RESUMO: Nos sistemas tradicionais de produção de ovinos em regiões tropicais, a avaliação e monitoramento do crescimento dos animais não são práticas comuns. Isso se deve principalmente à adoção limitada de tecnologia e aos altos custos associados à aquisição de balanças para animais. O presente estudo teve como objetivo desenvolver equações para prever o peso corporal (PC) de borregas Pelibuey usando uma fórmula de Volume Corporal (VC). Foram obtidos dados de PC e VC de 85 borregas. Os modelos avaliados foram os seguintes: 1) linear, 2) quadrático, 3) cúbico, 4) alométrico, 5) exponencial e 6) logarítmico. Além disso, a capacidade preditiva dos modelos para o PC foi avaliada por meio de validação cruzada k-fold (k=10). O PC e VC foram 20,60 ± 8,73 kg e 17,54 ± 7,89 dm3, respectivamente. O modelo quadrático apresentou o maior r2 e os menores valores de erro do quadrático médio, raiz do erro do quadrático médio e critério de informação bayesiano, enquanto a técnica de validação cruzada k-fold também teve o maior r2 e os menores valores de erro quadrático médio de predição e erro médio absoluto. O modelo quadrático foi o melhor desempenho matemático para predizer o PC de cordeiras Pelibuey em crescimento usando o VC. RESUMO tropicais comuns (PC . (VC) 8 seguintes 1 linear 2 3 cúbico 4 alométrico 5 6 logarítmico disso kfold k fold k=10. k10 k=10 10 (k=10) 2060 20 60 20,6 873 73 8,7 1754 17 54 17,5 789 7 89 7,8 dm3 dm respectivamente r bayesiano absoluto (VC k1 k=1 (k=10 206 20, 87 8, 175 17, 78 7, k= (k=1 (k= (k

ABSTRACT: In traditional sheep production systems in tropical regions, the evaluation and monitoring of animal growth are not commonly practiced. This is primarily attributed to the limited adoption of technology and the high costs associated with acquiring livestock scales. The present study developed equations to predict body weight of Pelibuey ewe lambs using a Body Volume (BV) formula. BW and BV were obtained from 85 ewe lambs. The models evaluated were as follows: 1) linear, 2) quadratic, 3) cubic, 4) allometric, 5) exponential and 6) logarithmic. In addition, the models’ predictive ability for BW was assessed by k-fold (k=10) cross-validation. The BW and BV were 20.60 ± 8.73 kg and 17.54 ± 7.89 dm3, respectively. The quadratic model showed the highest r2 and the lowest values of mean square error, root mean square error, and bayesian information criterion, while the k-fold cross-validation technique also had the highest r2 and the lowest values of mean squared prediction error and mean absolute error. The quadratic model was the best performing mathematical model for predicting BW of growing Pelibuey ewe lambs using BV. ABSTRACT regions practiced scales (BV formula 8 follows 1 linear 2 3 cubic 4 allometric 5 6 logarithmic addition kfold k fold k=10 k10 10 (k=10 crossvalidation. crossvalidation cross validation. validation 2060 20 60 20.6 873 73 8.7 1754 17 54 17.5 789 7 89 7.8 dm3 dm respectively r criterion k=1 k1 (k=1 206 20. 87 8. 175 17. 78 7. k= (k= (k

Abstract: This study was conducted to evaluate body fat reserves (BFD) and their relationship to ultrasound back fat thickness (BFT) measurements in twenty Pelibuey ewes. The BFT was determined 24 h before slaughter using real-time ultrasound equipment with a 6/8 MHz probe. At slaughter, internal fat (TIF) was dissected and weighed. The carcasses were split into two halves, weighed and chilled (6°C for 24 h). The left half-carcasses were completely dissected into muscle, bone and subcutaneous and intermuscular fat (carcass fat, TCF), and weighed separately. The r values for BFT and BFD ranged from 0.39 to 0.72. Regression equations between BFT and BFD had an R2 ranging from 0.15 to 0.52. Using BFT to predict BFD in Pelibuey ewes was poorly correlated.

Resumen: El estudio se realizó para evaluar las reservas corporales de grasa (DCG) y su relación con el espesor de la grasa subcutánea (EGS) medido con ultrasonido en 20 ovejas Pelibuey. EL EGS se determinó utilizando un equipo de ultrasonido en tiempo real con sonda de 6/8 MHz. Al sacrificio, la grasa interna (TIF) fue disecada y pesada; la canal se dividió en dos mitades, se pesaron y refrigeraron (6° C durante 24 h). La media canal izquierda se diseccionó en: músculo, hueso y grasa subcutánea e intermuscular (grasa de la canal, TCF), y fueron pesados por separado. Los valores de r para EGS y DCG variaron de 0.39 a 0.72. Las ecuaciones de regresión entre EGS y DCG tuvieron un R2 que varió de 0.15 a 0.52. El uso del EGS para predecir DCG en ovejas Pelibuey fue pobremente correlacionada.

The aim of this study was to evaluate carcass and non-carcass components of adult Pelibuey ewes subjected to three levels of metabolizable energy intake (MEI). Eighteen 3-year-old Pelibuey ewes with body weight (BW) of 37.6 ± 4.0 kg and body condition of 2.5 ± 0.20 were randomly assigned to three groups of six ewes each in a completely randomized design. Ewes were housed in metabolic crates and fed three levels of MEI: low (L), medium (M), and high (H) for 65 d. Feed offered was adjusted every 15 d based on ewe BW. The MEI was 0.247, 0.472 and 0.532 MJ/ kgBW0.75d-1 for L, M and H levels, respectively. Data recorded at slaughter were weights of viscera, offal and carcass. Carcass was split at the dorsal midline into two equal halves, weighed, and chilled at 6°C for 24 h. The left half carcass was then divided into five cuts, each of which was dissected into fat, muscle and bone, and weighed separately. Hot and cold carcass weight and hot carcass dressing were greater for the H group than for the L group (p < 0.05). The weights of rib/flank and shoulder were different among groups (p < 0.05). Weights of empty rumen, liver, lungs and trachea, skin and internal fat were greater for the H group than for the L group (p < 0.05). A high level of MEI improves commercial dressing percentage due to increased lean meat and fat deposition with a lower proportion of bone in the carcass of adult Pelibuey ewes.

El objetivo del presente estudio fue evaluar los componentes de la canal y no canal de ovejas Pelibuey sometidas a tres niveles de consumo de energía metabolizable (CEM). Dieciocho ovejas Pelibuey de 3 años de edad, peso vivo (PV) de 37.6 ± 4.0 kg y condición corporal de 2.5 ± 0.20 fueron asignadas aleatoriamente a uno de tres grupos de seis animales, bajo un diseño completamente a la azar. Las ovejas fueron mantenidas en jaulas metabólicas y alimentadas con tres niveles de CEM: Bajo (B), Medio (M) y Alto (A) durante 65 d. El alimento ofrecido fue ajustadocada 15 d con base al PV. El CEM fue: 0.247, 0.472 y 0.532 MJ/ kgPV0.75d-1 para B, M y A, respectivamente. Al sacrificio se registró el peso de las visceras, desperdicios y canal; esta última fue dividida en dos partes, pesadas y refrigeradas a 6°C por 24 horas. La media canal izquierda fue seccionada en cinco cortes; los cuales fueron separados en grasa, músculo y hueso, para pesarlos por separado. El peso de la canal caliente y fría, y el rendimiento de la canal caliente fueron mayores para A respecto a B (p < 0.05). El peso del costillar y paleta fueron diferentes entre grupos (p < 0.05). El peso del rumen vacío, hígado, pulmones y tráquea, piel y la grasa interna fueron superiores en A con respecto a B (p < 0.05). Altos CEM mejoran el rendimiento comercial debido al incremento en la deposición de musculo y grasa, con una baja proporción de hueso en la canal de ovejas Pelibuey.