Exogenous genistein in late gestation: effects on fetal development and sow and piglet performance

Due to their functional similarity to estradiol, phytoestrogens could prove to be beneficial in late gestating sows. The goal of this study was to determine the impact of providing the phytoestrogen genistein during late pregnancy on the performance of sows and their litters. In total, 56 gilts were equally divided into the two following groups on day 90 of gestation: (1) controls (CTL); and (2) two daily i.m. injections of 220 mg of genistein (GEN). Treatments were carried out until farrowing. Jugular blood samples were collected from 16 gilts/treatment on days 89 and 110 of gestation, and on days 3 and 21 of lactation. Milk samples were also obtained from those sows on day 3 of lactation. A male piglet from 16 CTL and 15 GEN litters was slaughtered at 24 h postpartum and a blood sample was obtained. The liver, heart and visceral organs were weighed and the semitendinosus (ST) muscle was collected and carcass composition was determined. The treatment increased (P<0.05) the concentrations of genistein and daidzein in the plasma of gilts on day 110 of gestation and of genistein in the plasma of piglets at 24 h postpartum. It also increased IGF1 concentrations in gilts at the end of the treatment period (P<0.05). Genistein had no impact (P>0.1) on weight or backfat loss of sows during lactation, milk composition or weights of piglets. The pre-weaning mortality rate of piglets was very low (<7%), yet the odds ratio comparing CTL with GEN sows indicated almost twice as many chances of pre-weaning deaths occurring in litters from CTL than GEN sows. Weights of the piglet carcasses were similar for both treatments, as well as weights of the various organs and of the ST muscle (P>0.1). However, carcasses from GEN litters contained more fat than those from CTL litters (9.63% v. 8.34%, P<0.05). None of the biochemical properties of the ST muscle differed between groups (P>0.1). In conclusion, injecting gilts with 440 mg/day of genistein in late gestation increased IGF1 concentrations in gilts and carcass fat in neonatal piglets, but had minimal effect on muscle development of piglets at birth and on the performance of lactating sows and their litters.     

Effects of NaOH treatment on condensed tannin contents and gas production kinetics of tree leaves

Effects of NaOH treatment on the crude protein (CP), condensed tannin (CT) and in vitro gas production kinetics of leaves of Arbutus andrachne, Glycyrrhiza glabra L. and wheat straw were determined. Wheat straw, which is tannin-free, was used as the standard. The NaOH treatment was completed by pulverization of samples with 0, 20, 40, 60 and 80 g/L of NaOH solution in the proportion of 1 L of solution to 1 kg of sample. Gas production was determined at 3, 6, 12, 24, 48, 72 and 96 h of incubation. NaOH treatment linearly decreased (P<0.001) the CT contents of leaves of Arbutus andrachne and Glycyrrhiza glabra L. whereas NaOH treatment had no effect on the CP contents of Arbutus andrachne, Glycyrrhiza glabra L. and wheat straw. The 80 g/L NaOH treatment reduced the CT content of leaves of Arbutus andrachne and Glycyrrhiza glabra L. by 59.6% and 86.7%, respectively. NaOH treatment linearly decreased (P<0.01) gas production rate of Arbutus andrachne although it linearly increased (P<0.01) gas production rate of wheat straw. In contrast, NaOH treatment had no effect on gas production rate of leaves of Glycyrrhiza glabra L. NaOH treatment linearly decreased (P<0.001) potential gas production of leaves of Arbutus andrachne and Glycyrrhiza glabra L. whereas NaOH treatment linearly increased (P<0.001) potential gas production of wheat straw. Treatment with NaOH can be used to improve the nutritive value of tannin-free forages such as straw, but not for tannin-containing leaves.     

Effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics on lactational feed intake of sows over two successive parities

The effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics (fermentation kinetics and short-chain fatty acids (SCFA)-profile) on lactational feed intake of sows and their piglet growth over two parities were investigated using an in vitro–in vivo methodology. After breeding, 90 multiparous Landrace sows were randomized to one of three experimental diets: the control (CON) diet, konjac flour (KF) diet or sugar beet pulp (SBP) diet. All diets had similar levels of net energy, CP, insoluble fiber and NDF, but KF and SBP diets had higher soluble fiber levels than the CON diet. During gestation, the sows were restrictively fed with three different diets, but during lactation, all the sows were similarly fed ad libitum. The three gestation diets were enzymatically hydrolyzed using pepsin and pancreatin, and enzymolyzed residues were used in in vitro fermentation. Gas and SCFA production were monitored during fermentation. After fermentation, enzymolyzed residues of KF or SBP diets resulted in higher final asymptotic gas volume than those of the CON diet. The enzymolyzed residues of KF diet were mainly part of rapidly fermented fractions, whereas those of SBP diet were mainly part of slowly fermented fractions. In addition, the acetic acid, butyric acid and total SCFA concentrations of enzymolyzed residues of KF diet were higher (P<0.01) than the control and SBP diets. In the in vivo studies, on day 90 of gestation, the KF diet sows had higher plasma SCFA concentration (P<0.05) at 4 h after feeding than the CON diet sows. Furthermore, the KF diet sows had lower plasma free fatty acid (FFA) concentration (P<0.01) at 4 h after feeding, and a lower value of homeostasis model assessment (HOMA)-insulin resistance (P<0.05), but a higher value of HOMA-insulin sensitivity (P<0.01). The KF diet sows also consumed more feed during lactation (P<0.01) and weaned significantly heavier pigs (P<0.01) than the CON diet sows. The overall results showed that the high fermentation capacity KF diet contributed to an increased lactational feed intake and improved performance of piglets in the second reproductive cycle.     

Effects of water restriction on growth performance,feed nutrient digestibility,carcass and meat traits of rabbits

The study investigates the effects of a post-weaning water restriction on performance, nutrient digestibility, carcass traits and meat quality of 84-day-old rabbits. A total of 1388 weaned rabbits (35 days) were randomly divided into two groups on the basis of BW and sex. The two groups were fed the same diets ad libitum both in the post-weaning (35 to 60 days) and fattening (61 to 84 days) periods. In the post-weaning period, one group (AL) also received drinking water ad libitum, whereas the other (WR) had a water restriction from 35 to 41 days 2 h/day; from 42 to 48 days 2.5 h/day; from 49 to 55 days 3 h/day; and from 56 to 60 days 4 h/day. During the fattening period, both groups had water-free access. Individual live weights and feed intake per cage were recorded weekly for 32 cages randomly chosen per group (64 rabbits) to calculate the BW gain, feed intake and feed conversion ratio (FCR). The apparent digestibility values of nutrients were measured using acid-insoluble ash. Carcass data were collected from 16 rabbits (8 males and 8 females) per group selected for similar final BW in both groups. Mortality from 35 to 60 days was higher in the AL group (10.1% v. 5.2%, for AL and WR, respectively, P < 0.0001). BW gain was higher for the AL group during both the post-weaning (+22.4%, P < 0.01) and the entire period (+7.5%, P < 0.05). Water restriction reduced feed intake both in the post-weaning (−17.4%, P < 0.0001) and in the entire period (−9.9%, P < 0.05). During the fattening period, FCR was lower for the WR group (5.15 v. 5.75 g/g, for WR and AL, respectively, P < 0.05). The apparent digestibilities of dry matter, organic matter, NDF, ADF and cellulose were greater in the restricted rabbits (+4.7%, +4.5%, +10.2%, +18.8% and +12.8%, P < 0.01, P < 0.01, P < 0.05, P < 0.01, P < 0.05, respectively). Perirenal and scapular fat percentages were higher in the AL rabbits (+30.7% and +116.6%, P < 0.01 and P < 0.001, respectively). Water restriction increased saturated fatty acids (C16:0, +12.9%, P < 0.05), lauroleic acid (C12:1, +75.0%, P < 0.01), n-3 polyunsaturated fatty acids (C20:5, +50.0%, P < 0.01 and C22:5, +16.6%, P < 0.05) and the n-3/n-6 ratio (+28.6%, P < 0.05). The applied water restriction between 35 and 60 days executed during the winter months improved the digestive health of rabbits, with no negative effects on carcass traits, or physical and chemical meat characteristics. However, from the animal welfare point of view, a water restriction can be criticized as a method to restrict feed intake.     

Impact of feed restriction on the performance of highly prolific lactating sows and its effect on the subsequent lactation

A total of 50 mixed parity sows of a high-prolificacy genetic line were used to evaluate the impact of feed restriction during lactation on their production and reproductive performance and their performance in the subsequent lactation. From day 7 of lactation, sows were distributed according to a completely randomized experimental design into two treatments. In treatment 1, sows were fed 8.0 kg feed/day (control) and in treatment 2, sows were fed 4.0 kg/day. The same suckling pressure was maintained until weaning on day 28 of lactation. Average minimum and maximum temperatures measured during the experimental period were 32.1°C and 16.5°C, respectively. Control sows presented significantly higher feed intake (P<0.001) compared with the restricted sows (6.43 v. 4.14 kg/day, respectively). Treatments influenced BW and backfat thickness losses (P<0.001). Control sows lost less BW than the restricted-fed sows (7.8 v. 28.2 kg). Restricted-fed sows lost more backfat thickness than those in the control group (3.97 v. 2.07 mm; P<0.01). Restricted-fed sows tended (P<0.10) to be lighter at weaning compared with the control sows (211 v. 227 kg). The composition of BW loss was influenced by the treatments (P<0.001), as the restricted-fed sows lost more body protein, lipids and energy compared with the control sows (3.90 v. 0.98 kg, 11.78 v. 4.83 kg and 584 v. 224 MJ, respectively). Litter weight gain was greater (P<0.05) in control sows than in restricted-fed sows (2.70 v. 2.43 kg/day). Daily milk production was 19% higher (P<0.01) in the control sows compared with the restricted-fed sows (8.33 v. 6.99 kg/day). However, restricted-fed sows presented a higher (P<0.05) lactation efficiency than the sows of the control group (82.30% v. 72.93%). No differences were detected (P>0.10) in weaning-to-estrus interval and averaged 4.3 days. No effect of the treatment (P>0.10) was observed on any of the studied performance traits in the subsequent lactation, except for litter size at birth that tended (15.2 v. 14.1; P<0.10) to be lower for the restricted sows. In conclusion, the present study demonstrated that feed restriction during lactation leads to intense catabolism of the body tissues of sows, negatively affecting their milk production, and the litter weight gain and possibly number of piglets born in the next litter. On the other hand, restricted-fed sows are more efficient, producing more milk per amount of feed intake.     

Genetic polymorphism c.1562C>T of the MMP-9 is associated with macroangiopathy in type 2 diabetes mellitus

Objective

To determine whether the matrix metalloproteinase-9 (MMP-9) c.1562C>T polymorphism has an effect on the plasma MMP-9 levels and the macroangiopathic complications in type 2 diabetes mellitus (T2DM).

Methods

The genotypes and allelic frequencies of the MMP-9 c.1562C>T were examined with polymerase chain reaction and restriction fragment length polymorphism in 320 patients with T2DM and 160 unrelated healthy subjects. The plasma concentrations of MMP-9 were determined in all subjects.

Results

The mean plasma concentrations of MMP-9 of patients with T2DM were significantly higher than that of controls and the plasma levels of MMP-9 were higher in diabetic patients with macroangiopathy than in patients without macroangiopathy (P < 0.05). The genotype (CC, CT, and TT) distribution of c.1562C>T polymorphism of the MMP-9 gene was 60.0%, 31.3%, and 8.8% in diabetic patients with macroangiopathy, 76.3%, 21.3%, and 2.5% in patients without macroangiopathy, and 77.5%, 21.3%, 1.3% in controls, respectively, a significant difference was found between diabetic patients with and without macroangiopathy (P < 0.05). The frequency of the allele T was higher in patients with macroangiopathy than in patients without macroangiopathy (24.4% vs 13.1%; P < 0.05). Moreover, the plasma MMP-9 levels were markedly higher in patients with TT genotype than those with CC or CT genotype in patients with macroangiopathy (P < 0.05).

Conclusion

The MMP-9 c.1562C>T gene polymorphism associated with a predisposition to increased plasma MMP-9 levels could constitute a useful predictive marker for diabetic macroangiopathy.     

Overexpression of β2AR improves contractile function and cellular survival in rabbit cardiomyocytes under chronic hypoxia

Chronic hypoxia usually evokes sustained release of endogenous neurohormones, leading to β₂-adrenergic receptor (β₂AR) desensitization and downregulation of expression, which impacts cellular contractility. We investigated whether exogenous β₂AR could compensate for the functional deficiency of β₂AR in rabbit cardiomyocytes under chronic hypoxia, and whether this led to improved contractility and cellular survival.A surgical experimental model of cyanotic heart disease was established in rabbits. Adv.hβ₂AR was transfected into cardiomyocytes isolated from animals subjected to 6-week systemic hypoxia. The levels of cellular contractile function, protein expression of hβ₂AR, p-Akt, p-Erk, and caspase-3, and cellular survival pre- and post-Adv.hβ₂AR delivery were determined.In the cyanotic cells, decreased shortening and lengthening of TPC and R50 were evident. Cellular diastolic functioning showed greater deterioration compared to the systolic function (P < 0.05). In cyanotic cells, the positive inotropic response to isoproterenol was decreased (P < 0.01), low levels of cellular survival were found, protein levels of β₂AR, p-Akt, and p-Erk were downregulated, and protein levels of caspase-3 were upregulated. After Adv.hβ₂AR delivery, enhanced contractile function was achieved (P < 0.01), TPC and R50 levels recovered up to 99% and 81.7% of the normal control levels, respectively (P < 0.05), and cellular survival improved (P < 0.01).Our results demonstrate that overexpression of the β₂AR gene in cardiomyocytes exposed to chronic hypoxia provides significant catecholamine-dependent inotropic support and cellular protection.     

Effect of concentrate feeding sequence on equine hindgut fermentation parameters

Feeding a diet with a small amount of hay and a high proportion of concentrate given in large meals entails a risk of colic to horses as this can impact the hindgut microbial ecosystem. To counteract this potential negative effect, one feeding strategy is to modify the distribution sequence of concentrate and hay. The purpose of the present study was to assess the impact of feeding the concentrate meal before or with the hay meal on fermentative parameters postprandial variations in caecum and right ventral colon contents and faeces. We focused on the comparison of pH value and volatile fatty acid (VFA) concentrations between the three compartments. Four horses fitted with two cannulas in the caecum and right ventral colon were fed a 100% hay diet (H) for a 3-week period, and then a 40% concentrate–60% hay diet for two consecutive periods of 3 weeks each. Concentrate and hay were offered simultaneously in two equal meals at 0800 and 1700 h (HC1) during one period, or separately in two equal meals at 0800 and 1600 h for the concentrate and at 1000 and 1730 h for hay (HC2) during the second one. During the 2^nd week of each diet period (H, HC1, HC2), caecal, right ventral colonic and faecal samples were collected before (0) and at 2, 4, 6 and 8 h after the morning meal. pH values and VFA concentrations were measured. Adding concentrate to the hay was associated with a decrease of pH value in the caecum, right ventral colon and faeces and an increase of faecal VFA concentrations (P<0.01). An impact of the concentrate feeding sequence was observed on caecal pH and faecal propionate concentration (P<0.001) but none on the other parameters investigated. In the caecum and right ventral colon, pH values decreased and VFA concentrations increased within the range of 4 to 8 h after the morning meal. Our data suggested that the variation of faecal pH could be an indicator of those of the caecal and right ventral colonic pH with a delay of 2 h. The present study showed that hay and commercial pelleted could be safely distributed simultaneously, thus making easier every day horse feeding.     

Validation of Brix refractometer to estimate colostrum immunoglobulin G content and composition in the sow

Colostrum is an essential source of immunoglobulin G (IgG) for neonate piglets. However, colostrum IgG content and nutritional composition can vary considerably among sows due to age, parity, feeding regime and immunological background. Currently, there is no practical way to obtain information about colostrum IgG concentration at herd level. We evaluated sows’ colostrum IgG content on-farm using a Brix refractometer and its performance was compared with that of an IgG ELISA. In addition, nutritional compositions of the colostrum samples were analyzed using Fourier transform IR spectroscopy. Colostrum samples (5 to 6 ml) (n=153) were obtained within 0 to 3 h of farrowing. However, to obtain a 24 h IgG profile for 11 sows, colostrum samples were collected at 0, 2, 4, 6, 8, 10, 16 and 24 h after farrowing. A 0.3 ml of freshly drawn colostrum sample was used for the on-farm measurement of Brix percentages using a digital refractometer shortly after collection. The remaining fractions of the samples were frozen and submitted to laboratory analysis for total IgG, using a commercially available pig IgG ELISA kit. For nutritional composition analysis, a 35 ml colostrum sample (n=34) was obtained immediately after birth of first piglet from the first three pairs of frontal teats. Colostrum concentrations of IgG averaged 52.03±30.70 mg/ml (mean±SEM) at 0 to 3 h after farrowing. Concentration of IgG decreased on average by 50% during the 1st day of lactation (P<0.01). Sow parity did not influence colostrum concentrations of IgG. Differences in colostrum composition were recorded between two herds and among the parity groups (P<0.05). The Brix refractometer measurement of colostrum and the corresponding log transformed IgG measurements from the ELISA were moderately correlated (r=0.63, P<0.001, n=153). Based on the classification we suggest here, low levels of IgG (14.5±1.8 mg/ml) were recorded for colostrum samples with Brix readings below 20%. Borderline colostrum IgG content (43.8±2.3 mg/ml) had Brix readings of 20% to 24%, adequate colostrum IgG content (50.7±2.1 mg/ml) had Brix % readings of 25% to 29% and very good IgG colostrum content (78.6±8.4 mg/ml) had Brix readings >30%. Colostrum IgG concentration is highly variable among sows, Brix measurement of a sows’ fresh colostrum is an inexpensive, rapid and satisfactorily accurate method of estimating IgG concentration, providing indication of differentiation between good and poor IgG content of colostrum.     

The effect of farrowing environment and previous experience on the maternal behaviour of sows in indoor pens and outdoor huts

Outdoor farrowing huts facilitate a less restricted maternal behaviour in sows compared with sows kept indoors in farrowing pens. The aim of our study was to investigate whether there are behavioural differences between primiparous sows kept outdoors in farrowing huts and indoors in pens, and whether the maternal behaviour during the second parity, when all sows were kept outdoors in farrowing huts, would differ between sows that have experienced the indoor or the outdoor environment, respectively, during their first parturition. A total of 26 Yorkshire×Swedish Landrace sows were studied. Of these, 11 sows were housed outdoors in farrowing huts during both parturitions (group=OUTOUT). The other 15 sows were kept indoors in a barn with single farrowing pens during their first parturition. During their second parturition, sows were kept outdoors in farrowing huts (group=INOUT). The behaviour was video recorded from 2 h prepartum to 48 h postpartum. The sows’ responsiveness to playbacks of a piglet’s screams was tested on days 2 to 3 postpartum. Parity 1: during the last 2 h prepartum, OUTOUT sows had a higher proportion of observations in the sternal lying position (P<0.01). During parturition, OUTOUT sows changed posture more often (P<0.05) and were lying less (P<0.05) than INOUT sows. All sows in both groups responded with ‘lifting head’ towards the playback of piglet scream, whereas 100% of OUTOUT sows and only 43% of INOUT sows thereafter were ‘getting up’ (P <0.01). Parity 2: There were no behavioural differences between INOUT and OUTOUT sows. In conclusion, it is not problematic for a second parity sow with initial maternal experience from an indoor farrowing pen to be kept outdoors in farrowing huts during its following farrowing.     

Effects of in ovo feeding of creatine pyruvate on the hatchability,growth performance and energy status in embryos and broiler chickens

The effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the hatchability, growth performance and energy status of embryos and broilers (Arbor Acres) were investigated. Five treatments were arranged as non-injected treatment (Control), 0.6 ml physiological saline (0.75%) injected treatment (Saline), and IOF treatments injected with 0.6 ml physiological saline (0.75%) containing 3, 6 or 12 mg CrPyr (CrPyr₃, CrPyr₆ or CrPyr₁₂) into the amnion per fertile egg on day 17.5 of incubation. After hatching, 80 male chicks from each treatment with similar weight close to the average BW of their pooled group were selected and randomly assigned into eight replicates of 10 chicks each. The results showed that the hatchability was not affected among groups, whereas the hatching weight of broilers in CrPyr₁₂ was significantly higher than the control and saline groups (P<0.05). At 21 day post-hatch, the BWs of broilers in CrPyr₆ and CrPyr₁₂ were increased relative to the control and saline groups (P<0.05). Chickens in CrPyr₆ and CrPyr₁₂ exhibited higher BW gain and feed intake than the control and saline groups during 8 to 21 days post-hatch and the entire experiment period (P<0.05). Compared with the control and saline groups, the total and relative weight of pectoral muscle of embryos or chickens were greater in CrPyr₆ and CrPyr₁₂ at 19^th day of incubation (19 E), hatch, 3 and 21 days post-hatch (P<0.05). The concentrations of glucose and glycogen in liver were increased in CrPyr₆ and CrPyr₁₂ at 19 E and hatch (P<0.05). Neither glycogen nor glucose concentration in pectoral muscle was altered among treatments (P>0.05). Irrespective of dosage, the concentrations of creatine and phosphocreatine, and activities of creatine kinase in embryos were enhanced in CrPyr treatments at 19 E when compared with the control and saline groups (P<0.05). The activities of glucose-6-phosphatase in liver in CrPyr₆ and CrPyr₁₂ treatments were higher than the control and saline groups at 19 E (P<0.05). In conclusion, these results indicated that IOF of CrPyr, especially at the level of 12 mg/egg, could improve energy status of embryos and hatchlings, which was useful for enhancing hatching weight, BW and pectoral muscle weight until the end of the experiments at 21 days post-hatch in broilers.     

Effect of dietary β-glucan on growth performance,fecal microbial shedding and immunological responses after lipopolysaccharide challenge in weaned pigs

Two experiments (Exp.) were conducted to evaluate the effects of β-glucan inclusion in the diet on growth performance and immune function after lipopolysaccharide (LPS) challenge. In Exp. 1, a total of 40 weaned pigs (progeny of Landrace×Yorkshire sows by Duroc) with an initial body weight (BW) of 7.89 ± 0.84 kg (21 ± 2 d) of age) were used in a 28-day (d) experiment to determine the effects of dietary β-glucan on growth performance. Pigs were allotted randomly to two treatments consisting of addition of 0 or 0.1 g β-glucan/kg diet with four replicate pens per treatment and five pigs per pen. Growth performance was not affected by β-glucan supplementation throughout the experiment. However, dietary β-glucan reduced (P<0.05) the number of fecal Escherichia coli. In Exp. 2, a total of 20 weaned barrows (6.22 ± 0.25 kg of BW and 21 ± 2 d of age) individually raised in metabolic cages were used to evaluate immunological responses following LPS challenge. Pigs were fed 0 or 0.1 g β-glucan/kg diet for 42 d. At the end of the trial, half of the pigs (n = 5) from each treatment were injected intraperitoneal with E. coli LPS at a concentration of 100 μg/kg BW and the other half were injected with sterile saline solution. Treatments were arranged as a 2×2 factorial, with the main effect of LPS challenge (saline vs. LPS) and β-glucan supplementation (0 g/kg vs. 0.1 g/kg). After LPS injection, blood was taken at 0, 2, 4, 6, 8 and 12 hours (h) for the blood cell counts and blood inflammatory response. Dietary β-glucan increased (P<0.05) leukocytes counts at 4, 6 and 8 h, and blood lymphocyte concentrations at 2, 4 and 6 h and LPS challenge increased (P<0.05) counts of leukocytes at 2, 4, 6 and 8 h and blood lymphocyte at 2 and 4 h post-challenge. The rectal temperature was increased (P<0.05) at 2, 4, 6 and 8 h after LPS challenge. Dietary β-glucan reduced (P<0.05) and LPS challenge increased (P<0.05) blood plasma tumor necrosis factor-α (TNF-α) concentration at 2 and 4 h post-challenge. Dietary β-glucan increased (P<0.05) the concentration of the cluster of differentiation antigens 4 cells (CD4⁺) at 2, 4 and 6 h, and of 8 (CD8⁺) at 4 and 6 h post-challenge, respectively. The LPS challenge increased (P<0.05) CD4⁺ and CD8⁺ cell concentrations at 2, 4 and 6 h post-challenge. The CD4⁺:CD8⁺ ratio was reduced (P<0.05) by LPS challenge but was increased (P<0.05) by dietary β-glucan at 2, 4, 6 and 8 h post-challenge. In conclusion, dietary β-glucan decreased E. coli numbers but did not affect growth performance in weaned pigs and may offer benefits on immune function in weaned pigs challenged with LPS.     

Effect of a disinfection strategy on the methicillin‐resistant Staphylococcus aureus CC398 prevalence of sows,their piglets and the barn environment

Aims

To assess, in a cleaned and disinfected barn environment, the efficacy of an animal disinfection strategy to reduce the livestock‐associated methicillin‐resistant Staphylococcus aureus (LA‐MRSA) prevalence in sows, their offspring and the barn environment.

Methods and Results

On each farm, six sow rounds were sampled; sows were divided into either a test or control group. Per round, 20 sows and 40 of their piglets were sampled at different time points together with the barn environment. The disinfection strategy of the test groups consisted of washing the sows with a shampoo followed by disinfection of the skin with a solution containing chlorhexidine digluconate and isopropanol. On the first day of disinfection and 6 days after stopping the disinfection, a significant decrease (P < 0·01) of on average 68 and 66% in sow MRSA prevalence was observed on both farms, whereas no decrease was seen in the control groups. Just before weaning, 21–28 days after the end of the disinfection strategy, the difference in MRSA prevalence between both groups was reduced to 4% and no longer significant (P = 0·20). The MRSA prevalence of the piglets in the test groups was significantly lower (26%; P < 0·01) 6 days after the end of disinfection. Just before weaning, this difference was reduced to 5% but still significant (P < 0·01). In the swine nursery unit, no significant difference (P = 0·99) was seen between both groups. Based on semi‐quantitative counts, a relationship (r² > 0·6; P < 0·01) was seen between MRSA contamination in the barn environment and the MRSA prevalence in pigs.

Conclusion

Results show that the tested disinfection strategy reduces temporarily the sow and piglet MRSA status, but does not result in a final reduction in MRSA at weaning or in the nursery unit.

Significance and Impact of the Study

First report on the efficacy of an animal disinfection strategy to reduce LA‐MRSA prevalence in sows, their offspring and the barn environment.     

Higher light intensity and mat temperature attract piglets to creep areas in farrowing pens

Loose farrowing pens have been considered as alternatives to crates to enhance sow welfare. A major concern with pen systems is often higher piglet pre-weaning mortality, especially due to crushing by the sow. An optimal management of light and mat surface temperature may promote greater piglet use of the creep, which has been associated with reduced piglet crushing. A total of 108 sows and their piglets were studied in sow welfare and piglet protection pens on a commercial piggery, across two replicates. Sows were randomly assigned to pens arranged within two creep treatments (bright creep: 300 lx v. dark creep: 4 lx), considering mat temperature as a covariate. Twelve sows and their litters in each treatment (24 in total) had their behaviour continuously recorded for 72-h postpartum (pp), and four focal piglets per litter were weighed on the first and third days pp. In situ behaviour observations were performed daily (from 0800 to 1700 h) on all sows and their litters, every 15 min over 72-h pp to record piglet time spent in the creep, latency to enter the creep for the first time, latency for the litter to remain in the creep for at least 10 min, and piglet and sow use of pen areas immediately in front of (A2) and farthest from the creep (A3). Piglets with access to bright creeps spent on average 7.2% more time (P<0.01) in the creeps than piglets in pens with Dark creeps. In addition, for each degree increase in mat temperature, piglets spent on average 2.1% more time (P<0.01) in the creep. Piglets in pens with bright creeps spent less time in A2 (P=0.04) and the least time in A3 (P=0.01). Light or mat temperature did not affect sow use of pen areas or piglet weight gain. Piglets with bright creeps tended (P=0.06) to take longer to enter the creep for the first time after birth, but the latency for 30.0% of the litter to remain clustered for 10 min tended (P=0.08) to be shorter in bright compared to dark creeps. Overall, piglet use of the creep increased with warm mat temperatures and brightness, which should be further investigated as potential strategies to promote piglet safety and reduce crushing in pen farrowing systems.     

A cross-sectional study to collect risk factors associated with stillbirths in pig herds

The aim of this study was to identify risk factors for stillborn piglets at herd level in commercial pig herds. A written questionnaire, containing semi-open questions directly or indirectly related to stillborn piglets, was sent to 250 randomly selected pig herds (>150 sows) in northern Belgium. In total 111/250 questionnaires were returned (response rate of 44.4%) and 107 were valid for analysis. The average reported frequency of stillbirth was 7.5% (S.D. 2.8%). The relationship between risk factors and stillbirths was evaluated with a generalized linear effects model with the percentage of stillborn piglets as outcome variable. Type of breed used on the farm was significantly (P < 0.01) associated with the percentage of stillborn piglets. A high temperature in the farrowing unit (≥22 °C compared to <22 °C) was associated with significantly (P < 0.01) more stillbirths, whereas showering sows with warm water before parturition resulted in significantly less stillbirths (5.8%) than no showering (7.7%) (P < 0.01) and was not significantly different from showering with cold water (7.0%) (P = 0.26). When supervision of farrowing was performed occasionally, significantly more stillbirths (8.1%) were observed in comparison with no attending to farrowing (6.5%) (P < 0.01) or frequent supervision of farrowing (6.9%) (P < 0.01). Significant interactions were found between breed and showering sows prior parturition or supervision of sows at parturition, and between temperature in the farrowing unit at parturition and showering procedure of the sows. In conclusion, this study has clearly demonstrated that breed is a major factor involved in the frequency of stillbirth. Additionally, some management practices before or at parturition may reduce the number of stillborn piglets.     

The behaviour and welfare of sows and piglets in farrowing crates or lactation pens

Temporary confinement during parturition and early postpartum may provide an intermediary step preceding loose housing that offers improvement in sow and piglet welfare. Three experiments were conducted to investigate the implications of replacing farrowing crates (FCs) with an alternative housing system from 3 days postpartum until weaning. In each experiment sows farrowed in FCs and were randomly allocated at day 3 of lactation to either a FC or a pen with increased floor space (lactation pen (LP)) until weaning. In experiment 1, piglet growth and sow and piglet skin injuries were recorded for 32 sows and 128 focal piglets in these litters. Behaviour around nursing and piglet behavioural time budgets were also recorded for 24 of these litters (96 focal piglets for time budgets). In experiment 2, measures of skin injury and behavioural time budgets were conducted on 28 sows and 112 focal piglets. The behavioural response of sows to piglet vocalisation (maternal responsiveness test (MRT)) was also assessed. In experiment 3, piglet mortality from day 3 of lactation until weaning was recorded in 672 litters over 12 months. While housing did not affect piglet weight gain in experiment 1, or piglet skin injuries in experiments 1 or 2, sows in both experiments sustained more injuries in LP than FC (experiment 1, 2.9 v. 1.4; experiment 2, 2.5 v. 0.8 lesions/sow; P<0.05). Sow–piglet interactions were more frequent in LP than FC at days 11 and 18 postpartum in both experiment 1 (day 11, 1.4% v. 1.2%; day 18, 1.7% v. 1.0% of observations; P=0.05) and 2 (day 11, 1.0% v. 0.3%; and at day 18 were 1.0% v. 0.6% of observations; P<0.01), and LP sows were more responsive in the MRT in experiment 2 (2 v. 0 median number of tests in which sows react, P<0.01). In experiment 1 piglets played more (0.7% v. 0.3% of observations, P=0.05) and manipulated others less (0.3% v. 0.7% of observations, P=0.04) in LP, but more piglets missed nursing bouts (0.2 v. 0.1 piglets/bout, P<0.01) compared with FC. There was no effect of housing on piglet mortality from day 3 of lactation until weaning in experiment 3 (0.63 and 0.64 deaths/litter for LP and FC, respectively, P>0.05). Thus, housing sows and litters in LP from day 3 of lactation minimises piglet mortality while improving maternal behaviour in sows and social behaviour in piglets.     

Ovulation frequency among sows group-housed during late lactation

Ovulation frequency during late lactation was determined among 114 sows from four commercial farms that group-housed the sows from about 3 weeks of lactation until weaning (G-farms), and among 21 sows from one farm that kept the sows individually penned throughout lactation (C-farm). Ovulation frequency was determined by applying a progesterone assay on faecal samples collected at weekly intervals from time of grouping until 3 weeks after weaning. The groups consisted of 11–22 sows and boar contact was not allowed during the 5–6 week lactation period. G-farm sows were fed ad libitum while C-farm sows were provided with a restricted food ration. During the group-housing period, 28% of the G-farm sows ovulated, whereas none of the singly housed sows ovulated during the corresponding period (P = 0.005). Ovulation frequency varied considerably between sow groups (0–54%) (P = 0.004), owing partly to differences in age. Not a single primiparous sow ovulated, whereas ovulation frequency among second to fourth parity sows and older sows (fifth parity and over) was 6% and 48%, respectively (P < 0.001). At the time of grouping and weaning, neither backfat thickness nor litter size differed between the sows that ovulated and those that were anoestrous. Preweaning mammary gland atrophy, indicating that milk production had ceased, was noted in 16% of the G-farm sows that ovulated but in only one (1%) of the anoestrus sows. Only 65% of the sows showing lactational ovulation were mated within 10 days after weaning. By contrast, 87% of the G-farms sows that were anoestrus during lactation and 100% of the C-farm sows were mated within this period.     

Rumen microbial responses in fermentation characteristics and production of CLA and methane to linoleic acid in associated with malate or fumarate

An in vitro incubation in batch was conducted to investigate the effect of propionate precursor (malate or fumarate) on fermentation characteristics, and production of CLA and methane by rumen microbes when incubated with linoleic acid (C_18:2). Sixty milligrams of C_18:2 alone (LA), 60 mg C_18:2 with 24 mM malic acid (M-LA), or 60 mg C_18:2 with 24 mM fumaric acid (F-LA) was added to 150 ml culture solution consisting of 75 ml strained rumen fluid and 75 ml McDougall's artificial saliva. Culture solution for incubation was also made without malate, fumarate, and C_18:2 (control). Two grams of feed consisting of 1.4 g concentrate and 0.6 g ground alfalfa (DM basis) was also added to the culture solution of each treatment. An in vitro incubation in batch was made anaerobically in a shaking incubator for up to 12 h at 39 °C.The pH of the culture solution was increased (P<0.0001) in M-LA or F-LA treatments from 3 h to 12 h compared with the control and LA treatments. At 12 h incubation, the concentration of total VFA in the culture solution was higher (P<0.01) in M-LA and F-LA than in control and LA treatments. Concentration of C₃ by M-LA and F-LA was increased at 3 h (P<0.01), 6 h (P<0.01) and 12 h (P<0.01) compared with control and LA. However, no difference in C₃ concentration was observed between control and LA, or between M-LA and F-LA. Accumulated total gas produced for up to 12 h incubation was increased (P<0.01) by M-LA or F-LA compared with the control. Accumulated total methane produced for up to 12 h incubation, however, was greatly reduced (P<0.01) by all the supplements compared with control, and its production from M-LA or F-LA was smaller than the LA. The M-LA or F-LA also increased (P<0.05–<0.001) the concentrations of cis9, trans11-CLA for all incubation times and trans10, cis12-CLA at 1 h (P<0.01), 3 h (P<0.05), and 12 h (P<0.05) incubation times compared with LA.It can be concluded that malate and fumarate, as propionate precursors, act as alternative electron sinks and may compete with CH₄ generation and bio-hydrogenation of C_18:2 in the utilization of metabolic H₂. The highest CLA concentration at the early incubation stage (1 h) was accompanied by reduced propionate proportion. Linoleic acid is also considered one of the potential alternatives to suppress CH₄ generation.     

Novel distribution of calreticulin to cardiomyocyte mitochondria and its increase in a rat model of dilated cardiomyopathy

Background

Calreticulin (CRT), a Ca²⁺-binding chaperone of the endoplasmic reticulum, can also be found in several other locations including the cytosol, nucleus, secretory granules, the outer side of the plasma membrane, and the extracellular matrix. Whether CRT is localized at mitochondria of cardiomyocytes and whether such localization is affected under DCM are still unclear.

Methods and results

The DCM model was generated in rats by the daily oral administration of furazolidone for thirty weeks. Echocardiographic and hemodynamic studies demonstrated enlarged left ventricular dimensions and reduced systolic and diastolic function in DCM rats. Immuno-electron microscopy and Western blot showed that CRT was present in cardiomyocyte mitochondria and the mitochondrial content of CRT was increased in DCM hearts (P < 0.05). Morphometric analysis showed notable myocardial apoptosis and mitochondrial swelling with fractured or dissolved cristae in the DCM hearts. Compared with the control group, the mitochondrial membrane potential level of the freshly isolated cardiac mitochondria and the enzyme activities of cytochrome c oxidase and succinate dehydrogenase in the model group were significantly decreased (P < 0.05), and the myocardial apoptosis index and the caspase activities of caspase-9 and caspase-3 were significantly increased (P < 0.05). Pearson linear correlation analysis showed that the mitochondrial content of CRT had negative correlations with the mitochondrial function, and a positive correlation with myocardial apoptosis index (P < 0.001). The protein expression level of cytochrome c and the phosphorylation activity of STAT3 in the mitochondrial fraction were significantly decreased in the model group compared with the control group (P < 0.05).

Conclusions

These data demonstrate that CRT is localized at cardiomyocyte mitochondria and its mitochondrial content is increased in DCM hearts.