RESUMO
Dairy herds have adopted sexed semen (SS) and beef semen (BS) to control heifer inventory and increase calf sales revenue. Beef in vitro-produced embryo transfer (beef IVP-ET) may be an alternative to increase calf sales revenue. Besides, raising those Jersey beef crossbred and/or pure beef animals in a dairy system may be a new source of revenue. We aimed to evaluate breed strategies combining dairy conventional semen (CS), SS, BS, and beef IVP-ET on herd dynamics and profitability by marketing those animals with one-day-old or raising them to 180 kg. A Markov chain model was developed to maximize the profitability of Jersey herds by changing the number of dairy heifers sold at birth and the culling rate of 3rd and greater parity cows. The model presents inputs on the reproductive and productive performance of heifers and cows over time. The last year's data (year 10 - steady state) was used to calculate accrual operational cost and revenue per cow per year. We varied the breeding strategy by breeding order and parities, the embryo transfer cost ($85 or $170), the pure beef calf market price ($200 or $300), and by marketing Jersey-beef and pure beef animals with one-day-old or raising them to 180 kg. A total of 8 scenarios + default scenario were simulated. Overall, the proportion of SS use was 47.3 ± 0.6%. For the scenarios replacing all CS breedings with BS breedings, the proportion of CS and BS used was 52.3 ± 0.6. When beef IVP-ET was used, the percentage of BS and beef IVP-ET used was 22.4 ± 0.1% and 31.0 ± 0.1%, respectively. We observed that when we compared SS:BS with the default scenario, the production of purebred Jersey male calves was reduced by 83.5%, and profit/cow per year was increased from $113.5 to $203.3 with SS:BS. When a beef IVP-ET of $85 per transfer was used (scenarios 2 and 3), profit/cow per year was $145.5 and $176.2 for a pure-beef calf price of $200 and $300, respectively. In scenario 4, with a beef IVP-ET cost of $170, the lowest profit ($52.9 per cow per year) was found when marketing one-day-old pure-beef calves at $200. The highest profit was achieved for scenario raising the Jersey-beef crossbred animals to 180 kg ($232.9, scenario 6), followed by scenario 7 ($222.9, SS:BS:IVP-ET) with an embryo transfer cost of $85. Under the current market conditions, combining SS and BS in the reproductive program was a feasible economic opportunity for Jersey herds, yielding the highest net return. The adoption of beef IVP-ET in a reproductive program can potentially increase profit/cow per year, but its profitability will depend on the beef IVP-ET pregnancy cost, the pure-beef market price, calf performance, and the herd reproductive performance. In conclusion, raising the Jersey-beef crossbred calves may be a profitable strategy, and dairy producers need to evaluate the best option to invest in since it will take an extra risk to produce high-quality animals to the market.
RESUMO
Un programa de control de calidad en medicina nuclear incluye la verificación de la eficiencia de equipos utilizados para el diagnóstico y tratamiento, hasta la formación. En este estudio se evaluaron las medidas de actividad realizada por los usuarios que trabajan en los servicios de medicina nuclear en Sergipe, Brazil. En las medidas de actividad se estableció uno y se caracteriza entre las medidas de fuentes radiactivas selladas de actividad normal, 133Ba y 57Co, llevada a cabo por distintos profesionales, con el fin de comprobar la reproducibilidad de estas medidas cuando se compara con el valor por defecto de la actividad de cada fuente. Los resultados de inter-medidas en estado satisfactorio y pueden ser utilizados como parámetros en el evaluación futuro de los servicios de medicina nuclear.
A program of quality control program in nuclear medicine includes the verification of the efficiency of any equipment used for diagnosis and treatment, until the personal training. In this study were evaluated measures of activity undertaken by users who work in nuclear medicine services in Sergipe, Brazil. In measures of activity was established and characterized an inter measures of activity sealed radioactive sources standard, 133Ba and 57Co, carried out by different professionals, aiming to verify the reproducibility of these measures when compared with the default value of the activity of each source. The results of inter-measures were in satisfactory and can be used as parameters in future evaluation services in nuclear medicine.