Virginio Aguirre

Reproductive activity of Suffolk ewes in seasonal anestrus after being exposed to Saint Croix or Suffolk rams

The purpose of this study was to examine the hypothesis that rams of a tropical breed may be more effective than rams of temperate breed in inducing a reproductive response in ewes of temperate origin during the anoestrous period. Thirty Suffolk ewes in seasonal anestrus were assigned to one of three groups. In the control group (n=9), no males were present, while in the second group (Suffolk rams [SUF]; n=9) ewes were exposed to Suffolk males continuously for 13 days and twice per day from days 14-30, while in the third (Saint croix rams [SCR]; n=12), ewes were treated as in SUF, but rams were from the Saint Croix breed. Sexual receptivity was recorded daily for 30 days after introduction of the males and lambing data were recorded in the fall in SUF and SCR groups. In addition, serum progesterone (P4) concentration was used to monitor ovarian activity in all groups. No reproductive activity was observed in controls. In SUF, six ewes ovulated but did not show estrus, while in SCR all ewes showed estrus, ovulated and were mated. In addition, all but one of the ewes in SCR lambed. It was concluded the Saint Croix rams were more effective than Suffolk rams in inducing an estrous response, conception and pregnancy in anestrous Suffolk ewes.

Effects of high concentrate supplementation of Saint Croix sheep during peripartum on neonatal lamb behaviour

ABSTRACT The aim of this study was to determine whether increasing concentrate supplementation to ewes during the peripartum would benefit ewe and lamb vigour. Pregnant ewes were randomly assigned to either a maintenance group (MG) or a supplementation group (SG). The diets given covered energy requirements and consisted of pasture, forages and commercial concentrate; however, SG ewes received higher concentrate ration. Body weight and blood metabolites were assessed weekly. Lambs were weighed and their behaviour was observed. Data were analysed using repeated-measures test or ANOVA. During peripartum, the body weight was significantly higher in SG ewes compared with MG ewes (P = .02). Indicators of energy metabolism were similar between groups (P > .05). Latency to first suck was 10 minutes shorter in SG lambs compared with MG lambs (P = .005). Lamb weight was similar between groups, and there was a negative correlation between lamb birthweight and time to first suckle that was independent of diet group. This study demonstrates that high concentrate supplementation of ewes during peripartum results in higher body weight postpartum but does not change metabolic status. Latency to first suck was shorter in lambs born to SG ewes suggestive of enhanced vigour related to supplementation.

The tail in tropical hair ewes (Ovis aries) that are in estrus is used as a proceptive signal and favors ram’ copulation

Two experiments were performed to determine if the tail has a role: 1) in proceptive behavior, and 2) in facilitating copulation in hair sheep. The movements and position of the tail of estrous and non-estrous ewes in response to male courtship were compared in the first study. In the second study, the courtship of rams and mating behavior directed towards tailed or tail-docked, in estrus or diestrus ewes, were compared. Both experiments were conducted with restrained ewes during 3 min assessment periods. In Experiment 1, tail movements occurred in short episodes in response to physical contact of the male, but the rest of the time the tail of non-estrous ewes was drawn inward to the body, while in estrous ewes it simply hung naturally straight downward. Ewes in estrus had many tail moving episodes (P <0.001) with more movements per episode (P <0.001), that were of greater amplitude (P <0.001) and greater elevation in angle from the body (P <0.001) than in non-estrus ewes. In Experiment 2, ejaculation latencies with non-estrous ewes were longer than with estrous ewes (P <0.0001), and rams had more attempts to mount (P = 0.008), and more completed mounts (P = 0.0003) in non-estrous than estrous ewes. In addition, rams ejaculated more times (P <0.0001), and had a greater ejaculations/(mounts + ejaculations) ratio in estrous than non-estrous ewes (P <0.0001). More rams also had anal intromissions in docked than in intact tail-ewes (P = 0.0002). In conclusion, movements and position of the tail of estrous ewes is a primary component of the proceptive behavior that facilitates mating and serves as a physical barrier to avoid anal intromissions in hair sheep.

Farm Animal Welfare and Children

Children are future consumers; they will impact future animal welfare standards. This pilot study evaluated a nonhuman animal welfare education program, building a farm animal attitude questionnaire for 8- to 10-year-old children. The educational material focused on the behaviors and needs of cows, chickens, and pigs. Knowledge acquisition and attitude change were measured before and after the intervention for children in the intervention group and at a 2-week interval for children in the control group. Reliability of the attitude scale was measured by correlating the answers from the control group at two different time points. Eleven items were significantly correlated at the time points, indicating that those questions were reliably testing children’s views on these items. The educational intervention was successful in increasing children’s knowledge of farm animals and resulted in some changes in attitudes. The type of favorite animal reported shifted to more farm animals after the intervention.

Short-term under-nutrition affects feeding and sexual behaviour in oestrous- synchronized Saint Croix ewes (Ovis aries)

ABSTRACT To determine the effect of short-term under-nutrition on feeding and sexual behaviour in oestrous sheep, the oestrus cycles of 51 Saint Croix ewes were synchronized, and they were randomly assigned to one of two groups. Each group was maintained on a Taiwan grass (Pennisetum purpureum) pasture for 102 h after sponge withdrawal. This diet provided 400 g of dry matter/100 kg of body weight/day, the total available for one group (T), whilst another group (T + C) received an additional 350 g/animal/day of concentrate. Before and after the experimental period, all animals received the additional concentrate. A pen with two one-way gates was located in the centre of each pasture to capture those ewes showing proceptive behaviour towards a ram tethered inside, while sexual receptivity tests were performed every 6 h for 102 h, starting at sponge withdrawal, by moving the ewes to an adjacent pen and exposing them to an intact ram. Foraging behaviour was recorded by scan samples before the sexual receptivity tests. Progesterone concentration was determined on days 2 and 11 after sponge withdrawal. Only 26% of the ewes in the T + C group and none in the T group displayed proceptive behaviour. In both groups, all ewes displayed sexual receptivity and ovulated. Grazing, rumination and walking were higher in T ewes. The frequency and the duration of lying were higher in the T + C than in the T ewes. It was concluded that the short-term nutritional deficiency induced changes in foraging behaviour and decreased ram-seeking behaviour in oestrous-synchronized ewes.