Behavioral responses of the pampas deer (<i>Ozotoceros bezoarticus</i>) to human disturbance in San Luis province, Argentina

Pampas deer (Ozotoceros bezoarticus, Linnaeus 1758) is a South American cervid, associated with grasslands and savannas; in Argentina this species is listed as endangered. Our aim was to analyze the behavioral responses of the pampas deer to human presence, and to evaluate possible effects of their poaching. We recorded behavioral responses from 382 pampas deer groups during eight vehicle surveys, in "El Centenario" ranch (San Luis Province). Data were analyzed using the G-test of independence and logistic regression. Almost half of the groups (48.17 percent) remained on site. Behavioral responses differed significantly according to group size and composition and observer distance; being this last the variable most influencing flight, groups were more likely to flee at shorter distances. In return, behavioral responses were independent from habitat type, transect type and season. Our results suggest certain human tolerance and that consequently, poaching would not have important effects on this population.Facultad de Ciencias Naturales y Muse

Un importante hallazgo para la lingüística aborigen : El libro inencontrable del P. Valdivia

Fil: Márquez Miranda, Fernando. Departamento de Arqueología y Etnografía; Facultad de Ciencias Naturales y Museo; Universidad Nacional de La Plat

Antler velvet is thicker in adult than in yearling pampas deer (Ozotoceros bezoarticus): a histological study

Background: Antlers are lined by soft velvet tissue during antler growth. Later, the velvet is shed before rut onset. There are no detailed histological descriptions of the growing velvet, nor whether the velvet changes according to stag age. Our aims were to: 1) describe the basic histology of pampas deer antler velvet from adult and yearling males; and 2) determine the influence of age and time of antler growth on velvet’s tissues morphometry. Materials and methods: Samples were collected from 10 stags allocated in two groups, either adult (3–5 years old, n = 5) or yearling males (2 years old, n = 5). The day of antler cast was recorded for each animal. In spring, the stags were anaesthetised and velvet samples were collected from the third tine’s distal end. Samples were described qualitatively and a restricted morphometrical analysis of the antler velvet was performed. Results: The number of keratinocyte layers and the thicknesses of: total epidermis, corneum, intermediate and basale epidermal strata, total dermis, superficial and deep dermis were determined. Age and days after antler casting positively influenced in conjunction epidermal thickness (p = 0.037), and tended to influence both stratum intermedium (p = 0.076) and stratum corneum (p = 0.1) thicknesses. Age influenced stratum corneum thickness (p = 0.04). The pampas deer antler velvet lacked both sweat glands and arrector pili muscles. Conclusions: The deep dermis was densely irrigated but displayed abundant and well developed collagen bundles. Both total epidermal and stratum corneum thicknesses related positively to the age of the animals but were not to the time since antler cast.

The continuous presence of ewes in estrus in spring influences testicular volume, testicular echogenicity and testosterone concentration, but not LH pulsatility in rams

The continuous presence of active male small ruminants prevents seasonal anestrus in females, but evidence of the same mechanism operating from the females to the males is scarce. This study assessed the effects of the continuous presence of ewes in estrus in spring on ram sexual activity, testicular size and echogenicity, and LH and testosterone concentrations. On 1 March, 20 rams were assigned to two groups (n = 10 each): isolated (ISO) from other sheep, or stimulated (STI) by 12 ewes, which were separated from the rams by an openwork metal barrier, allowing contact between sexes. Each week, four ewes were induced into estrus by intravaginal sponges. Live weight, scrotal circumference, testicular width (TW) and length (TL) were recorded at the beginning and at the end of the experiment, and testicular volume (TV) was calculated; at the same time, testicular ultrasonography and color Doppler scanning were performed. Blood samples (March to May) were collected once per week for testosterone determinations, and at the end of the experiment, blood samples were collected for 6 h at 20-min intervals for LH analysis. Rams were exposed to four estrous ewes in a serving-capacity test. Scrotal circumference, TW and TL were higher in the STI than in the ISO rams (P < 0.05) in May, and TV was higher (P < 0.05) in the STI (391 ± 17 cm3) than in the ISO rams (354 ± 24 cm3). In ISO rams, the number of white pixels was higher (P < 0.01) in May (348 ± 74) than in March (94 ± 21) and differed significantly (P < 0.01) from that of the STI rams in May (160 ± 33). In ISO rams, the number of grey pixels was higher (P < 0.05) in May (107 ± 3) than it was in March (99 ± 1). Stimulated and ISO rams did not differ significantly in mean LH plasma concentrations (0.8 ± 0.5 v. 0.9 ± 0.4 ng/ml), LH pulses (2.1 ± 0.5 v. 2.2 ± 0.2) and amplitude (2.0 ± 0.4 v. 3.2 ± 0.7 ng/ml, respectively). Stimulated rams had significantly higher testosterone concentrations than ISO rams from April to the end of the experiment. Stimulated rams performed more (P < 0.05) mountings with intromission (3.0 ± 0.4) than did ISO rams (1.5 ± 0.5). In conclusion, after 3 months in the continuous presence of ewes in estrus in spring, rams had higher TV and some testicular echogenic parameters were modified than isolated rams. Although exposed rams also had higher levels of testosterone after 2 months in the presence of estrous ewes, their LH pulsatility at the end of the study was not modified

Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season

Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP)-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C) ewes (n = 35) were in permanent contact with rams, the ram effect (RE) ewes (n = 36) were isolated for 34 days prior to contact with rams. At sponge withdrawal, all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4–6 days after estrus. Four weeks later, pregnancy was determined by transrectal ultrasonography. In eight ewes from each group, ovaries were ultrasonographically scanned; FSH, LH, and estradiol-17β were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH, LH, estradiol-17β concentrations, growth of the ovulatory follicle, onset of estrus, ovulation rate, or pregnancy rate. Experiment 2 was performed with 14 ewes during the nonbreeding season. Ewes were isolated from rams for 1 month, and received a 6-day MAP priming. Ovaries were ultrasonographically scanned every 12 hours, and FSH, LH, estradiol-17β, and progesterone were measured. Ewes that ovulated and came into estrus had higher FSH and estradiol-17β levels before introduction of the rams than did ewes that had a silent ovulation. The endocrine pattern of the induced follicular phase of ewes that came into estrus was more similar to a normal follicular phase, than in ewes that had a silent ovulation. The follicle that finally ovulated tended to emerge earlier and in a more synchronized fashion in those ewes that did come into estrus. All ewes that ovulated had an LH surge and reached higher maximum FSH levels than ewes that did not ovulate, none of which had an LH surge. We conclude that (a) the effect of ram introduction in cyclic ewes treated with MAP may vary depending on the time of the breeding season at which teasing is performed; (b) patterns of FSH, and estradiol-17β concentrations, as indicators of activity of the reproductive axis, may be used to classify depth of anestrus; and (c) the endocrine pattern of the induced follicular phase, which is related to the depth of anestrus, may be reflected in the behavioral responses to MAP priming and the ram effect

Minimising the stress of weaning of beef calves: a review

Weaning of beef calves is usually done abruptly and early compared to the natural weaning of the species, and is associated with simultaneous exposure of calves to a range of social and environmental stressors. Behavioural and physiological responses to weaning indicate detrimental effects on the welfare of these animals. The development and assessment of weaning methods aiming at reducing or avoiding this problem must be supported by scientific knowledge of the morphological, physiological and psychological mechanisms involved in the establishment, maintenance and braking of the cow-calf bond. Solutions also depend on the understanding of the various stressors associated with weaning, among which are the change in diet, cessation of nursing, separation from the dam, the change to a new spatial environment and the need for social reorganization following removal of the adults from the group. This review discusses these issues and assesses the effectiveness of the methods so far proposed for improving the welfare of beef calves during the weaning period

Comportamiento homosexual en rumiantes machos. Revisión

In several male ruminants, including both, domestic and wild species, it has been reported the presence of homosexualbehaviour  between  males.  The  aim  of  this  review  was  to  summarize  the  information  about  neuroendocrinologicaldifferences  between  homo  and  heterosexual  individuals,  and  the  relationship  between  homosexual  behaviour  andsexual steroid concentration. Moreover, we present information that link homosexual behavior with social dominance,age,  social  environment  during  the  developmental  period,  and  environment  disturbances.  Therefore,  we  includeinformation  about  other  physiologic  aspects,  such  as  reproductive  seasonality,  including  unpublished  informationabout  seasonal  changes  in  domestic  rams  and  captive  male  Iberian  ibex,  and  the  relationship  between  seasonalchanges  in  testosterone  and  behaviour.  Other  topic  discussed  is  the  “buller  syndrome”,  which  is  commonly  observedin  steers,  in  which  is  observed  that  some  males  are  repeatedly  mounted  by  others  males.  In  brief,  homosexualbehaviour  in  male  ruminants  is  multietiologic,  and  some  aspects  are  understudied,  so  the  interpretation  may  becautiously  considered  before  deep  studies  are  developed.En varias especies de rumiantes, tanto domésticos como silvestres, se ha reportado la existencia del comportamiento homosexual entre los machos. El objetivo de esta revisión fue sintetizar la información disponible sobre las diferencias neuroendocrinas entre individuos homo y heterosexuales, y la relación entre la presencia del comportamiento homosexual y la concentración de esteroides sexuales. A su vez, se presenta información que vincula el comportamiento homosexual con la dominancia social, la edad, el ambiente social durante el desarrollo, y los disturbios ambientales. También se analiza como varía el comportamiento homosexual de acuerdo a la estacionalidad reproductiva. Además, se incluye información original sobre la estacionalidad del comportamiento homosexual en carneros domésticos, y de machos de cabra montesa, y su vínculo con la secreción de testosterona. Otro aspecto discutido es el “síndrome de buller” en novillos, individuos que son sistemáticamente montados por otros, y algunos de los factores asociados con la ocurrencia de este síndrome. En síntesis, el comportamiento homosexual en los rumiantes machos tiene un origen etiológico diverso, estando algunos aspectos aún poco estudiados, por lo que toda interpretación debe ser considerada con cautela, siendo por lo tanto un campo de estudio a profundizar

Evaluación del nivel de LH plasmático en diferentes protocolos de sincronización del estro para inseminación artificial a tiempo fijo en vacas lecheras Brown Swiss Mestizas

Investigación realizada en la Hacienda “SAN ANTONIO” ubicada en el km 10 vía a Misahualli, en el cantón Tena, Provincia de Napo. Se evaluó el efecto de diferentes protocolos de sincronización del estro para Inseminación Artificial a Tiempo Fijo, en vacas Brown Swiss mestizas, para determinar los niveles de LH plasmáticos y otras características relacionadas con la taza de concepción. Utilizando el método científico experimental la distribución de los tratamientos fueron Completamente al Azar y no fue necesaria la utilización de Diseño Experimenta. Se analizaron vacas lecheras Brown Swiss mestizas y con la ayuda de registro reproductivo/productivo y registro sanitario, se determinaron diferentes variables durante 120 días de investigación. Los resultados obtenidos demuestran que los mayores perfiles de LH plasmático y porcentaje de tasa de concepción fueron identificados en las vacas tratadas con Norgestomet – GnRH, con 31,42 ng/ml y 100% respectivamente. Concluyéndose que es posible la utilización de Norgestomet – GnRH, para la sincronización del estro para Inseminación Artificial a Tiempo Fijo, en vacas Brown Swiss mestizas, al determinarse los mejores parámetros reproductivos, así como también los mejores rendimientos económicos determinándose un valor de beneficio costo de 1.244 USD. Por lo anterior se recomienda aplicar el tratamiento Norgestomet – GnRH, en los protocolos de sincronización del estro para inseminación artificial a tiempo fijo en vacas, a fin de mejorar el perfil de LH antes de la ovulación. La calidad del cuerpo lúteo y tasa de concepción, fueron también mejorados. Se recomienda difundir los resultados obtenidos a nivel de ganadería lechera, con el objetivo de incrementar la fertilidad bovina, consecuentemente obtener mayores rendimientos económicos de los productores.Evaluation of plasma lh level in different protocols for timing estro artificial insemination fixed time brown swiss crossbred dairy cows in the farmer "SAN ANTONIO" located at km 10 way to Misahualli, Canton Tena Napo Province. The effect of different estrus synchronization protocols for a Fixed Time Artificial Insemination was evaluated in crossbred Brown Swiss cows to determine plasma levels of LH and related cup design features. Using the experimental scientific method the distribution of treatments were completely randomized and the usage of Experimental Design was not needed. It was analyzed crossbred Brown Swiss cows, and with the help of reproductive / productive registration and health record, different variables were determined during 120 research days. The results had shown that higher plasma LH profiles and percent conception rate were identified in treated cows Norgestomet - GnRH , with 31.42 ng / ml and 100% respectively. As conclusion, there is possible the use of Norgestomet - GnRH for estrus synchronization for Artificial Insemination at Fixed Time in crossbred Brown Swiss cows , because the best reproductive parameters were found , as well the best economic returns with a value of benefit - cost of $ 1244. Therefore it is recommended to apply the treatment Norgestomet - GnRH in estrus synchronization protocols for fixed-time artificial insemination in cows , in order to raise the profile of LH before ovulation. The corpus luteum quality and conception rate also were improved. It is recommended also to disseminate the results at the level of dairy farming, with the aim of increasing bovine fertility consequently to obtain higher economic returns for producers

Effect of Nutrition, Lactation and Gonadotropin Stimulation on Ram-Induced LH Surge and Subsequent Fertility in Early Post-Partum Ewes during Seasonal Anestrous

This study evaluated the effect of lactation, exogenous gonadotropin (GS), and nutritional supplementation (SUPP) on fertility of Katahdin ewes during seasonal anestrous. Experiment 1 evaluated effects of lactation and GS on ram-induced LH surge. Lactating (65 to 80 d postpartum; pp) and dry ewes were randomly assigned to be treated with an estrus induction protocol (EIP) consisting of a 5-d treatment with a CIDR device with an injection of a gonadotropin mixture (240 IU eCG and 120 IU hCG; P.G. 600RTM; 3 ml/animal i.m.; n = 16) or no further treatment (n=16) at removal of CIDRs. Experiment 2 was similar to experiment 1 and evaluated the specific effects of lactation and GS on the ram-induced LH surge and subsequent fertility. Lactating (approximately 68.7 +/- 1.3 days pp) and dry ewes were treated with CIDR device with (n = 42) or without (n = 38) an injection of the gonadotropin mixture. In Experiment 3, effects of both levels of nutritional supplementation and GS on fertility of lactating ewes were evaluated. Lactating ewes (n = 87) on pasture, were assigned randomly and then balanced for litter size to receive either a low or high amount of grain supplementation (13.3% Crude Protein; CP; 0.68 kg or 1.14 kg/d/animal; equivalent to 30 and 50% of projected Dry matter intake; DMI, respectively) from 1.5 to 2.5 months postpartum and then treated with CIDR for 5 days with or without GS at CIDR removal. Analysis of Variance (ANOVA) was used to evaluate the main effects and their interactions on response variables. In experiment 1, the proportion of ewes with a detectable LH surge was greater (P = 0.0001) in ewes treated with EIP with an injection of gonadotropin mixture, but there was no effect of lactation status. In experiment 2, the mean proportion of ewes with detectable LH surge tended to be higher in ewes receiving GS than in ewes not receiving GS (P = 0.07; 87.1% vs 57.2%, respectively). Estrous response was higher in ewes receiving than in ewes not receiving GS (P = 0.0045; 63.9% vs 38.6%, respectively) with no effect of lactation status. GS tended to increase estrous response in lactating but not dry ewes (LACT x GS, P = 0.1). Conception and pregnancy rates were lower in lactating ewes compared to dry ewes (P = 0.0172, 0.0131). In Experiment 3, estrous response was greater in ewes receiving than in those not receiving GS (P = 0.009; 67.4 +/- 7 and 33.6 +/- 7%, respectively) and tended to be greater in ewes receiving the high vs. low level of supplementation (P = 0.10; 58.6 +/- 8 and 42.3 +/- 6%, respectively). The pregnancy rate (PR) was increased by GS (P = 0.003; 49 +/- 7 and 19.9 +/- 7%, for ewes receiving and not receiving GS, respectively) and by increasing the amount of supplement (P = 0.05; 43.8 +/- 8 and 25.1 +/- 6%, for ewes receiving the high and low level of supplementation, respectively). The interaction of GS and nutritional supplementation was not significant for any of the variables measured (P \u3e 0.1). The mean peak concentration of LH and time to peak concentration in ewes with detectable LH surge were not affected by any treatment in this study. In conclusion, during anestrous, early postpartum fertility is reduced by lactation in Katahdin ewes, but fertility in lactating ewes can be restored to that of dry ewes with nutritional supplementation and by providing exogenous gonadotropin as part of an EIP