Search

Social interactions among individuals are abundant, both in natural and domestic populations, and may affect phenotypes of individuals. Recent research has demonstrated that the social effect of an individual on the phenotype of its social partners may have a genetic component, known as an indirect genetic effect (IGE). Little is known, however, of nongenetic factors underlying such social effects. Early-life environments often have large effects on phenotypes of the individuals themselves later in life. Offspring development in many mammalian species, for example, depends on interactions with the mother and siblings. In domestic pigs, individuals sharing the same juvenile environment develop similar body weight later in life. We, therefore, hypothesized that offspring originating from the same early-life environment also develop common social skills that generate early-life social effects (ELSEs) that affect the phenotypes of their social partners later in life. We, therefore, quantified IGEs and ELSEs on growth in domestic pigs. Results show that individuals from the same early-life environment express similar social effects on the growth of their social partners, and that such ELSEs shape the growth rate of social partners more than IGEs. Thus, the social skills that individuals develop in early life have a long-lasting impact on the phenotypes of social partners. Early-life and genetic social effects were independent of the corresponding direct effects of offspring on their own growth, indicating that individuals may enhance the growth of their social partners without a personal cost. Our findings also illustrate how research devoted to quantifying IGEs may miss nongenetic and potentially confounded social mechanisms which may bias the estimates of IGEs.

Social interactions among individuals are abundant, both in natural and domestic populations, and may affect phenotypes of individuals. Recent research has demonstrated that the social effect of an individual on the phenotype of its social partners may have a genetic component, known as an Indirect Genetic Effect (IGE). Little is known, however, of non-genetic factors underlying such social effects. Early life environments often have large effects on phenotypes of the individuals themselves later in life. Offspring development in many mammalian species, for example, depends on interactions with the mother and siblings. In domestic pigs, individuals sharing the same juvenile environment develop similar body weight later in life. We, therefore, hypothesized that offspring originating from the same early-life environment also develop common social skills, which generate Early-Life Social Effects (ELSE) that affect the phenotypes of their social partners later in life. We, therefore, quantified IGEs and ELSEs on growth in domestic pigs. Results show that individuals from the same early-life environment express similar social effects on the growth of their social partners, and that such ELSE shape the growth rate of social partners more than IGE. Thus, the social skills that individuals develop in early-life have a long-lasting impact on the phenotypes of social partners. Early-life and genetic social effects were independent of the corresponding direct effects of offspring on their own growth, indicating that individuals may enhance the growth of their social partners without a personal cost. Our findings also illustrate how research devoted to quantifying IGEs may miss non-genetic and potentially confounded social mechanisms, which may bias the estimates of IGEs.

Mussel meal has potential as an alternative protein source for pig since it has high portein content and a balanced Amino acid pattern. Mussels are good filterers of Water and an effective Tool to clean Waters from nitrogen and phosphorus. Using mussel meal as feedstuff in animal production could close the aro-aqua nutrient cycle, bringing nutrients back from the Water to the agro-ecosystem. Session 26 - Theatre 7.

Mussel meal has potential as an alternative protein source for pig since it has high portein content and a balanced Amino acid pattern. Mussels are good filterers of Water and an effective Tool to clean Waters from nitrogen and phosphorus. Using mussel meal as feedstuff in animal production could close the aro-aqua nutrient cycle, bringing nutrients back from the Water to the agro-ecosystem. Session 26 - Theatre 7.

Mussel meal has potential as an alternative protein source for pig since it has high portein content and a balanced Amino acid pattern. Mussels are good filterers of Water and an effective Tool to clean Waters from nitrogen and phosphorus. Using mussel meal as feedstuff in animal production could close the aro-aqua nutrient cycle, bringing nutrients back from the Water to the agro-ecosystem. Session 26 - Theatre 7.

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed.

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed.

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed.

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed.

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed.

This study investigated the effect of continuous elevated cortisol concentrations during standing oestrus on time of ovulation and patterns Of progesterone. oestradiol and luteinising, hormone (LH) in sows. The elevation of cortisol concentrations was achieved through repeated intravenous injections of synthetic adrenocorticotropic hormone (ACTH) every 2 It for approximately 48 h, from the onset of the second standing oestrus alter weaning. Treatment was terminated when ovulation was detected (monitored by transrectal ultrasonography every 4h) or when (lie sow had received a maximum of 24 injections. The close of ACTH (2.5 mu g/kg) was chosen to mimic the cortisol concentrations seen during mixing of unfamiliar SOWS. The sows (n = 14) Were surgically fitted with jugular vein catheters and randomly divided into a control (C group) where only NaCl solution were injected) or an ACTH group. Blood samples were collected every 2 h. In parallel with the blood sampling, saliva samples for cortisol analyses were taken from eight sows before onset of treatment and from four of the sows during treatment. There was no difference in time from onset of standing, oestrus to ovulation between the two groups. The interval between the peaks of oestradiol and LH to ovulation was prolonged in the ACTH group compared to the C group (p less than 0.05). with a tendency towards all earlier decline of oestradiol in the ACTH group. Cortisol and progesterone Concentrations were significantly elevated during treatment in the ACTH group (p less than 0.001). with cortisol peak concentrations occurring between 40 and 80 min after each ACTH injection. Cortisol concentrations in saliva and Plasma were highly correlated (p less than 0.001). In conclusion, elevated cortisol concentrations from the onset of standing oestrus increase progesterone concentrations and prolong the interval between oestradiol and LH peaks to ovulation, the latter possible due to an early decline in oestradiol concentrations

This study investigated the effect of continuous elevated cortisol concentrations during standing oestrus on time of ovulation and patterns Of progesterone. oestradiol and luteinising, hormone (LH) in sows. The elevation of cortisol concentrations was achieved through repeated intravenous injections of synthetic adrenocorticotropic hormone (ACTH) every 2 It for approximately 48 h, from the onset of the second standing oestrus alter weaning. Treatment was terminated when ovulation was detected (monitored by transrectal ultrasonography every 4h) or when (lie sow had received a maximum of 24 injections. The close of ACTH (2.5 mu g/kg) was chosen to mimic the cortisol concentrations seen during mixing of unfamiliar SOWS. The sows (n = 14) Were surgically fitted with jugular vein catheters and randomly divided into a control (C group) where only NaCl solution were injected) or an ACTH group. Blood samples were collected every 2 h. In parallel with the blood sampling, saliva samples for cortisol analyses were taken from eight sows before onset of treatment and from four of the sows during treatment. There was no difference in time from onset of standing, oestrus to ovulation between the two groups. The interval between the peaks of oestradiol and LH to ovulation was prolonged in the ACTH group compared to the C group (p less than 0.05). with a tendency towards all earlier decline of oestradiol in the ACTH group. Cortisol and progesterone Concentrations were significantly elevated during treatment in the ACTH group (p less than 0.001). with cortisol peak concentrations occurring between 40 and 80 min after each ACTH injection. Cortisol concentrations in saliva and Plasma were highly correlated (p less than 0.001). In conclusion, elevated cortisol concentrations from the onset of standing oestrus increase progesterone concentrations and prolong the interval between oestradiol and LH peaks to ovulation, the latter possible due to an early decline in oestradiol concentrations

Use of bull semen with high levels of sperm abnormalities, reflecting genital dysfunction, is not recommended for artificial insemination (AI) since it would most likely lead to subfertility. Sperm quality, including sperm morphology, may deteriorate with increasing age of the bull thus becoming a source of concern when using older, progeny-tested AI bull sires. Although a relationship between sperm morphology and fertility after AI in progeny-tested bull sires has been reported, it is yet unclear which sperm abnormalities are most critical. This constituted the core aim of a 22-month long retrospective study in proven (aged 60-84 months at the start of the study) AI sires of the Swedish Red (SR, n = 8) and Swedish Holstein (SLB, n = 4) breeds where their semen (107 freezing batches in total, built by a single ejaculate (n = 3) or pooling two consecutive ejaculates (n = 104) collected at 1-3 months interval), were subjected to detailed morphological examinations on wet- and dry, stained smears. Attention was paid to between- and within-bull variations with regard to presence and level of sperm abnormalities. Sperm morphology differed significantly between sires and ejaculates, with 6/12 sires having ejaculates containing greater than 10% of morphologically deviating sperm head shapes, a commonly used threshold for young At bulls in Sweden. However, with the exception of pear-shaped or narrow-at-the-base anomalies, the mean values for individual defects were always within the limits expected for a normal bull sire, and were therefore considered acceptable. The percentage of morphologically normal spermatozoa was positively related to fertility, whose output differed significantly among bulls. Among sperm abnormalities, the proportion of morphologically deviating sperm head shapes were negatively correlated with fertility, pear-shaped sperm heads in particular. In conclusion, the relationship between sperm morphology and fertility after AI calls for frequent (2-3 mont

This study investigated whether injections of ACTH for 48 h, from the onset of the second standing estrus after weaning, had any impact on time of ovulation and patterns of progesterone, estradiol, luteinizing hormone (LH), and inhibin a. The studied sows (n = 15) were fitted with jugular vein catheters and randomly divided into a control (C group) and an ACTH group. From the onset of standing estrus, the sows were injected (NaCl or synthetic ACTH, 5 mu g/kg) every 4 h; blood samples were collected immediately before and 45 min after each injection. Ovulation was monitored using ultrasonography. The ACTH-group sows stopped displaying signs of standing estrus sooner after ovulation in their second estrus, but no impact was found on time of ovulation. There were no significant differences in the intervals between LH peak, estradiol peak, and the onset of standing estrus between the C and ACTH groups. The cortisol and progesterone concentrations were significantly elevated (p less than 0.001) in samples taken 45 min after ACTH injection. There were minor differences in estradiol and LH concentrations between the groups. Overall inhibin a concentrations were significantly higher during the treatment period in the ACTH than in the C group, but there were no significant differences between samples taken either 45 min or 4h after injection. In conclusion, injections of synthetic ACTH during estrus in the sow apparently disturb the duration of signs of standing estrus and the hormonal pattern of progesterone, and possibly of inhibin ot, estradiol and LH. (c) 2006 Elsevier Inc. All rights reserved.

This study aimed to determine whether pre-pubertal exposure in boars to di(2-ethylhexyl) phthalate (DEHP), a plasticizer reported to have toxic effects on rodent reproduction, would affect the sperm ability to undergo capacitation and acrosome reaction (AR) in vitro or give rise to a higher degree of chromatin instability associated with acid-induced denaturation. Spermatozoa were collected from 16 boars (n = 8/group) 8-9 months of age, exposed to 300 mg/kg body weight of DEHP or placebo per os three times a week, from 3 to 7 weeks of age. The spermatozoa were cryopreserved and examined post-thaw by flow cytometry for their ability to capacitate in vitro when exposed to the effector bicarbonate and to acrosome-react when exposed to calcium ionophores, using the lipid stain Merocyanine-540 (m-540), and peanut agglutinin-fluorescein isothiocyanate, respectively, as probes. The ability of the DNA to sustain denaturation in vitro was tested using a sperm chromatin structure assay (SCSA). No significant differences between the DEHP-exposed group and controls were found for any of the sperm attributes examined. Frozen-thawed spermatozoa showed similar rates of non-capacitated cells between groups, and were capacitated at similar rates. Rates of induced ARs were also similar. Values of DNA denaturation were low and showed no differences between groups. In conclusion, pre-pubertal exposure to DEHP does not seem, under the conditions of the present experiment, to affect the ability of frozen-thawed spermatozoa collected post-puberty to capacitate or acrosome-react (the main requisites for fertilization) or to present damage in their nuclear genome. (c) 2007 Elsevier Inc. All rights reserved.

Use of bull semen with high levels of sperm abnormalities, reflecting genital dysfunction, is not recommendable to use for AI since it most likely leads to sub-fertility. Sperm morphology deteriorates with age, a source of concern when using ageing progeny-tested AI-bull sires. However, whether a relationship between sperm morphology and fertility after AI in progeny-tested bull sires is present remains to be proven and constituted the reason for a retrospective study of progeny-tested bull sires of the Swedish Red and White (SRB) and Swedish Holstein (SLB) breeds performed with data of 8 SRB and 4 SLB sires analysed in an University specialized andrological laboratory. Particular attention was paid to the influence of age and breed as well as the variation between- and within-bull for presence and level of sperm abnormalities. Sperm morphology differed between sires, ejaculates and breed, with 6/12 sires having ejaculates with more than 10% of morphologically deviating sperm heads, a commonly used threshold for young At bulls. However, with the exception of pear-shaped or narrow at the base anomalies, individual defect mean values were always within what is expected for a bull sire and considered within acceptable limits. Breed and age affected some semen (ejaculate volume) and sperm morphology variables (nuclear pouches, acrosome defects and head contour). Estimated breeding values for male fertility output differed significantly among bulls, with the percentage of morphologically normal spermatozoa in the overall ejaculate being positively related to fertility. Few individual sperm abnormalities correlated negatively to fertility, as pear-shaped sperm heads, proximal droplets or loose heads (SRB), probably owing to the reduced sire material examined. In conclusion, the presence of relationships between sperm morphology and fertility after AI calls for routine, frequently done assessments of sperm morphology in AI-stud bull sires during their entire active life.

Glycosaminoglycans (GAGs) are present in the oviduct in which the major part of sperm capacitation occurs. In this study we have tested how capacitation of frozen-thawed bull spermatozoa is effected by exposure to different GAGs detectable or possibly present in oviductal fluid; i.e. heparin, hyaluronan, heparan sulphate, dermatan sulphate and chondroitin sulphate. Following exposure of different duration, the spermatozoa were stained with either Chlortetracycline (CTC) or merocyanine-540 and evaluated with epifluorescent light microscopy or flow cytometry, respectively. Heparin elicited a significant increase in the number of alive, capacitated spermatozoa, either expressed as higher merocyanine-540 fluorescence (p less than 0.0001) or as B-pattern (p = 0.0021) in the CTC assay, during 4 h of incubation. When comparing the different GAG treatments one by one to the negative control in the flow cytometric study, only heparin and dermatan sulphate were significant (p less than 0.0001) higher than the control at 0-30 min of incubation. Duration of incubation did not affect the proportion of capacitated spermatozoa when measured as merocyanine-540 fluorescence or CTC B-pattern, but the length of the incubation did affect the number of dead (Yo-PRO 1 positive) spermatozoa (p less than 0.0001). Exposure to zona pellucida proteins significantly increased the proportion of acrosome reacted spermatozoa (p = 0.016). Both heparin and dermatan sulphate induce capacitation of frozen-thawed bull spermatozoa in vitro.

Late effects of pre-pubertal oral exposure to di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in, for example, polyvinyl chloride-products, on semen quality in young boars have not been clear-cut. The aim of this study was to determine whether stress imposed on spermatozoa would reveal such effects. Semen was collected from post-pubertal boars (8-9 months of age), which had been exposed to 300 mg kg(-1) body weight of DEHP per os three times a week from 3 to 7 weeks of age and from control siblings given placebo (water). The semen was cryopreserved and examined for plasma membrane integrity post-thaw using the short hypo-osmotic swelling test and flow cytometry (propidium iodide /SYBR-14). Sperm motility was assessed by computer-assisted sperm analysis. No significant difference in plasma membrane integrity could be found between the groups. The DEHP-exposed group had a significantly lower percentage of linearly motile spermatozoa at 30 min (P less than 0.05) and 120 min (P less than 0.001) after thawing, and a larger amplitude of lateral displacement of the head 120 min after thawing (P less than 0.05), compared with controls. In summary, spermatozoa from boars pre-pubertally exposed to low doses of DEHP, showed kinematic deviations post-thaw that could be related to DEHP exposure.

Late effects of pre-pubertal oral exposure to di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in, for example, polyvinyl chloride-products, on semen quality in young boars have not been clear-cut. The aim of this study was to determine whether stress imposed on spermatozoa would reveal such effects. Semen was collected from post-pubertal boars (8-9 months of age), which had been exposed to 300 mg kg(-1) body weight of DEHP per os three times a week from 3 to 7 weeks of age and from control siblings given placebo (water). The semen was cryopreserved and examined for plasma membrane integrity post-thaw using the short hypo-osmotic swelling test and flow cytometry (propidium iodide /SYBR-14). Sperm motility was assessed by computer-assisted sperm analysis. No significant difference in plasma membrane integrity could be found between the groups. The DEHP-exposed group had a significantly lower percentage of linearly motile spermatozoa at 30 min (P less than 0.05) and 120 min (P less than 0.001) after thawing, and a larger amplitude of lateral displacement of the head 120 min after thawing (P less than 0.05), compared with controls. In summary, spermatozoa from boars pre-pubertally exposed to low doses of DEHP, showed kinematic deviations post-thaw that could be related to DEHP exposure.