Abstract Paper aims This study analyzes the comprehension of production engineering students about the influence of some key variables on the process performance measures in a service process. Originality This paper points out the need for educators to re-evaluate their approaches to teaching the Operations Management (OM) principles related to process flow measures. Research method This study used scenario-based role-playing experiments with 2×2×2 between-subject factorial design with three independent variables (variability of activities, capacity utilization, and resource pooling) and four dependent variables related to key internal process performance measures (Flow Time, Overall Quality of service, Quality of service employees, and Queue Size). The sample was composed of 178 undergraduate production engineering students from a large university in Brazil from various institution units. Main findings These results show that students perceived the use of resource pooling as an impactful practice. However, the students did not correctly identify the effects of increasing resource utilization and the variability on flow time and queue size when activities are pooled. Implications for theory and practice The teaching of basic concepts of OM requires the support of computational tools. Undergraduate courses that contemplate subjects in the field of OM should work more intensely on simulation-based learning.

Com o objetivo de avaliar a influência da relação volumoso:concentrado sobre a composição tecidual e os rendimentos de carcaça e de cortes comerciais de cordeiros Morada Nova em confinamento, utilizaram-se 18 cordeiros com peso vivo (PV) inicial de 15 kg, distribuídos em seis grupos de três animais (um em cada dieta), de acordo com a relação volumoso(V):concentrado(C): 40:60, 55:45 e 70:30. Foram avaliados os pesos de corpo vazio (PCV), de carcaça quente (PCQ) e de carcaça fria (PCF), a partir dos quais foram calculados os rendimentos biológico (RB), de carcaça quente (RCQ) e de carcaça fria (RCF) e a perda de peso por resfriamento (PPR). A carcaça foi dividida em cinco cortes cárneos (perna, lombo, costelas, paleta e pescoço), os quais foram pesados para cálculo de seus rendimentos em relação ao peso da meia-carcaça. A perna foi dissecada em músculo, osso e gordura e os pesos desses tecidos foram expressos em peso absoluto e em porcentagem da perna. Calcularam-se as relações músculo:osso e músculo:gordura, o índice de musculosidade da perna (IMP) e a área de olho-de-lombo (AOL). O aumento de 30 para 60% de concentrado na dieta elevou os rendimentos de carcaça quente e carcaça fria, assim como o rendimento biológico. Os crescentes teores de concentrado na dieta não afetaram a porcentagem de músculo na perna, mas proporcionaram maior deposição de gordura e maior área de olho-de-lombo.

Eighteen lambs averaging initial body weight (BW) of 15 kg were allotted to six groups of three animals (one lamb per diet) and were fed diets with following forage:concentrate ratios (F:C): 1) 40F:60C; 2) 55F:45C; or 3) 70F:30C. Lambs of each group were slaughtered when the animal fed the diet with the highest concentrate level reached 25 kg of BW. Animals were slaughtered after 16 h of fasting (feed and water). After obtaining the slaughter body weight (SBW), animals were anesthetized by electric discharge and killed by bleeding of the carotid arteries and jugular veins. Blood was then collected and weigthed. Soon after evisceration, skin, head and extremities of the fore and rear members were removed. The gastrointestinal tract (GIT) was emptied, weighted and the value added to that of blood to obtain the empty body weight (EBW), which was calculated by subtracting SBW from GIT + blood weights. The carcasses were weighted and stored at 4°C within a 24-hours period. The empty body (EBW), hot carcass (HCW) and cold carcass weights (CCW) were all used to calculate the biological (BY), hot carcass (HCY) and cold carcass yields (CCY) as well as the weight loss by cooling process (CWL). The carcass was divided in five cuts (leg, loin, ribs, shoulder clod and neck) that were weighted for calculation of cut yields. The leg was dissected in muscle, bone and fat, and weights of these tissues were expressed in absolute weight and in percentage of leg weight. The muscle:bone and muscle:fat ratios, index of leg muscularity (ILM) and the loin eye area (LEA) were also calculated. Increasing dietary concentrate from 30 to 60% increased not only hot and cold carcass yields but also biological yield. The increasing levels of concentrate in the diet showed no effect on the percentage of leg muscle. However, it was observed an increase in both fat deposition and rib eye area.

Este trabalho foi desenvolvido para se determinar a composição corporal e as exigências nutricionais de cálcio (Ca), fósforo (P), magnésio (Mg), sódio (Na) e potássio de ovinos da raça Morada Nova. Foram utilizados 30 cordeiros com peso vivo (PV) médio inicial de 15 kg e 70 dias de idade. Seis cordeiros foram abatidos aos 15 kg, para determinação da composição corporal inicial (animais-referência) pela metodologia do abate comparativo; seis foram abatidos aos 20 kg (abate intermediário) e os demais distribuídos em seis grupos de três animais (um para cada dieta), de acordo com as relações volumoso(V):concentrado(C): 1) 40V:60C; 2) 55V:45C; e 3) 70V:30C. Os animais, em cada grupo, foram abatidos quando o cordeiro que recebia a dieta com maior teor de concentrado atingiu 25 kg de PV. A composição corporal variou de 14,33 a 12,42 g de Ca; 8,12 a 7,15 g de P; 0,47 a 0,46 g de Mg; 1,60 a 1,40 g de Na e de 2,30 a 2,23 g de K por kg de peso de corpo vazio. As exigências líquidas de ganho variaram de 13,54 a 11,74 mg de Ca; 7,96 a 7,02 mg de P; 0,57 a 0,55 mg de Mg; 1,54 a 1,35 mg de Na e de 2,75 a 2,68 mg de K por g de ganho de PV. As exigências dietéticas diárias de macrominerais para cordeiros dos 15 aos 25 kg de PV, ganhando 100 g/dia, variaram de 2,76 a 3,12 g de Ca; 1,91 a 2,95 de g de P; 0,60 a 0,77 g de Mg; 0,60 a 0,86 g de Na e de 1,51 a 2,63 g de K.

The objective of this trial was to determine the body composition and nutritional requirements of macrominerals for Morada Nova sheep. Thirty lambs averaging 15 kg of initial body weight (BW) and 70 days of age were used in this study. Six lambs (reference-animals) were slaughtered with 15 kg of BW to determine the initial body composition using the comparative slaughter methodology; six other lambs were slaughtered with 20 kg of BW (intermediary slaughter) and the remaining 18 lambs were distributed to six groups of three animals (one lamb for each treatment) and received diets with the following forage(F):concentrate(C) ratio: 1) 40F:60C; 2) 55F:45C; and 3) 70F:30C. Animals from each group were slaughtered when the lamb that had been fed the diet with the highest concentrate level reached 25 kg of BW. Body composition varied from 14.33 to 12.42 g of Ca, 8.12 to 7.15 g of P, 0.47 to 0.46 g of Mg, 1.60 to 1.40 g of Na, and 2.30 to 2.23 g of K per kg of empty body weight. Net gain requirements ranged from 13.54 to 11.74 mg of Ca, 7.96 to 7.02 mg of P, 0.57 to 0.55 mg of Mg, 1.54 to 1.35 mg of Na, and 2.75 to 2.68 mg of K per g of gained BW. Daily macromineral requirements for lambs from 15 to 25 kg of BW gaining 100 g/day varied from 2.76 to 4.74 g Ca, 1.91 to 3.15 g of P, 0.60 to 0.93 g of Mg, 0.60 to 0.76 g of Na, and 1.51 to 1.79 g of K.

Este trabalho foi realizado objetivando-se determinar a composição corporal de proteína, gordura e energia e as exigências nutricionais de proteína e energia para mantença e ganho de peso de ovinos Morada Nova. Foram utilizados 30 cordeiros com peso vivo (PV) médio inicial de 15 kg. Para determinação da composição corporal, pela metodologia do abate comparativo, seis cordeiros (animais-referência) foram abatidos aos 15 kg, seis aos 20 kg (abate intermediário) e os demais foram distribuídos em seis grupos (um para cada dieta) de três animais, de acordo com a relação volumoso(V):concentrado(C): 40:60, 55:45 e 70:30. Os cordeiros em cada grupo foram abatidos quando o que recebia a dieta com maior teor de concentrado atingiu 25 kg de PV. A composição corporal variou de 181,53 a 178,74 g de proteína; 72,37 a 131,11 g de gordura e 1,81 a 2,34 Mcal de energia por kg de peso de corpo vazio (PCV). As exigências líquidas de ganho variaram de 222,30 a 218,6 g de proteína e de 3,30 a 4,28 Mcal de energia por kg de PV ganho. As perdas endógenas de nitrogênio foram de 0,332 g/kg0,75/dia. A exigência líquida de energia para mantença, estimada pela produção de calor em jejum, foi de 52,49 kcal/kg0,75 de PCV. As exigências de proteína e energia metabolizável para cordeiros dos 15 aos 25 kg de PV, com ganho de peso diário de 100 g, oscilaram de 53,46 a 60,19 g/dia e de 1,47 a 2,00 Mcal/dia, respectivamente.

This investigation was carried out to determine body composition of protein, fat, and energy as well as nutritional requirements of protein and energy for maintenance and weight gain of Morada Nova Lambs. Thirty lambs averaging 15 kg of initial body weight (BW) were used in this trial. To determine the body composition using the comparative slaughter approach six lambs were slaughtered at 15 kg (reference animals), six at 20 kg (intermediary slaughter), and the remaining were distributed in one of six groups of three animals (one animal per diet) receiving the following forage (F):concentrate(C) ratios: 1) 40F:60C; 2) 55F:45C, and 3) 70F:30C. Lambs in each group were slaughtered when the animal fed the highest amount of concentrate reached 25 kg of BW. Body composition varied from 181.53 to 178.74 g of protein, 72.37 to 131.11 g of fat, and 1.81 to 2.34 Mcal of energy per kg of empty body weight (EBW). The net requirements of gain varied from 222.30 to 218.6 g of protein and from 3.30 to 4.28 Mcal of energy per kg of gained BW. The endogenous losses of nitrogen were of 0.332 g/kg0.75/day. The net requirement of energy for maintenance, estimated by heat production in fasted animals, was of 52.49 Kcal/kg0.75 of EBW. The requirements of metabolizable protein and energy for lambs from 15 to 25 kg of BW with daily weight gain of 100 g varied from 53.46 to 60.19 g/day and from 1.47 a 2.00 Mcal/day, respectively.

Foi estudada a qualidade da carne ovina submetida a diferentes teores de sal no processo de salga, utilizando-se 18 pernas desossadas provenientes de cordeiros ½ Ile de France ½ Ideal, machos inteiros, com peso vivo médio de 30kg. Os tratamentos constituíram-se em: T1 - controle; T2 - salga a 15% e T3 - salga a 20%. As mantas de carne foram lavadas rapidamente em água corrente para remoção do excesso de sal e secadas à sombra. As análises foram realizadas antes da salga e 67 horas após o início da mesma. As perdas de peso ao cozimento, maciez, cor, umidade (2, 4, 16, 28, 40 e 67 horas após o início da salga) e número de TBARS, substâncias reativas ao ácido 2-tiobarbitúrico, foram realizadas no músculo Semimembranosus. Os diferentes teores de sal não influenciaram (P>0,05) na luminosidade da carne, entretanto os teores de vermelho e amarelo, que foram influenciados (P<0,05). As perdas de peso ao cozimento e a umidade foram menores (P<0,05) nas carnes salgadas. A carne dos tratamentos controle e com 15% de salga, apresentou maior (P<0,05) maciez, em relação à carne do tratamento com 20% de salga. A carne que foi submetida a 20% de salga, apresentou maior oxidação lípidica, não diferindo da salga a 15%. A salga a 15% forneceu melhores resultados com valores de perdas de peso ao cozimento, cor, umidade e número de TBARS semelhante a salga a 20%, porém com maior maciez.

The effects was studied of different salt quantities during salting process in qualitative parameters of sheep meat. Were used 18 boned legs from ram lambs ½ Ile de France ½ Ideal, slaughtered with 30kg of body weight. The treatments were: T1 - control; T2 - salting at 15%; T3 - salting at 20%. Meat slices were washed with water to remove salt excess and dried in shadow. Analysis were done before salting and 67 hours after salting. Cooking losses, tenderness, colour, humidity (2, 4, 16, 28, 40 and 67 hours after the beginning of the process) and number of TBARS (2-tiobarbituric acid reactive substances) were done on Semimembranosus muscle. Different quantities of salt had no effect on meat lightness (P>0.05), although redness and yellowness were affected (P<0.05). Cooking losses and humidity were lower (P<0.05) for salted meat. The tenderness was higher (P<0.05) for meats submitted to control treatment and 15% of salting, compared to meats salted with 20%. Meats submitted to 20% of salting showed higher number of TBARS, not differing 15% of salting. The utilization of 15% of salting showed better results, with cooking losses, colour, humidity and number of TBARS similar to salting at 20%, however the meat was more tender.