The ontogenetic allometry of body morphology and chemical composition in dairy goat wethers.

We studied the ontogenetic growth of goat wethers (castrated male goats) of the Saanen and Swiss Alpine breeds based on a large range of intraspecific body mass (BM). The body parts and the chemical constituents of the empty body were described by the allometric function by using BM and the empty body mass (EBM) as the predictors for morphological traits and chemical composition, respectively. We fitted the allometric scaling function by applying the SAS NLMIXED procedure, but to evaluate assumptions regarding variances in morphological and compositional traits, we combined the scaling function with homoscedastic (MOD1), and the heteroscedastic exponential (MOD2) and power-of-the-mean (MOD3) variance functions. We also predicted the ontogenetic growth by using the traditional log-log transformation and back-transformed results into the arithmetic scale (MOD4). We obtained predictions from MOD4 in the arithmetic scale by a two-step process, and evaluated MOD1, MOD2 and MOD3 by a model selection framework, and compared MOD4 with MOD1, MOD2 and MOD3 based on goodness-of-fit measures. Based on information criteria for model selection, heterogeneous variance functions were more likely to describe 10 over 36 traits with a low level of model selection uncertainty. One trait was predicted by averaging the MOD1 and MOD2 variance functions; and nine traits were better described by averaging the MOD2 and MOD3 variance functions. The predictions for other 16 traits were averaged from MOD1, MOD2 and MOD3. However, MOD4 better described 11 traits according to the goodness-of-fit measures. Depending on the variable being analyzed, the body parts and the chemical amounts exhibited the three types of allometric behavior with respect to BM and EBM, that is, positive, negative and isometric ontogenetic growth. Reference BMs, that is, 20, 27, 35 and 45 kg, were used to compute the net protein and energy requirements based on the first derivative of the scaling function, and the results were presented in reference to the EBM and EBM0.75. Both the net protein and energy requirements scaled to EBM0.75 increased from 20 to 45 kg of BM.

Alterações radiográficas do aparato podotroclear de equinos da Polícia Militar de Minas Gerais sem sinais clínicos de doença do osso navicular / Radiographic changes in the podotroclear apparatus from Minas Gerais State Military horses without clinical signs of navicular disease

Os objetivos deste experimento foram identificar e associar alterações radiográficas do aparato podotoclear de equinos do Regimento de Cavalaria Alferes Tiradentes da Policia Militar do estado de Minas Gerais sem histórico e sinais clínicos de doença do osso navicular. Foi avaliado um total de 33 equinos, de ambos os sexos, com idade entre 10 e 20 anos. Os dígitos torácicos foram radiografados de forma padronizada nas projeções lateromedial (LM), dorsoproximal palmarodistal 65º (DPPD) e palmaroproximal palmarodistal (SK). A radiopacidade medular aumentada em projeção SK foi a principal alteração radiográfica detectada. Essa alteração foi associada a maior número de invaginações sinovais, a maior espessura de cortical em relação à medular em exposição SK e a maior relação corticomedular em exposição LM (P<0,05). Esses achados indicam uma predisposição da população equina para desenvolver a síndrome do osso navicular, possivelmente associada ao trauma repetitivo promovido pelo constante trabalho em piso duro.

The aims of this study were to identify and associate radiographic changes of podotoclear apparatus in horses from the Tiradentes Calvary Regiment of the Military Police of Minas Gerais State without history and clinical signs of navicular disease. 33 horses from both sexes, aged between 10 and 20 years were evaluated. The thoracic digits were radiographed in a standardized manner in lateralmedial (LM), palmaroproximal-distodorsal 65o(DPPD) and palmaroproximal-distopalmar (SK) projections. The increased medullary radiopacity in SK projection was the main radiological change detected and was associated with a higher number of synoval invaginations, increased cortical thickness in relation to medulla in SK exposure and increased corticomedullar in LM exposure (P < 0.05). These findings indicate a predisposition of this population to develop navicular syndrome, which is possibly associated with repetitive trauma promoted by constant work on hard floors.

Using the Small Ruminant Nutrition System to develop and evaluate an alternative approach to estimating the dry matter intake of goats when accounting for ruminal fiber stratification.

The first objective of this research was to assess the ability of the Small Ruminant Nutrition System (SRNS) mechanistic model to predict metabolizable energy intake (MEI) and milk yield (MY) when using a heterogeneous fiber pool scenario (GnG1), compared with a traditional, homogeneous scenario (G1). The second objective was to evaluate an alternative approach to estimating the dry matter intake (DMI) of goats to be used in the SRNS model. The GnG1 scenario considers an age-dependent fractional transference rate for fiber particles from the first ruminal fiber pool (raft) to an escapable pool (λr), and that this second ruminal fiber pool (i.e., escapable pool) follows an age-independent fractional escape rate for fiber particles (ke). Scenario G1 adopted only a single fractional passage rate (kp). All parameters were estimated individually by using equations published in the literature, except for 2 passage rate equations in the G1 scenario: 1 developed with sheep data (G1-S) and another developed with goat data (G1-G). The alternative approach to estimating DMI was based on an optimization process using a series of dietary constraints. The DMI, MEI, and MY estimated for the GnG1 and G1 scenarios were compared with the results of an independent dataset (n=327) that contained information regarding DMI, MEI, MY, and milk and dietary compositions. The evaluation of the scenarios was performed using the coefficient of determination (R(2)) between the observed and predicted values, mean bias (MB), bias correction factor (Cb), and concordance correlation coefficient. The MEI estimated by the GnG1 scenario yielded precise and accurate values (R(2) = 082; MB = 0.21 Mcal/d; Cb = 0.98) similar to those of the G1-S (R(2) = 0.85; MB = 0.10 Mcal/d; Cb=0.99) and G1-G (R(2) = 0.84; MB = 0.18 Mcal/d; Cb = 0.98) scenarios. The results were also similar for the MY, but a substantial MB was found as follows: GnG1 (R(2) = 0.74; MB = 0.70 kg/d; Cb = 0.79), G1-S (R(2) = 0.71; MB = 0.58 kg/d(1); Cb = 0.85) and G1-G (R(2) = 0.71; MB = 0.65 kg/d; Cb = 0.82). The alternative approach for DMI prediction provided better results with the G1-G scenario (R(2)=0.88; MB = -71.67 g/d; Cb = 0.98). We concluded that the GnG1 scenario is valid within mechanistic models such as the SRNS and that the alternative approach for estimating DMI is reasonable and can be used in diet formulations for goats.

Estudo da correlação de medidas radiográficas indicadoras de laminite em éguas da raça Mangalarga Marchador com e sem sinais de sobrepeso / Correlation study about radiographic measurements signaling laminitis in Mangalarga Marchador mares with or without signs of overweight

A avaliação radiográfica do casco é essencial no diagnóstico e na avaliação da laminite em equinos, contudo poucos estudos têm sido feitos em raças nacionais. O objetivo deste trabalho foi realizar a morfometria de imagens radiográficas obtidas do dígito de éguas Mangalarga Marchador (MM), a fim de obter um perfil de medidas indicadoras de laminite nessa população e comparar grupos sem (escore corporal 5 e 6) e com (escore corporal 7 e 8) sinais de sobrepeso. Não houve diferença significativa entre os valores para as medidas dos dois grupos (P>0,05), mas verificou-se correlação positiva entre a distância entre os planos da linha coronária e do ápice do processo extensor (afundamento da falange distal) e indicadores de deposição de gordura localizada no pescoço e na base da cauda. Os achados demonstram que a morfometria radiográfica do dígito dessa população de equinos Mangalarga Marchador difere da de raças estrangeiras. Além disso, nos animais estudados, éguas com escore corporal 7 e 8 não aparentaram estarem mais sujeitas à laminite, uma vez que não houve diferença entre a morfometria de éguas com escore inferior. Entretanto, as correlações positivas entre índices de obesidade e a distância de afundamento da falange distal indicam que éguas Mangalarga Marchador também estão sujeitas à ocorrência de laminite associada à obesidade...

The radiographic evaluation of the hoof is essential in the diagnosis and follow-up of equine laminitis; however, few studies have been conducted in Brazilian breeds. The aim was to perform the morphometry of radiographic images taken from the digit of Mangalarga Marchador in order to obtain a profile of measurements indicative of laminitis in this population. We also compared measurements form mares without (body score 5 and 6) and with (body score 7 and 8) signs of overweight. There was no significant difference between measurements from the two groups (P> 0.05), but there was significant positive correlation between founder distance and signs of adiposity in the neck and in the base of the tail. Findings from this study demonstrate that radiographic morphology of the hoof from this population of Mangalarga Marchador mares differ from standard international reference values. Furthermore, in this group of mares, those with body condition grading 7 and 8 did not seem to be more prone to develop laminitis, since there was no difference when they were compared with mares showing lower grades. However, a significant correlation among founder distance and signs of adiposity in the neck and base of tail indicate that Mangalarga Marchador mares are also prone to obesity-associated laminitis...

Estudo radiográfico do posicionamento da falange distal e suas possíveis correlações com obesidade em equinos de patrulhamento da Polícia Militar do Estado de Minas Gerais / Radiographic study of the distal phalanx position and their possible correlation with obesity in patrol horses from the Military Police of Minas Gerais

Com o objetivo de se verificarem possíveis correlações entre a falange distal, o estojo córneo e a obesidade, 55 equinos de patrulhamento provenientes do Regimento de Cavalaria Alferes Tiradentes do Estado de Minas Gerais - RCAT tiveram seus dígitos torácicos radiografados. Posteriormente, os animais foram classificados quanto ao acúmulo de tecido adiposo regional por métodos subjetivos (escore corporal e escore de pescoço) e objetivos (índice de massa corporal, circunferência do pescoço e determinação de espessura do tecido adiposo por meio de ultrassonografia na inserção da cauda e do abdômen). Na população estudada, o índice de massa corporal evidenciou que 52,6 por cento dos equinos se encontravam acima do peso. A circunferência do pescoço a 50 por cento de seu comprimento dorsal e a medida ultrassonográfica na inserção da cauda se mostraram os melhores métodos objetivos para quantificar o acúmulo de tecido adiposo. Foram identificadas particularidades radiográficas características da população estudada que diferem de parâmetros internacionais. Observaram-se correlações significantes entre sinais de obesidade e medidas radiográficas indicadoras de laminite, sugerindo associação entre essas duas condições na população estudada...

With the aim to verify possible correlations between the spatial relationship between the distal phalanx and the hoof and signs of obesity, 55 horses from the Cavalry Regiment Alferes Tiradentes of Minas Gerais State Police - RCAT had x-rays taken from their thoracic hoofs. After that, horses were classified based on their subjective (body condition and neck scores) and objective (body mass index, neck circumferences, ultrasound measurement of fat tissue of the tail and on abdomen) methods for adiposity. Within the population, the body mass index showed that 52.6 percent of horses were overweight. Neck circumference at 50 percent of its dorsal length and ultrasound measurement of fat thickness on the insertion of the tail were the best objective methods. We identified specific radiographic characteristics of the population that were different from international parameters. Significant correlations among signs of obesity and measurements that indicate lamintis were found, suggesting association between these conditions in this horse population...

Assessment of the heterogeneous ruminal fiber pool and development of a mathematical approach for predicting the mean retention time of feeds in goats.

The objectives of this study were to evaluate ruminal fiber stratification and to develop a mathematical approach for predicting the mean retention time (MRT) of forage and concentrates in goats. A dataset from 3 studies was used that contained information regarding fiber and lignin intake as well as ruminal content and the kinetics of fiber passage for forage and concentrates. The kinetic information was obtained through pulse dose and the fecal concentration measurement of forage and concentrate markers in the same animals that were used to measure ruminal content. The evaluation of heterogeneous fiber pools in the rumen was performed using the Lucas' test assumptions, and the marker excretion profiles were interpreted using a model known in the literature as GNG1. The GNG1 model assumes an age-dependent fractional rate for the transfer of particles from the raft to the escapable pool in the rumen (λ(r); h(-1)) and an age-independent fractional rate for the escape of particles from the escapable pool to the remaining parts of the stomach (k(e); h(-1)). The equations used to predict the MRT for forage and concentrate fiber were developed using stepwise regression. A sensitivity analysis was conducted using a Monte Carlo simulation to investigate the relationships between the dependent and independent variables and between forage and concentrate passage rates. The Lucas' test yields goodness-of-fit estimates for NDF analysis; however, the homogeneous fiber pool approach could not be applied because a positive intercept (P < 0.05) was identified for lignin ruminal content. The stepwise regression model for MRT estimation had an approximate coefficient of determination and a root mean square error (RMSE) for forage of 0.53 and 9.78 h, respectively, and for concentrate of 0.49 and 5.86 h, respectively. The sensitivity analysis yielded a mean rate of passage (k(p)) value for forage of 0.0322 h(-1) (0.0158 to 0.0556 h(-1)) with 99% confidence interval. For the concentrate, the mean k(p) value was of 0.0334 h(-1) (0.0146 to 0.0570 h(-1)). A heterogeneous ruminal fiber pool should be assumed for goats fed diets with considerable fiber contents. The results of the sensitivity analysis indicated that both λ(r) and k(e) are of similar importance to the rate of passage in goats. The rates of passage of forage and concentrates in goats present a high degree of overlap and are closely related.

Evaluation of acid detergent insoluble protein as an estimator of rumen non-degradable protein in tropical grass forages / Evaluation of acid detergent insoluble protein as an estimator of rumen non-degradable protein in tropical grass forages / Avaliação da proteína insolúvel em detergente ácido como estimador da proteína não degradável no rúmen para forragens tropicais

Estimou-se a fração protéica não degradável no rúmen obtida a partir dos compostos nitrogenados insolúveis em detergente ácido (PIDA). Foram utilizadas 96 amostras obtidas por simulação manual de pastejo e extrusa esofágica em dois sistemas de pastejo rotacionado com capim-elefante (Pennisetum purpureum cv. Napier) e com capim-mombaça (Pannicum maximum cv. Mombaça). A fração protéica não degradável no rúmen observada ou real foi obtida por intermédio de incubação ruminal das amostras por 240 horas, seguida de tratamento com detergente neutro, denominada proteína não degradável insolúvel em detergente neutro (PIIDN). A comparação entre valores preditos e observados foi feita por intermédio do ajustamento de equação de regressão linear simples de valores preditos sobre valores observados (PIIDN). Os resultados permitiram evidenciar a não-equivalência (P<0,01) e a não associação (P>0,28) entre os valores preditos e observados da fração protéica não degradável. Sugere-se que a PIDA não seja adotada como estimador da fração protéica não degradável, a qual deve ser estimada por intermédio de métodos biológicos, dentre os quais sugerem-se os protocolos adotados para obtenção das concentrações de PIIDN.

Parâmetros cinéticos da degradação in vitro de alimentos incubados com inóculo microbiano de diferentes espécies de ruminantes / Kinetic parameters of the ruminal in vitro degradation of feedstuffs given to different ruminant species

Parâmetros cinéticos da degradação ruminal de alguns alimentos utilizados para ruminantes de zoológicos foram estimados mediante incubação in vitro com líquido ruminal de audade (Ammotragus lervia), cervo sambar (Cervus unicolor), elande (Taurotragus oryx), bovino (Bos taurus), bubalino (Bubalus bubalis), caprino (Capra hircus) e ovino (Ovis aries). Os parâmetros cinéticos foram estimados pela técnica da produção de gás, cujos dados foram ajustados pelos modelos de um e de duplo compartimento. Não foram detectadas diferenças nos parâmetros cinéticos que permitissem agrupar os alimentos (fibrosos não fibrosos) e os animais (domésticos silvestres). O modelo de duplo compartimento foi o mais adequado para a estimação dos parâmetros cinéticos da degradação ruminal. Inóculo microbiano oriundo de ruminantes domésticos não é recomendado para estimar parâmetros cinéticos da degradação ruminal de alimentos utilizados para ruminantes silvestres de zoológicos.