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The effect of naloxone on reproductive behavior and plasma prolactin levels after weaning in third lactation sows

Sat, 01 Jan 2011 00:00:00 GMT

Title: The effect of naloxone on reproductive behavior and plasma prolactin levels after weaning in third lactation sows Authors: Fuentes Hernández, Víctor Octavio; Bernal Canseco, Adriana; Fuentes Castro, Minerva Lidia; Orozco Hernández, José Rogelio Abstract: ABSTRACT The present study was undertaken to study the effect of small doses of naloxone on behavior, prolactin plasma levels, interval of weaning to first estrus, and duration of estrus in third lactation sows. Thirty York x Landrace sows weaned at 25 to 27 days postpartum were selected and separated at random in two groups of 15. One group served as control and the other received every twelve hours two mg of naloxone im. Treatment with small doses of naloxone started three days before and continued for three days after weaning similarly the control group was injected with two mL of a saline solution. Naloxone treated sows showed estrus 88.8 ± 6.2 hours after weaning (P<0.1), control sows estrus was evident 102.37 ± 7.2 hours after weaning. Duration of estrus in treated and nontreated was 85.6 ± 3.8 and 42.6 ± 3.7 hours, respectively. Prolactin levels decreased rapidly after weaning in both groups, but Prolactin plasma levels in naloxone treated sows were below control levels (15 ± 2 and 7 ± 0.3 Ng, respectively; P<0.1). Behaviour scores showed that naloxone treated sows accepted mounting with a significant reduction in aggressive behaviour as compared with controls. It was concluded that opioids are important modulators of sow sexual behaviour. RESUMEN El presente trabajo se realizó con la finalidad de estudiar el efecto de la administración de pequeñas dosis de naloxona sobre el comportamiento sexual, los niveles plasmáticos de prolactina, el intervalo entre el destete y el primer estro y la duración del mismo. Con este propósito se seleccionaron treinta cerdas York x Landrace destetadas a los 25 y 27 días posparto. Se dividieron al azar en dos grupos de 15. Uno de los dos grupos se utilizó como control y el otro recibió una inyección intramuscular de dos mg de naloxona cada 12 horas, el tratamiento con el antagonista opioide se inició desde tres días antes del destete y se continuó por tres días después. El grupo control recibió el mismo tratamiento con inyecciones de solución salina. Las cerdas tratadas con naloxona presentaron estro a las 88 ± 6,2 horas después del destete, mientras que en las cerdas controles el estro se hizo evidente 102,37 ± 7,2 horas después (P<0,01). La duración del estro en cerdas tratadas y no tratadas fue de 85,6 ± 3,8 y 42,6 ± 3,7 horas, respectivamente. Los niveles de prolactina disminuyeron rápidamente en ambos grupos después del destete, pero los niveles plasmáticos de prolactina en las cerdas tratadas se mantuvieron por debajo de los controles (15 ± 2 y 7 ± 0,3 ng, respectivamente; P<0,01). Los resultados del comportamiento mostraron que las cerdas tratadas con naloxona aceptaron la monta con un comportamiento significativamente menos agresivo que las cerdas controles. Se llegó a la conclusion que los opioide endógenos son moduladores importantes del comportamiento reproductivo en la hembra porcina. Description: Artículo

The Effect of Naloxone on Blood Progesterone of Creole Mexican Ewes with Induced Short Luteal Phase During the Anoestrus Season

Thu, 01 Jan 2009 00:00:00 GMT

Title: The Effect of Naloxone on Blood Progesterone of Creole Mexican Ewes with Induced Short Luteal Phase During the Anoestrus Season Authors: Fuentes Hernández, Víctor Octavio; Fuentes, C.P.I.; Bernal Canseco, Adriana; García De La Pena, C.R. Abstract: Abstract: From an extensive sheep flock, 20 creole mexican ewes were selected, age fluctuated between 2 and 6 years, allocated at random in groups of 10. Group 1 (n = 10) received a subcutaneous implant with 15 mg naloxone HCL. Group 2 (n = 10) was sham treated on the may 30-2008. Total 7 days after receiving the implant they were treated with GnRH (250 ng iv at 2 h interval for 24 h) and one final GnRH iv injection of 125 μg. Blood samples were collected at 12 h intervals since, the beginning of the experiment and continued until 15 days after the last injection of GnRH. In 2 of the control ewes it was observed that progesterone concentrations increased since 36 h after the first dose of GnRH until a maximal of 3 ng mL-1 of plasma progesterone concentration was reached on day 7 and the remaining 8 control ewes showed short luteal phases with a maximum of 1 ng mL-1 of plasma progesterone. In ewes treated with naloxone 3 showed short luteal phases and 7 naloxone treated ewes had plasma progesterone concentrations similar to control ewes with normal luteal phases. There was a significant effect of treatment (p<0.0019) between control and naloxone treated ewes. This results show that endogenous opioids are important modulators of reproduction in the ewe. Description: Artículo

Continuous presence of male on estrus onset, estrus duration, and ovulation in estrus-synchronized Boer goats

Fri, 01 Apr 2016 00:00:00 GMT

Title: Continuous presence of male on estrus onset, estrus duration, and ovulation in estrus-synchronized Boer goats Authors: Romano, Juan E.; Alkar, Abdalhamid; Fuentes Hernández, Víctor Octavio; Amstalden, Marcel Abstract: The objectives of the present study were to assess the effect of permanent contact of teasers without copulation on the interval from controlled internal drug release (CIDR) removal to estrus onset, estrus duration, ovulation time, number of ovulations, and interval from CIDR removal to ovulation time on estrus-synchronized Boer goats. During the fall season, a controlled randomized design experiment with two groups, control (CON; n = 18) and treatment (TRE; n = 18), was performed. The TRE group was maintained permanently in a pen with an aproned buck immediately after CIDR removal. The CON group was maintained in a different pen without permanent exposure to the male. All females were estrus synchronized with CIDR maintained in the vagina for 7 days and received 50 μg of GnRH im at device insertion and 5 mg of natural prostaglandin F-2α at device removal. Females were considered to be in estrus when they accepted mounting by the aproned bucks. Estrus was detected four times a day after CIDR removal (at 6 AM, 12 noon, 6 PM, and 12 midnight) using bucks with canvas apron as teasers. The ovulation time and number of ovulations were assessed by transrectal ultrasonography starting 24 hours after estrus onset and repeated every 6 hours until complete ovulation was detected. The estrus onset for the CON group was 44.0 ± 8.3 hours and for the TRE group, it was 37.0 ± 7.7 hours (P = 0.01). Estrus duration from the CON group was 43.7 ± 9.2 hours and for the TRE group, it was 38.3 ± 6.6 hours (P = 0.05). The first, last, and mean ovulation times for the CON group were 32.4 ± 5.3, 38.4 ± 3.4, and 35.4 ± 3.9 hours, and for the TRE group, the times were 31.8 ± 2.8, 36.7 ± 3.0, and 35.8 ± 3.6 hours, respectively (P = 0.85, P = 0.23, and P = 0.82, respectively). The number of ovulations for the CON and TRE groups was 2.6 ± 0.7 and 2.6 ± 0.6 ovulations, respectively (P = 0.96). The interval time for CIDR removal to ovulation for the CON group was 79.2 ± 8.2 hours and for the TRE group, the interval time was 73.2 ± 6.2 hours (P = 0.05). It was concluded that the permanent presence of male without copulation with estrus-synchronized does hastened estrus onset, reduced estrus duration, and decreased the interval time from CIDR removal to ovulation without modification of ovulation time and number of ovulations in Boer goats.

Physical and chemical characteristics of Native Maize from the Jalisco Highlands and their influence on the Nixtamalization Process

Thu, 01 Sep 2022 00:00:00 GMT

Title: Physical and chemical characteristics of Native Maize from the Jalisco Highlands and their influence on the Nixtamalization Process Authors: Ramírez Vega, Humberto; Vázquez Carrillo, Gricelda; Muñóz Rosales, Gabriela Minerva; Martínez Loperena, Raquel; Heredia Nava, Darwin; Martínez Sifuentes, José Ángel; Anaya Esparza, Luis Miguel; Gómez Rodríguez, Víctor Manuel Abstract: Abstract From a cultural point of view, Maize is the most important crop in Mexico, and is also an essential food in the Mexican diet. This study aimed to evaluate the physical and chemical characteristics of maize grain and their influence on the quality of dough and tortillas produced with three native maize cultivars from western Mexico. Physical, structural, and chemical characteristics of the grain were evaluated, including hectolitric weight, 100-grain weight, flotation index, grain structure, grain color, pedicel, pericarp, germ, and floury endosperm, vitreous endosperm, ethereal extract, and protein. Nixtamal and tortilla quality include nixtamal moisture, dough moisture, freshly made tortilla moisture, total soluble solids, pericarp remnant, dough yield, and hot tortilla yield. In general, statistical differences (p ≤ 0.05) were found in almost all variables analyzed. The principal component analysis (PCA) showed that two principal components (PCs), described approximately 79% of the variation, and a positive correlation between the characteristics of freshly made tortilla moisture (FMTM), dough yield (DY), and nixtamal moisture (NM), as well as dough moisture (DM) and hot tortilla yield (HTY). Future studies on these and other native maize cultivars of western Mexico must be conducted to assess the physicochemical and phytochemical characteristics of maize grains that may be useful for food and pharmaceutical applications, contributing to the conservation, propagation, and use of natural and ancient resources.