Blood metabolites and fecal starch as indicators of feed efficiency of beef cattle in the feedlot / [Metabolitos sanguíneos e amido fecal como indicadores da eficiência alimentar do gado de corte em confinamento]

The use of blood metabolites (BM), fecal starch (FS), and apparent digestion of starch, (ATTSD) as indicators of feed efficiency (FE) in beef cattle in the feedlot was studied. Fourteen bulls were used, originating in an industrial cross, without a defined racial group, with mean body weight of 284.86kg, individually fed, being evaluated in a 42-day confinement system. After the evaluation, the animals were divided into two groups according to the individual FE: high feed efficiency (HE) and low feed efficiency (LE). There was a difference between the groups in the variables FE, feed conversion (FC), final weight (FW), and daily weight gain (DWG). The FE had a positive correlation with DWG, FC, and FW. There was no difference between the groups for the variables BM, FS, and ATTSD, nor was there any correlation between these variables and FE. Considering the feed cost, the HE animals proved more profitable. BM, FS, and ATTSD did not statistically show potential to be used as indicators of FE, despite the evidence of numerical differences of these variables between the different groups, tendency of correlations with FE, and discriminating function with potential assertiveness.(AU)

Foi estudada a utilização dos metabólitos sanguíneos (BM), do amido fecal (FS) e da digestão aparente do amido (ATTSD) como indicadores de eficiência alimentar (FE) em bovinos de corte em confinamento. Utilizaram-se 14 touros, originários de cruzamento industrial, sem grupo racial definido, peso corporal médio de 284,86kg, alimentados individualmente, sendo avaliados em sistema de confinamento por 42 dias. Após a avaliação, dividiram-se os animais em dois grupos, de acordo com a FE individual: alta eficiência alimentar (HE) e baixa eficiência alimentar (LE). Houve diferença entre os grupos nas variáveis FE, conversão alimentar (FC), peso final (FW) e ganho de peso diário (DWG). A FE teve correlação positiva com DWG, FC e FW. Não houve diferença entre os grupos para as variáveis BM, FS e ATTSD, tampouco houve correlação entre essas variáveis e a FE. Considerando-se o custo alimentar, os animais HE mostraram-se mais lucrativos. BM, FS e ATTSD não mostraram, estatisticamente, potencial para serem utilizados como indicadores de FE, apesar da evidência de diferenças numéricas dessas variáveis entre os diferentes grupos, tendência de correlações com a FE e de função discriminante com potencial assertividade.(AU)

Infrared thermography as a noninvasive method to assess scrotal insulation on sperm production in beef bulls.

This study evaluated the thermoregulation and spermatogenic changes by scrotal temperature gradient using infrared thermography in testicular compromised bulls. Bulls were insulated (n = 6) for 72 hr and control animals (n = 3) remained without insulation during all the experimental period. Seminal evaluation was performed prior, at insult removal and once per week for 13 consecutive weeks. Mean temperature gradient in insulated animals was lower at the time of insulation removal compared to the week prior and after the insult (p < .05). Two weeks after insult, sperm motility was lower in insulated compared to control animals (p < .01) and spermatozoa total defects were higher in insulated compared to control animals (p < .05). Two and seven weeks after insult, the major defects were higher in insulated compared to control animals (p < .05). Scrotal temperature gradient showed a positive correlation with sperm mass motion (p < .01) and a negative correlation with ocular globe temperature (p < .01) in insulated animals. The infrared thermography can be used to evaluate ocular globe temperature in bulls; however, it is only effective to detect changes in scrotal temperature gradient at the insult removal.

Reticulo-rumen temperature as a predictor of calving time in primiparous and parous Holstein females.

The objective of this research was to define and analyze drops in reticulo-rumen temperature (Trr) as an indicator of calving time in Holstein females. Data were collected from 111 primiparous and 150 parous Holstein females between November 2012 and March 2013. Between -15 and -5 d relative to anticipated calving date, each female received an orally administered temperature sensing reticulo-rumen bolus that collected temperatures hourly. Daily mean Trr was calculated from d -5 to 0 relative to using all Trr values (A-Trr) or only Trr values ≥37.7°C (W-Trr) not altered by water intake. To identify a Trr drop, 2 methodologies for computing the baseline temperature were used. Generalized linear models (GLM) were used to estimate the probability of calving within the next 12 or 24 h for primiparous, parous, and all females, based on the size of the Trr drop. For all GLM, a large drop in Trr corresponded with a large estimated probability of calving. The predictive power of the GLM was assessed using receiver-operating characteristic (ROC) curves. The ROC curve analyses showed that all models, regardless of methodology in calculation of the baseline or tested category (primiparous or parous), were able to predict calving; however, area under the ROC curve values, an indication of prediction quality, were greater for methods predicting calving within 24 h. Further comparisons between GLM for primiparous and parous, and using baseline 1 and 2, provide insight on the differences in predictive performance. Based on the GLM, Trr drops of 0.2, 0.3, and 0.4°C were identified as useful indicators of parturition and further analyzed using sensitivity, specificity, and diagnostic odds ratios. Based on sensitivity, specificity, and diagnostic odds ratios, the best indicator of calving was an average Trr drop ≥0.2°C, regardless of methodology used to compute the baseline or category of animal evaluated.

Avaliação econômica da terminação de bovinos de corte em pastagem irrigada / Economic evaluation of finishing beef cattle on irrigated pasture

Foi avaliada a viabilidade econômica de três sistemas de produção por meio da mensuração dos custos de produção e da análise dos indicadores financeiros. Os três sistemas (S1, S2 e S3), situados na fronteira oeste do Rio Grande do Sul, foram avaliados no período de outubro de 2010 a outubro de 2011. A pastagem estabelecida no S1 foi de azevém (Lolium multiflorumLam)e trevo branco (Trifolium repensLam); no S2, trevo branco, trevo vermelho (Trifolium pratenseLam), cornichão (Lotus corniculatusLam), azevém e aveia preta (Avena strigosaSchreb); e no S3, azevém, cornichão, trevo branco e trevo vermelho. Os animais foram pesados na entrada e na saída das pastagens. A coleta de dados para mensuração do custo foi realizada mensalmente utilizando-se planilhas apropriadas. As produtividades foram de 369, 772 e 637kg/ha para os sistemas S1, S2 e S3, respectivamente. O S2 apresentou o maior custo total (R$ 2.101,59/ha), enquanto o menor foi obtido pelo S1 (R$ 1.626,93/ha). Na análise do custo operacional médio dos três sistemas, os itens que apresentaram maiores valores foram a implantação de pastagem, a energia elétrica, a manutenção da pastagem e a depreciação. Quanto às margens, os sistemas S1, S2 e S3 apresentaram, respectivamente, R$ 33,46, 1.162,55 e 701,01/ha para margem bruta; R$ -63,51, 955,40 e 541,05/ha para margem operacional; e R$ -583,18, 291,61 e -28,99/ha para lucro total. A rentabilidade foi de -0,47, 4,37 e 3,01% e a lucratividade foi de -5,94, 39,92 e 27,38% para o S1, S2 e S3, respectivamente. A irrigação de pastagens para terminação de bovinos é viável economicamente, no entanto a sua adoção deve sempre visar a altas produtividades zootécnicas devido ao seu elevado custo de produção.

The economic viability of three systems of production was evaluated through the measurement of costs and analysis of financial indicators. The three systems (S1, S2 and S3), located on the Western Border of Rio Grande do Sul, were evaluated from October 2010 to October 2011. The pasture established is S1 was ryegrass (Lolium multiflorum Lam) and white clover (Trifolium repens Lam), in S2, white clover, red clover (Trifolium pratense Lam), Bird's-foot trefoil (Lotus corniculatus Lam), ryegrass and oats (Avena strigosa Schreb), and in S3, ryegrass, birdsfoot trefoil, white clover and red clover. The animals were weighed before and after the pastures. Data collection was conducted monthly, using spreadsheets suitable for the measurement of production cost. Productivities were 369, 772 and 637 kg/ha for systems S1, S2 and S3, respectively. S2 had the highest total cost (R$ 2101.59/ha), while the lower was obtained by S1 (R$ 1626.93/ha). In the analysis of the average operating costs, items that showed the highest values were the establishment of pasture, electricity, maintenance of pasture and depreciation. As for margins, the systems S1, S2, and S3 were, respectively, R$ 33.46, 1162.55 and 701.01/ha for gross margin; R$ -63.51, 955.40 and 541.05 ha-1 for operating margin; and R$ -583.18, -28.99 and 291.61 ha-1 for total profit. The return was -0.47, 4.37 and 3.01% and profitability was -5.94, 39.92 and 27.38% for the S1, S2 and S3 respectively. The positive result found in the financial evaluation of the three systems studied indicates the economic viability of irrigated pasture in finishing cattle. Irrigation of pasture for finishing cattle is economically feasible, however, its application should always aim high yields husbandry due to their high cost of production.

Origins and genetic diversity of British cattle breeds in Brazil assessed by pedigree analyses.

Pedigree information available for Angus (ANG), Devon (DEV), Hereford (HER), and Shorthorn (SHO) cattle in Brazil was analyzed to appraise the genetic diversity and population structure of these breeds. Pedigree records collected from the beginning of the 20th century until 2010 were used in the analyses. Over time, the number of herdbook registrations declined in HER after a peak in the 1970s, remained low in DEV and SHO, and increased steadily in ANG since the 1990s, such that it the latter is now the leading British cattle breed in Brazil. The average number of offspring registered per sire ranged from about 12 (SHO) to 20 (DEV) and the mean generation interval ranged from about 6.0 (HER and SHO) to 6.4 (ANG) years. In the reference population (calves born in 2009 and 2010, plus those born in 2008 for SHO) the mean equivalent number of generations known ranged from about 7 (SHO) to 9 (HER). In the 4 breeds studied, nearly all animals born over the last few years are inbred, even though the mean level of inbreeding in the reference population is below 4% in all breeds. The rate of inbreeding per generation, computed from the individual increase in inbreeding, ranged from about 0.2 (ANG) to 0.5% (DEV), with a corresponding effective population size of 245 and 92, respectively, which is above the recommended minimum critical threshold. The number of founders/ancestors contributing with 50% of the reference population gene pool was 211/26 for ANG, 41/14 for DEV, 164/25 for HER, and 79/10 for SHO, with effective number of founders/ancestors/founder genomes of 470/68/36, 89/33/16, 289/59/30, and 200/28/18 for ANG, DEV, HER, and SHO, respectively. The genetic contribution of different countries to the gene pool of each breed indicated that, throughout the period studied, DEV genes originated predominantly from the United Kingdom, while for the other breeds there was a changing pattern over time. Until the 1970s Argentina was the major supplier of ANG, while HER and SHO genes were mostly from Uruguay, but since then the United States took the leading role as supplier of ANG, HER, and SHO genes to Brazil. Our results reveal a mild increase in inbreeding in all breeds studied, with effective population size estimates indicating that reasonable levels of genetic diversity have been maintained in all 4 breeds. Continuous monitoring of inbreeding trends and of parameters derived from probability of gene origin should be ensured to warrant the long-term maintenance of genetic diversity.

Confiança e agregação de valor em carnes com indicação geográfica / Trust and added value on meat with geographic indication

O aumento da procura por produtos agroalimentares com certificação relacionada à origem geográfica tem ocorrido, buscando atender nichos específicos de mercado. Nesse sentido, este trabalho identificou a percepção dos consumidores brasileiros com relação às indicações geográficas e sua disposição em pagar por esse atributo. Como método, realizou-se uma survey utilizando-se o software Sphinx, via internet, com 272 consumidores de carne bovina. Constatou-se que a percepção do consumidor sobre as indicações geográficas em carnes é, de maneira geral, positiva, sendo este atributo reconhecido como um indicador de qualidade. Os consumidores entrevistados acreditam que essas carnes oferecem maior segurança alimentar e são mais confiáveis que o produto sem a indicação de origem geográfica, sendo possível agregar valor em função de tais diferenciais. Além disso, o consumidor valorizou esse atributo e está disposto a pagar mais pelas carnes com selo de indicação geográfica.

The increased demand for agrifood products with certification related to the geographical origin has occurred on both global and national levels, seeking to meet specific market niches. In this sense, this article aims to identify consumer perceptions with respect to geographical indicators and their willingness to pay for this attribute. As a method, there was an internet survey among 272 consumers of beef with the help of the Sphinx software. It was found that consumer perception on geographical indications in meat is generally positive, and this attribute is recognized as a quality indicator. Consumers believe that this meat offers security and is more reliable than the product that doesn’t mention source, and you can add value to these differences. In addition, consumers value this attribute and are willing to pay more for meat with the seal of geographical indication.

Desempenho e características da carcaça de novilhos terminados em pastejo rotacionado ou em confinamento / Performance and carcass characteristics of steers finished in rotational grassing or feedlot

Foram avaliados o desempenho e as características de carcaça de 36 novilhos Brahman (Bh), Brangus (Bg) e Hereford adaptado (He), terminados em pastejo com suplementação (PSu) ou em confinamento (Conf). Os animais foram abatidos quando apresentavam espessura de gordura maior do que 4mm. Na dieta do Conf, a relação volumoso:concentrado foi de 60:40 (com base na matéria seca), continha 13 por cento de proteína bruta (PB) e 62 por cento de nutrientes digestíveis totais (NDT). O capim-mombaça continha, em média, 7 por cento de PB e 54 por cento de NDT, e o suplemento 24 por cento de PB e 76 por cento de NDT. Foi observada diferença (P<0,05) no sistema de terminação para o ganho de peso médio diário, com 1,200kg/cab/dia para Conf e 0,675kg/cab/dia para Psu. Os novilhos Bh e Bg pesaram, em média, 445,8kg, e o rendimento da carcaça quente foi de 58,4 por cento, valores maiores que os 399,1kg e 55,4 por cento obtidos pelos animais He. A área de olho de Longissimus foi maior para os animais Bg, 76,42cm². A maciez, 3,71 vs 4,89, e a espessura de gordura subcutânea, 4,64 vs 3,39, foram melhores nos animais terminados em Conf do que nos animais em Psu, respectivamente.

The productive performance and carcass of the 36 Brahman (Bh), Brangus (Bg) and adapted Hereford (He) steers finished on feedlot (FD) or on rotational grazing with supplementation system (GS) were evaluated. The animals were slaughtered when the subcutaneous fat thickness was over 4mm. The feedlot diet had a forage: concentrate of 60:40 (in dry matter) 13 percent crude protein (CP), 62 percent of NDT. The mombaça gras CP level was 7 percent and 54 percent of NDT. The supplement had supplied 24 percent of CP and 76 percent of NDT. A significant difference was observed for the average daily gain, being 1,200kg/head/day for FD steers and 0.675kg/head/day for GS steers. The effect of breed on slaughter weight was observed, being 445.8kg for Bh and Bg and 399.19kg for He. The hot dressing percentage was higher for Bh and Bg than for He, 58.4 percent vs 55.4 percent. The rib eye area was higher for Bg, 76.42cm² and tenderness measured by the shear force was lower for FD steers, at 3.71 than for GS steers, at 4.89. The subcutaneous fat thickness was higher for FD steers, at 4.64 than for GS steers, at 3.39mm.

Determinação da circunferência escrotal em touros de corte no Rio Grande do Sul / Measurement of scrotal circumference in beef bulls in Rio Grande do Sul

The variability of scrotal circumference and the effects of age and breed as well as the relationship between testicular weight (TW), scrotal circumference (SC), and live weight (BW) were investigated in bulls. Devon, Polled Hereford, and Red Angus breeds showed higher SC values than the other British, Continental, Synthetic, and Zebu studied breeds. The percentage of culled bulls because of low SC ranged from 7.01 to 24.25 percent. The increase of SC was proportional to the increase in TW and they were highly correlated (r²= 0.90). The results suggest that SC in young bulls is the best way to predict TW and, therefore, a useful tool for their selection.

A variabilidade da circunferência escrotal e os efeitos de idade e raça,assim como, as relações existentes entre o peso testicular (PT), a circunferência escrotal (CE) e o peso vivo (PV) foram investigados em touros. As raças Devon, Polled Hereford e Red Angus apresentaram valores de CE mais altos que as demais raças avaliadas, tanto inglesas, como continentais, sintéticas e zebuínas. O percentual descartado de touros devido à baixa CE variou de 7,0 a 24,2 por cento. O aumento da CE acompanhou o aumento do PT dos animais, e estes foram altamente relacionados, r² = 0,90. Os resultados sugerem que, em touros jovens, a CE é a melhor forma de predizer o PT e, portanto, uma ferramenta útil para selecionar touros.

Efeitos do peso vivo sobre a comercialização de bezerros de corte em leilões / Effects of the live weight on the commercialization of beef calves in auction barn

Analisaram-se os efeitos da média de peso vivo de 1.880 lotes de bezerros comercializados em 13 leilões, no Rio Grande do Sul, sobre o valor de venda final por unidade de peso, e caracterizou-se a frequência dos lotes conforme a classe de peso durante as estações de outono e primavera, no período de 2004 a 2006. Os dados foram corrigidos pelo índice geral de preços - disponibilidade interna e analisados por meio de histogramas de frequência e análises de regressão e correlação. O peso vivo influenciou o preço dos bezerros, e a magnitude do efeito foi maior nos anos de grande demanda. Observou-se correlação negativa entre preço e peso dos bezerros na primavera, reflexo da oferta de animais mais pesados, devido aos efeitos de estação do ano ou à maior idade dos bezerros, comparados aos ofertados no outono. Não se observou maior liquidez dos bezerros comercializados no outono em relação aos da primavera. A conjuntura da cadeia da carne bovina e os preços de outras categorias têm grande relação com os preços pagos. A aquisição de animais de menor ou maior peso na ocasião da transação comercial pode auxiliar na redução dos custos que a reposição representa na produção.

The effects of the live weight of 1,880 lots of calves marketed in 13 auctions in the State of Rio Grande do Sul, Brazil, on the value of final sale per unit of weight were evaluated, as well as the frequency of the lots according to the weight class during the autumn and spring seasons, in the period from 2004 to 2006, was characterized. The data were analyzed by frequency histograms, regression, and correlation analyses. The live weight is one of the characteristics that influenced the price of the calves; however, the magnitude of the effect was higher in years of great demand. A negative correlation was observed between price and weight of the calves in spring, which were results of the offer of heavier animals, due to the season effects or the oldest age of the calves compared to those presented in the autumn. The chain conjuncture of the bovine meat and the prices of other categories have great relation with the prices paid. Therefore, the acquisition of highter or heavier animals in the occasion of the business deal may help in the reduction of the costs represented by the replacement in the production.

Taxas de prenhez em novilhas de corte acasaladas aos 18 e 24 meses de idade / Differences in pregnancy rate of beef heifers mating at 18 and 24 months of age

Avaliaram-se os efeitos da idade de acasalamento e classe de peso sobre a taxa de prenhez (TP) de novilhas de corte Hereford (n=119) acasaladas aos 18 (18M) ou 24 meses (24M) e classificadas em leves (18ML = 260kg; 24ML = 280kg) e pesadas (18MP = 300kg; 24MP = 330kg). O período de monta foi de 05/04 a 21/05/01 (outono) e de 04/11 a 20/12/01 (primavera) para 18M e 24M, respectivamente. Avaliaram-se os efeitos do peso no início do acasalamento (PIA), escore da condição corporal (CCI) e ganho de peso (GDM). Não ocorreram diferenças (P>0,05) na TP entre os grupos 18MP (73,3 por cento), 24ML (72,4 por cento) e 24MP (83,3 por cento), mas a TP foi mais baixa entre as novilhas 18ML (26,7 por cento). O GDM foi maior para novilhas 24M (0,664 vs 0,537kg/d) (P<0,05) que para as 18M. No grupo 18MP, as novilhas que conceberam tiveram maior GDM (0,621 vs 0,429kg/d) em relação às falhadas. O CCI foi mais alto (P<0,10) nas novilhas que conceberam (3,5) que nas falhadas (3,32). Observou-se efeito quadrático do PIA (P<0,01) sobre a TP (Y= -993,03 + 6,4543PIA - 0,0097PIA²; R²=0,98).

The effects of the mating age and weight class on the pregnancy rate (PR) of Hereford heifers (n=119) at 18 (18M) or 24 months (24M) of age were evaluated. The heifers were divided into classes as light (18ML=260kg; 24ML=280kg) or heavy (18MP=300kg; 24MP=330kg). The breeding seasons were: 18M: 04/05 - 05/21 (fall) and 24M: 11/04 - 12/21 (spring). The traits analyzed were live weight (LW) and body condition score (BCS) at the beginning of the mating season and the average daily gain (ADG) on the pregnancy rate (PR). The PR were 73.3 percent (18MP), 72.4 percent (24ML), 83.3 percent (24MP) (P>0.05) and the 18ML heifers have shown lower PR (26.7 percent) (P<0.05). The 24M heifers showed higher ADG (0.664 vs 0.537kg/d) than the 18M heifers and in this group the open heifers had lower ADG (0.429 vs 0.621kg/d) than the pregnant heifers. The BCS were higher (P<0.10) for the pregnant heifers (3.50) than the open (3.24) heifers. A quadratic effect of LW on the PR (Y= -993.03 + 6.4543LW - 0.0097LW²; R²=0.98) was observed.