On the effects of the <Emphasis Type="Italic">Fusarium</Emphasis> toxin deoxynivalenol (DON) administered per os or intraperitoneal infusion to sows during days 63 to 70 of gestation

Six pregnant sows of 180.6 ± 5.6 kg were fed either a Fusarium-contaminated (4.42 mg DON and 48.3 μg ZON per kg, DON per os, n = 3) or a control diet (0.15 mg DON and 5 μg ZON/kg) in the period of days 63 and 70 of gestation. On day 63 of gestation, sows fed the control diet were implanted with an intraperitoneal osmotic minipump (delivery rate of 10 μL/h, for 7 days) containing 50 mg pure (98%) DON in 2 ml 50% DMSO (DON ip, n = 3). Frequent plasma samples were taken to estimate the kinetics after oral and ip DON exposure. The intended continuous delivery of DON by the intraperitoneal minipump could not be shown, as there was a plasma peak (C_max) of 4.2–6.4 ng DON/mL either immediately (sow IP-2+3) or 2.5 h (sow IP-1) after implantation of the pump followed by a one-exponential decline with a mean half-time (t_1/2) of 1.75–4.0 h and only negligible DON plasma concentrations after 12 h. Therefore, the DON ip exposure has to be regarded as one single dose 1 week before termination of experiment. The DON per os sows showed a mean basis level (after achieving a steady state) of DON plasma concentration of about 6–8 ng/mL, as also indicated by the plasma DON concentration at the termination of the experiment. On day 70, caesarean section was carried out, the fetuses were killed immediately after birth, and samples of plasma, urine, and bile were taken to analyze the concentration of DON and its metabolite de-epoxy-DON. At necropsy there were no macroscopic lesions observed in any organ of either sows or piglets. Histopathological evaluation of sows liver and spleen revealed no alterations. The proliferation rate of peripheral blood mononuclear cells (PBMC) with or without stimulation was not affected by the kind of DON treatment. The exposure of pregnant sows at mid-gestation (days 63–70, period of organogenesis) to a Fusarium toxin-contaminated diet (4.42 mg DON and 0.048 mg ZON per kg) or pure DON via intraperitoneal osmotic minipump did not cause adverse effects on health, fertility, maintenance of pregnancy, and performance of sows and their fetuses. However, DON was detected in fetus plasma, indicating that this toxin can pass the placental barrier and may cause changes in the proportion of white blood cells (lower monocyte and neutrophil and higher lymphocyte proportion in DON per os fetuses).     

Effect of Different Selenium Sources on Productive Performance,Serum and Milk Se Concentrations,and Antioxidant Status of Sows

The experiment was conducted to study the effects of different selenium (Se) sources on productive performance, serum and milk Se concentrations, and antioxidant status of sows. A total of 12 sows (Landrace×Yorkshire) with same pregnancy were randomly divided into two groups; each group was replicated six times. These two groups received the same basal gestation and lactation diets containing 0.042 mg Se/kg, supplemented with 0.3 mg Se/kg sodium selenite or selenomethionine (i.e., seneno-dl-methylseleno), respectively. The feeding trial lasted for 60 days, with 32 and 28 days for gestation and lactation period, respectively. Compared with sodium selenite, maternal selenomethionine intake significantly increased (P < 0.05) the weaning litter weight and average weight of piglet. The Se concentration in the serum, colostrum, and milk of sows were significantly higher (p < 0.05) in the selenomethionine-treated group. The antioxidant status was greatly improved in sows of selenomethionine-treated group and was illuminated by the increased total antioxidant capability (T-AOC; P < 0.05) and decreased malondialdehyde (MDA; P < 0.01) level in the serum of sows, increased T-AOC (P < 0.05), glutathione (GSH) peroxidase (P < 0.05), superoxide dismutase (P < 0.05) and GSH (P < 0.05), and MDA (P < 0.05) level in the colostrum and milk of sows. These results suggested that maternal selenomethionine intake improved Se concentration and antioxidant status of sows, thus maintain maternal health and increase productive performance after Se was transferred to its offspring.     

Supplementing sow diets with palm oil during late gestation and lactation: effects on milk production,sow hormonal profiles and growth and development of her offspring

The supplementing of sow diets with lipids during pregnancy and lactation has been shown to reduce sow condition loss and improve piglet performance. The aim of this study was to determine the effects of supplemental palm oil (PO) on sow performance, plasma metabolites and hormones, milk profiles and pre-weaning piglet development. A commercial sow ration (C) or an experimental diet supplemented with 10% extra energy in the form of PO, were provided from day 90 of gestation until weaning (24 to 28 days postpartum) in two groups of eight multiparous sows. Gestation length of PO sows increased by 1 day (P<0.05). Maternal BW changes were similar throughout the trial, but loss of backfat during lactation was reduced in PO animals (C: −3.6±0.8 mm; PO: −0.1±0.8 mm; P<0.01). Milk fat was increased by PO supplementation (C day 3: 8.0±0.3% fat; PO day 3: 9.1±0.3% fat; C day 7: 7.8±0.5% fat; PO day 7: 9.9±0.5% fat; P<0.05) and hence milk energy yield of PO sows was also elevated (P<0.05). The proportion of saturated fatty acids was greater in colostrum from PO sows (C: 29.19±0.31 g/100 g of fat; PO: 30.77±0.36 g/100 g of fat; P<0.01). Blood samples taken on 105 days of gestation, within 24 h of farrowing, day 7 of lactation and at weaning (28±3 days post-farrowing) showed there were no differences in plasma concentrations of triacylglycerol, non-esterified fatty acids, insulin or IGF-1 throughout the trial. However, circulating plasma concentrations of both glucose and leptin were elevated during lactation in PO sows (P<0.05 and P<0.005, respectively) and thyroxine was greater at weaning in PO sows (P<0.05). Piglet weight and body composition were similar at birth, as were piglet growth rates throughout the pre-weaning period. A period of 7 days after birth, C piglets contained more body fat, as indicated by their lower fat-free mass per kg (C: 66.4±0.8 arbitrary units/kg; PO: 69.7±0.8 arbitrary unit/kg; P<0.01), but by day 14 of life this situation was reversed (C: 65.8±0.6 arbitrary units/kg; PO: 63.6±0.6 arbitrary units/kg; P<0.05). Following weaning, PO sows exhibited an increased ratio of male to female offspring at their subsequent farrowing (C: 1.0±0.3; PO: 2.2±0.2; P<0.05). We conclude that supplementation of sow diets with PO during late gestation and lactation appears to increase sow milk fat content and hence energy supply to piglets. Furthermore, elevated glucose concentrations in the sow during lactation may be suggestive of impaired glucose homoeostasis.     

Energetics of offspring production: a comparison of a marsupial (Monodelphis domestica) and a eutherian (Mesocricetus auratus)

This study compares the energetic cost of reproduction during gestation and lactation of a eutherian, the golden hamster (Mesocricetus auratus), and a similar-sized (60–120 g) marsupial, the gray short-tailed opossum (Monodelphis domestica). Food consumption was monitored in 20 reproductively active (RA) opossums and 16 RA hamsters from conception to weaning and at equivalent intervals in 19 non-reproductive (NR) opossums and 21 NR hamsters, all maintained within their zone of thermoneutrality (30 °C). Total energy assimilated from conception to weaning [opossums: 1261.3 ± 28.0 Kcal (1 Kcal = 4.1868 J) and hamsters: 1647.5 ± 60.6 Kcal] was positively correlated with litter size and mass per young in both species. Maternal mass-specific assimilated energy was significantly greater in hamsters than in opossums during gestation (P < 0.001), but not during lactation or from conception to weaning (P > 0.05). Efficiency of offspring production (energy stored in young/incremental energy in RA females) was higher in hamsters than in opossums and, in both species, it was higher during lactation than in gestation. The energetic cost of reproduction (per young per day) was higher in hamsters than in opossums. The marsupial mode of reproduction, as seen in opossums, yields young at lower cost but requires a longer reproductive period than is the case for a similar-sized eutherian. Accepted: 8 September 1998     

Effects of Zinc Glycine Chelate on Oxidative Stress,Contents of Trace Elements,and Intestinal Morphology in Broilers

Three hundred and sixty healthy Ross × Ross 1-day-old broilers were used to study the effects of zinc glycine chelate (Zn-Gly) on oxidative stress, contents of trace elements, and intestinal morphology. All broilers were randomly assigned to six treatment groups, which replicates three times. Diets were as follows: (1) control (containing 29.3 mg zinc (Zn)/kg basic diet (0–21 days) and 27.8 mg Zn/kg (22–42 days)); (2) basic diet plus 30 mg Zn/kg from Zn-Gly; (3) basic diet plus 60 mg Zn/kg from Zn-Gly; (4) basic diet plus 90 mg Zn/kg from Zn-Gly; (5) basic diet plus 120 mg Zn/kg from Zn-Gly; and (6) positive control, basic diet plus 120 mg Zn/kg from zinc sulfate (ZnSO₄). The results showed that the addition of 90 or 120 mg/kg Zn-Gly led to an improvement of activity of Cu/Zn superoxide dismutase and glutathione peroxidase and a reduction of malondialdehyde content in livers at 21 and 42 days. With 90 mg/kg Zn-Gly, the content of sera zinc increased by 17.55% (P < 0.05) in 21-day broilers and 10.77% (P > 0.05) in 42-day broilers compared with that of the control. Adding 120 mg/kg Zn-Gly or ZnSO₄ to broilers' diets greatly enhanced the content of zinc in feces at 21 days (P < 0.05) and at 42 days (P < 0.05). For 42-day chickens, increased villus height and decreased crypt depth of the jejunum could be observed in the second growth stage of broilers fed with 90 mg/kg Zn-Gly. Also, intestinal wall thickness decreased (P < 0.05). In addition, adding 90 mg/kg Zn-Gly to the diet markedly elevated villus length of duodenum and decreased crypt depth of ileum (P < 0.05) in 42-day broilers.     

Sample clean-up methods,immunoaffinity chromatography and solid phase extraction,for determination of deoxynivalenol and deepoxy deoxynivalenol in swine serum

Concentrations of deoxynivalenol (DON) and deepoxy deoxynivalenol (DOM-1) in animal blood are important parameters for studies in toxicology and biological detoxification of DON. Clean-up methods, using either immunoaffinity chromatography (IAC) or solid phase extraction (SPE), were compared in order to determine the free form of DON or DOM-1 and the sum amount (free form plus glucuronide conjugated form of DON or DOM-1), respectively, in swine serum. Detection was achieved by high performance liquid chromatography with ultraviolet detection (HPLC-UV). Compared with the SPE-HPLC method, the IAC-HPLC method provided lower quantitation limit (DON: 18 vs 42 ng/ml; DOM-1: 21 vs 30 ng/ml) and higher recoveries (DON: 93.4–102.7% vs 63.7–85.3%; DOM-1: 85.5–91.1% vs 68.0–82.6%). Compared with previously published methods, the developed IAC-HPLC method removed analytical interferences from swine serum in one quick and easy step, and eliminated steps of extraction with organic solvent and/or pre-purification using SPE cartridges. This IAC-HPLC method was used to analyze swine serum samples collected from pigs that were evaluated in a feeding trial of a microbiological detoxification of DON. No DON or DOM-1 were detected in serum samples from pigs given a toxin-free diet or a microbial control diet. In serum samples from pigs given a DON diet (5 mg/kg of DON), free form DON and sum free DON + conjugated DON were 38.8 ± 13.7 and 49.8 ± 14.1 ng/ml, respectively. In serum samples from those given a detoxified-DON diet (DON was transformed to DOM-1), free form DOM-1 was detected but not quantified, and the sum DOM-1 was found as 47.5 ± 6.3 ng/ml.     

Energy gain and loss during lactation and postweaning in southern elephant seal pups (Mirounga leonina) at King George Island

Deuterium-labeled water was used to measure changes in the proximate body composition during the lactation period and after weaning in southern elephant seal pups at King George Island, South Shetland Islands, Antarctica. During the lactation period (23.0 ± 1.4 days) pups gained a mean of 4.9 ± 0.5 kg/day (n=7). Of the total mass gain (112 ± 8 kg), 38% was water, 48% was fat, and 11% was protein. This represented an increase in total body gross energy of 2437 ± 145 MJ. The proportion of body mass represented by fat was less than 2% at birth, increasing to 35 ± 2% at weaning. We followed the pups during a mean period of 36 ± 3 days after weaning. During this period, pups had a mean loss of 1.21 ± 0.10 kg/day (n=7) comprising 39% water, 48% fat, and 12% protein. The energy cost over this period was 952 ± 168 MJ, which represented, on average, 39% of the total energy gained during the suckling period. Accepted: 3 January 2000     

Effects of different amounts and type of diet during weaning-to-estrus interval on reproductive performance of primiparous and multiparous sows

During weaning-to-estrus interval (WEI), the sows are usually fed with high feed level to improve the reproductive performance. However, the WEI has been reduced over the years which may reduce the impact of feed level on performance in the modern genetic lines. The aim of this study was to evaluate the effect of two feeding levels (moderate feeding level (MFL): 2.7 kg/day and high feeding level (HFL): 4.3 kg/day) and two diet types (gestation: 13.67 MJ/kg of metabolizable energy (ME) and 0.62% of standard ileal digestible lysine (SID Lys) and lactation: 14.34 MJ ME/kg and 1.20% of SID Lys) offered during the WEI on reproductive performance. In total, 19.0% of sows were excluded from the analysis due to feed intake below 75% (9.6% and 28.5% in MFL and HFL groups, respectively), remaining 254 primiparous and 806 multiparous sows. Follicular size and change in BW were measured in subsamples of 180 and 227 females, respectively. Data were analyzed considering the sow as the experimental unit. Feeding level, diet type, parity and their interactions were included as fixed effects, whereas the day of weaning was considered as a random effect. The feed intake of MFL and HFL groups averaged 2.5 ± 0.02 and 3.8 ± 0.02 kg/day, respectively. There was an interaction between feeding level and parity for daily feed intake. Within HFL, multiparous sows consumed 181 g/day more than primiparous sows (P < 0.01), but no difference was observed within MFL (P > 0.05). Both primiparous and multiparous sows lost proportionally less weight when fed HFL than MFL gestation diet during WEI. The percentage of weight loss was lower in HFL than in the MFL group in multiparous sows fed the lactation diet. The WEI was not affected by feeding level, diet type or its interaction (P > 0.05), but it was longer in primiparous than in multiparous sows (P = 0.001). There was no effect of feeding level, diet type, parity or their interactions on anestrus and farrowing rates. Multiparous sows showed greater follicular size, and greater numbers of total born and born alive piglets in the subsequent cycle than primiparous sows (P < 0.05). In conclusion, feeding weaned primiparous and multiparous sows with 4.3 kg/day of a gestation (58.78 MJ ME and 26.66 g SID Lys) or a lactation diet (61.66 MJ ME and 51.60 g SID Lys) does not improve follicular size and reproductive performance in the subsequent cycle.     

Mass transfer from mothers to pups and mass recovery by mothers during the post-breeding foraging period in southern elephant seals (Mirounga leonina) at King George Island

Mass transfer from mother to pup during the lactation period, and mass recovery for the same females during the foraging period were measured in the southern elephant seal at King George Island, Antarctica. During the 19.2 ± 0.9-day lactation period measured (which represented 87% of the entire nursing), females lost a mean mass of 10.56 ± 1.76 kg/day (n = 27), while their pups gained a mean mass of 5.27 ± 1.1 kg/day. There was a correlation between daily body weight gain in pups and daily weight loss by their mothers. Pup weaning mass was positively related to maternal post-partum mass. Serial samples showed that weight losses by females and gains by their pups were not linear over lactation, but showed lower values at the beginning and at the end of lactation. During the 60.5 ± 6.2-day foraging phase between the end of lactation and molt, females gained 2.21 ± 0.65 kg/day (n = 12), or 54% of the mass lost during nursing. Growth rates reported here are higher than those reported in other breeding sites. However, the ratio of body mass loss by females to gain by their pups was similar, suggesting that higher growth rates and greater weaning mass at South Shetland are due to a higher mean weight of females on arrival at this breeding site. The foraging period was shorter and the mass gained greater than those measured at South Georgia; this could be related to relatively shorter distances to foraging areas. Received: 20 September 1996 / Accepted: 28 April 1997     

Effect of Different Levels of Copper and Molybdenum Supplements on Performance,Nutrient Digestibility,and Follicle Characteristics in Cashmere Goats

A 2 × 3 factorial arrangement of treatments was used to investigate the effects of different levels of copper (Cu, 0, 19, and 38 mg/kg, dry matter (DM)) and molybdenum (Mo, 0 and 5 mg/kg, DM) supplements and an interaction of these two factors on growth performance, nutrient digestibility, and cashmere and follicle characteristics in cashmere goats. Thirty-six Liaoning cashmere goats (approximately 1.5 years of age; 27.53 ± 1.38 kg of body weight) were assigned randomly to one of six treatments and fed with Chinese wildrye- and alfalfa hay-based treatment diets (the basal diet contained 4.72 mg Cu/kg, 1.65 mg Mo/kg, and 0.21% S.). Body weight was measured on two consecutive days at the start and the end of the 70-day experimental period. On day 30, the metabolism trial was conducted to study the effects of dietary Cu and Mo on nutrient digestibility. The cashmere and skin samples were collected on day 70. Copper supplementation increased (P < 0.05) growth performance and fiber digestion, but there were no differences (P > 0.05) between Cu-supplemented groups. Addition of 19 mg Cu/kg DM increased (P < 0.05) cashmere growth length or growth rate by increasing the number of active secondary follicles. Molybdenum supplementation decreased (P < 0.05) growth, but did not affect (P > 0.05) nutrient digestion, cashmere, and follicle characteristics. There is a tendency or significant interaction effect of Cu and Mo on growth performance (P = 0.057), cashmere growth (P = 0.076), or diameter (P < 0.05) which might be accomplished by changing the number of secondary follicle and active secondary follicle, and secondary to primary follicle ratio. In conclusion, the optimal supplemental Cu level for Liaoning cashmere goats fed with the basal diet was 19 mg/kg DM (the total dietary Cu level of 23.72 mg/kg DM), while 38 mg Cu/kg DM supplementation was found to be needed when 5 mg Mo/kg was added in the basal diet during the cashmere growing period.     

The effect of a non-starch polysaccharide-hydrolysing enzyme (Rovabio® Excel) on feed intake and body condition of sows during lactation and on progeny growth performance

A total of 200 (Large White × Landrace) sows were used in a 39-day study to evaluate the effects of feeding a non-starch polysaccharide (NSP)-hydrolysing enzyme multicomplex (Rovabio® Excel) in conjunction with a high- or reduced nutrient-density diet during lactation on sow body condition, feed intake and progeny performance. Eight sows were selected each week for 25 weeks, blocked by parity and BW into groups of four, and within the block randomly assigned to one of the four treatments (n = 50/treatment). Treatments were: (1) LND: low energy (13.14 MJ of DE/kg), low CP (15%) diet; (2) LND + RE: LND with 50 mg/kg NSP-hydrolysing enzyme; (3) HND: high energy (14.5 MJ of DE/kg), high CP (16.5%) diet; and (4) HND + RE: HND with 50 mg/kg NSP-hydrolysing enzyme. Sows were fed treatment diets from day 109 of gestation until the day of subsequent service. Between weaning and re-service, Rovabio® Excel addition to LND diets resulted in an increase in energy intake; however, a reduction was observed when supplemented to the HND diet (P < 0.05). The inclusion of Rovabio® Excel increased feed and energy intake during week 3 (days 15 to 21) of lactation (P < 0.05). Sows fed diets supplemented with Rovabio® Excel had greater back-fat depth at weaning and service (P < 0.05); however, the magnitude of change in back-fat depth during lactation and from farrowing to service was not different between treatments. Feeding the HND diet increased energy intake before farrowing, throughout lactation and during the weaning to service interval (P < 0.01); however, overall, average daily feed intake tended to be reduced (P < 0.10). At service, sows fed the HND diet were heavier than sows fed the LND diet (P < 0.05); however, the magnitude of change in BW between treatments was not different. Feeding the HND diet to sows resulted in a tendency for heavier piglets at birth (P = 0.10) that tended to grow at a faster rate and be heavier at weaning than piglets from sows fed the LND diet (P = 0.06). These results indicate that NSP-degrading enzymes offer minimal benefit to sows and their progeny when fed before and during lactation; however, increasing energy intake of sows during lactation may beneficially affect progeny.     

Effects of dietary menhaden oil on growth and reproduction in gilts farrowed by sows that consumed diets containing menhaden oil during gestation and lactation

In sows, n-3 fatty acids increase litter sizes, however, effects on gilt reproductive development have not been adequately studied. Moreover, not determined are effects of feeding n-3 fatty acids to sows on reproduction in offspring. The objective here was to determine effects of 4% dietary menhaden oil on growth and puberty in gilts farrowed by sows fed menhaden oil. Sows (n = 44) were assigned to: (1) control gestation and lactation diets, or (2) diets including menhaden oil. For primiparous sows only, total litter size and born alive were greater (P < 0.05) in females fed menhaden oil. Conversely, pigs from primiparous controls were heavier (P < 0.05) than pigs from primiparous sows fed menhaden oil (parity by diet interactions, P < 0.01). Diet did not affect (P > 0.20) other sow and litter characteristics. At weaning, 84 gilts from control- or menhaden oil sows were placed three gilts per pen and provided control diets or diets containing menhaden oil. Nursery and grow-finish feed intake and feed efficiency were similar (P > 0.21) for gilts from the different sows and weight gain was similar (P > 0.24) for gilts fed control or menhaden diets. Gilts fed menhaden oil tended to eat less in the nursery (1.18±0.08 kg v. 0.98±0.08 kg; P = 0.09) and overall (1.83±0.04 kg v. 1.72±0.04 kg; P = 0.06). Thus, overall feed to gain was greater (2.52±0.03 v. 2.33±0.03; P < 0.01) and nursery (2.12±0.04 v. 1.80±0.04; P = 0.10) and grow-finish (3.07±0.19 v. 2.58±0.19; P = 0.08) feed to gain tended to be greater, for control gilts. Age at puberty was greater (P = 0.02) for gilts from menhaden oil-fed sows (205.1±3.2 days) compared to gilts from controls (193.9±3.2 days) and tended to be greater (P = 0.09), for controls (203.5±3.2 days) compared to gilts fed menhaden oil (195.5±3.2 days). A tendency existed (P = 0.09) for greater follicular fluid in gilts fed menhaden oil, however, ovulation rate and ovarian, luteal and uterine weights were not affected by sow diet, gilt diet or the interaction (P > 0.23). Feeding gilts menhaden oil enhanced feed efficiency and hastened puberty onset. Gilts from sows consuming menhaden oil exhibited delayed puberty and retaining females from sows fed this feedstuff may be ill advised.     

Temporal and spatial distributions of dissolved organic carbon and nitrogen in two small lakes on the Southwestern China Plateau

Temporal and spatial distributions of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), chlorophyll-a and inorganic nitrogen were investigated in two small mountainous lakes (Lake Hongfeng and Baihua), on the Southwestern China Plateau, based on almost 2 years’ field observation. DOC concentrations ranged from 163 μM to 248 μM in Lake Hongfeng and from 143 μM to 308 μM in Lake Baihua, respectively, during the study period. DON concentrations ranged from 7 μM to 26 μM in Lake Hongfeng and from 14 μM to 47 μM in Lake Baihua. DOC showed vertical heterogeneity with higher concentrations in the epilimnion than in the hypolimnion during the stratification period. The DON concentration profiles appeared to be more variable than the DOC profiles. Apparent DON maxima occurred in the upper layer of water. In Lake Hongfeng, DOC concentration in the surface water was highest at the end of spring and early summer. DON concentration was 2–5 μM higher in May 2003 and in June 2004 than in adjacent months. DOC and chlorophyll-a concentrations were significantly correlated (r = 0.79, P < 0.05). The period of highest concentrations of DOC in Lake Hongfeng was also the season of concentrated rainfall. Algae activity and allochthonous input might result in an increase of DOC and DON concentrations together. In Lake Baihua, the maximum concentrations of DOC and DON in the surface water occurred simultaneously in May 2003 and February 2004. DOC concentrations were significantly correlated with DON (r = 0.90, P < 0.01), indicating the common sources. Allochthonous input, biological processes, stratification and mixing were the most important factors controlling the distributions and cycling of dissolved organic matter (DOM) and inorganic nitrogen in these two lakes. Inference from the corresponding vertical distributions of DOM and inorganic nitrogen indicated that DOM played potential roles in the internal loading of nitrogen and metabolism in the water body in these small lakes. The carbon/nitrogen (C/N) ratio showed a potential significance for tracing the source and biogeochemical processes of DOM in the lakes. These results are of significance in the further understanding of biogeochemical cycling and environmental effects of DOM and nitrogen in lake ecosystems.     

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.     

Effect of oral polyamine supplementation pre-weaning on piglet growth and intestinal characteristics

A high proportion of piglets fail to adapt to the changing composition of their diet at weaning, resulting in weight loss and increased susceptibility to pathogens. Polyamines are present in sow milk and promote neonatal maturation of the gut. We hypothesised that oral spermine and spermidine supplementation before weaning would increase piglet growth and promote gastrointestinal development at weaning. In Experiment One, one pair of liveweight (LW)-matched piglets per litter from first and third lactation sows received 2 ml of a 0 (Control) or 463 nmol/ml spermine solution at 14, 16, 18, 20 and 22 days of age (n=6 piglets/treatment per parity). Villus height and crypt depth in the duodenum and jejunum were measured at weaning (day 23 postpartum). In Experiment Two, piglets suckling 18 first and 18 third lactation sows were used. Within each litter, piglets received 2 ml of either water (Control), 463 nmol/ml spermine solution or 2013 nmol/ml spermidine solution at 14, 16, 18, 22 and 24 days of age (n=54 piglets/treatment per sow parity). Piglets were weighed individually at 14, 18, 24 (weaning) and 61 days of age. In Experiment One, oral spermine supplementation resulted in a 41% increase in villus height, a 21% decrease in crypt depth and 79% decrease in the villus height : crypt depth ratio compared with control piglets (P<0.01). In Experiment Two, spermine and spermidine-supplemented piglets suckling first lactation sows grew faster (P<0.05) between days 14 and 18 postpartum than control piglets: 0.230±0.011 and 0.227±0.012 v. 0.183±0.012 kg/day, respectively. Spermine supplementation tended (P<0.1) to increase piglet LW gain from weaning to day 37 post-weaning compared with control piglets (0.373±0.009 v. 0.341±0.010 kg/day). In conclusion, spermine supplementation increased villus height at weaning, and appears to have the potential to improve the pre- and post-weaning growth of conventionally weaned piglets.     

Co-occurrence of mycotoxins in swine feed produced in Portugal

A total of 404 samples of commercial swine feed from Portugal feed mills were analysed by HPLC methods for the presence of mycotoxins: 277 samples of feed for fattening pigs were analysed for ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON), and 127 samples of feed for sows were analysed for ZEA and fumonisins (FB₁ + FB₂). Concerning feed for fattening pigs, 21 (7.6%) samples were positive for OTA, (2–6.8 μg/kg), 69 (24.9%) were positive for ZEA (5–73 μg/kg), and 47 (16.9%) were positive for DON (100–864 μg/kg). In feed for sows, the results showed 29.9% of positive samples for ZEA (5–57.7 μg/kg) and 8.7% positive samples for FB₁ and FB₂ (50–391.4 μg/kg). Co-occurrence of DON/ZEA was found most frequently, but simultaneous contamination with OTA/ZEA and OTA/DON was also found.     

Seasonal variability of inorganic and organic nitrogen in the North Sea

This study considers the cycling of nitrogen in the waters of the North Sea, particularly focussing on organic nitrogen. Dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON) and particulate organic nitrogen (PON) were measured in the North Sea over a one-year period (autumn 2004–summer 2005). The surface water concentrations of nitrate, ammonium, DON and PON during the present study ranged from <0.1–7.2 μM, <0.1–2.0 μM, 1.9–11.2 μM and 0.3–5.6 μM, respectively, with DON the dominant fraction of total nitrogen at all times. These nutrients concentrations were significantly lower compared to previous studies in the southern North Sea. The seasonal variations showed high mean surface concentrations of nitrate (4.7 ± 0.6 μM) and DON (8.9 ± 0.9 μM), low ammonium (<0.1 μM) and PON (0.8 ± 0.1 μM) in winter, shifting to low nitrate (0.3 ± 0.3 μM) and DON (4.2 ± 1.2 μM) in summer, with high ammonium (0.8 ± 0.4 μM) in autumn and PON (2.5 ± 1.2 μM) in spring. Highest mean surface DON concentration was measured in winter and may be due to resuspension of the organic matter from the bottom sediments. For autumn and spring, phytoplankton DON release was likely to be the most significant source of DON as shown by high concentrations of low molecular weight (LMW) DON and its positive correlation to chlorophyll a. Low total and LMW DON concentrations during summer were likely to be due to the uptake of the LMW DON fraction by phytoplankton and bacteria and the stratification of the water column. DON is therefore shown to be a potentially important source of nitrogen in shelf seas especially after the spring bloom has depleted nitrate to limiting concentrations. Handling editor: L. Naselli-Flores     

Selenomethionine: an Effective Selenium Source for Sow to Improve Se Distribution,Antioxidant Status,and Growth Performance of Pig Offspring

The present study was to investigate the efficiency of maternal selenomethionine intake on growth performance, Se distribution, and antioxidant status of pig offspring by comparing with sodium selenite. A total of 12 sows (Landrace × Yorkshire) with same pregnancy were randomly divided into two groups; each group was replicated six times. These two groups received the same basal gestation and lactation diets containing 0.04 mg Se/kg, supplemented with 0.3 mg Se/kg sodium selenite and selenomethionine (i.e., seneno-dl-methylseleno), respectively. The feeding trial lasted for 60 days, with 32 and 28 days for gestation and lactation period, respectively. Compared with sodium selenite, maternal selenomethionine intake significantly (p < 0.05) increased the daily weight gain of piglet from birth to weaning. The Se concentration in the colostrum and milk and tissue Se content of piglets were significantly higher (p < 0.05) in the selenomethionine-treated group. The antioxidant status was greatly improved in piglets of selenomethionine-treated group and was illuminated by the increased total antioxidant capability, glutathione peroxidase, superoxide dismutase, and glutathione, and decreased the malondialdehyde level in the organs of piglets. The increased (p < 0.05) triiodothyronine (T₃) and decreased (p < 0.05) thyroxine (T₄) concentration indicated the improved protein synthesis and energy production in the selenomethionine-treated group. The increased (p < 0.05) pancreatic digestive enzymes of protease, amylase, and lipase activities indicated that maternal selenomethionine intake may have a positive effect on the degradation and absorption of nutrients in its piglets. In summary, we concluded that maternal selenomethionine intake increased Se deposition, antioxidant status, and nutrient use efficiency, thus providing an effective way to improve the growth performance of piglets from birth to weaning.     

Anaesthesia of free-ranging Northern chamois (<Emphasis Type="Italic">Rupicapra rupicapra</Emphasis>) with xylazine/ketamine and reversal with atipamezole

One-hundred and fifty-five free-ranging Northern chamois (Rupicapra rupicapra) were anaesthetised in the course of a restocking programme using xylazine plus ketamine. Mean ± SD dosages for xylazine and ketamine were 1.9 ± 0.5 and 2.2 ± 0.7 mg/kg, respectively. In 57 chamois, sedation was reversed using 0.3 ± 0.1 mg/kg atipamezole. Although all the anaesthetic dosages tested immobilised free-ranging Northern chamois, shorter induction times (4.8 ± 2.6 min), deeper sedation with no reaction to handling in >90% of the animals and quick reversal (4.0 ± 2.7 min) were obtained using 2.5 mg/kg xylazine plus 3.0 mg/kg ketamine reversed with 0.25 mg/kg atipamezole. Under the conditions of this study, suggested standard doses are 63 mg/animal xylazine plus 76 mg/animal ketamine reversed by 6.3 mg/animal atipamezole. This anaesthetic protocol improves the results from the previous study of Dematteis et al. (Vet Rec 163:184–189, 2008) using xylazine alone.