Influence of weaning management at 30, 75 and 180 days of age on non-esterified fatty acids and reproductive performance in beef cows.

This study aimed to investigate the effect of age at weaning of calves on non-esterified fatty acids (NEFA) and reproductive parameters of beef cows. Animals (n = 65) were randomly assigned to three treatments after calving: hyper-early weaning (W30) at 32 ± 0.89 days, early weaning (W75) at 77 ± 0.95 days, and conventional weaning (W180) at 183 ± 0.82 days. Body weight (BW) and body condition score (BCS) were evaluated at parturition (AP) and at 30, 45, 64, 81, 100 and 115 days postpartum (dPP). Blood samples were collected to analyze NEFA levels and progesterone (P4) at 30, 45, 64 and 81 dPP. Higher BW and BCS were observed from 64 to 115 dPP in W30 cows than W180 ones (p < 0.05). Cows subjected to W30 condition had higher levels of NEFA at 30 dPP compared to 64 and 81 dPP (p < 0.05). We also observed that cows from W180 group showed decreased levels of NEFA at 30 dPP compared to 45 (p < 0.01) and 64 dPP (p < 0.05). The highest P4 level was observed at 64 dPP in W30 cows compared to W75 and W180 (p < 0.05). We also observed higher CR of W30 (86%) compared to W180 (47%) at 45 dPP (p < 0.05). The overall pregnancy rate (PR) was higher for W30 (95.5%) than W180 (73.9%). In addition, higher BW at calving and P4 levels at 30 dPP were positively correlated with the possibility of pregnancy (p < 0.05). Improvement in BW and BCS were observed in cows subjected to hyper-early weaning management. However, levels of NEFA decreased as the postpartum period progressed. We concluded that cows who weaned calves hyper-early have greater chances of increasing cyclicity and PRs.

Price determinants of beef bulls sold in livestock auctions

The main objective of this study was to evaluate the effects of phenotypic, genotypic, and auction characteristics that may influence the selling prices of bulls. Data from 1,540 Braford and 1,179 Brangus bulls sold at auctions in the state of Rio Grande do Sul, Brazil, were collected and evaluated individually. Body condition score (BCS), muscularity, frame, foreskin size, presence or absence of horns, and data regarding the auction such as name/venue, event edition, forms of payment, among others, were considered. Information such as weight at the time of sale, scrotal circumference (SC), expected profit differences, selection indexes, and date of birth were collected from the catalogs supplied at the auctions. To obtain the influence of the selected explanatory variables throughout the conditional distribution of bull prices, a quantile regression was used, and the quantiles were established as follows: 10th, 25th, 50th, 75th, and 90th. The buyers of Braford and Brangus bulls valued characteristics such as age, weight, and SC in relation to frame, muscularity, BCS, and foreskin size. In addition, the price behavior at different auctions was positively related to the operation time of the auction in this market and with the reputation of the seller. Regarding genetic variables of Brangus bulls, these had little or no influence on the selling price. There was a positive influence on the weaning index in the 90th quantile and on the final index in the 50th and 75th quantiles. Buyers of synthetic bull breeds at auctions value the phenotypic characteristics of bulls more than they do genetic characteristics, which may not reflect permanent gains in the cattle herd.(AU)

The influence of weaning age and biocholine supplementation to post-weaning growth and puberty in Brangus heifers.

This experiment was conducted to determine the effect of earlier weaning in addition to biocholine supplementation on age at puberty of Brangus heifers. Brangus calves were randomized and divided into three weaning ages groups, at 30 (Hyper-early weaning; HW), 75 (Early weaning; EW) and 180 days (Conventional weaning; CW). Then, calves were supplemented using the additive Biocholine (BIO) or not (CON). Animals were subjected to puberty induction and the presence of estrus was observed for 7 days. In addition, transrectal ultrasonography was performed to assess the ovarian activity and the presence of corpus luteum to determine heifer puberty. We also evaluated the body weight (BW; Kg), hip height (HH; cm), thoracic perimeter (TP; cm) and BW:HH ratio during the experimental period. BIO group showed higher ADG (>226 g/day) when the animals were exposed to ryegrass pasture compared to CON (P < 0.05). We observed an interaction between weaning x biocholine and CW-BIO heifers showed greater HH more compared to CW-CON (P < 0.05). Overall, animals that have reached puberty at day 8 after puberty induction showed 331.0 ± 5.04 kg BW, 122.0 ± 0.56 cm HH and 165.4 ± 0.75 cm TP and 2.7 ± 0.03 BW:HH. At the time of ovulation detection, the heifers from the HW group had 32.1 kg BW, 3.93 cm HH and 0.18 cm BW:HH greater compared to CW (P < 0.05). The BIO supplementation together with ryegrass pasture, led to an increase in ADG weight throughout the evaluated period. We concluded that HW heifers showed an adequate body development throughout the experimental period until puberty appearance at the same age as others weaned groups.

Fetal programming in sheep: Effects on pre- and postnatal organs and glands development in lambs.

The present systematic review and meta-analysis aim to summarize the effects of maternal undernutrition or overnutrition during pregnancy on the absolute weight and relative weight of the organs (liver, kidneys, heart, spleen, and lung) and glands (adrenal, pancreas, and thyroid) measured during gestation, birth and the postnatal period in lambs. After completing the search, selection, and data extraction steps, the measure of effect was generated by the individual comparison of each variable response compared with the average of the control and treated group (undernutrition or overnutrition) using the DerSimonian and Laird method for random effects. The liver was the organ most affected by maternal undernutrition, as the absolute weight of the liver was reduced during pregnancy, birth, and the postnatal period. The extent of this effect is related to the duration of the intervention. Reductions in the absolute fetal weight of the lungs and spleen have also been observed. No change in organs weight were observed when the results were expressed as relative weight. For overnutrition, the fetal weight of the liver was reduced to both absolute and relative values. In contrast, the relative weight of the kidneys has been increased. For the glands analyzed, no changes in weight were observed in either scenario (absolute or relative weight). Thus, the organs are more likely to suffer weight changes, especially during pregnancy, as a result of maternal nutrition. However, this change in organ weight seems to be closely related to the reduction in body weight of the progeny as a whole.

Feed technologies and efficiency in cow-calf systems

This study was performed to evaluate the efficiency index of cow-calf systems, based on different feed technologies commonly employed in the Rio Grande do Sul state, southern Brazil. Hence, the efficiency of 35 cow-calf herds was evaluated by Data Envelopment Analysis (DEA). Data was collected by online survey and in-depth interviews, as well as data registers from the cow-calf systems, located in 31 municipalities. The analyzed indicators included rates of mortality, pregnancy, birth, and productivity. The feed technologies evaluated were the use of cultivated pastures during winter and summer, supplementation during winter and summer, creep feeding, deferral of natural pasture, use of grazing systems, and employee's capacitation. Approximately 80% of the evaluated farms showed low-to-medium Efficiency Index (EI; up to 0.79 in a scale of 0 to 1), 13% presented high EI, and only 7% had very high EI (above 0.95). The use of cultivated pastures with the inclusion of protein supplementation and employees' capacitation were highlighted as the main practices to increase efficiency of cow-calf systems in Rio Grande do Sul. The technologies identified as most impactful raise the EI of production systems from low to medium. Our results assist in decision-making in the use of feed technologies, pointing out a direction for the use of technologies that make breeding systems more efficient from a productive point of view.(AU)

Libido and serving skills of Zebu cattle bulls / Libido e habilidade física em touros zebuínos

The goal of this study was to evaluate the rejection rates of Zebu bulls during behavioral assessment (libido and serving ability) and the importance of this step in bull breeding soundness evaluation (BBSE). A totalof 1,534 bulls reared in the state of Rio Grande do Sul, Brazil, of Nelore (1,340), Brahman (76), Guzerá (98), and Tabapuã (210) breeds were evaluated. The evaluation consisted of four steps. Step I was the general physical examination, Step II genital tract examination, Step III semen evaluation, and Step IV behavioral assessment of libido and the ability to complete copulation. To evaluate the relationship between the binary variables of approved or rejected during different steps of the BBSE, and age groups (young and mature bulls), chi-square tests and logistic regression were used. The general rejection rates in the BBSE were 5.64% and 15.20% for young and mature Zebu bulls, respectively. Problems with the sexual behavior (libido and/or serving ability) of bulls accounted for the rejection of 0.46% and 2.29% of young and mature Zebubulls, respectively. The lack of libido and serving ability was shown to be an important problem concerning the total number of possible causes of Zebu bull rejection during the BBSE. This result suggests that the behavioral step should be performed regularly, rather than being complementary to the standard BBSE in Zebu cattle.

O objetivo deste estudo foi avaliar as taxas de reprovação de touros zebuínos durante a avaliação comportamental (libido e habilidade física) e a importância desta etapa no Exame Andrológico em Touros (EAT). Foram avaliados 1.534 touros, criados no estado do Rio Grande do Sul, Brasil, das raças Nelore(1.340), Brahman (76), Guzerá (98) e Tabapuã (210). A avaliação constou de quatro etapas. Etapa I foi o exame físico geral, Etapa II o exame do trato genital, Etapa III a avaliação do sêmen, e a Etapa IV a avaliação comportamental de libido e habilidade física para completar a cópula. Para avaliar a relação entre a variável binária aprovado ou reprovado durante as diferentes etapas do exame andrológico e as faixas etárias (touros jovens e adultos), foram utilizados os testes de qui-quadrado e de regressão logística. As taxas gerais de reprovação no EAT foram de 5,64% e 15,20% para os touros Zebu jovens e adultos, respectivamente. Problemas no comportamento sexual (libido e/ou habilidade física) dos touros foram responsáveis pela reprovação de 0,46% e 2,29% dos touros zebuínos jovens e adultos, respectivamente. A falta de libido e de habilidade física mostrou-se um problema importante em relação ao número total de possíveis causas de reprovação de touros zebuínos no EAT. Esse resultado sugere que a etapa comportamental deve ser realizada regularmente, ao invés de ser apenas complementar ao EAT padrão em bovinos zebuínos.

Libido and serving skills of Zebu cattle bulls / Libido e habilidade física em touros zebuínos

The goal of this study was to evaluate the rejection rates of Zebu bulls during behavioral assessment (libido and serving ability) and the importance of this step in bull breeding soundness evaluation (BBSE). A totalof 1,534 bulls reared in the state of Rio Grande do Sul, Brazil, of Nelore (1,340), Brahman (76), Guzerá (98), and Tabapuã (210) breeds were evaluated. The evaluation consisted of four steps. Step I was the general physical examination, Step II genital tract examination, Step III semen evaluation, and Step IV behavioral assessment of libido and the ability to complete copulation. To evaluate the relationship between the binary variables of approved or rejected during different steps of the BBSE, and age groups (young and mature bulls), chi-square tests and logistic regression were used. The general rejection rates in the BBSE were 5.64% and 15.20% for young and mature Zebu bulls, respectively. Problems with the sexual behavior (libido and/or serving ability) of bulls accounted for the rejection of 0.46% and 2.29% of young and mature Zebubulls, respectively. The lack of libido and serving ability was shown to be an important problem concerning the total number of possible causes of Zebu bull rejection during the BBSE. This result suggests that the behavioral step should be performed regularly, rather than being complementary to the standard BBSE in Zebu cattle.(AU)

O objetivo deste estudo foi avaliar as taxas de reprovação de touros zebuínos durante a avaliação comportamental (libido e habilidade física) e a importância desta etapa no Exame Andrológico em Touros (EAT). Foram avaliados 1.534 touros, criados no estado do Rio Grande do Sul, Brasil, das raças Nelore(1.340), Brahman (76), Guzerá (98) e Tabapuã (210). A avaliação constou de quatro etapas. Etapa I foi o exame físico geral, Etapa II o exame do trato genital, Etapa III a avaliação do sêmen, e a Etapa IV a avaliação comportamental de libido e habilidade física para completar a cópula. Para avaliar a relação entre a variável binária aprovado ou reprovado durante as diferentes etapas do exame andrológico e as faixas etárias (touros jovens e adultos), foram utilizados os testes de qui-quadrado e de regressão logística. As taxas gerais de reprovação no EAT foram de 5,64% e 15,20% para os touros Zebu jovens e adultos, respectivamente. Problemas no comportamento sexual (libido e/ou habilidade física) dos touros foram responsáveis pela reprovação de 0,46% e 2,29% dos touros zebuínos jovens e adultos, respectivamente. A falta de libido e de habilidade física mostrou-se um problema importante em relação ao número total de possíveis causas de reprovação de touros zebuínos no EAT. Esse resultado sugere que a etapa comportamental deve ser realizada regularmente, ao invés de ser apenas complementar ao EAT padrão em bovinos zebuínos.(AU)

Perception of beef quality for Spanish and Brazilian consumers.

Understanding the priorities of beef consumers is important for planning strategies to attract and maintain each customer. Using self-administered interviews with Spanish and Brazilian adults who regularly consume beef, we analyzed their purchasing behaviors in relation to their perceptions and priorities regarding beef quality that guide their choices. The current study identifies the influences of information (labeling and marketing) requirements, concerns about humane production systems, and the intrinsic characteristics of beef. To evaluate the data extracted from the interviews, the questions were grouped into four main factors. While extrinsic factors are the highest valued in both Spain and Brazil, those such as beef freshness and tenderness present inverse concerns between the two countries based on cultural dissimilarities. The data also reveals a clear symmetry among consumers who increasingly seek specific pre-purchase information and products with guaranteed superior quality. Despite other characteristics that differentiate developed and developing countries, the perceptions of quality among consumers in Spain and Brazil are decidedly similar.

Concerns, attitudes, and opinions of meat buyers in Garanhuns, Pernambuco, Brazil

With the objective of identifying the concerns, attitudes, and opinions of meat buyers and their relationship with their choice of place of purchase (supermarkets, free fair, or butchers), 381 consumers in the city of Garanhuns, Brazil, were interviewed. Data analysis was performed using descriptive statistics and discriminant analysis, complemented by stepwise regression, Wilks' Lambda test, and Fisher's linear test. Most of the respondents expressed that inadequate commercialization of meat occurred in free fairs, and the lack of hygiene and the fact that meat was exposed in the environment without refrigeration were the main preoccupations. They also reported that meat consumption without inspection could lead to disease transmission, with pork being considered the most dangerous. Based on the theory of planned behavior, buyers agreed that their attitudes toward the purchase of meat (concern with food safety, price, animal welfare, environment, and slave labor) influenced their purchasing decisions. Regarding the subjective norms, the results indicated that purchase intention could be modulated by the opinion and judgment that other people exercise on the buyer's choice decision. Regarding perceived control, the respondents said that they were confused at the time of purchase and got irritated after making a purchase that did not satisfy their desires. The factors that differentiated consumers who prefer to buy meat in supermarkets from those who prefer butchers and free fairs are mainly the price of the product, custom/tradition, customer service, and hygiene of the establishment. Buyers who have a lower level of schooling and live in rural areas also tended to buy meat in free fairs.

Efficiency in Cow-Calf Systems With Different Ages of Cow Culling.

The bioeconomic efficiency of cow-calf systems was compared by a deterministic dynamic simulation. The simulation model considered stable cow-calf systems differentiated by the maximum age for culling cows, lifetime, culled at 4-13 years old. The necessary supply of metabolizable energy for the herd was established as natural grasslands, cultivated pasture in the winter/spring, and pre-dried pasture produced by the system. The biological efficiency of the systems was considered the ratio between the production of total live weight and the metabolizable energy consumed over one production cycle. Economic efficiency was determined by the ratio between gross margin and production area and the ratio between gross margin and number of cows. Bioeconomic efficiency was determined by a simple linear regression between biological efficiency, economic efficiency per area, and economic efficiency per cow. The efficiency of the animal unit, considering biological efficiency and economic efficiency per area were better in the system that culled cows at 4 years old, while economic efficiency per cow was better in the system that culled cows at 13 years old. In determining the bioeconomic efficiency of the systems, the best results were found in the system that culled cows at 6 years old, which suggests that the best efficiency of a cow-calf herd is reached when the adult age and mature weight of the cow are reached, and there is no more energy used for growing. The results indicate that stable cow-calf herds express their best biological efficiency and economic efficiency per area when the cow culling age is lower. However, economic efficiency per cow depends on cows that remain in the herd as long as possible. The culling age of cow that balances these biological and economic indicators is reached around 5 and half years.

Pregnant beef cow's nutrition and its effects on postnatal weight and carcass quality of their progeny.

A systematic review (SR) and meta-analysis (MA) were performed to evaluate the effects of different energy levels (metabolizable energy, ME) and crude protein (CP), supplied to pregnant cows, on weight of their progenies at 60 (BW60), 100 (BW100), 180 (BW180) and 205 (BW205) days of age, average daily gain (ADG), and weight, age, loin eye area (LEA), marbling and fat thickness (FT) at slaughter. The SR was performed on two electronic databases. The MA for random effects was performed for each response variable separately. The BW60 was reduced (P<0.001; I2 = 78.9%) when cows consumed CP and ME above the required levels during the third trimester of pregnancy (3TRI). The BW205 was lower (P<0.001; I2 = 92.6%) when cows consumed ME above the recommended levels in the second trimester of pregnancy (2TRI) and 3TRI. Conversely, the ADG was higher when cows consumed CP (P = 0.032; I2 = 96.1%) and ME (P<0.001; I2 = 96.1%) above the required levels. The steers whose mothers consumed CP and ME above the required levels during the 3TRI were slaughtered 5.5 days earlier (P = 0.015; I2 = 98.5%) compared to other steers. The marbling was higher (P<0.001; I2 = 91.7%) in calves born to mothers consuming CP and ME above the recommended levels, regardless of the gestation phase. The FT was higher (P<0.001; I2 = 0%) in the offspring of cows that consumed CP and ME above the required levels during the 3TRI. Thus, CP and ME intake, at levels higher than those recommended by the NRC, by pregnant cows in the 3TRI reduces the progeny weight up to 205 days of age. However, this is advantageous during the finishing phase, as it reduces slaughter age and increases the ADG and carcass quality by improving marbling and FT.

Effect of scrotal insulation on sperm quality and seminal plasma proteome of Brangus bulls.

Seminal plasma (SP) contributes to sperm physiology and metabolism, prevents premature capacitation, and protects sperm against oxidative stress. In order to evaluate the impact of heat stress in the semen of tropically adapted Brangus breed and in their seminal plasma proteome, we studied the effects of scrotal insulation for 72 h. Semen samples from six bulls, between 7 and 8 years of age, were collected prior to scrotal insulation (pre-insulation), and at 4 and 11 wk after insulation. Seminal plasma samples were analyzed by 2D SDS-PAGE and liquid chromatography coupled with mass spectrometry (LC-MS/MS). Insulation caused decrease in vigour, gross and total motility after 4 wk of scrotal insult (P < 0.001). Total defects in sperm were higher after 4 wk compared to pre-insulation and 11 wk after scrotal insulation (P < 0.001). The analysis of the 2D protein profile of the SP resulted in the identification 183 unique protein spots in all gels evaluated. There was no difference in mean number of protein spots amongst time points. Eight protein spots were more abundant in SP after scrotal insulation, returning to the same expression level at 11 wk post-insulation. One spot had higher abundance at 11 wk post-insulation, and one spot had decreased abundance 4 wk after insulation. The ten protein spots with differential abundance amongst time points were identified as Seminal plasma protein PDC-109, Seminal plasma protein A3, Seminal plasma protein BSP-30 kDa, Spermadhesin-1 and Metalloproteinase inhibitor 2. The validation of these five proteins as biomarkers for thermal testicular stress in Brangus breed would allow the development of new biotechnologies that could improve bovine semen analysis in breeding systems in tropical and subtropical conditions. A close association between the identified BSP and Spermadhesin-1 was evidenced in protein-protein interaction analysis. Based on gene ontology analysis, variation in sperm function after insulation could be explained by variation in the expressed proteins in the SP. Further studies are required to verify if these proteins could be used as biomarkers for the identification of bulls with increased seminal resistance to heat stress in Brangus breed.

Modelling beef cattle production systems from the Pampas in Brazil to assess intensification options

Traditional livestock productivity is hard to estimate, since it depends on a gamut of animal production indicators that are difficult to measure for many farms. Thus, we propose an analytical method for estimating productivity and understanding the importance of animal production indicators under different full-cycle cattle production systems in Brazil. To evaluate the impact of these indicators, equations were derived from a comutational model of herd evolution for estimating the output parameters of the system as follows: productivity per hectare (PH) and offtake rate (COR), as a function of the indicators; calving rate (CR), mating age (AM), age of slaughter (AS) and stocking rate (SR). For this analysis, twenty-seven scenarios (simulation data) of low to high productivity were used, resulting from the combination of the following factors and levels: 1) calving rate of 50, 65 and 80 %; 2) mating age of heifers of one, two and three, years of age; and 3) age at slaughter of one, two and three year old steers. The scenario with the highest impact for each parameter and the indicator of highest impact for each scenario were identified for the production conditions in the region. Under most scenarios, a reduction in mating age had a greater impact on the productivity indexes compared to a reduction in slaughter age. Appropriate management of available technologies enables farmers to compare the marginal impacts of specific indicators on full-cycle production systems for beef cattle.

Modelling beef cattle production systems from the Pampas in Brazil to assess intensification options

Traditional livestock productivity is hard to estimate, since it depends on a gamut of animal production indicators that are difficult to measure for many farms. Thus, we propose an analytical method for estimating productivity and understanding the importance of animal production indicators under different full-cycle cattle production systems in Brazil. To evaluate the impact of these indicators, equations were derived from a comutational model of herd evolution for estimating the output parameters of the system as follows: productivity per hectare (PH) and offtake rate (COR), as a function of the indicators; calving rate (CR), mating age (AM), age of slaughter (AS) and stocking rate (SR). For this analysis, twenty-seven scenarios (simulation data) of low to high productivity were used, resulting from the combination of the following factors and levels: 1) calving rate of 50, 65 and 80 %; 2) mating age of heifers of one, two and three, years of age; and 3) age at slaughter of one, two and three year old steers. The scenario with the highest impact for each parameter and the indicator of highest impact for each scenario were identified for the production conditions in the region. Under most scenarios, a reduction in mating age had a greater impact on the productivity indexes compared to a reduction in slaughter age. Appropriate management of available technologies enables farmers to compare the marginal impacts of specific indicators on full-cycle production systems for beef cattle.(AU)

Association of the forage management practices, weaning rate, and factors that influence technological adoption in beef cattle production

The objective of this study was to verify the association of improved native grassland and winter and summer pastures on the weaning rate in beef cattle production. Subsequently, we also verified the socioeconomic and productive characteristics related to the adoption of technologies to increase the weaning rate of the farmers. The survey was conducted with 73 producers of Hereford and Braford cattle in the state of Rio Grande do Sul, Brazil. A data analysis was performed using the minimum ordinal squares method and the regression analysis (Tobit). The results showed that cattle farmers who adopt winter pastures have greater weaning rates, and the factors that influence this adoption are related to a greater number of employees on the farm and the use of a crop-livestock production system. In addition, farmers who receive a greater number of technical assistance visits per year are more likely to adopt winter pastures and improved native grassland. This information can be useful in the formulation of technological dissemination programs that aim at a sustainable production of beef cattle.(AU)

Infrared thermography and Doppler ultrasonography to evaluate the effects of scrotal insulation on testicular blood flow dynamics in bulls / Termografia infravermelho e ultrassonografia Doppler na avaliação dos efeitos da insulação escrotal sobre o fluxo sanguíneo testicular em touros

The aim of this study was to evaluate the dynamics of the scrotal temperature, sperm quality and testicular blood flow by using infrared thermography and Doppler ultrasonography in bulls submitted to scrotal insulation. Braford bulls (n = 8) at 18 months of age, were assigned into the following groups: insulated for 72 h (G 72; n = 2), 96 h (G 96, n = 2), 120 h (G 120, n = 2), and control animals (CON; n = 2) that remained without insulation. Infrared thermography and Doppler ultrasonography parameters were measured at four different time points: immediately after the scrotal insulation (M0), within 10 min (M10), 30 min (M30) and 60 min (M60) after scrotal insulation. The sperm quality was evaluated weekly (S1/S12). The data were analyzed by ANOVA, t-test (paired) and Pearson's correlation with a significance level of 5%. None of the observed variables were different between the insulated groups (P > 0.05). Insulated animals showed higher scrotal temperature in M0 compared to that in the M10, M30 and M60 periods (P < 0.05). There was no difference in the pulsatility and resistive indexes after scrotal insulation. However, blood flow velocity was higher in M10 compared to that in the M0, M30 and M60 periods (P < 0.05). The sperm quality was higher (P < 0.05) in all twelve collections from the control group compared with the insulated groups. Scrotal insulation resulted in changes in the sperm quality, scrotal temperature and testicular blood flow velocity.(AU)

O objetivo deste estudo foi avaliar a dinâmica da temperatura escrotal, a qualidade espermática e o fluxo sanguíneo testicular utilizando a termografia infravermelho e a ultrassonografia Doppler em touros submetidos a insulação escrotal. Touros Braford (n=8) aos 18 meses de idade, foram distribuídos nos seguintes grupos: insulados por 72 h (G 72; n=2), 96 h (G 96; n=2), 120 h (G120, n=2), e animais controle (CON; n=2) que permaneceram sem insulação. Os parâmetros de termografia infravermelha e ultrassonografia Doppler foram medidos em quatro diferentes momentos: imediatamente após a insulação escrotal (M0), aos 10 min (M10), 30 min (M30) e 60 min (M60) após a insulação escrotal. A qualidade espermática foi avaliada semanalmente (S1 / S12). Os dados foram analisados por ANOVA, teste t (pareado) e correlação de Pearson com nível de significância de 5%. Nenhuma das variáveis observadas foi diferente entre os grupos insulados (P > 0,05). Os animais insulados apresentaram maior temperatura escrotal em M0 quando comparados aos M10, M30 e M60 (P < 0,05). Não houve diferença nos índices de pulsatilidade e resistividade após a insulação escrotal. No entanto, a velocidade do fluxo sanguíneo foi maior em M10 em relação aos períodos M0, M30 e M60 (P < 0,05). A qualidade espermática foi maior (P < 0,05) em todas as doze coletas do grupo controle em comparação com os grupos insulados. A insulação escrotal resultou em mudanças na qualidade espermática, temperatura escrotal e na velocidade do fluxo sanguíneo testicular.(AU)

Heritability estimation and genetic correlations for mature weight, visual scores, and growth traits in Nellore cattle

This study was intended to estimate the genetic associations between growth traits and visual scores with possible changes in mature weight (MW) in 397,900 Nellore animals. A bi-character analysis was performed to estimate the (co)variances and genetic parameters for MW, which comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, and WM) and yearling (YC, YP, and YM), birth weight (BW), weight from birth to weaning (WG), weight from weaning to yearling (YG), and final index (FIND). The observed mean MW was 417.6±56.2 kg, and the direct genetic effect mean estimated heritability (h²a1) of MW was 0.45. Overall, the BW was 31.0±3.7 kg, and the estimated h² was 0.34. The heritability estimate of the maternal additive genetic component (h²m2) of BW was 0.07. We calculated the mean WG to be 144.1±26.3 and estimated the h²a2 as 0.18 and h²m2 as 0.07. The value for h²a YG (0.17) and YW (0.26) were also estimated. The heritability of the weaning WC (0.17), WP (0.19), and WM (0.17) and yearling YC (0.25), YP (0.27), and YM (0.25) were estimated using visual scores. The h²m values for weaning WC, WP, and WM (0.06) with visual scores were estimated. The genetic correlations between body weight (BoW) at YC and WC (0.62) were considered moderately high and positive. In addition, YP (0.18), YM (0.15), WP (0.13), and WM (0.14) were considered moderately low compared with MW. The genetic correlation between BW and FIND (0.38) was considered positive and moderate. The heritability estimation indicates that growth traits, visual scores, and weight of adult cows could be changed by selection. Cows that presented the highest h²a values for live weight responded rapidly to selection based on growth characteristics, visual scores, and FIND and might result in increased final MW.(AU)

Typology of beef production systems according to bioeconomic efficiency in the south of Brazil / Tipologia de sistemas de produção de carne bovina de acordo com a eficiência bioeconômica no sul do Brasil

The objective of this study was to evaluate the bioeconomic efficiency of beef cattle production systems in the south of Brazil. A survey was conducted with 33 beef cattle farmers operating with complete cycle production systems in areas larger or equal to 900 ha. Answers were classified in two drivers, technology (TEC) and management (MAN), which were separated into subfactors with their respective components. Multiple correspondence analysis, Tukey test, cluster analysis, and Pearson correlation were the statistics procedures. The TEC components were above normal for Brazilian farmers, but the gross margin is still lower than that needed to generate financial resources for a proper remuneration of cattle farmer. Farmers were classified into three clusters according to bioeconomic efficiency: low (LEL), intermediate (IEL), or high-efficiency level (HEL). The TEC driver differentiated the LEL x HEL clusters and the MAN, mainly expressed in costs, the IEL x HEL. Positive correlation between age at first mating and age at slaughter in the HEL cluster explains the higher costs when compared to IEL because of the use of differentiated feed resources. Investments in technologies related to herd feeding in HEL cluster improved the productivity by only 20% and the cost per hectare by 95 USD ha-1 in comparison to IEL cluster. The main differences between farmers are because of the use of technologies related to feeding and cost management. Therefore, before implementing a new technology, an economic evaluation is necessary.(AU)

O objetivo deste estudo foi avaliar a eficiência bioeconômica em sistemas de produção de bovinos de corte no sul do Brasil. A pesquisa foi realizada com 33 pecuaristas que operam com sistemas de produção baseado em ciclo completo, em áreas maiores ou iguais a 900 hectares. As respostas foram classificadas em dois fatores: tecnologia (TEC) e gestão (GES), os quais foram separados em subfatores com seus respectivos componentes. A análise de correspondência múltipla, teste de Tukey, análise de cluster e correlação de Pearson foram os procedimentos estatísticos. Os componentes do TEC estavam acima do normal para os pecuaristas brasileiros, mas a margem bruta ainda é menor do que a necessária para gerar recursos financeiros para uma remuneração adequada ao pecuarista. Os pecuaristas foram classificados em três grupos de acordo com a eficiência bioeconômica: baixo (BNE), intermediário (INE) ou alto nível de eficiência (ANE). O driver TEC diferenciou os clusters BNE x ANE e o GES, expresso principalmente em custos, o INE x ANE. A correlação positiva entre a idade no primeiro acasalamento e a idade ao abate no agrupamento ANE explica os custos mais elevados quando comparados aos INE, devido ao uso de recursos alimentares diferenciados. Os investimentos em tecnologias relacionadas à alimentação de rebanho no agrupamento ANE melhoraram a produtividade em apenas 20% e o custo por hectare em 95 USD ha-1 em comparação ao cluster INE. As principais diferenças entre os pecuaristas se devem ao uso de tecnologias relacionadas à alimentação e ao gerenciamento de custos. Portanto, antes de implementar uma nova tecnologia, uma avaliação econômica é necessária.(AU)

Typology of beef production systems according to bioeconomic efficiency in the south of Brazil / Tipologia de sistemas de produção de carne bovina de acordo com a eficiência bioeconômica no sul do Brasil

ABSTRACT: The objective of this study was to evaluate the bioeconomic efficiency of beef cattle production systems in the south of Brazil. A survey was conducted with 33 beef cattle farmers operating with complete cycle production systems in areas larger or equal to 900 ha. Answers were classified in two drivers, technology (TEC) and management (MAN), which were separated into subfactors with their respective components. Multiple correspondence analysis, Tukey test, cluster analysis, and Pearson correlation were the statistics procedures. The TEC components were above normal for Brazilian farmers, but the gross margin is still lower than that needed to generate financial resources for a proper remuneration of cattle farmer. Farmers were classified into three clusters according to bioeconomic efficiency: low (LEL), intermediate (IEL), or high-efficiency level (HEL). The TEC driver differentiated the LEL x HEL clusters and the MAN, mainly expressed in costs, the IEL x HEL. Positive correlation between age at first mating and age at slaughter in the HEL cluster explains the higher costs when compared to IEL because of the use of differentiated feed resources. Investments in technologies related to herd feeding in HEL cluster improved the productivity by only 20% and the cost per hectare by 95 USD ha-1 in comparison to IEL cluster. The main differences between farmers are because of the use of technologies related to feeding and cost management. Therefore, before implementing a new technology, an economic evaluation is necessary.

RESUMO: O objetivo deste estudo foi avaliar a eficiência bioeconômica em sistemas de produção de bovinos de corte no sul do Brasil. A pesquisa foi realizada com 33 pecuaristas que operam com sistemas de produção baseado em ciclo completo, em áreas maiores ou iguais a 900 hectares. As respostas foram classificadas em dois fatores: tecnologia (TEC) e gestão (GES), os quais foram separados em subfatores com seus respectivos componentes. A análise de correspondência múltipla, teste de Tukey, análise de cluster e correlação de Pearson foram os procedimentos estatísticos. Os componentes do TEC estavam acima do normal para os pecuaristas brasileiros, mas a margem bruta ainda é menor do que a necessária para gerar recursos financeiros para uma remuneração adequada ao pecuarista. Os pecuaristas foram classificados em três grupos de acordo com a eficiência bioeconômica: baixo (BNE), intermediário (INE) ou alto nível de eficiência (ANE). O driver TEC diferenciou os clusters BNE x ANE e o GES, expresso principalmente em custos, o INE x ANE. A correlação positiva entre a idade no primeiro acasalamento e a idade ao abate no agrupamento ANE explica os custos mais elevados quando comparados aos INE, devido ao uso de recursos alimentares diferenciados. Os investimentos em tecnologias relacionadas à alimentação de rebanho no agrupamento ANE melhoraram a produtividade em apenas 20% e o custo por hectare em 95 USD ha-1 em comparação ao cluster INE. As principais diferenças entre os pecuaristas se devem ao uso de tecnologias relacionadas à alimentação e ao gerenciamento de custos. Portanto, antes de implementar uma nova tecnologia, uma avaliação econômica é necessária.

How do Brazilian citizens perceive animal welfare conditions in poultry, beef, and dairy supply chains?

The aim of this study was to understand the perceptions of Brazilian citizens about the general conditions of animal welfare in the poultry, beef, and dairy supply chains. To reach this aim, an online survey was conducted. The analysis was based on descriptive statistics and three logistic regression models. Results of descriptive statistics showed that citizens in Brazil had mostly negative perceptions about the conditions of animal welfare in the poultry, beef, and dairy supply chains. Results of the logistic regression models showed that citizens with a background in agricultural/veterinary sciences, and citizens who reported a higher level of knowledge about poultry and dairy supply chains were more likely to perceive the general conditions of animal welfare in these two supply chains as being bad. Citizens who reported previous contact with poultry farms were also more likely to perceive the general conditions of animal welfare in the poultry supply chain as being bad. In addition, the perception that farmers are mainly focused on the economic aspect of farming and less on animal welfare, the perception that animals do not have a good quality of life while housed on farms, and the perception that animals are not adequately transported and slaughtered, negatively impact on perceptions about the general conditions of animal welfare in the poultry, beef, and dairy supply chains.