ABSTRACT This study was aimed to elaborate a young bull fattening supplement with Valencia orange by-products (Citrus sinensis var. valencia) in the north of Veracruz state. It was performed in a Livestock Production Unit (UPP) from the Municipality of Álamo-Temapache, Veracruz. Geographically located at North latitude: 20° 55' 19", West latitude 97° 41' 44. This place is found at 40 meters height above sea level with an average annual temperature of 19-36 ° C. 40 Zebu x Swiss bulls, with 300 kg weight approximately, were housed and assigned under a completely randomized design in four treatments, and ten repetitions (n = 10). T1 (control) fresh forage; T2: formulated concentrate based on orange bagasse + fresh forage; T3: concentrate formulated with orange peel + fresh forage; T4: concentrate formulated with orange silage + fresh forage. Food was offered twice a day "ad libitum" considering 3.0 % (NRC) of the live weight during the 90 days of the experiment, with two weightings at the beginning and at the end. The average daily gain (P<0.05) was 2.97 kg/animal and the cold carcass yield was 55.3%, to the animals that received a by-product supplementation based on orange silo (T4) 13.3% PC it promoted higher performance in fattening cattle.

RESUMEN Este trabajo tuvo como objetivo elaborar un concentrado alimenticio con subproductos de naranja valencia Citrus sinensis var. valencia como suplemento para toretes de engorda en el norte del estado de Veracruz. Se desarrolló en una Unidad de Producción Pecuaria (UPP) del Municipio de Álamo-Temapache, Veracruz. Geográficamente localizado entre los meridianos Latitud norte: 20° 55' 19", Latitud oeste 97° 41' 44”. La localidad se encuentra a una altura de 40 msnm y temperatura media anual de 19-36°C. Se evaluaron, 40 toretes Cebú x Suizo, con un peso aproximado de 300 Kg, que fueron estabulados y asignados bajo un diseño completamente aleatorio en cuatro tratamientos y diez repeticiones (n=10 c/u). T1 (testigo) forraje fresco; T2: concentrado formulado a base de bagazo de naranja + forraje fresco; T3: concentrado formulado con cascara de naranja + forraje fresco; T4: concentrado formulado a base de ensilado de naranja + forraje fresco. El alimento se ofreció dos veces al día a libre acceso considerando el 3.0% (NRC) del peso vivo durante los 90 días del experimento, realizándose dos pesajes al inicio y final. El promedio de ganancia diaria (P < 0.05) fue 2.97 kg/animal y rendimiento en canal fría de 55.3%, para los animales que recibieron una suplementación de subproductos a base de silo naranja (T4) al 13.3% PC, promovió un mayor rendimiento en los bovinos de engorda.

ABSTRACT The effects of propylene glycol (PG) delivered in the peripartum, on body condition (CC), concentrations of β-hydroxybutyrate (BHBA), prevalence of subclinical ketosis (CS), milk production (PL) and open days (DA) were determined in multiparous dairy cows from the tropic of Veracruz. Three weeks before, the cows were randomly selected to receive 250 ml of PG / day (n = 18) or H2O (Control, n = 18) orally and continued with the treatment until the third week postpartum. The CC was measured every week and milk daily. Starting the week of delivery, a milk sample was taken weekly for 4 weeks to determine BHBA and prevalence of CS (BHBA ≥ 200μmol / l). The statistical analysis was performed using STATISTICA 7. The PG cows maintained better (P˂0.05) CC at the fourth postpartum week (3.21 ± 0.18) than the control cows (2.7 ± 0.18). PG cows had lower (P˂0.05) CS prevalence and BHBA concentrations (0% and 51.6 ± 41.0 μmol/l) than control cows (64% and 214.5 ± 41.6 μmol/l, respectively). The PG cows produced 933.2 more liters of milk / lactation. The DAs were similar (P = 0.10) in both groups. Concluding that the treatment with peripartum PG increased the milk production, decreased the concentrations of β-hydroxybutyrate and the prevalence of CS, maintained better the CC, but did not reduce the DA.

RESUMEN Se determinaron los efectos de propilenglicol (PG) suministrado en el periparto, en la condición corporal (CC), concentraciones de β-hidroxibutirato (BHBA), prevalencia de cetosis subclínica (CS), producción de leche (PL) y días abiertos (DA), en vacas lecheras multíparas del trópico veracruzano. Tres semanas preparto las vacas fueron seleccionadas aleatoriamente para recibir 250 ml de PG/día (n=18) o H2O (Control, n=18) vía oral y continuaron con el tratamiento hasta la tercera semana posparto. La CC se midió cada semana y la leche diariamente. Iniciando la semana del parto se tomó una muestra de leche semanalmente durante 4 semanas para determinar BHBA y prevalencia de CS (BHBA ≥ 200µmol/l). El análisis estadístico se realizó utilizando STATISTICA 7. Las vacas PG mantuvieron mejor (P˂0.05) CC a la cuarta semana posparto (3.21±0.18) que las vacas control (2.7±0.18). Las vacas PG tuvieron menor (P˂0.05) prevalencia de CS y concentraciones de BHBA (0% y 51.6±41.0 µmol/l) que las vacas control (64% y 214.5±41.6 µmol/l, respectivamente). Las vacas PG produjeron 933.2 más litros de leche/lactancia. Los DA fueron similares (P=0.10) en ambos grupos. Concluyendo que el tratamiento con PG periparto incrementó la producción de leche, disminuyó las concentraciones de β-hidroxibutirato y la prevalencia de CS, mantuvo mejor la CC, pero no redujo los DA.

ABSTRACT This work was carried out in the Tamalín Municipality, located at the north of the state of Veracruz, Mexico, between the coordinates 21° 20' north latitude and 97° 49' west longitude, at a height of 140 sea level. The objective of this research was to know the main tree species and fodder shrubs that are consumed by cattle, as well as to identify their different uses. To this end, a survey previously prepared was applied to the local producers. The most relevant results in the production units evaluated showed that the consumption of these trees and fodder shrubs improved the body condition of the livestock (85%) and knowledge of how easily are propagated these tree species (75%). It is very important to emphasize its significant use as living fences, medicinal, poles and in the furniture making. As for the majority of the species studied, they showed acceptable nutritional contents. Highlighting that the Crude Protein (PC) being much higher than that of the tropical grasses (Panicum maximum, Cynodon plectostachyus) and in several cases, also higher than that of the commercial concentrates (oats, barley, rye).

RESUMEN El trabajo se realizó en el municipio Tamalín, ubicado al norte del estado de Veracruz, México, entre las coordenadas 21° 20' Latitud Norte y 97° 49' Longitud Oeste, a una altura de 140 msnm. El objetivo de esta investigación tuvo la finalidad de conocer las principales especies de árboles y arbustos forrajeros consumidos por los bovinos, los que son establecidos en unidades de producción extensiva, así como identificar sus diferentes usos. Para ello se aplicó una encuesta a los productores de la localidad utilizando un cuestionario previamente elaborado. Los resultados más relevantes en las unidades de producción evaluados, demostraron que el consumo de estos árboles y arbustos forrajeros mejoran la condición corporal de ganado en un 85%, así como la fácil propagación observada en el área de estudio (75%). Es de suma importancia destacar el uso significativo, como: construcción de cercos vivos, medicinales, postes y elaboración de muebles. En cuanto a la mayoría de las especies estudiadas, estas mostraron contenidos nutricionales aceptables. Destacando la Proteína Cruda (PC), siendo muy superior al de los pastos tropicales (Panicum máximum, Cynodon plectostachyus) y en varios casos, también superior al de los concentrados comerciales (avena, cebada, centeno).

Abstract: The objective of this work was to evaluate the effect of poultry by-products, on the weight gain and yield of the carcass, under a stabling system. 30 Cebu x Suizo heifers, weighing approximately 300 kg and 30 months of age were used, which were assigned, to a completely randomized design in three treatments. The treatments were the following: T1, (control) energy concentrate; T2, energy concentrate + 30% poultry manure and T3, energy concentrate + 30% poultry meal. The composition of the energy concentrate was based on ground sorghum, corn grain, wheat bran, ground bales and salt blocks of minerals. Each treatment was offered twice a day at a rate of 3% of the live weight for 90 days. The average daily weight gain (p ≤ 0.05) was .964, 1.04, 1.15 kg/animal, respectively. A significant effect (p ≤ 0.05) was observed on the percentage of yield of the channel of 47.02; 49.08 and 52.03 %, for T1, T2, and T3, respectively. The results indicate that supplementation based on poultry meal promoted a higher productive-yield in heifers supplemented under a stabling system.

Resumen: El objetivo de este trabajo fue evaluar el efecto de los subproductos avícolas, sobre la ganancia de peso y rendimiento de la canal, bajo un sistema de estabulación. Se emplearon 30 novillonas Cebú x Suizo, con un peso aproximado de 300 kg y 30 meses de edad, que fueron asignadas, bajo un diseño completamente aleatorio en tres tratamientos. T1 (testigo) concentrado energético; T2 concentrado energético+ 30% pollinaza y T3 concentrado energético + 30% de harina de ave. La composición del concentrado energético se basó en sorgo molido, maíz en grano, salvado de trigo, paca molida y sal mineral. Cada tratamiento se ofreció dos veces al día a razón del 3% del peso vivo durante 90 días. El promedio de ganancia diaria de peso (p ≤ 0.05) fue 0.964, 1.04, 1.15 kg/animal, respectivamente. Se observó un efecto significativo (p ≤ 0.05) sobre el porcentaje de rendimiento de la canal de 47.02; 49.08 y 52.03 %, para T1, T2 y T3, respectivamente. Los resultados indican que la suplementación a base de harina de ave promovió un mayor rendimiento productivo en las novillonas suplementadas bajo un sistema de estabulación.

ABSTRACT The objective of the study was to determine the effect of routine intramuscular injection of oxytocin to induce milk ejection on behavior assessed in terms of stress and rectal temperature in crossbred cows (Bos indicus × Bos taurus) in the tropics of Veracruz, México. Immediately after calving, cows were milked twice a day (n = 210) and randomly assigned to receive at each milking: 10 IU (0.5 mL) of oxytocin intramuscularly (n = 70); 0.5 mL of saline solution intramuscularly (n = 70); or no injection (n = 70). The following behavioral indicators of stress were observed: trampling, kicking, tail movement, failure to eat, jumping to avoid injection, vocalization, urination, and defecation. After milking, rectal temperature (RT) was measured. Statistical analysis was performed using ANOVA and chi-square. There were no differences in terms of behavioral stress indicators or rectal temperature in cows injected with oxytocin or saline solution, but both groups had greater behavioral indicators of stress and RT compared with non-injected cows. Cows injected with oxytocin or saline solution manifested a higher percentage of animals that trampled (96.8%), kicked (32%), ceased eating (61.2%), moved the tail (81.2%), jumped (20.9%) and avoided the injection (78.2%), compared with non-injected cows. Cows injected with oxytocin and saline solution had higher rectal temperature (39.13±0.08 ºC) compared with non-injected cows (38.96±0.12 ºC). All injected cows had higher behavioral indicators of stress measurements and rectal temperature regardless of the solution, suggesting that cows injected routinely and intramuscularly do not become habituated to this, even though some cows were injected more than 600 times throughout lactation.