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The effects on cow and calf performance of replacing grass silage with brewers grains in diets based on barley straw and fed to pregnant beef cows are reported. Using a 2 × 2 factorial arrangement of breed and diet, cows pregnant by artificial insemination (n = 34) of two breeds (cross-bred Limousin, n = 19 and pure-bred Luing, n = 15) were fed diets ad libitum which consisted of either (g/kg dry matter) barley straw (664) and grass silage (325; GS) or barley straw (783) and brewers grains (206, BG) and offered as total mixed rations. From gestation day (GD) 168 until 266, individual daily feed intakes were recorded and cow body weight (BW) and body condition score (BCS) measured weekly. Calving date, calf sex, birth and weaning BW, and calf age at weaning were also recorded. Between GD 168 and 266, cross-bred Limousin cows gained more weight than Luing cows (p < 0.05) and cows offered BG gained more weight than cows offered GS (p < 0.001). Luing cows lost more BCS than cross-bred Limousin cows (p < 0.05), but diet did not affect BCS. There were no differences in dry matter intake as a result of breed or diet. Calf birth BW, however, was greater for cows fed BG than GS (44 vs. 38 kg, SEM 1.0, p < 0.001) with no difference between breeds. At weaning, calves born to BG-fed cows were heavier than those born to GS-fed cows (330 vs. 286 kg, SEM 9.3, p < 0.01). In conclusion, replacement of grass silage with brewers grains improved the performance of beef cows and increased calf birth and weaning BW. Further analysis indicated that the superior performance of cows offered the BG diet was most likely due to increases in protein supply which may have improved both energy and protein supply to the foetus.
Assuntos
Ração Animal/análise , Bovinos/fisiologia , Dieta/veterinária , Grão Comestível , Hordeum , Poaceae , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Bovinos/genética , Feminino , Fenômenos Fisiológicos da Nutrição Materna , Parto , Caules de Planta , GravidezRESUMO
The aim of this study was to assess the on-line implementation of visible and near infrared reflectance (Vis-NIR) spectroscopy as an early predictor of beef quality traits, by direct application of a fibre-optic probe to the muscle immediately after exposing the meat surface in the abattoir. Samples from M.longissimus thoracis from 194 heifers and steers were scanned at quartering 48h postmortem over the Vis-NIR spectral range from 350 to 1800nm. Thereafter, samples from M.longissimus thoraciset lumborum were analysed for colour (L(∗), a(∗), b(∗); 48h postmortem), cooking loss (14 days postmortem), instrumental texture (Volodkevitch, 10 days aged meat; slice shear force, 3 and 14 days aged meat) and sensory characteristics. Vis-NIR calibrations, tested by cross-validation, showed high predictability for L(∗), a(∗) and b(∗) (R(2)=0.86, 0.86 and 0.91; SE(CV)=0.96, 0.95 and 0.69, respectively). The accuracy of Vis-NIR to estimate cooking loss and instrumental texture ranged from R(2)=0.31 to 0.54, suggesting relatively low prediction ability. Sensory characteristics assessed on 14 days aged meat samples showed R(2) in the range from 0.21 (juiciness) to 0.59 (flavour). Considering the subjective assessment of sensory characteristics the correlations of Vis-NIR measurements and several meat quality traits in the range from 0.46 to 0.95 support the use of on-line Vis-NIR in the abattoir. Improvement of predictability was achieved if only extreme classes of meat characteristics have to be predicted by Vis-NIR spectroscopy.
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Adding nitrate to or increasing the concentration of lipid in the diet are established strategies for reducing enteric methane (CH4) emissions, but their effectiveness when used in combination has been largely unexplored. This study investigated the effect of dietary nitrate and increased lipid included alone or together on CH4 emissions and performance traits of finishing beef cattle. The experiment was a 2×4 factorial design comprising two breeds (cross-bred Aberdeen Angus (AAx) and cross-bred Limousin (LIMx) steers) and four dietary treatments (each based on 550 g forage : 450 g concentrate/kg dry matter (DM)). The four dietary treatments were assigned according to a 2×2 factorial design where the control treatment contained rapeseed meal as the main protein source, which was replaced either with nitrate (21.5 g nitrate/kg DM); maize distillers dark grains (MDDG, which increased diet ether extract from 24 to 37 g/kg DM) or both nitrate and MDDG. Steers (n=20/dietary treatment) were allocated to each of the four treatments in equal numbers of each breed with feed offered ad libitum. After 28 days adaptation to dietary treatments, individual animal intake, performance and feed efficiency were recorded for 56 days. Thereafter, CH4 emissions were measured over 13 weeks (six steers/week). Increasing dietary lipid did not adversely affect animal performance and showed no interactions with dietary nitrate. In contrast, addition of nitrate to diets resulted in poorer live-weight gain (P<0.01) and increased feed conversion ratio (P<0.05) compared with diets not containing nitrate. Daily CH4 output was lower (P<0.001) on nitrate-containing diets but increasing dietary lipid resulted in only a non-significant reduction in CH4. There were no interactions associated with CH4 emissions between dietary nitrate and lipid. Cross-bred Aberdeen Angus steers achieved greater live-weight gains (P<0.01), but had greater DM intakes (P<0.001), greater fat depth (P<0.01) and poorer residual feed intakes (P<0.01) than LIMx steers. Cross-bred Aberdeen Angus steers had higher daily CH4 outputs (P<0.001) but emitted less CH4 per kilogram DM intake than LIMx steers (P<0.05). In conclusion, inclusion of nitrate reduced CH4 emissions in growing beef cattle although the efficacy of nitrate was less than in previous work. When increased dietary lipid and nitrate inclusion were combined there was no evidence of an interaction between treatments and therefore combining different nutritional treatments to mitigate CH4 emissions could be a useful means of achieving reductions in CH4 while minimising any adverse effects.
Assuntos
Ração Animal/análise , Bovinos/fisiologia , Metano/metabolismo , Nitratos/farmacologia , Animais , Brassica rapa , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Gorduras na Dieta/metabolismo , Masculino , Aumento de Peso/efeitos dos fármacos , Zea maysRESUMO
This study was undertaken to further develop our understanding of the links between breed, diet and the rumen microbial community and determine their effect on production characteristics and methane (CH4) emissions from beef cattle. The experiment was of a 2×2 factorial design, comprising two breeds (crossbred Charolais (CHX); purebred Luing (LU)) and two diets (concentrate-straw or silage-based). In total, 80 steers were used and balanced for sire within each breed, farm of origin and BW across diets. The diets (fed as total mixed rations) consisted of (g/kg dry matter (DM)) forage to concentrate ratios of either 500 : 500 (Mixed) or 79 : 921 (Concentrate). Steers were adapted to the diets over a 4-week period and performance and feed efficiency were then measured over a 56-day test period. Directly after the 56-day test, CH4 and carbon dioxide (CO2) emissions were measured (six steers/week) over a 13-week period. Compared with LU steers, CHX steers had greater average daily gain (ADG; P<0.05) and significantly (P<0.001) lower residual feed intake. Crossbred Charolais steers had superior conformation and fatness scores (P<0.001) than LU steers. Although steers consumed, on a DM basis, more Concentrate than Mixed diet (P<0.01), there were no differences between diets in either ADG or feed efficiency during the 56-day test. At slaughter, however, Concentrate-fed steers were heavier (P<0.05) and had greater carcass weights than Mixed-fed steers (P<0.001). Breed of steer did not influence CH4 production, but it was substantially lower when the Concentrate rather than Mixed diet was fed (P<0.001). Rumen fluid from Concentrate-fed steers contained greater proportions of propionic acid (P<0.001) and lower proportions of acetic acid (P<0.001), fewer archaea (P<0.01) and protozoa (P=0.09), but more Clostridium Cluster XIVa (P<0.01) and Bacteroides plus Prevotella (P<0.001) than Mixed-fed steers. When the CH4 to CO2 molar ratio was considered as a proxy method for CH4 production (g/kg DM intake), only weak relationships were found within diets. In conclusion, although feeding Concentrate and Mixed diets produced substantial differences in CH4 emissions and rumen characteristics, differences in performance were influenced more markedly by breed.
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Bovinos/fisiologia , Metano/metabolismo , Carne Vermelha/normas , Rúmen/metabolismo , Silagem/análise , Ácido Acético/análise , Animais , Cruzamento , Bovinos/classificação , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Masculino , Propionatos/análise , Rúmen/química , Rúmen/microbiologia , Rúmen/parasitologiaRESUMO
Adding nitrate to the diet or increasing the concentration of dietary lipid are effective strategies for reducing enteric methane emissions. This study investigated their effect on health and performance of finishing beef cattle. The experiment was a two×two×three factorial design comprising two breeds (CHX, crossbred Charolais; LU, Luing); two basal diets consisting of (g/kg dry matter (DM), forage to concentrate ratios) 520 : 480 (Mixed) or 84 : 916 (Concentrate); and three treatments: (i) control with rapeseed meal as the main protein source replaced with either (ii) calcium nitrate (18 g nitrate/kg diet DM) or (iii) rapeseed cake (RSC, increasing acid hydrolysed ether extract from 25 to 48 g/kg diet DM). Steers (n=84) were allocated to each of the six basal diet×treatments in equal numbers of each breed with feed offered ad libitum. Blood methaemoglobin (MetHb) concentrations (marker for nitrate poisoning) were monitored throughout the study in steers receiving nitrate. After dietary adaptation over 28 days, individual animal intake, performance and feed efficiency were recorded for a test period of 56 days. Blood MetHb concentrations were low and similar up to 14 g nitrate/kg diet DM but increased when nitrate increased to 18 g nitrate/kg diet DM (P0.05). Neither basal diet nor treatment affected carcass quality (P>0.05), but CHX steers achieved a greater killing out proportion (P<0.001) than LU steers. Thus, adding nitrate to the diet or increasing the level of dietary lipid through the use of cold-pressed RSC, did not adversely affect health or performance of finishing beef steers when used within the diets studied.
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Ração Animal/análise , Brassica rapa/química , Compostos de Cálcio/metabolismo , Bovinos/fisiologia , Dieta/veterinária , Metabolismo dos Lipídeos , Metemoglobina/metabolismo , Nitratos/metabolismo , Criação de Animais Domésticos , Animais , Bovinos/genética , Masculino , Carne Vermelha/análiseRESUMO
Increasing the concentration of dietary lipid is a promising strategy for reducing methane (CH4) emissions from ruminants. This study investigated the effect of replacing grass silage with brewers' grains on CH4 emissions of pregnant, non-lactating beef cows of two breeds. The experiment was a two×two factorial design comprising two breeds (LIMx, crossbred Limousin; and LUI, purebred Luing) and two diets consisting of (g/kg diet dry matter (DM)) barley straw (687) and grass silage (301, GS), or barley straw (763) and brewers' grains (226, BG), which were offered ad libitum. Replacing GS with BG increased the acid-hydrolysed ether extract concentration from 21 to 37 g/kg diet DM. Cows (n=48) were group-housed in equal numbers of each breed across two pens and each diet was allocated to one pen. Before measurements of CH4, individual dry matter intake (DMI), weekly BW and weekly body condition score were measured for a minimum of 3 weeks, following a 4-week period to acclimatise to the diets. CH4 emissions were subsequently measured on one occasion from each cow using individual respiration chambers. Due to occasional equipment failures, CH4 measurements were run over 9 weeks giving 10 observations for each breed×treatment combination (total n=40). There were no differences between diets for daily DMI measured in the chambers (9.92 v. 9.86 kg/day for BG and GS, respectively; P>0.05). Cows offered the BG diet produced less daily CH4 than GS-fed cows (131 v. 156 g/day: P0.05). However, when expressed as a proportion of metabolic BW (BW0.75), LUI cows had greater DMI than LIMx cows (84.5 v. 75.7 g DMI/kg BW0.75, P<0.05) and produced more CH4 per kg BW0.75 than LIMx cows (1.30 v. 1.05 g CH4/kg BW0.75; P<0.01). Molar proportions of acetate were higher (P<0.001) and propionate and butyrate lower (P<0.01) in rumen fluid samples from BG-fed compared with GS-fed cows. This study demonstrated that replacing GS with BG in barley straw-based diets can effectively reduce CH4 emissions from beef cows, with no suppression of DMI.
Assuntos
Bovinos/fisiologia , Dieta/veterinária , Hordeum/química , Metano/metabolismo , Poaceae/química , Silagem/análise , Animais , Gorduras na Dieta/metabolismo , Feminino , Gravidez , Rúmen/metabolismoRESUMO
The objectives of this study were to investigate the effects of (1) the addition of nitrate and (2) an increase in dietary oil on methane (CH4) and hydrogen (H2) emissions from 2 breeds (cross-bred Charolais and purebred Luing) of finishing beef cattle receiving 2 contrasting basal diets consisting (grams per kilogram DM) of 500:500 (Mixed) and 80:920 (Concentrate) forage to concentrate ratios. Within each basal diet there were 3 treatments: (i) control treatments (mixed-CTL and concentrate-CTL) contained rapeseed meal as the protein source, which was replaced with either (ii) calcium nitrate (mixed-NIT and concentrate-NIT) supplying 21.5 g nitrate/kg DM, or (iii) rapeseed cake (mixed-RSC and concentrate-RSC) to increase dietary oil from 27 (CTL) to 53 g/kg DM (RSC). Following adaption to diets, CH4 and H2 emissions were measured on 1 occasion from each of the 76 steers over a 13-wk period. Dry matter intakes tended (P = 0.051) to be greater for the concentrate diet than the mixed diet; however, when expressed as grams DMI per kilogram BW, there was no difference between diets (P = 0.41). Dry matter intakes for NIT or RSC did not differ from CTL. Steers fed a concentrate diet produced less CH4 and H2 than those fed a mixed diet (P < 0.001). Molar proportions of acetate (P < 0.001) and butyrate (P < 0.01) were lower and propionate (P < 0.001) and valerate (P < 0.05) higher in the rumen fluid from steers fed the concentrate diet. For the mixed diet, CH4 yield (grams per kilogram DMI) was decreased by 17% when nitrate was added (P < 0.01), while H2 yield increased by 160% (P < 0.001). The addition of RSC to the mixed diet decreased CH4 yield by 7.5% (P = 0.18). However, for the concentrate diet neither addition of nitrate (P = 0.65) nor increasing dietary oil content (P = 0.46) decreased CH4 yield compared to concentrate-CTL. Molar proportions of acetate were higher (P < 0.001) and those of propionate lower (P < 0.01) in rumen fluid from NIT treatments compared to respective CTL treatments. Overall, reductions in CH4 emissions from adding nitrate or increasing the oil content of the mixed diet were similar to those expected from previous reports. However, the lack of an effect of these mitigation strategies when used with high concentrate diets has not been previously reported. This study shows that the effect of CH4 mitigation strategies is basal diet-dependent.
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Ração Animal/classificação , Compostos de Cálcio/farmacologia , Bovinos/metabolismo , Gorduras Insaturadas na Dieta/farmacologia , Suplementos Nutricionais , Metano/metabolismo , Nitratos/farmacologia , Rúmen/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Brassica rapa , Compostos de Cálcio/administração & dosagem , Dieta/veterinária , Gorduras Insaturadas na Dieta/administração & dosagem , Grão Comestível , Efeito Estufa , Hidrogênio/metabolismo , Masculino , Nitratos/administração & dosagem , Nitratos/sangue , Rúmen/metabolismoRESUMO
A 5 MHz continuous-wave Doppler probe was used intraoperatively to evaluate 25 in situ saphenous vein bypass grafts. At least one arteriovenous fistula per case and five retained competent posterior valvular leaflets were identified before completion angiography. The Doppler was able to distinguish a retained valve from an arteriovenous fistula on clinical grounds but not by waveform analysis. Intraoperative assessment of in situ saphenous vein bypass grafts with the continuous-wave Doppler can identify retained valves that might be missed by angiography. It can reduce the number of angiograms needed to demonstrate a technically perfect result, thus saving operative time and contrast agent load to the patient.
Assuntos
Arteriopatias Oclusivas/cirurgia , Artéria Femoral/cirurgia , Cuidados Intraoperatórios , Perna (Membro)/irrigação sanguínea , Veia Safena/transplante , Ultrassonografia , Fístula Arteriovenosa/diagnóstico , Oclusão de Enxerto Vascular/diagnóstico , HumanosRESUMO
To estimate the number of physically disabled persons in Wellington a 10 percent random sample of households and institutions in the Wellington Hospital Board area was surveyed. There was a high response rate and from the results it has been established that the overall prevalence of physical disability in the population aged five years and over is 87.3 (+/- 4.2) per 1000. For persons living in the community (that is, excluding those in residential or hospital care) the rate of disability is 82.7 (+/- 3.5) per 1000. The rate of handicapping disability in the community is 41.3 (+/- 2.5) per 1000. The main disabling conditions most frequently reported were arthritis and deafness.
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Pessoas com Deficiência , Adolescente , Adulto , Fatores Etários , Idoso , Artrite/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Fatores SexuaisRESUMO
The laser methane detector (LMD) has been proposed as a method to characterize enteric methane (CH4) emissions from animals in a natural environment. To validate LMD use, its CH4 outputs (LMD-CH4), were compared against CH4 measured with respiration chambers (chamber-CH4). The LMD was used to measure CH4 concentration (µL/L) in the exhaled air of 24 lactating ewes and 72 finishing steers. In ewes, LMD was used on 1 d for each ewe, for 2-min periods at 5 hourly observation periods (P1 to P5, respectively) after feeding. In steers fed either low- or high-concentrate diets, LMD was used once daily for a 4-min period for 3 d. The week after LMD-CH4 measurement, ewes or steers entered respiration chambers to quantify daily CH4 output (g/d). The LMD outputs consisted of periodic events of high CH4 concentrations superimposed on a background of oscillating lower CH4 concentrations. The high CH4 events were attributed to eructation and the lower background CH4 to respiration. After fitting a double normal distribution to the data set, a threshold of 99% of probability of the lower distribution was used to separate respiration from eructation events. The correlation between mean LMD-CH4 and chamber-CH4 was not high, and only improved correlations were observed after data were separated in 2 levels. In ewes, a model with LMD and DMI (adjusted R(2) = 0.92) improved the relationship between DMI and chamber-CH4 alone (adjusted R(2) = 0.79) and between LMD and chamber-CH4 alone (adjusted R(2) = 0.86). In both experiments, chamber-CH4 was best explained by models with length of eructation events (time) and maximum values of CH4 concentration during respiration events (µL/L; P < 0.01). Correlation between methods differed between observation periods, indicating the best results of the LMD were observed from 3 to 5 h after feeding. Given the short time and ease of use of LMD, there is potential for its commercial application and field-based studies. Although good indicators of quantity of CH4 were obtained with respiration and eructation CH4, the method needed to separate the data into high and low levels of CH4 was not simple to apply in practice. Further assessment of the LMD should be performed in relation to animal feeding behavior and physiology to validate assumptions of eructation and respiration levels, and other sources of variation should be tested (i.e., micrometeorology) to better investigate its potential application for CH4 testing in outdoor conditions.
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Bovinos/metabolismo , Técnicas de Química Analítica/instrumentação , Lasers , Metano/metabolismo , Ovinos/metabolismo , Ar Condicionado , Animais , Técnicas de Química Analítica/métodos , Sistema Digestório/metabolismo , Meio Ambiente , Feminino , Lactação/metabolismo , Masculino , Metano/análise , Sistema Respiratório/metabolismoRESUMO
Handling temperament tests for beef cattle have been related to production traits, with calmer temperaments having greater growth rates. In most tests of temperament or personality, observation of the animal takes place over a short period of time, sometimes completed in a matter of minutes. This study investigated whether behavior observed in a temperament test was reflective of the steer's behavior in the home pen. Indoor-housed, crossbred, Bos taurus beef steers (n = 67) were fitted with triaxial activity monitors (IceTags; IceRobotics Ltd., South Queensferry, Edinburgh, Scotland) and activity was recorded for 2 periods of 14 d each. Also, each steer was scored on 4 measures of temperament: 2 handling tests (flight speed and chute score) and 2 feeding behavior scores (aggression at feeders and ability to displace at feeders). Each temperament observation was repeated 4 times, with repeatability of the traits ranging from 0.23 (aggression) to 0.48 (flight speed). Activity measures derived from the accelerometer data, such as bout lengths, were found to be highly repeatable between the 2 periods of activity monitoring (repeatabilities of 0.67 and 0.70 for average lying bout duration and average standing bout duration, respectively). Steers with high flight speeds were also more active in the home pen (MotionIndex: rs = 0.35, P = 0.004; average step count: rs = 0.34, P = 0.005) than steers with low flight speeds. Steers that were more capable of displacing other steers at feeders had longer average standing bout durations (rs = 0.26, P = 0.036), which were more variable (standing time SD: rs = 0.27, P = 0.030), and lay down for less time (rs = -0.35, P = 0.004). No correlations were found between aggression at feeders or chute score and home pen behavior. Results of this study are the first to demonstrate that short-term temperament tests are related to longer-term behavior data in beef steers and these results should be taken into consideration for future research.
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Comportamento Animal , Bovinos/fisiologia , Abrigo para Animais , Temperamento , Animais , Masculino , Monitorização Fisiológica/veterinária , Fatores de TempoRESUMO
The objective of this study was to examine the online use of near infrared reflectance (NIR) spectroscopy to estimate the concentration of individual and groups of fatty acids (FA) as well as intramuscular fat (IMF) in crossbred Aberdeen Angus (AA×) and Limousin (LIM×) cattle. This was achieved by direct application of a fibre-optic probe to the muscle immediately after exposing the meat surface in the abattoir at 48 h post mortem. Samples of M. longissimus thoracis from 88 AA× and 106 LIM× were scanned over the NIR spectral range from 350 to 1800 nm and samples of the M. longissimus lumborum were analysed for IMF content and FA composition. Statistically significant differences (P < 0.001) were observed in most FA between the two breeds studied, with FA concentration being higher in AA× meat mainly. NIR calibrations, tested by cross-validation, showed moderate to high predictability in LIM× meat samples for C16:0, C16:1, C18:0, trans11 C18:1, C18:1, C18:2 n-6, C20:1, cis9, trans11 C18:2, SFA (saturated FA), MUFA (monounsaturated FA), PUFA (polyunsaturated FA) and IMF content with R(2) (SE(CV), mg/100 g muscle) of 0.69 (146), 0.69 (28), 0.71 (62), 0.70 (8.1), 0.76 (192), 0.65 (13), 0.71 (0.9), 0.71 (2.9), 0.68 (235), 0.75 (240), 0.64 (17) and 0.75 (477), respectively. FA such as C14:0, C18:3 n-3, C20:4 n-6, C20:5 n-3, C22:6 n-3, n-6 and n-3 were more difficult to predict by NIR in these LIM× samples (R(2) = 0.12 to 0.62; SECV = 0.5 to 26 mg/100 g muscle). In contrast, NIR showed low predictability for FA in AA× beef samples. In particular for LIM×, the correlations of NIR measurements and several FA in the range from 0.81 to 0.87 indicated that the NIR spectroscopy is a useful online technique for the early, fast and relatively inexpensive estimation of FA composition in the abattoir.
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Government policies relating to red meat production take account of the carbon footprint, environmental impact, and contributions to human health and nutrition, biodiversity and food security. This paper reviews the impact of grazing on these parameters and their interactions, identifying those practices that best meet governments' strategic goals. The recent focus of research on livestock grazing and biodiversity has been on reducing grazing intensity on hill and upland areas. Although this produces rapid increases in sward height and herbage mass, changes in structural diversity and plant species are slower, with no appreciable short-term increases in biodiversity so that environmental policies that simply involve reductions in numbers of livestock may not result in increased biodiversity. Furthermore, upland areas rely heavily on nutrient inputs to pastures so that withdrawal of these inputs can threaten food security. Differences in grazing patterns among breeds increase our ability to manage biodiversity if they are matched appropriately to different conservation grazing goals. Lowland grassland systems differ from upland pastures in that additional nutrients in the form of organic and inorganic fertilisers are more frequently applied to lowland pastures. Appropriate management of these nutrient applications is required, to reduce the associated environmental impact. New slurry-spreading techniques and technologies (e.g. the trailing shoe) help reduce nutrient losses but high nitrogen losses from urine deposition remain a key issue for lowland grassland systems. Nitrification inhibitors have the greatest potential to successfully tackle this problem. Greenhouse gas (GHG) emissions are lower from indoor-based systems that use concentrates to shorten finishing periods. The challenge is to achieve the same level of performance from grass-based systems. Research has shown potential solutions through the use of forages containing condensed tannins or establishing swards with a high proportion of clover and high-sugar grasses. Relative to feeding conserved forage or concentrates, grazing fresh grass not only reduces GHG emissions but also enhances the fatty acid composition of meat in terms of consumer health. It is possible to influence biodiversity, nutrient utilisation, GHG emissions and the nutritional quality of meat in grass-based systems, but each of these parameters is intrinsically linked and should not be considered in isolation. Interactions between these parameters must be considered carefully when policies are being developed, in order to ensure that strategies designed to achieve positive gains in one category do not lead to a negative impact in another. Some win-win outcomes are identified.
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Fearful behavioral responses to handling (temperament) are undesirably associated with ADG and meat quality in infrequently handled Bos indicus cattle. It has never been assessed whether these relationships exist in calmer Bos taurus breeds in systems where handling is more frequent. Such systems predominate in some countries where beef production is a major agricultural activity. During fattening, 144 crossbred cattle from Limousin and Aberdeen Angus sires were assessed for temperament using 4 approaches: response to movement along a race (race score; 4 occasions), restraint in a crush (crush score; 4 occasions), flight speed from the crush (flight speed; 4 occasions), and isolation in a pen with a human (isolation score; 1 occasion in yr 1, 2 occasions in yr 2). Measurements of ADG were made between birth and slaughter and between 16 and 18 mo of age during fattening. Fattening occurred indoors on a complete mixed diet fed for ad libitum intake. Meat quality was measured by pH, color, and Volodkevitch shear force and by a sensory panel. The repeatability of temperament traits was 0.17 (race score), 0.35 (crush score), 0.51 (flight speed), and 0.36 (isolation score). The proportion of the total variance of temperament traits attributable to the sire and the social group was low (0.003 to 0.402). However, the sire did affect behavior in all tests apart from the crush score (ranging from P = 0.02 to P < 0.001). Correlations between behavior in the different tests (ranging from r = 0.21 to 0.54, and P = 0.02 to P < 0.001) apart from between-flight speed and isolation score indicate that fearful behavior was consistently shown across assessment methods. A calm response in the crush score test was associated with a greater ADG during fattening (P = 0.05), whereas a calm response during the isolation test was associated with a greater ADG in cold carcass weight (P = 0.02). Animals with a calm isolation score had less tender meat as judged by the sensory panel (P = 0.03), but no other effects were apparent between temperament and meat quality measures, although several tendencies (0.06 ≤ P ≤ 0.10) were found. Temperament did not appear to relate to meat quality in this study of frequently handled Bos taurus genotypes, which is in contrast to other studies using different beef production systems. Genetic correlations between temperament and meat quality under these conditions could, although not measured in this study, still exist in the absence of phenotypic correlations.
Assuntos
Carne/normas , Criação de Animais Domésticos , Animais , Comportamento Animal , Bovinos , Medo , Feminino , Masculino , TemperamentoRESUMO
The potential of X-ray computed tomography (CT) as a predictor of cuts composition and meat quality traits using a multivariate calibration method (partial least square regression, PLSR) was investigated in beef cattle. Sirloins from 88 crossbred Aberdeen Angus (AAx) and 106 Limousin (LIMx) cattle were scanned using spiral CT. Subsequently, they were dissected and analyzed for technological and sensory parameters, as well as for intramuscular fat (IMF) content and fatty acid composition. CT-PLSR calibrations, tested by cross-validation, were able to predict with high accuracy the subcutaneous fat (R2, RMSECV=0.94, 34.60 g and 0.92, 34.46 g), intermuscular fat (R2, RMSECV=0.81, 161.54 g and 0.86, 42.16 g), total fat (R2, RMSECV=0.89, 65.96 g and 0.93, 48.35 g) and muscle content (R2, RMSECV=0.99, 58.55 g and 0.97, 57.45 g) in AAx and LIMx samples, respectively. Accurate CT predictions were found for fatty acid profile (R2=0.61-0.75) and intramuscular fat content (R2=0.71-0.76) in both sire breeds. However, low to very low accuracies were obtained for technological and sensory traits with R2 ranged from 0.01 to 0.26. The image analysis evaluated provides the basis for an alternative approach to deliver very accurate predictions of cuts composition, IMF content and fatty acid profile with lower costs than the reference methods (dissection, chemical analysis), without damaging or depreciating the beef cuts.
Assuntos
Tecido Adiposo/química , Gorduras na Dieta/análise , Ácidos Graxos/análise , Análise de Alimentos/métodos , Carne/análise , Músculo Esquelético/química , Tomografia Computadorizada Espiral/métodos , Animais , Bovinos , Carne/normas , Reprodutibilidade dos TestesRESUMO
More than 800 beef primal cuts from 44 Aberdeen Angus and Limousin-cross steers carcasses were scanned using spiral computed tomography (CT) and dissected. Thresholds for the segmentation of fat, muscle and bone in the CT spirals were estimated with the objective of assessing the weight of these tissues in the primal cuts and in the entire carcasses. Thresholds were estimated using half of the dataset (DBE) and then validated in the other half (DBV). Automatic image analysis procedures were used to assess tissue weights. The R(2) of the regression between primal tissue weight by dissection and CT were high in both datasets for fat (DBE, 0.89; DBV, 0.92), muscle (DBE, 0.99; DBV, 0.99) and bone (DBE, 0.95; DBV, 0.97). The estimation of total carcass tissue weights were also very accurate for the three tissues (R(2) values of 0.95 to 0.96), indicating that CT scanning may deliver very accurate information on beef carcass composition faster and with lower cost than physical dissection and without damaging or depreciating the primal joints.
Assuntos
Indústria de Embalagem de Carne/métodos , Carne , Tomografia Computadorizada Espiral , Tecido Adiposo Branco/anatomia & histologia , Animais , Composição Corporal , Peso Corporal , Osso e Ossos/anatomia & histologia , Bovinos , Dissecação , Tecnologia de Alimentos/métodos , Masculino , Indústria de Embalagem de Carne/economia , Músculo Esquelético/anatomia & histologia , Tamanho do Órgão , Especificidade de Órgãos , Valores de Referência , Reprodutibilidade dos Testes , Especificidade da EspécieRESUMO
The potential of the composition of the forerib measured by X-ray computed tomography (CT) as a predictor of carcass composition was evaluated using data recorded on 30 Aberdeen Angus and 43 Limousin crossbred heifers and steers. The left sides of the carcasses were split into 20 cuts, which were CT scanned and fully dissected into fat, muscle and bone. Carcass and forerib tissue weights were assessed by dissection and CT. Carcass composition was assessed very accurately by CT scanning of the primal cuts (adj-R2 = 0.97 for the three tissues). CT scanning predicted weights of fat, muscle and bone of the forerib with adj-R2 of 0.95, 0.91 and 0.75, respectively. Single regression models with the weights of fat, muscle or bone in the forerib measured by CT as the only predictors to estimate fat, muscle or bone of the left carcass obtained by CT showed adjusted coefficients of determination (adj-R2) of 0.79, 0.60 and 0.52, respectively. By additionally fitting breed and sex, accuracy increased to 0.85, 0.73 and 0.67. Using carcass and forerib weights in addition to the previous predictors improved significantly the prediction accuracy of carcass fat and muscle weights to adj-R2 values of 0.92 and 0.96, respectively, while the highest value for carcass bone weight was 0.77. In general, equations derived using CT data had lower adj-R2 values for bone, but better accuracies for fat and muscle compared to those obtained using dissection. CT scanning could be considered as an alternative very accurate and fast method to assess beef carcass composition that could be very useful for breeding programmes and research studies involving a large number of animals, including the calibration of other indirect methods (e.g. in vivo and carcass video image analysis).
RESUMO
Retained surgical sponge is an infrequently reported condition that may be recognized incidentally during the early postoperative period, produce serious complications, or remain dormant for years. Clinical manifestations of the retained surgical sponge are a function of bacterial contamination and of the location of the sponge within the body cavity. Few sequelae follow external extrusion but internal erosion may lead to abscess, fistulas, and intestinal obstruction. Prevention requires constant sensitivity of the surgeon to this potential threat to the safe practice of surgery. The surgeon must account for an incorrect sponge count by adequate examination of the operative field and by roentgenographic studies when the issue remains in doubt. A correct sponge count does not fully preclude a retained sponge, however, and inspection of the operative field should be routine in all patients at risk.
Assuntos
Equipamentos Cirúrgicos , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Infecções Bacterianas/etiologia , Feminino , Humanos , Obstrução Intestinal/etiologia , Complicações Intraoperatórias/prevenção & controle , Masculino , Imperícia , Pessoa de Meia-Idade , Radiografia AbdominalRESUMO
An in sacco mobile bag technique was used to determine the rate and extent of disappearance of unmolassed sugar-beet pulp, soyabean hulls, hay cubes and an oat hull-naked oats mixture (67:33, w/w) in the foregut and total digestive tract of ponies. Ponies were administered naso-gastrically polyester mesh bags containing 350 mg feed, in a Latin square design. Bags were collected at the ileo-caecal junction (small intestine bag, SIB) and in the faeces (faecal bag, FB) and their residues analysed for proximate constituents and NSP composition and content. DM disappearances from individual bags were fitted to degradation profiles (Ørskov & McDonald, 1979) and effective degradability values determined. Significant differences (P<0.05) in DM, organic matter and crude protein losses from SIB were noted between feeds with hay cubes and oat hulls-naked oats > sugar-beet pulp and soyabean hulls. Acid-detergent fibre, neutral-detergent fibre and NSP disappearances were small and varied little between feeds. In contrast, FB losses showed significant (P<0.05) differences for all constituents measured with sugar-beet pulp > soyabean hulls > hay cubes > oat hulls-naked oats. Crude protein losses from sugar-beet pulp and soyabean hulls in FB were significantly higher (P<0.05) than from SIB. FB degradation curves showed degradation to be affected by bag residence time with sugar-beet pulp > soyabean hulls and the effective degradability showed that significantly more (P<0.05) sugar-beet pulp was lost at 40.0 and 60.0 h than for the other three feeds. These results show that sugar-beet pulp and soyabean hulls are rapidly degraded by ponies and could be used as alternatives to hay in equid rations. However, the foregut availability of crude protein from sugar-beet pulp is poor, so a readily digestible source of crude protein should be offered to animals with high protein demands when diets are based on sugar-beet pulp.