The objective of the study was to evaluate two methods of detection of oestrus in two seasons and their influence on reproductive efficiency in Holstein cows. A total of 1445 records was evaluated from an intensive commercial farm located in the north of Lima, Peru in 2014. The methods of detection of oestrus were a commercial activity meter (T1), visual observation (T2) and the combination of both methods (T3). The reproductive parameters evaluated were the rate of heat detection,  conception rate, number of services per conception, open days and parity number. The highest number of heats was detected with T3 (52.2%) compared to 27.5% of T1 and 20.2% of T2 (p<0.05). T1 was more efficient in detecting heats during the summer (34.7% heats) compared to T2 (13.2%) (p<0.05). T1 showed a higher number of heats in the first and second lactations (30.3 and 26.5%, respectively) compared t...

El objetivo del estudio fue evaluar dos métodos de detección del celo en dos épocas del año y su influencia sobre la eficiencia reproductiva de vacas Holstein. Se evaluaron 1445 registros de un establo comercial de explotación intensiva ubicada en el norte de Lima, Perú en 2014. Los métodos de detección de celo fueron un medidor de actividad comercial (T1), la observación visual (T2) y la combinación de ambos métodos (T3). Los parámetros reproductivos evaluados fueron la tasa de detección de celos, la tasa de concepción, el número de servicios por concepción, los días abiertos y el número de parto. El mayor número de celos fue detectado con T3 (52.2%) en comparación al 27.5% de T1 y al 20.2% de T2 (p<0.05). T1 fue más eficiente en la detección de celos durante el verano (34.7% de celos) en comparación con T2 (13.2%) (p<0.05). T1 detectó mayor número de celo...

The purpose of this study was to evaluate the yield of dry matter (DM), crude protein (CP) and in vitro digestibility of dry matter (IVDMD) at four cutting heights and five maturity times of Pennisetum sp (Maralfalfa) during the periods of greatest and least precipitation in Pucallpa, Peru. Cuts were made at 0, 10, 20 and 30 cm height from the ground at 28, 35, 42, 49 and 56 days of regrowth. Plant height, number of stems, number, length and width of leaves, DM, CP and IVDMD yield were evaluated under a complete randomized design with a 4x5 factorial arrangement and 4 repetitions. The plant reached 120.5 cm in height at 56 days of regrowth. At the beginning of the growth period, it had 28 stems and 127 leaves, decreasing until it was established on 15 stems and 58 leaves after 56 days. In that same period the leaves grow up to 77.9 cm long and 2.3 cm wide. The DM performance increases wh...