The performance of estrus synchronization protocols may be influenced by stressful environmental conditions, even in tropically adapted cattle. This study evaluated the efficacy of two synchronization protocols for fixed-time artificial insemination (FTAI) in crossbred Gyr dairy cows and their relationship with heat stress under Peruvian tropical conditions. Multiparous lactating cows under semi-intensive systems were synchronized and divided into two groups: the conventional protocol (PC9) and the prolonged proestrus protocol (J-Synch6). Estrus manifestation, pregnancy rate, and their association with the temperature–humidity index (THI) were analyzed across seven phases of the FTAI program (73 days). In PC9 cows, no significant effect of the number of hours in each heat stress category according to THI was found. Conversely, in J-Synch6 cows, more hours in Category 0 (THI < 72) durin...

El propósito del estudio fue caracterizar los sistemas agroforestales SAF, de la cuenca media margen derecha del río Huallaga - Aucayacu, departamento de Huánuco. A través de encuestas realizada a 16 propietarios se caracterizó y tipificó propiedades demostrativas PD, determinándose tres tipos (pequeños, medianas y grandes) con características socioeconómicas y biofísicas diferentes; donde anteriormente predominaba el cultivo de coca (Erythroxylum coca Lam. y E. novogranatense Morris). Posteriormente se seleccionaron 14 propiedades demostrativas distribuidas en cuatro sectores Maronilla (5), Pucayacu - 7 de octubre (2), Aucayacu (4) Los Milagros (3). Se determinaron siete sistemas de uso de la tierra (bosque, purma, monocultivos, pastos, SAF, y otros). Se identificaron 22 SAF, distribuidos: Maronilla (11), Pucayacu - 7 de octubre (4), Aucayacu (4) y en Los Milagros (3). La den...

La presente investigación evaluó la eficacia de dos protocolos de sincronización de celo para inseminación artificial a tiempo fijo (IATF) en vacas Gyr lecheras y sus cruces, desarrollados en el distrito de Juan Guerra, región San Martín, entre octubre de 2021 y septiembre de 2022. Se trabajó con 159 vacas multíparas en lactación de 90 a 180 días abiertos, manejadas en un sistema semi intensivo, distribuidas en dos grupos: protocolo convencional (PC9) y protocolo de proestro prolongado (J-Synch6). Se analizaron la manifestación de celo, la tasa de preñez y la influencia del índice de temperatura-humedad (ITH) en ambos parámetros. No se observaron diferencias significativas en la manifestación de celo (60% J-Synch6 vs. 59.6% PC9), ni en el porcentaje de preñez (42.5% J-Synch6 vs. 39.2% PC9), lo que indica que ambos protocolos son igualmente efectivos para inducir celo y lo...

Background: The implementation of routine fixed-time artificial insemination programs can generate significant waste and costs, which good management practices can help mitigate. The objective of the study was to assess the effects of second- and third-use progesterone devices on estrus characteristics and pregnancy rates in synchronized crossbred Gyr cows. Methods: Ten cows were synchronized with first-use Bovine Intravaginal Progesterone Devices (DIB), nine with second-use DIB and ten with third-use DIB. All cows were ≥90 days postpartum, had an average milk production of 6.9±1.9 L/day and were aged 4-10 years. Estrus signs were recorded at insemination and pregnancies were confirmed at 60 days by ultrasonography. Result: No significant associations were found between DIB use intensity and estrus detection patch response, mucus color, body condition score (CC), calvings, or breed pu...

Introduction: Agroclimatic conditions are key determinants in the development of animal production and reproduction, with specific breed differences in vulnerability to environmental stress. This research aims to determine the influence of agroclimatic factors on the efficiency of multi-ovulation in cattle in the Peruvian tropics. Methods: The study was conducted at the “El Porvenir” Agricultural Experimental Station (EEA) of the National Institute of Agricultural Innovation (INIA), located in the district of Juan Guerra, province and department of San Martín, Peru. Throughout a year, four collections of structures were made from 12 Bos indicus donor cows from the genetic nucleus of the PROMEG Tropical project every 2 months under intensive breeding conditions. The cows were classified according to their production: milk (five individuals of the Gyr breed and two of the Guzerat bree...