige un sacrifice financier de la part des familles : en bilan cumulé sur 5 années, on constate que, dans les grands troupeaux, 37 % du revenu a été immobilisé pour la croissance des capitaux propres (dont 5 % pour le foncier), 63 % seulement ont pu être prélevés pour la famille., Since the number of cattle units per worker is one of the most determining factors in a suckling cow farm’s revenue, specialized breeders are continually being forced to increase both their number of stock and the size of their domain. The French average herd, in 1992, for specialized breeders was 37 suckling cows. This value was 46 in the Burgundy region. There may be grounds for concern that this continual increase in the number of cattle per farm may have possible negative consequences on their technical and economic performances. Increasing the animal concentration brings with it certain risks. Certain operations, most notably calving and the care of the calves, cannot be automated and the farmers are compelled to do these by hand. In addition, the relatively low return resulting from suckling cow farming limits the farmer’s reinvestment capacity. This article evaluated the performance of farms in the centre of France that have large herds of Charolais (more than 50 calvings per worker). The zootechnical performances and economic results of ten large herds over a 13 year period were compared with reference data from 37 farms studied over the same period in the same region. The results showed that the performances in large herds did not, in fact, decrease. In order to ensure a high level of performance for these large herds, certain conditions were necessary. The breeders needed to be technically competent. They understood the specific characteristics of suckling cattle and knew how to make the best use of them. They understood such details as building adaptations, including free-stall housing and surveillance systems which aided with calving. The herds maintained a steady, continuous increase, essentially due to internal breeding and the maintenance of a sufficient number of heifers. These farms were capable of continually adapting to new technologies. The most rigorous condition related to capitalization. A significant financial sacrifice was delabded from the farming families. A five-year review demonstrated that for large herds, 37% of the revenue was used to increase the main capital (of which 5% was for land ownership costs). This left only 63% available for the family.

Atferdsstudie på beitesynkronitet på tre av de fem vanligste kjøttferasene i Norge. Målet med oppgaven var å undersøke om det var forskjeller i aktivitetsbudsjett, beitesynkronitet og distribusjon av dyr på innmarksbeite hos kjøttferasene Aberdeen Angus, Charolais og Limousin. Seks beiter i Nord-Trøndelag ble valgt ut til atferdsstudiet basert på kriterier som beiteutforming, beitestørrelse, oversiktelighet og besetningsstørrelse. Det innebar at det var to beiter per rase, og til sammen ble det gjennomført seks døgn med atferdsregistreringer på hver rase med tre døgn med observasjoner på hvert beite. Atferdsregistreringene ble gjennomført kl. 06.00-24.00, og det ble gjort registreringer for atferdsegenskapene beiter, ligger, står, går og annet. Beitene ble delt inn i ruter på ca. 45 x 45 meter og for hvert femte minutt ble flokken registrert, og antall dyr som var engasjert med de ulike atferdsegenskapene i de ulike rutene ble notert på et manuelt registreringsark. For å si noe om forskjeller i beitesynkronitet mellom de tre rasene ble flokken definert som å beite synkront når > 75 % av flokken beitet. LS-means for rase, korrigert for de andre signifikante effektene det er mulig å korrigere for av de som er registrert, viste at Limousin brukte mer tid på å beite enn Aberdeen Angus og Charolais (47,7 % mot 39,3 og 37,4 %; P < 0,01). Det var ingen signifikante forskjeller i beitetid mellom Aberdeen Angus og Charolais. Aberdeen Angus og Charolais brukte mer tid på å ligge enn Limousin (39,1 og 38,9 % mot 31,8 %; P < 0,01). Ingen signifikante forskjeller i tid brukt på å ligge ble funnet mellom Aberdeen Angus og Charolais. Charolais brukte mer tid på å stå enn Aberdeen Angus og Limousin (16,1 % mot 13,4 og 10,9 %; P < 0,01), og Aberdeen Angus brukte mer tid på å stå enn Limousin (P < 0,01). En Pearson-test viste at Aberdeen Angus og Limousin brukte mer tid på å beite synkront enn Charolais (32,6 og 31,4 % mot 21,2 %; P < 0,01), men det var ingen signifikante forskjeller mellom Aberdeen Angus og Limousin. Charolais beitet aldri synkront i de to første timene av observasjonsperioden. LS-means for rase for antall ruter dyrene var fordelt over ved synkron beiting, viste at Limousin var fordelt over flere ruter enn Aberdeen Angus og Charolais (3,87 ruter mot 3,34 og 2,46 ruter; P < 0,01). Charolais var fordelt over flere ruter enn Aberdeen Angus (P < 0,01). The aim of this study was to detect if there were any differences in activity budget, synchrony of grazing behavior and distribution of animals on pasture for the beef cattle breeds Aberdeen Angus, Charolais and Limousin grazing cultivated pastures. Six different pastures located in the county of Nord-Trøndelag were chosen for the behavior studies. The pastures were selected based on criteria such as size and shape of the pasture, easiness of observability and size of the herd. A total of six days of observations were recorded for each breed distributed over two different pastures within breeds, giving three days of registrations on each pasture. The behavioral registrations were carried out between 06.00-24.00, and the activities grazing, lying, standing, walking and other were registered. The pastures were divided into patches measuring approximately 45 x 45 meters. Every five minutes the herd was observed, and the number of animals which were engaged in a particular behavior within each patch was recorded and noted manually on a sheet. To estimate the synchronized grazing-behavior the herd was defined as grazing in synchrony when > 75 % of the herd was grazing simultaneously. The LS-means for breed, corrected for the other significant effects it was possible to correct for of those registered, showed that Limousin spent more time grazing than Aberdeen Angus and Charolais (47,7 % versus 39,3 and 37,4 %; P < 0,01), but no significant differences were found between Aberdeen Angus and Charolais. Aberdeen Angus and Charolais spent less time lying than Limousin (39,1 and 38,9 % versus 31,8 %; P < 0,01). There were no significant differences on the time spent lying between Aberdeen Angus and Charolais. Charolais spent more time standing than Aberdeen Angus and Limousin (16,1 % versus 13,4 and 10,9 %; P < 0,01), and Aberdeen Angus spent more time standing than Limousin (P < 0,01). A Pearson-test was used to detect differences in the synchronized grazing-behavior, and the results showed that Aberdeen Angus and Limousin spent more time grazing in synchrony than Charolais (32,6 and 31,4 % versus 21,2 %; < 0,01), but no significant differences were found between Aberdeen Angus and Limousin. Charolais never grazed in synchrony during the first two hours of observations. LS-means for breed on the number of patches the animals were distributed across when synchronized grazing occurred, showed that Aberdeen Angus were distributed over more patches than and Charolais (3,87 patches versus 3,34 and 2,46 patches; P < 0,01), and Charolais was distributed over more patches than Aberdeen Angus (P < 0,01).

Linkage disequilibrium (LD) and the persistence of its phase across populations are important for genomic selection as well as fine scale mapping of quantitative trait loci. However knowledge of LD in beef cattle, as well as the persistence of LD phase between crossbreds and purebreds, is limited. The objective of this study was to understand the patterns of LD in Angus, Charolais, and crossbred beef cattle based on 31’073, 32’088 and 33’286 SNP in each population, respectively. Amount of LD decreased rapidly from 0.29 to 0.23 to 0.19 in Angus (AN), 0.22 to 0.16 to 0.12 in Charolais (CH), 0.21 to 0.15 to 0.11 in Crossbreds (C), when the distance range between markers changed from 0-30kb to 30-70kb and then to 70-100kb, respectively. Breeds and chromosomes had significant effects (P

Avaliou-se o desempenho de novilhas de corte até o parto submetidas a diferentes níveis de suplementação em pastagem natural durante o primeiro período reprodutivo, dos 14 aos 17 meses. Foram utilizadas 98 novilhas contemporâneas do mesmo rebanho dos grupos genéticos Charolês, Nelore e suas cruzas, com peso médio de 255 kg. As novilhas foram distribuídas em três grupos: sem suplementação; com suplementação de 3,5 g/kg do peso corporal; com suplementação de 7,0 g/kg do peso corporal. O peso ao final e o ganho de peso médio diário durante o período de suplementação foi maior entre as novilhas do grupo com suplementação na proporção de 7,0 g/kg (322 e 0,701 kg) em comparação àquelas sob suplementação na proporção de 3,5 g/kg (302 e 0,464 kg) e sem suplementação (288 e 0,425 kg), que não diferiram entre si. O escore de condição corporal ao final da suplementação diferiu entre os três grupos com 3,07; 3,33 e 3,47 pontos, respectivamente, para novilhas sem suplementação; com suplementação na proporção de 3,5 g/kg do peso corporal; com suplementação na proporção de 7,0 g/kg do peso corporal. A porcentagem de prenhez foi influenciada significativamente pelo nível de suplementação, sendo de 35,0; 34,2 e 70,0%, respectivamente. Os dois grupos sob suplementação tiveram maior taxa de concepção na metade inicial do período reprodutivo. A média de idade das novilhas ao parto foi de 785, 778 e 761 dias, respectivamente. O ganho médio diário e a condição corporal foram semelhantes entre as novilhas dos dois grupos genéticos, porém o peso ao início e ao final do período de suplementação foi maior nas filhas de touros charoleses em relação às de touros nelores, refletindo-se nas taxas de manifestação de estro (68,8 vs. 38,2) e de prenhez (60,9 vs. 26,5). As características relacionadas ao parto das novilhas não foram influenciadas pelos níveis de suplementação durante o período reprodutivo. A suplementação durante o período de acasalamento aumenta o desempenho reprodutivo de novilhas aos 14 meses de idade. The objective was to evaluate the performance of beef heifers until calving receiving different levels of supplementation on native pasture during the first breeding season, from 14 to 17 months: no supplementation; 3.5 g/kg of body weight; and 7.0 g/kg of body weight. Ninety-eight Charolais, Nellore and their crosses, with average initial weight of 255 kg, were used. Weight at the end and average daily weight gain during the supplementation period were higher for 7.0 g/kg of supplement heifers (322 and 0.701 kg) compared to those with 3.5 g/kg of supplement (302 and 0.464 kg) and heifers without supplementation (288 and 0.425 kg), which did not differ from each other. Body condition score at the end of the supplementation was different between the three treatments, being 3.03, 3.33 and 3.47 points for heifers without supplementation; 3.5 g/kg of body weight; and 7.0 g/kg of body weight, respectively. Pregnancy rate was significantly affected by supplementation level, being 35.0, 34.2 and 70.0%, respectively. Heifers of the two supplementation treatments had higher conception rate at the first half of the reproductive period. Average heifer ages at calving were of 785, 778 and 761 days, respectively. The average daily weight and body condition of the heifers of the two genetic groups were similar; however, the initial and final weight of the supplementation period was higher for Charolais bulls daughters, compared with Nellore bulls daughters, reflecting on the heat (68.8 vs. 38.2%) and pregnancy (60.9 vs. 26.5%) rates. Characteristics related to calving were not affected by the supplementation levels during the reproductive period. The supplementation during the first breeding season increases reproductive performance of heifers at 14 months of age.

Conselho Nacional de Desenvolvimento Científico e Tecnológico The aim of the present study was to evaluate the effect of the use of Alexander grass silage (Urochloa plantaginea) on body tissues that are not part of the carcass, as well as the quantitative and qualitative aspects of the carcass and meat from feedlot finished steers. It was used 12 castrated, pure and crossbred Charolais x Nellore steers, age and initial weight were 20 months and 245 kg respectively, distributed in two different treatments: Alexander grass silage (AS) = animals fed with 51% of Alexander silage and 49% of concentrate and, sorghum silage (SS) = animals fed with 53% sorghum silage and 47% of concentrate (control group). The diet was calculated searching to meet the minimal nutritional requirements in order to obtain an average daily weight gain of 1.2 kg/animal and, estimating a dry matter intake of 2.5 kg/100 kg alive. The experimental design used was randomized blocks with two treatments and six samples per treatment; each experimental unit consisted of one animal. The slaughter weight (SW), empty body weight (EBW) and, the relationship between EBW/SW were similar for animals in the tested roughage, with mean values of 442.66 kg, 381.45 kg and 0.86 respectively. The rumen-reticulum expressed in kg and, the gastrointestinal content in absolute or relative weight for 100 kg of empty body weight (%EBW) were higher for AS animals while, the liver in %EBW was higher for SS animals. AS animals showed higher kidney fat deposition, both in absolute weight and %EBW and, increased deposition of fat in the abomasum %EBW. However, in total numbers, the fats that are not part of the carcass did not differ between treatments. Hot carcass yield and fat thickness were similar between animals in the tested roughage, with an average of 58.8% and 4.7 mm, respectively. The same behavior was observed for meat color, texture and marbling. Nevertheless, the meat from AS animals showed a greater muscle and fat liquid loss when subjected to cooking. There was no difference in meat chemical composition between the tested roughage with mean values of 20.27, 76.17, 2.11 and 1.14% for crude protein, moisture, ether extract and mineral matter respectively. O objetivo do presente estudo foi avaliar o efeito do uso da silagem de papuã (Urochloa plantaginea) sobre os tecidos corporais que não perfazem a carcaça, bem como, os aspectos quantitativos e qualitativos da carcaça e da carne de novilhos terminados em confinamento. Utilizaram-se 12 bovinos machos castrados, puros e mestiços Charolês x Nelore, com idade e peso médio inicial de 20 meses e 245 kg respectivamente, distribuídos em dois tratamentos: Silagem de Papuã (SP) = animais recebendo 51% de silagem de papuã e 49% de concentrado e Silagem de Sorgo (SS) = animais recebendo 53% de silagem de sorgo e 47% de concentrado (grupo controle). A dieta foi calculada buscando-se atender os requerimentos mínimos nutricionais, a fim de obter-se um ganho de peso médio diário de 1,2 kg/animal, estimando-se um consumo de matéria seca 2,5 kg/100 kg de peso vivo. O delineamento experimental utilizado foi de blocos ao acaso, com dois tratamentos e seis amostras por tratamento, sendo cada unidade experimental composta por um animal. O peso de abate (PAB), peso de corpo vazio (PCV), assim como a relação entre PCV/PAB foram similares entre os animais dos volumosos testados, apresentando valores médios de 442,66 kg, 381,45 kg e 0,86 respectivamente. Os órgãos rúmen-retículo expressos em kg, e o conteúdo gastrintestinal tanto em peso absoluto ou relativo a 100 kg de peso de corpo vazio (%PCV), foram superiores nos animais SP, já o órgão fígado em %PCV foi superior nos animais SS. Os animais SP apresentaram maior deposição de gordura renal, tanto em peso absoluto quanto em %PCV, e maior deposição de gordura do abomaso em %PCV. Porém na totalidade, as gorduras que não perfazem a carcaça não apresentaram diferença entre os tratamentos. O rendimento de carcaça quente e a espessura de gordura foram similares entre os animais dos volumosos testados, apresentando médias de 58,8% e 4,7 mm, respectivamente. Mesmo comportamento se observou quanto à coloração, textura e marmorização da carne. No entanto, a carne provenientes de animais SP apresentou maior perda de líquidos e gordura muscular quando submetidas à cocção. Não houve diferença na composição química da carne entre os volumosos testados, apresentando valores médios de 20,27; 76,17; 2,11 e 1,14% para proteína bruta, umidade, extrato etéreo e matéria mineral respectivamente.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior The aim of this study was to evaluate the influence of different sources of carbohydrates (corn, soybean hulls and wheat bran) on ingestive behavior of twenty four steers with initial average of age and weight of 20 months and 330 kg and Charolais or Nellore predominance. The time spent in feeding activities (214min./day) and total rumination (458min./day) weren t influenced by diet carbohydrate sources. The animals in the wheat bran treatment spent less time in total idling (678min.) in relation to the corn (768min./day) and soybean hulls treatment (774min./day). The neutral detergent fiber (NDF) intake was higher for the animals fed with soybean hulls and wheat bran (5.18 and 5.42 kg/day respectively) compared with those who received corn as a carbohydrate source (3.35kg/day), however the non-fibrous carbohydrates intake was higher for this source of carbohydrate (4.29kg/day), intermediate for wheat bran (2.53kg/day) and lower for those in soybean hulls treatment. The steers fed with soybean hulls presented less intake of digestible energy (27.62Mcal/day) in relation to the corn (35. 5 Mcal/day) and wheat bran (33. 25 Mcal/day) treatments. Rumination efficiency of NDF was higher for soybean hulls (11.92g/min.) and wheat bran (10.23g/min.) compared to corn (7.68g/min.). The chewing time per ruminal bolus was lower for soybean hulls (0.88min./bolus) compared to the diets containing corn (0.96min./bolus) and wheat bran (0.95min./bolus). The animals with Charolais predominance presented higher feeding periods (29.41min.) in relation to the steers with Nellore predominance (24.95min.). The sources of carbohydrates tested didn t influence the feeding and total rumination time of the animals. The animals with Nellore predominance remain less time in lying idling, present longer periods of feeding and spend more time in chewing per ruminal bolus. Objetivou-se, com este estudo, avaliar a influência de diferentes fontes de carboidratos (milho, casca de soja ou farelo de trigo) sobre o comportamento ingestivo de 24 novilhos castrados com idade e peso médio inicial de 20 meses e 330 kg das predominâncias Charolês ou Nelore. Os tempos despendidos com alimentação (214min./dia) e ruminação total (458min./dia) não foram influenciados pelas fontes de carboidratos. Os animais do tratamento farelo de trigo permaneceram menos tempo em ócio total (678min.) em relação ao milho (768min./dia) e a casca de soja (774min./dia). O consumo da fibra em detergente neutro (FDN) foi maior para os animais alimentados com casca de soja e farelo de trigo (5,18 e 5,42kg/dia respectivamente) comparado aos que receberam milho como fonte de carboidrato (3,35kg/dia), no entanto o consumo de carboidratos não-fibrosos foi superior para esta fonte de carboidrato (4,29kg/dia), intermediário para o farelo de trigo (2,53kg/dia) e inferior para aqueles do tratamento casca de soja. Os novilhos alimentados com casca de soja apresentaram menor consumo de energia digestível (27,62 Mcal/dia) em relação aos tratamentos milho (35,5 Mcal/dia) e farelo de trigo (33,25 Mcal/dia). A eficiência de ruminação FDN foi superior para a casca de soja (11,92g/min.) e farelo de trigo (10,23g/min.) em comparação ao milho (7,68g/min.). O tempo de mastigações por bolo ruminal foi menor para a casca de soja (0,88min./bolo) em comparação as dietas contendo milho (0,96min./bolo) e farelo de trigo (0,95min./bolo). Os animais de predominância Charolês apresentaram maiores períodos de alimentação (29,41min.) em relação aos novilhos de predominância Nelore (24,95min.). As fontes de carboidrato testadas não influenciam o tempo de alimentação e de ruminação total dos animais. Novilhos de predominância Nelore permanecem menos em ócio deitado, apresentam períodos de alimentação mais demorados e gastam mais tempo de mastigação por bolo ruminal.

Twenty-three Charolais steers, slaughtered at 31 months of age and an average live weight of either 674 kg (light group; n =13) or 751 kg (heavy group; n =10) were used to determine the effect of increasing weight at slaughter by genetic selection on meat quality traits. Steers were born to pure-bred Charolais cows from an INRA experimental herd, reared and finished under the same breeding practices. The quality of meat from the M. rectus abdominis excised 24 h postmortem was scored after 14 days ageing between 0 and 10 by sensory analysis using four descriptors: global assessment, initial tenderness, overall tenderness, juiciness and flavor intensity. Shear force measurements were evaluated on raw and broiled meat after 14 days of ageing. The pH, collagen and lipid contents, the collagen solubility, isocitrate dehydrogenase (ICDH), lactate dehydrogenase and cytochrome- c oxidase activities and the proportion of myosin heavy chain isoforms were measured 24 h post-slaughter. The heavy group was characterized by a significantly higher empty live weight (683 vs 614 kg) and carcass weight (before removing external fat: 469 vs 408 kg; after removing external fat: 463 vs 403 kg) at slaughter than the light one but an equivalent fatness score (2.74 on 5). Scores of heavy steer M. rectus abdominis were significantly higher for descriptors of initial tenderness (6.95 vs 6.31) and overall tenderness (6.79 vs 6.22) although the intramuscular fat content was equivalent for light and heavy group samples (16.6% of dry matter on average). Global assessment and flavor intensity were also slightly in favor of heavy group samples (6.49 vs 5.85 and 6.48 vs 6.07), but no differences were found between the two groups in meat juiciness (6.10 on average). Shear force on raw and broiled meat was not significantly different between groups (5.13 and 6.98 daN on average). No significant differences were found between groups on total and soluble collagen contents ( p =0.32 and p =0.49 respectively). The heavy group was associated with a more glycolytic metabolism (LDH enzyme: 620 vs 528 μmol/min/g; p =0.03) and a higher myosin heavy chain IIx proportion (39.1% vs 32.3%; p =0.07) without any modification in oxidative enzyme activities (ICDH and COX; p =0.49 and 0.84).

Cilj istraživanja bio je komisijskom prosudbom ocijeniti vanjštinu mladih Charolais bikova namjenjenih za daljni rasplod. Najviše bikova (83%) za mišićnu razvijenost imalo ocjenu 55-75 bodova, dok je 7% bikova imalo ocjenu veću od 76 bodova. S obzirom na razvijenost skeleta najveći broj bikova (74%) imao je raspon ocjena od 61-76 dok je 16% bikova imalo ocjenu veću od 77 bodova. U pogledu funkcionalnih svojstava većina istraživanih bikova (71%) imao je ocjenu između 63-75 bodova dok je 11% bikova imalo ocjenu veću od 76 bodova.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior The objective was to analyse the effect of subcutaneous fat thickness (SFT), conformation (CONF), cold carcass weight (CCW) and age on carcass and meat quality of 152 Nellore cull cows and 240 Charolais cull cows. The data were submitted to a regression analysis by PROC REG and PROC STEPWISE procedures. Cold carcass yield was influenced by SFT (Y = 47.36274 + .45159x) and CCW (Y = 42.84735 + .02857x) in Nellore cull cows. It was observed, for Nellore cull cows, interaction equations for pistol cut percentage (Y = 48.3228 + .35761CONF - .00739 CCW), forequarter weight (Y = 68.64009 + .51448SFT + .06195CCW) and side cut weight (Y = 22.53615 + .33861SFT + .02735CCW). Nellore cull cows presented positively relation between Longissimus dorsi area and CCW, however it presented negativly relation with SFT (Y = 50.6691 - .47432SFT + .05012CCW). The accretion of 1 kg in CCW or 1 point in conformation of the carcass of Nellore cows resulted in an increase of .12 and 1.7 kg, respectively, in muscle weight. SFT and age influenced positively fat tissue and negatively muscle participation in carcass of Nellore cows. Muscle:bone relation increased with CCW and decreased with age advance in Nellore cows. For Nellore cull cows, the SFT had a quadratic relation with tenderness and shear force, presenting greater tenderness (5.3 points) when SFT had 7.8 mm and lower shear force (6.6 kgf/cm2) when SFT reached 5.6 mm. Each point increased in conformation of Charolais carcasses added 12 kg in slaughter weight, as well as 1 kg added to CCW represented adition slaughter weight of .4 kg. Pistol cut of Charolais cows, when expressed in kg, had positively relation to CCW, however had negatively relation to CONF. Each millimeter or kg added to SFT or CCW, in Charolais cows, resulted in a reduction of .4 and .04 cm2 in Longissimus dorsi area. Carcasses muscle and fat quantities of Charolais cows was positively influenced by SFT and CCW. However, age and conformation influenced negatively muscle and fat quantities, respectively, in Charolais cows carcasses. The addition of 1 kg of CCW increased in .003 points Charolais meat tenderness, while shear force presented a quadratic relation to SFT, being animals with 5.3 mm the ones with higher value for this characteristic (5.6 kgf/cm2). Objetivou-se analisar o efeito da espessura de gordura subcutânea, conformação, peso de carcaça fria e idade sobre as características da carcaça e da carne de 152 vacas de descarte da raça Nelore e 240 vacas de descarte da raça Charolês. Os dados foram submetidos à análise de regressão pelo PROC REG e PROC STEPWISE. O rendimento de carcaça fria foi influenciado pela espessura de gordura (EGS) (Y=47,36274+0,45159x) e peso de carcaça fria (PCF) (Y=42,84735+0,02857x) em vacas de descarte Nelore. Em vacas de descarte Nelore observou-se equações com interação significativas para as características de traseiro especial (%) (Y = 48,3228 + 0,35761CONF - 0,00739 PCF), dianteiro (kg) (Y = 68,64009 + 0,51448EGS + 0,06195PCF) e ponta de agulha (kg) (Y = 22,53615 + 0,33861EGS + 0,02735PCF). Vacas de descarte Nelore apresentam relação entre a área de olho de lombo e o peso de carcaça fria positiva, porém negativa com EGS (Y = 50,6691 - 0,47432EGS + 0,05012PCF). O acréscimo de 1 quilograma no PCF ou 1 ponto na conformação da carcaça de vacas Nelore, resultou no aumento do peso de músculo em 0,12 e 1,7 kg, respectivamente. A EGS e a idade influenciaram positivamente a participação de tecido adiposo na carcaça, e negativamente a participação de tecido muscular de vacas de descarte Nelore. A relação músculo:osso aumentou com a elevação do PCF e decresceu com o avanço da idade de vacas de descarte Nelore. Para vacas de descarte Nelore, a EGS se relacionou de forma quadrática com a maciez subjetiva e objetiva, obtendo-se melhor maciez (5,3 pontos) com 7,8 mm de EGS e menor força de cisalhamento (6,6 kgf/cm2) quando a EGS atingiu 5,6 mm. Cada 1 ponto a mais na CONF de vacas de descarte Charolês repercutiu em 12 kg a mais no peso de abate, bem como cada 1 kg a mais no PCF representou 0,4 kg a mais no peso de abate. Em vacas de descarte Charolês, o corte comercial traseiro especial, quando expresso em peso absoluto, teve relação positiva com PCF, porém negativa com CONF. Vacas de descarte Charolês apresentam decréscimo de 0,4 e 0,04 cm2 na área de olho de lombo com o aumento de 1 milímetro na EGS ou 1 kg no PCF, respectivamente. As quantidades de músculo e de gordura da carcaça de vacas de descarte Charolês foram influenciadas, positivamente, pela EGS e PCF. Porém a idade e a conformação influenciaram negativamente a quantidade de músculo e gordura, respectivamente, em vacas de descarte Charolês. O aumento em 1 kg no PCF aumenta em 0,003 pontos a maciez da carne de vacas de descarte Charolês, enquanto que a força de cisalhamento apresentou relação quadrática com a EGS, sendo que animais com 5,3 mm de gordura apresentaram o menor valor para a força de cisalhamento (5,6 kgf/cm2).

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Objetivou-se com este estudo avaliar as características dos componentes externos e da gordura de descarte de novilhos de duas condições sexuais e dois genótipos terminados em confinamento. A idade e o peso médios dos animais ao início do período experimental foram de 12 meses e 267,0 kg, respectivamente. Os novilhos foram confinados até atingirem o peso de abate pré-estabelecido médio de 400 kg. A dieta foi formulada com relação volumoso:concentrado de 50:50, com base na matéria seca, com 10% de proteína bruta. O delineamento experimental utilizado foi o inteiramente casualizado, em arranjo fatorial de 2 × 2, composto de duas condições sexuais e dois grupos genéticos. O peso de corpo vazio (PCV), os rendimentos de carcaça em relação ao peso de corpo vazio e a relação entre o peso de corpo vazio e o peso de abate foram similares entre genótipos e condições sexuais. Para o peso absoluto das orelhas, observou-se interação significativa entre genótipo e condição sexual dos novilhos. Animais castrados apresentaram maiores valores de gordura intestinal em relação ao peso de corpo vazio (1,62 versus 1,18%) e ao peso ao abate (1,41 versus 1,02%) e de cabeça em relação ao peso ao abate (3,78 versus 3,29%). Os animais com predominância de sangue Charolês apresentaram maior peso absoluto de vassoura da cauda (0,16 versus 0,11 kg) e novilhos Nelore maiores pesos relativos de couro e gordura renal. Não há correlação entre o rendimento de carcaça e os componentes não-integrantes da carcaça. The objective of this study was to evaluate the characteristics of external components and discard fat of young steers with two different sexual conditions and two different genotypes, finished in feedlot. Average age and weight of the animals at the beginning of the experimental period were 12 months and 267.0 kg, respectively. The steers were in feedlot until reaching pre-established slaughter weight of 400 kg. Diet contained roughage:concentrate ratio of 50:50, on dry matter basis, with 10% crude protein. It was used a complete randomized experimental design, in a 2 × 2 factorial arrangement, composed of two sexual conditions and two genetic groups. Empty body weight (EBW), carcass dressing in relation to empty body weight and the relationship between empty body weight and slaughter weight were similar among genotypes and sexual conditions. For absolute weight of ears, it was observed significant interaction between genotypes and sexual conditions of steers. Castrated animals showed greater values of intestinal fat in relation to empty body weight (1.62 versus 1.18%). Animals with Charolais predominance showed greater absolute values to tail broom (0.16 versus 0.11 kg) and Nellore steers predominance presented greater weight related to rawhide and renal fat. There is no correlation among carcass dressing and non-integrant components of carcass.

The aim of this study was to evaluate the influence selected factors on growth and carcass value of bulls fattened to slaughter weight in the reference herd of Czech Pied cattle breed and its crosses with meat breeds. A total of 70 pieces were observed among breeds of bulls, 32 bulls were of Czech Pied breed, 29 bulls of Czech Pied breed hybrid beef breeds bulls and 9 were crossbred beef cattle. Bulls for fattening were stopped at the age of 9-12 months and were fattened for around two years, 24 months of age.

Steeds meer stieren worden in ketenverband gemest om tegemoet te komen aan de wensen van slagers en retailers.

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Background An important variability of contractile and metabolic properties between muscles has been highlighted. In the literature, the majority of studies on beef sensorial quality concerns M. longissimus thoracis. M. rectus abdominis (RA) is easy to sample without huge carcass depreciation and may appear as an alternative to M. longissimus thoracis for fast and routine physicochemical analysis. It was considered interesting to assess the muscle fibres of M. rectus abdominis in comparison with M. longissimus thoracis (LT) and M. triceps brachii (TB) on the basis of metabolic and contractile properties, area and myosin heavy chain isoforms (MyHC) proportions. Immuno-histochemical, histochemical, histological and enzymological techniques were used. This research concerned two populations of Charolais cattle: RA was compared to TB in a population of 19 steers while RA was compared to LT in a population of 153 heifers. Results RA muscle had higher mean fibre areas (3350 μm2 vs 2142 to 2639 μm2) than the two other muscles. In RA muscle, the slow-oxidative fibres were the largest (3957 μm2) and the fast-glycolytic the smallest (2868 μm2). The reverse was observed in TB muscle (1725 and 2436 μm2 respectively). In RA muscle, the distinction between fast-oxidative-glycolytic and fast-glycolytic fibres appeared difficult or impossible to establish, unlike in the other muscles. Consequently the classification based on ATPase and SDH activities seemed inappropriate, since the FOG fibres presented rather low SDH activity in this muscle in comparison to the other muscles of the carcass. RA muscle had a higher proportion of I fibres than TB and LT muscles, balanced by a lower proportion either of IIX fibres (in comparison to TB muscle) or of IIA fibres (in comparison to LT muscle). However, both oxidative and glycolytic enzyme activities were lower in RA than in TB muscle, although the LDH/ICDH ratio was higher in RA muscle (522 vs 340). Oxidative enzyme activities were higher in RA than in LT muscle, whereas glycolytic enzyme activity was lower. In RA muscle, contractile and metabolic properties appeared to be less well-correlated than in the two other muscles. Conclusions RA muscle has some particularities in comparison to the LT and TB muscles, especially concerning the unusual large cross-section surface of SO fibres and the very low oxidative activity of intermediate IIA fibres.

O estudo foi realizado com o objetivo de avaliar as características de carcaça de novilhos e vacas de descarte de dois grupos genéticos sob diferentes frequencias de alimentação. Foram utilizados 12 novilhos e 12 vacas de descarte, de modo que cada categoria foi formada de seis animais 5/8 Charolês (C) - Nelore (N) e seis animais 5/8NC, submetidos a três frequencias alimentação; duas vezes ao dia (às 7 e 19 h); três vezes ao dia (às 7, 13 e 19 h); e quatro vezes ao dia (às 7, 11, 15 e 19 h). Os animais foram terminados em confinamento recebendo como volumoso silagem de milho e concentrado à base de farelo de trigo, grão de milho moído, farelo de soja, calcário calcítico e sal, com relação volumoso:concentrado 40:60. O aumento na frequência de alimentação não influenciou a qualidade da carcaça dos animais. As vacas apresentaram maiores pesos de abate e de carcaça quente e fria (509,7; 280,0; e 277,1 kg) em comparação aos novilhos (414,5; 230,5 e 228,1 kg), no entanto, os rendimentos de carcaça quente e fria e as perdas por resfriamento foram semelhantes entre novilhos e vacas de descarte. As características que expressam a musculosidade da carcaça foram melhores nas vacas, que apresentaram maior espessura de coxão (25,88 vs 23,33 cm). As características métricas foram mais expressivas nas vacas, que tiveram carcaças mais longas (132,8 vs 122,3 cm) e maior espessura de gordura (6,21 vs 3,83 mm). As vacas também foram superiores quanto aos pesos de dianteiro e traseiro (103,5 e 133,0 kg) em comparação aos novilhos (84,7 e 111,8 kg), que apresentaram maior percentual de traseiro na carcaça (49,06 vs 48,04%). Entre os grupos genéticos, os animais 5/8C 3/8N apresentaram maior espessura de coxão, área do músculo Longissimus dorsi e comprimento de carcaça (25,7 cm; 64,0 cm² e 137,0 cm) em comparação aos 5/8N 3/8C (23,5 cm; 57,0 cm² e 124,8 cm). The objective of this study was to evaluate carcass characteristics of steers and cull cows from two genetic groups, under different feeding frequencies. Twelve steers and twelve cull cows were used and each category consisted of six animals 5/8 Charolais (C) - Nellore (N) and six animals 5/8NC, under three feeding frequencies: twice a day (7 a.m. and 7 p.m.); three times a day (7 a.m., 1 p.m. and 7 p.m.) and four times a day (7 a.m., 11 a.m., 3 p.m. and 7 p.m.). The animals were feedlot finished receiving corn silage as forage and concentrate based on wheat bran, corn ground, soybean meal, limestone and salt, with a forage:concentrate ratio of 40:60. The increase in feeding frequency did not influence the animal carcass quality. The cows showed higher slaughter, hot and cold carcass weights (509.7; 280.0; and 277.1 kg) compared to the steers (414.5; 230.5 and 228.1 kg), but the hot and cold carcass dressing percentages and carcass chilling loss were similar in the steers and cull cows. The characteristics that express carcass muscularity were better in the cows that had greater thigh thickness (25.88 vs 23.33 cm). The metrical characteristics were more expressive in the cows which had longer carcasses (132.8 vc 122.3 cm) and greater fat thickness (6.21 vs 3.83 mm). The cows also were superior for forequarter and sawcut weights (103.5 and 133 kg) compared to the steers (84.7 and 111.8 kg), which presented higher sawcut percentage in the carcass (49.06 vs 48.04%). Between the genetic groups, 5/8C3/8N animals presented higher thigh thickness, Longissimus dorsi area and carcass length (25.7 cm; 64 cm² and 137 cm) compared to 5/8N3/8C (23.5 cm; 57 cm² and 124.8 cm).

"Con el propósito de probar que la fecha de parto incide sobre las características productivas y reproductivas postparto de vacas y becerros Charolais en agostaderos semiáridos del noreste de México, se analizaron 1665 registros de 583 vacas en dos años consecutivos. Los registros se agruparon, de acuerdo a la fecha de parto, en cuatro grupos de parición (G1, G2, G3 y G4) de 21 d consecutivos. En el análisis de varianza se utilizó un diseño experimental completamente al azar con diferente número de repeticiones (SAS, 1989) y covariables. No se encontró efecto (P>0.05) de la fecha del parto sobre el peso al nacer de la cría. El peso al destete de los becerros nacidos en el G1 de parición en el año actual fue superior (P0.05) en ambos años. Las vacas del G1 destetaron en dos años consecutivos 26, 46 y 69 kg más de becerro que las vacas de los grupos 2, 3 y 4. Los días al empadre y días a la preñez fueron inversos al grupo de parición, en tanto que los días abiertos presentaron una dependencia directa de estas 51 51 dos variables; las vacas del G1 (día juliano al parto 84) se preñaron 11, 25 y 41 d más pronto que las vacas de los grupos 2, 3 y 4. El día juliano al parto siguiente tuvo una tendencia similar a días al parto siguiente y ambos fueron inversos al intervalo entre partos; éste y los días al parto siguiente fueron directamente proporcionales al día juliano al parto siguiente. Se concluyó que, con apareamientos de 90 días en verano, las vacas que paren al inicio de primavera tienen mejor comportamiento productivo y reproductivo postparto" The objective of this study was to evaluate the effect of calving date on productive traits (weights at birth and weaning, preweaning daily gain and total kilograms of calf weaned in two consecutives years) and reproductive postpartum: days to mating (DAE), days to pregnancy (DPA), days open (DAB), days to following calving (DPS) calving interval (IEP) and julian day at calving (DJP) following from Charolais cows managed in semiarid rangelands. Date from 1665 records were analyzed out of 583 Charolais cows calving and weaning in two consecutive years (current and subsequent) during the years 1977 and 2000 at The Angeles ranch, located in northeastern Mexico (250 04' N x x and 1000 58' W). The animals were grazed under extensive grazing conditions in 6,704 ha with native vegetation throughout the year. The rotational grazing system was rotational with 20 paddocks, where the animals were rotated during the year between paddocks to another, with a stocking rate of 15 to 20 ha per animal unit per year. The management of cows and calves in the different years was very similar. The breeding season was of 90 days (June, July and August) using a bull of the same breed for every 20 to 30 cows. The calfs were born in spring (March, April and May) and weaned in fall at seven months age on average. The cows were grouped according to actual calving date, into four groups (G1, G2, G3, and G4) of 21 consecutive days. The analysis of variance was done using a completely randomized design with different number of repetitions and covariates. There was no effect (P>0.05) of the calving date on birth weight of calves in both years, but for the covariates age of cow, sex of calf and year of calving in the current year, and only sex of the calf in the subsequent year. There was significant effect (P

Fueron obtenidas muestras de toros Charolais de registro (N=130) candidatos a sementales para hatos pie de cría manejados en un centro de pruebas de comportamiento productivo, con la finalidad de estimar las frecuencias genotípicas y alélicas de tres marcadores simples de un solo nucleótido que han sido asociados con características de calidad de la carne en ganado bovino. Se analizaron dos polimorfismos en el gen Calpaína, CAPN316 y CAPN4751, y la mutación Q204X, privada de la raza Charolais, en el gen Miostatina. Se encontró alta frecuencia del alelo normal en CAPN316 (f=0.85) y frecuencia similares de los alelos normal y mutado para el marcador CAPN4751 (f= 0.58 y 0.48, respectivamente). Se analizó la frecuencia de la mutación Q204X del gen Miostatina, encontrándose baja frecuencia (f= 0.03) atribuible a la selección negativa para la característica de doble musculatura en los últimos 30 años. Se discuten las implicaciones del estudio y validación del efecto de estos marcadores en el sistema de productor de carne bovina. La implementación del uso de estos marcadores podría ayudar a incentivar el desarrollo del sistema, el fomento de nichos de mercado para la calidad de la carne y sobre aumentar la rentabilidad de los sistemas de producción de carne actuales. Samples from registered Charolais sire candidate bulls for breeding herds and managed in a performance test station (N=130) were analyzed in order to estimate genotypic and allelic frequencies of three single nucleotide polymorphisms associated to beef quality traits. Two Calpain gene SNP markers, CAPN316 and CAPN4751, and the Charolais private mutation Q204X associated to double-muscling phenotype, were assessed. High frequency of normal allele was observed in CAPN316 (f=0.85) and similar frequencies for normal and favorable alleles in CAPN4751 (f=0.58 and 0.42, respectively). For Q204X, a low prevalence for the double muscling promoter allele was observed (f=0.03) attributable to negative selection criterion over this trait in the last 30 years. Implication and validation effects of the marker effects on the beef production system are discussed. Implementation of marker assisted management could help system development, support creation of quality meat niches and facilitate the increasing profitability for current beef production industry. Foram obtidas amostras de machos da raça Charolês registrado (N=130) candidatos a serem reprodutores para fazendas de cria, manejados em una central de teste de desempenho, com a finalidade de estimar as freqüências genotípicas e gênicas de três marcadores de um só nucleótido, associados com características de qualidade da carne bovina. Foram analisados os polimorfismos do gen da Calpaína, CAPN316 e CAPN4751, e a mutação Q204X, privada da raza charolês, no gen da Miostatina. Foram encontradas freqüências altas do alelo normal na CAPN316 (f= 0.85) e freqüências similares dos alelos normal e mutado para o marcador CAPN4751 (f=0.58 e 0.48, respectivamente). Foi encontrada baixa freqüência da mutação Q204X do gen Miostatina (f=0.03) devido à seleção negativa para a característica de dupla musculatura nos últimos 30 anos. O uso destes marcadores poderia ajudar a incentivar o desenvolvimento e fomento de mercados específicos para qualidade de carne e aumentar a rentabilidade dos sistemas de produção de carne atuais.

Incidence of dystocia in cows bred with Charolais bulls is 14.3% compared to 1.9% for cows mated by Hereford bulls and 3.5 % for matings by bulls of other breeds. There are also marked differences in dystocia levels in matings by particular Charolais bulls. After routine rectal and ultrasound examination of a Charolais herd we have chosen 12 pluriparous pregnant cows. They were kept in the same herd and mated by the same bull. They were all five months pregnant and 4-6 years old. Weekly ultrasound examination was performed during the 5th, 6th, 7th, 8th and 9th month of pregnancy. We determined growth of placentomes (4 by each examination and each cow using middle value as a standard), eye and head diameter and thorax range (if reachable). We also monitored parturition and compared birth weight for each calf. We compared fetal sex for each calf and compared it with fetal growth and birth weight. We found strong correlations between diameters of placentomes and intensity of fetal growth based on fetometrical measurements. We also found strong linear correlations between the intensity of fetal growth and birth weight according to middle value of average cross section of placentomes. Cross section of placentomes incresed 3-5 mm daily We didn't find significant correlations between sex of calfs (male or female) with intensity (?) of fetal growth nor birth weight. We didn't observe dystocia in any of monitored cows.

Dystocia costitute a large and important part of the science of obstetrics. The economic importance of bovine dystocia in cattle industry forces researchers to find an easy way to produce large calf which will easy pass maternal genital tract or at least to find a way to determine wheter parturition needs to be guareded due to feto-maternal disproportion. It is practically impossible to guard every parturiton in large beeef herds what results with about a third of the total of the 17% of fetal and calf losses that occur at the time of parturition due to loss of observing the problem on time. The major cause of these losses was dystocia due to fetopelvic disproportion. To the loss of offspring must be added maternal deaths and subsequent infertility which derive from dystocia in all species as well as the cost of treatment and the deminished productive capacity of the dam. It has been known for many years that the incidence of fetomaternal disproportion is much higher in beef breeds and results with much higher probability of cesarean section or at least guided parturition. Incidence of dystocia in cows bred with Charolais bulls consists 14, 3% compared to 1, 9% for cows mated to Hereford bulls and 3, 5 % in matings by bulls of other breeds. There are also marked differences in dystocia levels in matings by particular Charolais bulls. The aim of this study was to explore optional way to diagnose fetal oversize in Charolais cows and monitor fetal growrh in the last trimester of pregnancy. After routin rectal and ultrasoud examination of Charolais herd we have chosen six multiparous pregnant cows. They were kept in the same herd and mated with the same bull. They all were five months pregnant and 4-6 years old. We followed pregnancy by ultrasound examination once weekly during 5., 6. , 7. 8. and 9. month of pregnancy. We followed growth of placentomes (four by each examination and each cow using middle value as a standard), eye and head diameter and thorax range (if reachable). We also monitored parturition and compared birth weight for each calf. We compared foetal sex for each calf and compared it with fetal growth and birth weight. We found strong correlations between diameters of placentomes and intensity of foetal growth on basis of fetometrical measurements. We also found strong linear correlations between intensity of fetal growth and birth weight. We didn't find significant correlations between sex of calfs (male or female) with intensity of fetal growth nor birth weight. We didn't observe dystocia in any of monitored cows.

Foram avaliados o desempenho, composição física, rendimento de cortes comerciais e a qualidade da carne de vinte e oito vacas Charolês, Nelore e suas cruzas, com peso vivo médio inicial de 409 kg, terminadas em campo nativo com alta participação de Eragrostis plana Nees., suplementadas por 99 dias com farelo de trigo (FTR) ou farelo de arroz integral (FAI), a 0,5% do peso vivo na matéria seca, com ou sem a inclusão de monensina sódica, separados em grupos de sete para a composição dos tratamentos. O uso de farelo de trigo proporcionou melhor conformação da carcaça (P0,05) pelo tipo de suplemento. A inclusão de monensina sódica não proporcionou diferenças significativas (P>0,05) nas variáveis estudadas. The performance, physical composition, income of commercial cuts the quality of the meat of twenty eight cows Charolais, Nellore and its cross, were evaluated with initial average live weight of 409kg, finished in native grass with high participation of Eragrostis plana Nees., supplemented per 99 days with wheat bran or rice bran 0.5% of the alive weight in the DM with or without the inclusion of sódica monensina. The use of wheat bran provided a better conformation of the carcass (P0.05) by the type of supplement. The inclusion of sodic monensin did not provide significant differences (P>0.05) in the variable studied.

Aiming to evaluate non apparent relations among individual studies and provide a set of more accurate information about supplement utilization on cool-season cultivated pastures, variables from nine experiments wich tested levels and kinds of supplements offered to beef heifers were analyzed. At first, data were stratified in two groups: with and without supplement utilization. Afterwards, supplements offered in different levels were collected in three groups, to estimate the effect of sources ( by-product , grain , ration ). Pasture was evaluated in relation to the availability, structure, chemical composition and digestibility. For animals and per unit of area, the variables analyzed were average daily gain (ADG), body condition score (BCS), back height, stocking rate and live weight gain per hectare. The addition and substitution rates and the efficiency of transformation of grass and supplement were calculated. The availability and the structure of the grass were similar for both groups. Heifers that received supplement presented greater ADG and ingested grass with lesser neutral detergent fiber detergent. At the end of the pasture utilization, the heifers that received supplement were heavier, higher and presented greater BCS. Females that received ration presented higher average daily gain than heifers that received grain or by-product (P0,05) among kinds of supplement. However, when the females received ration, the efficiency of transformation of the grass was higher. The choice of the kind of supplement to use in high quality pastures should be based on the purpose of the production system. Rations provide greater increments on the individual performance while by-products provide greater stocking rate and individual performance. Com o objetivo de avaliar relações não aparentes nos estudos individuais e providenciar um conjunto de informações mais acuradas sobre o uso de suplementos em pastagens cultivadas de clima temperado, foram analisadas em conjunto as variáveis medidas em nove experimentos, que testaram níveis e tipos de suplementos para novilhas de corte. Os dados foram inicialmente estratificados em dois grupos: com e sem o uso de suplemento. Posteriormente, os suplementos fornecidos em diferentes níveis, foram reunidos em três grupos, para estimar o efeito de fontes ( subproduto , grão , ração comercial ). O pasto foi avaliado quanto à disponibilidade, estrutura, composição química e digestibilidade. As variáveis analisadas nos animais e por unidade de área foram o ganho médio diário (GMD), escore de condição corporal (ECC), altura da cernelha, taxa de lotação e ganho de peso por área. Foram calculadas as taxas de adição e substituição, eficiência de transformação do pasto e do suplemento. A disponibilidade e a estrutura do pasto foram semelhantes para os grupos com e sem suplemento. Bezerras que receberam suplemento apresentaram maior GMD e consumiram pasto com menor teor de fibra em detergente neutro. Ao final do período de utilização da pastagem as bezerras que receberam suplemento foram mais pesadas, mais altas e apresentaram maior ECC. Fêmeas que receberam ração apresentaram maior ganho médio diário GMD que bezerras que receberam grão ou subproduto (P0,05) entre os tipos de suplemento. A eficiência de transformação do pasto, no entanto, foi maior quando as fêmeas receberam ração. Em pastagens de alta qualidade a escolha do tipo de suplemento depende do objetivo do sistema de produção. Rações proporcionam maiores incrementos no desempenho individual enquanto subprodutos proporcionam maiores taxas de lotação e desempenho individual.

Knowledge of livestock genetic diversity is an essential step to respond to commercial demands and reach production objectives in different environments and production systems. The evaluation of animal genetic diversity is achieved by using molecular markers. Microsatellites are the most used markers for studies of this type. Eleven microsatellites were used to evaluate the genetic variation from three populations of Charolais cattle located in northeast Mexico. The studied populations exhibited a high allelic variability with a mean heterozygosity of 0.5. A moderate genetic differentiation between the Charolais populations (F ST = 0.079; P < 0.001) was observed. This suggests subdivisions in Charolais breed established in Mexico, due to genetic material origin, reproductive and selective management and local isolation.

International audience; Ninety-nine Charolais heifers with an average age of 3 3 months and an average carcass weight of 3 81 kg were used to study the relationship between rearing practices and eating meat quality traits. Farm surveys were carried out to collect information about heifer rearing before weaning, during the growth period and during the finishing stage. The quality of meat from the M. rectus abdominis excised 24 h post mortem was scored between 0 and 10 by sensory analysis using four descriptors: initial tenderness, overall tenderness (OT), juiciness and flavour intensity. Intramuscular fat content was also measured. Four classes of rearing practices were differentiated by multiple correspondence analysis and hierarchical cluster analysis. The class I was based on a low feeding level during the growth period and a diet of hay and straw complemented with 8 kg of concentrates in the barn during the finishing period. A medium feeding level during the growth period and a finishing diet of grass at pasture and 6 kg of concentrates defined the class 3. The class 2 was linked to a high feeding level during the growth period and a supply of roughage and 6 kg of concentrates at pasture during the finishing stage. The class 4 was based on a high feeding level during the growth period and a finishing stage in the barn with maize silage and 5 kg of concentrates. There were no differences in meat juiciness and meat flavour intensity among the four practice classes. The classes 2 and 4 produced the tenderest meat (OT score: 5.5/10; p = 0.002), regardless of the finishing stage and the forage given to the animals. These classes were characterized by the highest feeding level, which allowed slaughter at a young age (32 months) resulting in the highest carcass weight (380 kg). The classes I and 3 classes were linked to the lowest tenderness (OT score: 4.8;p=0.002) although the intramuscular fat content was equivalent to the classes 2 and 4 (17.8% in average). The classes I and 3 were characterized by a moderate growth period due to a low feeding level and a short finishing stage (108 to 13 5 days). Indeed, the finishing period did not allow the animals to recover the growth deficit brought about by the growth period. This type of farming practice required slaughter at a more advanced age (35.9 months) for equivalent carcass weights of 389 kg.

Objetivou-se com este estudo avaliar a influência de duas taxas de ganho de peso de bezerras (baixa: 340 ± 32 g/dia ou moderada: 490 ± 29 g/dia) do nascimento aos 7 meses de idade e do tipo de pastagem no período pós-parto, quando vacas, sobre sua eficiência biológica e de seus bezerros até o desmame (aos 217 dias). Quando vacas e após o parto, os animais foram mantidos em pastagem nativa (PN) ou em pastagem cultivada (PC). Durante a lactação, vacas com baixa taxa de ganho de peso pré-desmame apresentaram maior produção de leite. Houve similaridade entre as taxas de ganho de peso baixa e moderada para a conversão de litros de leite (7,32 e 6,44 L/kg, respectivamente) e de kg de MS de leite produzido pelas vacas (1,00 e 0,86 kg/kg, respectivamente) em kg de ganho de peso dos bezerros; a exigência total de energia líquida para mantença (mantença + gestação + produção de leite) (TOTELm) (2.733,7 e 2.316,7 Mcal, respectivamente); TOTELm por kg de bezerro desmamado (14,7 e 14,7 Mcal/kg, respectivamente); e kg de bezerro desmamado por 100 kg de vaca ao desmame (42,0 e 38,7 kg/100 kg, respectivamente). No entanto, vacas com baixa taxa de ganho de peso pré-desmame desmamaram mais kg de bezerros por unidade de peso metabólico da vaca ao desmame (1,89 vs 1,73 kg/g). The objective of this experiment was to evaluate the influence of different rates of weight gain (low: 340 ± 32 g/day or moderate: 490 ± 29 g/day) of heifers, from birth until seven months of age, and the type of pasture after calving, as cows, on the biologic efficiency of cows and their calves until weaning at 217 days. After calving, the animals were maintained on native pasture (NP) or cultivated pasture (CP). During lactation, cows with low preweaning rate of weight gain showed higher milk production. Similarity between low and moderate rates of weight gain was verified for conversion of litres of milk (7.32 and 6.44 L/kg, respectively) and kg of dry matter of milk produced by cows (1.00 and 0.86 kg/kg, respectively) into kg of calves weight gain, total requirements of net energy for maintenance (maintenance plus gestation plus milk production) of cows (TOTNEm) (2733.7 and 2316.7 Mcal, respectively), TOTNEm per kg of weaned calve (14.7 and 14.7 Mcal/kg, respectively) and kg of weaned calve per 100 kg of cow at weaning (42.0 and 38.7 kg/100 kg, respectively). However, cows with low preweaning rate of weight gain weaned more kg of calves per unit of cow metabolic weight at weaning (1.89 vs. 1.73 kg/g).

Este trabalho teve o objetivo de avaliar o perfil metabólico protéico de vacas de corte suplementadas ou não do parto ao desmame, comparando os teores de nitrogênio uréico, no leite e no sangue, com a taxa de concepção das vacas e os tratamentos. Foram utilizadas 115 vacas dos grupos genéticos Charolês (C), Nelore (N) e suas respectivas cruzas. A idade das vacas variou de 3 a 13 anos, sendo divididas em três classes de idade: jovens, adultas e velhas, tendo sido avaliadas do parto até o desmame dos bezerros, aos 63 dias pós-parto. Foi verificada interação (P0,05) entre tratamentos e períodos. A taxa de concepção das vacas não foi influenciada pelos teores de NUS e NUL nem pela suplementação. This study evaluated the protein metabolic profile of beef cows supplemented or not, from calving to weaning; comparing urea nitrogen values, from milk and blood serum, with conception rate. 115 beef cows from Charolais, Nellore and its crosses were used. Cow's age ranged between 3 and 13 years old, and separate into three age classes: young, adult and old, being evaluate since calving until weaning, at day 63 postpartum. There was an interaction (P0.05) between treatment and period. SUN and MUN levels and supplementation didn't influence conception rate.

O experimento foi conduzido no Departamento de Zootecnia da Universidade Federal de Santa Maria, para avaliar produtiva e qualitativamente a pastagem de capim elefante e o desempenho animal sob pastejo. A área experimental foi composta de oito piquetes de 0,443ha cada de capim-elefante (Pennisetun purpureum, Schum. cv. "Tawian"), onde pastejaram 36 novilhos das raças Charolês, Nelore e suas cruzas, com três animais "testers" por piquete, em duas repetições. Foram estudadas as variáveis relacionadas à produtividade e à qualidade da pastagem e ao desempenho animal. As massas reais de lâminas foliares (MLF) de capim-elefante foram: 1.167; 1.543; 1.926 e 2.248kg MS LF/ha, o que constitui os tratamentos. A carga animal suportada pela pastagem, pode ser descrita pela equação y=2.243,14 - 0,32MLF (R2=0,4). O peso vivo final em kg apresentou resposta quadrática (PF=103,41 + 0,114x - 0,00003x², R2=0,5) com o acréscimo da MLF. O ganho de peso diário médio apresentou comportamento linear positivo (GMD = 0,25 + 0,0002MLF, R2=0,2). O aumento na massa de lâminas foliares de capim-elefante acarreta diminuição na carga animal suportada pela pastagem e aumenta o ganho de peso médio diário. The experiment was conducted at the animal science department of Universidade Federal de Santa Maria, to evaluate productive and qualitative characteristics of elephantgrass pasture and animal performance under grazing. The experimental area consisted of eight paddocks of 0.443 ha of elephantgrass (Pennisetun purpureum, Schum. cv. Taiwam), where 36 Charolais, Nelore and crossbred were kept, with three tester animals per paddock, with two repetitions. Variables related to pasture production and quality and animal performance were studied. Real leaf lamina masses (LLM) of elephantgrass were: 1.167; 1.543; 1.926 and 2.248kg of dry matter of leaf lamina/ha, constituting the treatments. Stocking rate (y=2.243.14 - .32LLM, R2=.4), showed a negative linear relationship. The final liveweight is kg, presented a quadratic effect (y = 103,41 + .114LLM - .00003LLm², R2=.5) with the LLM increase. The average daily weight gain showed positive linear effect (y = .25 + .0002LLM, R2=.2). The increase of the elephantgrass leaf lamina mass proportioned a decrease of stocking rate supported by the pasture and increased the average weight gain.

The aim of work – to determine efficienty of the Lithuanian Black-and-White cattle crossing with Charolais bull. The task of research: 1.To analyse the literature about the crossing Lithuanian Black-and-White caws with Charolais bull. 2.To determine the influence of Charolais bull on beef meat production and quality of Lithuanian Black-and-White cattle. Conclusions: 1.Charolais bulls were found to improve the weight of Lithuanian Black-and-White cattle at 18 month of age by 38.5 kg or 7.6 % (P>0,05) and reduced feed conversion per weight gain unit by 8.2 %. 2.The daily gain of the Charolais hybrids bulls was by 8.0 % bigger than that of the pure-blooded Lithuanian Black-and-White bulls. 3.Control slaughters indicated the bigger carcass mass for Charolais hybrids which was 20.7 kg, or 7.8 % bigger than the carcass mass of the pure-blooded Lithuanian Black-and-White young bulls. 4.Hybrids had a 1.5 % better carcass output, 4.0 % better ham output, and 2.4 % better output of ham edible parts in carcass, by 0.65 bigger the coefficient of succulence of this part of carcass and by 42.94 cm² bigger area of loin lean. 5.Crossbreeding had no significant influence on meat quality. A tendency was observed to lower meat pH, higher shear force and a better amino acids triptophan and oxyproline ratio 5.47 of hybrids (P

An allelic discrimination assay was designed and used to determine the genotypic and allelic frequencies of the myostatin (MSTN) gene Q204X allele from two Mexican Full-French herds. The assay is a simple high throughput genotyping method that could be applied to investigate the effect of the Q204X allele on the Charolais breed.

Con el objetivo de determinar la importancia de una correcta identificación de los individuos que participan en empadres múltiples, se utilizó un panel de microsatélites para la asignación o verificación de paternidad en un hato de ganado bovino de la raza Charolais. El panel de microsatélites utilizado fue capaz de asignar paternidad con 95 % de confianza, siempre que se incluyó en el análisis a la madre, a la cría y los posibles padres. Se observó que la ausencia o identificación errónea de cualquiera de los individuos que forman una familia, resultó en la falta de asignación de paternidad en el 24 % de la población analizada. Para determinar las diferencias asociadas a la paternidad incierta sobre los parámetros y valores genéticos en los sementales [varianza genética directa, varianza ambiental, índice de herencia directa, proporción de la varianza ambiental con respecto a la fenotípica, diferencias esperadas de la progenie (DEPs) y sus exactitudes], se analizó con un modelo animal, el peso al nacimiento de 32 becerros nacidos en el período 2000-2002. Se observó variación importante (hasta de 47 %) en los efectos y en los parámetros genéticos estimados a partir de dos bases de datos; en una de ellas se consideraron paternidades simuladas, y en la otra se utilizó la información proveniente de la identificación biológica. Se observó una marcada diferencia en el ordenamiento de los sementales al comparar las DEPs en cada una de las bases de datos, lo que muestra la necesidad de utilizar las pruebas de paternidad basadas en microsatélites, como un sistema de identificación que asegure el éxito de los programas de manejo y mejoramiento genético de los hatos con empadre múltiple.

Foram avaliadas as características qualitativas / quantitativas da carcaça de 22 novilhos das raças Charolês ou Nelore, que receberam três níveis de concentrado na dieta: 35; 50 e 65%, durante a fase de terminação em confinamento. Como volumoso, foram utilizadas as silagens de sorgo e de milho. Foi observada interação significativa (P0,05) do nível de concentrado para as demais características de carcaça estudadas. Os novilhos Charolês apresentaram maior peso de abate (372,2 contra 325,6kg), carcaça quente (201,1 contra 180,0kg) e fria (196,1 contra 175,5kg), de traseiro (52,0 contra 43,6kg) e de costilhar (12,4 contra 11,0kg), comprimento de carcaça (118,4 contra 111,8cm), espessura de coxão (25,4 contra 23,3cm), perímetro de braço (39,1 contra 34,6cm), conformação (11,3 contra 9,5 pontos), área do músculo Longissimus dorsi (66,4 contra 53,8cm²) e percentagem de traseiro (52.0 contra 49,4%). Os novilhos Nelore, por sua vez, apresentaram maior comprimento de perna (68,5 contra 58,1cm) e percentagem de dianteiro (38,1 contra 35,5%). The carcass quantitative characteristics of feedlot finished Charolais or Nellore steers, receiving three levels of concentrated in the diet: 35; 50 and 65%, were evaluated. Sorghum and corn silages were used as roughage. A significant interaction (P.05) of the concentrated level for the others characteristics studied was observed. The Charolais steers had presented higher slaughter weight (372.2 versus 325.6kg), hot carcass (201.1 versus 180.0kg) and cold carcass (196.6 versus 175.5kg), saw cut weight (52.0 versus 43.6kg) and side cut weight (42.4 versus 11.0kg), carcass length (118.4 versus 111.8cm), cushion thickness (25.4 versus 23.3cm), arm perimeter (39.1 versus 34.6cm), conformation (11.3 versus 9.5 points), Longissimus muscle area (66.4 versus 53.8cm²) and saw cut percentage (52.0 versus 49.4%). The Nellore steers presented higher leg length (68.5 versus 58.1cm) and fore quarter percentage (38.1 versus 35.5%).

O experimento foi conduzido para se avaliar a produção de leite de vacas de dois sistemas de acasalamento, puras Charolês (CH) e Nelore (NE) e mestiças F1 ½CH ½NE e ½NE ½CH, submetidas a diferentes sistemas de alimentação, e medir a heterose resultante. A produção de leite foi determinada aos 14, 42, 70 e 90 dias, sendo esta última coincidente com o desmame. Foram utilizadas 86 vacas, submetidas a um dos seguintes sistemas de alimentação: PN: vacas mantidas exclusivamente em pastagem nativa; PC + PN: vacas mantidas em pastagem cultivada (PC) de 15 de julho a 15 de setembro e o restante do tempo em PN; e PN + PC: vacas mantidas em PC de 15 de setembro a 15 de novembro e o restante do tempo em PN. A PC foi composta por aveia (Avena sativa), azevém (Lollium multiflorum) e trevo vesiculoso (Trifolium vesiculosum). Não houve diferença significativa entre os sistemas de alimentação PC + PN e PN + PC, agrupando-se os dois em um único sistema (PNC). Vacas mantidas em PN apresentaram menor produção média diária (3,93 vs. 5,46 L) e total de leite (291,4 vs. 401,7 L) e maior redução da produção (39 vs. 27%) que as mantidas em PNC. Não houve efeito do grupo genético da vaca dentro do sistema de acasalamento sobre as produções média e total de leite. Vacas mestiças F1 apresentaram maior produção de leite durante toda a lactação, de modo que a heterose para produção média diária de leite foi mais expressiva nas vacas mantidas em condições mais baixas de alimentação, exclusivamente em PN (92,4%), que nas vacas que tiveram acesso à pastagem cultivada PNC (18,1%). A persistência da lactação foi maior nas vacas filhas de touros NE que nas filhas de touros CH, assim como nas vacas puras em relação às mestiças F1. The objective of this trial was to evaluate the milk yield of cows of two breeding systems, straightbreds Charolais (CH) and Nellore (NE) and, crossbreds F1 ½CH ½NE and ½NE ½CH, submitted to different feeding systems, as well as measure the resultant heterosis. The milk yield was determined at 14, 42, 70 and 90 days, being this last one coincident with weaning. Eighty-six cows were used, and submitted to one of the following feeding systems: NP: cows maintained exclusively on native pasture (NP); CP + NP: cows maintained on cultivated pasture (CP) from July 15th until September 15th and the rest of the time on NP; and NP + CP: cows maintained on CP from September 15th until November 15th, and the rest of the time on NP. CP was composed by oat (Avena sativa), ryegrass (Lollium multiflorum) and clover (Trifolium vesiculosum). Since no significant difference was verified between CP + NP and NP + CP feeding systems, they were combined in one feeding system (NCP). Cows maintained on NP showed lower average daily (3.93 vs. 5.46 L) and total milk yield (291.4 vs. 401.7 L), in relation to cows maintained on NCP, as well as displayed higher reduction of the milk yield (39 vs. 27%, respectively). Average daily and total milk yield were not affected by cow genetic group within breeding system. F1 cows showed higher milk yield during the whole lactation period, being the heterosis for average daily milk yield more expressive for cows maintained on lower feeding conditions, exclusively on NP (92.4%) in relation to cows with access to NCP (18.1%). The lactation persistency was higher for cows sired by NE bulls than for cows sired by CH bulls, and for straightbreds in relation to F1 cows.