Serosurvey for viruses associated with reproductive failure in newly introduced gilts and in multiparous sows in Belgian sow herds

A serosurvey for viruses associated with reproductive disorders was conducted in 25 conventional Belgian farms. Serum antibody titers for porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine enteroviruses (PEV) and swine influenza viruses (SIV) were determined in gilts and sows. All the animals were seropositive for PCV2 and >95% were seropositive for all 4 embryopathogenic PEV serotypes. Consequently, special preventive measures appear to be unnecessary for these viruses. In I farm, non-vaccinated gilts were found to run a risk of developing PPV-induced reproductive disorders. Vaccination against PPV could exclude this risk. In 10 farms, gilts seronegative for one or more specific SIV subtypes were introduced into a herd that had previously been infected with the same subtypes. Vaccination of gilts against SIV may prevent reproductive disorders in gilts and respiratory problems in their offspring. In I farm, newly purchased gilts that were possibly shedding PRRSV were introduced into a PRRSV seronegative sow herd. Serological screening prior to purchase or vaccination of the sows could have resolved this dangerous situation

Behavioural and physiological consequences of acute social defeat in growing gilts: effects of the social environment

Endocrine, behavioural and immunologic processes, together with body growth, were evaluated in gilts that were defeated at 10 weeks of age in resident-intruder tests. Immediately after defeat, gilts were either separated from or reunited with a familiar conspecific (litter-mate; always a barrow). Gilts were assigned to one of four treatments: (a) DI: defeat, followed by isolation (separation from original litter-mate; n=8); (b) I: no defeat, isolation (control group; n=9); (c) DP; defeat, followed by pair-housing (reunion with original litter-mate; n=8); and (d) P: no defeat, pair-housing (control group; n=8). The following general conclusions were derived: (1) social defeat caused pronounced short-term elevations in hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal medullary activities, and of prolactin levels. Moreover, as soon as 1 h after defeat, percentages of blood lymphocytes and neutrophilic granulocytes were, respectively, decreased and increased; (2) social defeat had some long-lasting influence on behaviour and physiology, but isolation predominantly determined responses in the longer term. Defeat, as well as isolation, resulted in increased cardiovascular activities compared to P controls, as observed in a novel object test (NOT: +7 days) and an aversion test (AVT: +14 days). Moreover, defeated as well as isolated gilts did not habituate to a repeated novel environment test (NET: -7, +2 and +7 days) in terms of frequencies of vocalising, whereas P controls did. Isolation, through the separation from any other pig, was responsible for the other observed long-term characteristics, which developed progressively. Isolated gilts showed high mobilities and high cortisol responses in the repeated NET (+7 days), not being habituated. This contrasted the reactions of pair-housed gilts, which were much reduced. In addition to their high cardiovascular activities in the NOT and the AVT, isolated gilts also displayed higher heart rates in the repeated NET and during human presence following the NOT, compared to pair-housed gilts. Finally, isolated gilts were more inhibited to approach a novel object (in the NOT) than pair-housed pigs; and (3) stress responses of defeated gilts were modulated by the subsequent social environment. Stimulation of the HPA-axis (plasma- and salivary cortisol) was prolonged in those defeated gilts which were isolated (observed in the first hour). Changes in leucocyte subsets were still observed after 3 days in DI, but were `normalised' within 1 day in DP gilts. Two days after defeat, habituation to the repeated NET in terms of mobility and salivary cortisol responses occurred in control and DP gilts, but not in DI gilts. We argue that these effects of the social environment shortly after defeat were related to a stress-reducing effect of a stable social relationship, i.e. social support.

Personalities in female domesticated pigs: behavioural and physiological indications

The inconclusive evidence so far on the existence of distinct personality types in domesticated pigs, led us to perform the present experiment. A total of 128 gilts from 31 sows were systematically studied from birth to slaughter in two identical trials. Intra-test consistency in individual behavioural andror physiological reactions was studied in three different tests. We were not able to show consistencies in reactions of gilts over time to a backtest (at 2–4 days and 4 weeks of age) and to a novel environment test (at 10 and 24 weeks of age). Individual aggression, however, as measured in a group-feeding competition test in stable groups (at 10 and 24 weeks of age), proved to be highly consistent. Explanations for these discrepancies in intra-test consistencies are critically discussed. Inter-test consistencies were determined by relating the individual reactions of gilts to the backtest to various characteristics and responses to tests at a later age. The highest correlations were found when resistance in the first backtest was involved. No evidence was found for the existence of specific isolated categories of animals with respect to this resistance. For further analysis, extreme responding gilts in the first backtest (roughly the top and bottom 25% of the distribution) were classified as low resistant (LR; <3 escape attempts; n=31) or high resistant (HR; >4 escape attempts; n=45). By comparisons of mean responses of LR and HR gilts within groups, we have established a relationship between the backtest and several other variables. Behaviourally, the HR gilts showed more aggression in the group-feeding competition tests. Also, in the competition for the most productive teats at the anterior, a predominant position of HR piglets at this site was observed during the suckling period. The latter piglets also gained more weight during this period than LR ones. Compared to HR pigs, in the first novel environment test LR pigs hesitated longer to leave their home pens and to contact a human, but no difference in their locomotory behaviour was observed. Contrasts between LR and HR pigs in the second novel environment test were reduced or absent. Physiologically, when compared to HR gilts, LR ones had a higher reactivity of the hypothalamic–pituitary–adrenocortical (HPA) system. This was shown by higher cortisol responses to the first novel environment test, to routine weighing at 25 weeks of age, and to administration of a high dose of ACTH. It is discussed that these findings for LR and HR gilts, may provide support for the existence of behavioural and physiological responses in pigs, resembling those of proactive and reactive rodents.

Enhancement of pigmeat quality by altering pre-slaughter management

End of project reportThe studies presented in this report were conducted to investigate the effect of breed, slaughter weight, castration of male pigs and strategic feeding strategies on the performance of pigs to slaughter and on their carcass quality. The effect of breed, gender and feeding regimen on the performance of pigs and their carcass quality was examined in the first study (Section 3). From weaning to slaughter Landrace-sired pigs grew at a similar rate but had a better feed conversion efficiency compared with Duroc-sired pigs. Landrace-sired pigs also had a higher carcass lean and greater muscle depth than Duroc-sired pigs. Entire male pigs grew more efficiently, had lower lean content in their carcasses and had a reduced kill out yield when compared with gilts. The eye muscle depth was greater for gilts than entire males. Diluting the diet with grass-meal (GM) reduced growth rate, caused a deterioration in feed conversion efficiency, reduced back fat thickness, reduced eye muscle thickness and reduced kill out yield compared to the control feeding regimen of a cereal based diet. Compensatory growth was observed during a re-alimentation period following a period of diet dilution with grass-meal. However, where it did occur, in most cases it was only partial. Adding 5% rapeseed oil instead of lard to the finisher diet increased nitrogen utilization efficiency and phosphorous utilization efficiency. The effect of gender (boar, castrate, gilt) and slaughter weight (80 to 120kg) on pig performance, carcass quality, meat quality, and nitrogen excretion was investigated in the second study (Section 4). Boars grew faster than gilts and more efficiently than castrates or gilts. Castrates had a higher kill out yield than boars. Nitrogen excretion from castrates was similar to gilts which were both higher than that from boars. The processing value of carcasses from castrates may be higher than that of boars and gilts. In particular castrates had heavier loins and bellies than either boars or gilts. Carcasses from castrates and gilts had a higher temperature (recorded 24 hours post slaughter) than boars. However, pH24 was not affected by gender. The intramuscular fat content of the l. dorsi in castrates was higher than that of boars or gilts, however at 1.65% this was well below the level (2.0%) above which any noticeable sensory attributes might be detected. Feed intake increased with increasing slaughter weight and feed conversion efficiency deteriorated. N excretion also increased with each increment in weight. Carcass lean content increased up to 90kg live EOP 4939.doc 4 25/10/2005 weight then reached a plateau and declined after 110kg live weight. Heavier carcasses yielded more product for approximately the same slaughtering cost and the associated larger muscles could make it easier to use seam butchery techniques that result in lean, well-trimmed, attractive cuts and joints. The pH45 and pH24 were reduced with increasing slaughter weight and drip loss increased. Heavier pigs may be more prone to the development of PSE than lighter pigs as their carcass temperature remains higher for longer than that of lighter pigs

Induction of puberty and maintenance of pregnancy in prepuberal gilts

The effects of estradiol benzoate (EB) and human chorionic gonadotrophin (HCG) on ovulation, fertilization, and maintenance of pregnancy were tested on 53 prepuberal gilts during the year 1978. In Experiment I, 8 gilts averaging 170 days of age were in-jected with 0.4 mg EB twice daily for 3 consecutive days. Human chorionic gonadotrophin was administered (500 i.u.) 36 hours after the last EB injection. Gilts were slaughtered either 31, 55, 77, or 100 hours after HCG injection. Only 39% of the follicles in 2 gilts had ovulated by 77 hours post HCG injection but 83% had ovulated in another gilt by 100 hours. In Experiment II, 15 gilts averaging 176 days of age were put on trial. Five of these gilts were injected in the same manner as in Experiment I and were maintained in the same pen with 5 gilts and 2 boars which had no hormone treatment. Five more gilts were kept in a pen away from the sight and sound of a boar. There was no difference in age settled between the gilts maintained in the same pen. Two gilts receiving hormone treatment returned to estrus 18 and 21 days after HCG injection and farrowed an average of 8 live pigs while three gilts with only boar exposure farrowed an average of 5 live pigs. In Experiment III, 30 gilts averaging 150 days of age were alloted equally to 1 of 3 treatments. Twenty gilts were injected with EB and HCG in the same manner as in Experiment I and 10 of these gilts were artificially inseminated 48 to 72 hours after HCG injection. The other 10 gilts were maintained in an adjacent lot and observed for estrus. Ten gilts were also maintained in a pen away from the sight and sound of a boar. Estradiol benzoate treated gilts experienced first estrus earlier (P \u3c .01) than control gilts. Eight of the bred gilts returned to estrus at an average of 37.3 days post HCG injection. Four of these gilts were rebred to a boar and settled an average of 9.8 live feti past 80 days gestation. Progestin levels prior to the start of treatment were all below 1.5 ng/ml of plasma while at day 12 (HCG = day 0) of the induced cycle, proges-tin levels averaged 18.33 ng/ml (eliminating 3 gilts with levels below 1.5 ng/ml) for gilts receiving EB and HCG treatment. Progestin levels of the 4 gilts bred on the following estrus averaged 23.2 ng/ml on day 10

COMPARISON OF INTRAMUSCULAR FAT CONTENT IN THE FIRST FARROWING GILTS AND IN THE FATTENING GILTS

The aim of the study was to compare the slaughter value and meat quality of the first farrowing gilts with normal fattening gilts. The study was carried out on 30 primiparous gilts (A) and 39 fattening gilts (B). Age of A gilts at slaughter was 371.03 days and that of B gilts was two times lower and attained 179.64 days. However carcass fatness of the younger B gilts was higher than of primiparous gilts (P < 0.05) and carcass lean content was high in both gilt groups. Meat characteristics were determined in longissimus lumborum muscle. Some differences between the compared gilt groups were stated in muscle colour, WHC, protein and intramuscular fat content. Higher IMF content was found in primiparous gilts (1.88 ± 0.50 versus 1.19 ± 0.39%; P< 0.01)

Improving Secondary Stroke Prevention Among Underserved African Americans: Moving Beyond Health Attitudes

Obesity, a known risk factors for stroke, poses a great health risk for the African American community. Beliefs about health locus of control (HLOC) are predictive of many health behaviors related to both obesity and stroke prevention. Some have recommended targeting health interventions to individuals with internal HLOC, as they tend to be more amenable to changing health behaviors, but this can be exclusionary to African Americans, who tend to have higher levels of external locus of control. The present study is a pretest-posttest randomized control design examining the impact of a brief, CBT-based health management intervention developed for overweight and obese African American inpatients with primarily external HLOC recovering from TIA or ischemic stroke. Intervention participants with a predominately external HLOC demonstrated improvements in minutes per week spent exercising (M=73.87/ SD+ 29.23), daily servings of fruit (M=0.63/ SD+ 0.25) and daily servings of vegetable consumption (M=1.92/SD+ 0.93) at the four-week follow-up assessment. Significant improvements in tobacco cessation (t(19)=3.09, p\u3e.01) and medication adherence (t(19)=2.63, p\u3e.05) were also evidenced. The importance of designing a health intervention sensitive to the HLOC orientation of the population is highlighted and access to health resources is discussed as a possible mediator of the impact of HLOC on obesity-related health behavior

Is Physical Boar Exposure Required for Accurate Detection of Estrus in Gilts?

Accuracy of estrus detection in response to physical (PBE) vs fenceline (FBE) boar exposure was evaluated in 40 gilts during two successive estrous periods. Gilts heat checked with FBE expressed shorter estrous periods (.6 day) than PBE gilts. Estrus was detected within five minutes of boar exposure in 100 percent of gilts on both treatments except for PBE gilts on the first day of estrus. The first day of estrus was expressed after five minutes of boar exposure in 16.2 percent of PBE vs 0 percent of FBE gilts. The PBE gilts may be near the beginning of estrus. They are unresponsive to limited (15 min) FBE and slow to respond to PBE. Fertility was not compared in this study, but inseminations timed 12 to 24 hours after detection of estrus in these gilts (gilts not detected with FBE and slow to respond to PBE on their first day of estrus) will be too late to result in high fertility. Ovulation will occur or be in progress in these gilts at the time of insemination. Therefore, heat-detection with physical boar exposure rather than fence-line boar exposure is recommended to achieve proper timing of insemination and high fertility in gilts

Physico-chemical quality attributes and fatty acid profiles of pork from Windsnyer and Large White gilts

The objective of the study was to assess the physico-chemical pork quality attributes and fatty acid profiles of indigenous Windsnyer (WS) and Large White (LW) gilts. Twelve gilts of each breed were fed similar commercial diets from weaning until slaughter at the age of 21 weeks. The m. longissimus thoracis et lumborum was sampled. Differences in muscle pH values obtained 24 hours post mortem (pH24) were not significant in pork from the WS or LW gilts. Pork lightness 24 hours post mortem (L*24) was significantly lower in WS gilts than in LW gilts. Muscle saturated fatty acids (SFA) were higher in WS gilts than LW gilts. Fat of LW gilts had higher polyunsaturated (PUFA), n-6 fatty acids, n-3 fatty acids and PUFA: SFA ratio than WS gilts. The study showed preferential attributes of pork from LW gilts than from WS gilts. The accrued information could benefit the food industry by assisting researchers and nutritionists to interpret the quality of pork from different pig genotypes for health-conscious consumers. Furthermore, it aids in determining the concern about pork as a cardiovascular risk factor and acts as a planning tool for public-health programmes.Keywords: Fatty acids, indigenous pigs, pork quality, tendernes