Cryptosporidium and Giardia in different age groups of Danish cattle and pigs--occurrence and management associated risk factors

To obtain information both about the prevalence of Giardia and Cryptosporidium in Danish cattle and pigs as well as the possible influence of different management systems on the occurrence and intensity of infection, we conducted an epidemiological survey comprising 50 randomly selected dairy and sow herds, respectively. Each herd was visited once for the collection of faecal samples and registration of basic management parameters. Faecal samples were collected from three different age groups of animals, i.e. 5 sows/cows, 10 nursing piglets/calves less than 1 month, and 10 weaner pigs 8-45 kg/calves 1-12 months. The faecal samples were purified and the number of (oo)cysts quantified. The study revealed an age-specific herd prevalence of Cryptosporidium of 16, 31 and 100% for sows, piglets and weaners, respectively, and of 14, 96 and 84% for cows, young calves and older calves, respectively. For Giardia the age-specific herd prevalence was 18, 22 and 84% for the sows, piglets and weaners, while for cattle herds the prevalence was 60, 82 and 100% for cows, young calves and older calves, correspondingly. The (oo)cyst excretion levels varied considerably both within and between herds for all age groups. Risk factors were evaluated by using proportional odds models with (oo)cyst excretion levels divided into four categories as response. Among the numerous risk factors examined, only a few were demonstrated to have a statistically significant influence, e.g. the use of an empty period in the calf pen between introduction of calves for both parasites had a protective effect in young calves. For weaners, use of straw in the pen and high pressure cleaning between batches of weaners had a preventive effect against higher Cryptosporidium oocyst excretion levels.     

上海地区猪和奶牛血清中TTV（Torque Teno virns）感染的检测

于2009年3～5月采集上海地区的200份牛血清和400份猪血清,采用ELISA和荧光PCR方法检测其TTV（Torque Teno virus）感染状况。经ELISA检测,牛血清样品中检出阳性数2份,阳性率1．0％;猪血清样品中共检出阳性数15份,阳性率3．75％,其中生产母猪和育肥肉猪的阳性率分别为5．5％和2．0％,而荧光PCR检测结果均为阴性。结果表明上海地区猪和牛TTV感染现状处于较低水平。     

Comparative protein and amino acid digestibilities in growing pigs and sows.

An experiment was conducted to compare apparent total tract protein digestibilities and apparent ileal digestibilities of protein and amino acids in growing pigs and adult pregnant and lactating sows. Twelve growing pigs and 12 sows were used and surgically fitted with simple T-cannulas at the distal ileum. Six experimental diets based on corn, barley, wheat, soybean meal, canola meal, or meat and bone meal were formulated, and each diet was fed to growing pigs, gestating sows, and lactating sows for 7 d. Chromium oxide was included in all diets as an indigestible marker (.25%) for calculating nutrient digestibilities. Fecal material was collected on d 5 of each feeding period by grab sampling, and ileal samples were collected for 12 h/d during the last 2 d of each feeding period. Apparent fecal protein digestibilities for all feed ingredients were higher (P < .05) in gestating and lactating sows compared to growing pigs, but no differences between the two groups of sows were observed (P > .05). At the distal ileum, no differences (P > .05) in protein digestibilities were detected between sows and growing pigs regardless of feed ingredient. For all feed ingredients tested, lactating sows had apparent ileal digestibilities of most amino acids that were two to six percentage units higher than those obtained in growing pigs, but not all of the differences were significant. Gestating sows had digestibilities of most amino acids that were intermediate between those of growing pigs and lactating sows. The combined results from the six feed ingredients showed that lactating sows had higher (P < .05) digestibilities of all indispensable amino acids except arginine, and gestating sows had higher (P < .05) digestibilities of five of the indispensable amino acids than did growing pigs. The results of this experiment indicate that apparent fecal protein and apparent ileal amino acid digestibilities obtained in growing pigs are not always representative of digestibilities in either gestating or lactating sows.     

Feeding wash water solids to sows during gestation and lactation: sow productivity, pig performance, and tissue compositions.

Diets containing 0, 10, or 20% dried wash water solids (WWS) from a milk processing plant were fed to 54 Yorkshire gilts (160 to 270 kg) for five parities. Feed intake, weight changes, and morbidity of sows were measured; number of pigs per litter, birth weight, and weight gain of pigs were also determined. Blood, tissue, and milk samples were taken from sows for hematological and mineral analyses, and tissue samples were taken from newborn pigs from each treatment per parity. Overall, initial sow weight, sow weight at weaning, and weight losses were not affected (P greater than .05) by treatment. At 107 d of gestation, overall weights decreased (P less than .05) linearly with level of WWS in the diet. The number of pigs per litter and weight of pigs were not affected (P greater than .10) by diet. Concentrations of NA (P less than .10) and Cd (P less than .05) were lower in kidney of sows fed 20% WWS, and concentrations of Zn were lower in bone and in kidney of sows fed the 20% WWS diet. The Sr and Ba concentrations increased (P less than .05, P less than .10) linearly in bone from sows with level of WWS in the diet. In pigs, concentrations of Mn in kidney and Zn in liver were lower for the 20% WWS treatment. In conclusion, feeding WWS to sows over five parities had minimal adverse effects on sow productivity and pig performance; the reduction in Zn concentrations in tissues of sows and pigs seemed to be related to the Ca content of WWS.     

Effects of Feeding Level During Lactation on FSH and LH Secretion Patterns, and Follicular Development in Primiparous Sows

In the primiparous lactating sow undernutrition affects LH, but the effect on FSH is less clear. This study was conducted to investigate the effect of ad libitum (AL; n = 5) and restricted (RE; 70% of the AL feed; n = 5) feeding on the secretion patterns of FSH and LH, and on follicular development in primiparous lactating sows. Body side fat thickness (BSFT) was measured prior to farrowing and at weaning on day 21 postpartum (pp). Sows had an intravenous catheter fitted on day 6 or 7 pp. Blood samples were taken on days 12, 15 and 18 pp, every 15 min starting at 0700 h for 11 h, and plasma analysed for FSH and LH by radioimmunoassay (RIA). Daily transcutaneous ultrasonography of the ovaries was performed between days 10 and 20 pp to monitor follicular growth. Reduction in BSFT was higher in RE than in AL sows (p < 0.05). Mean and basal LH were significantly higher in AL than in RE sows on days 12 and 15 pp. (p < 0.05), and LH pulse frequency tended to be higher (p < 0.1). Mean FSH was higher in AL than in RE sows on days 15 and 18 (p < 0.05), and had a tendency to be higher on day 12 (p = 0.1). Follicle size increased in AL sows between days 10 and 20 of lactation (p < 0.05; r = 0.71), but remained unaffected in RE sows. In conclusion, the study demonstrates that feed restriction of primiparous sows during lactation affects not only LH, but also FSH, as well as lactational follicular growth. An association between those events is suggested.     

Prevalence of Campylobacter spp. and Yersinia spp. in the pig production

The aim of this study was to determine the prevalence of Campylobacter spp. and Yersinia spp. in a total of 1,040 faecal samples taken from animals at different ages from four farrowing and twelve fattening herds. In the farrowing unit, faeces were collected from 68 sows (faecal samples) and 256 suckling piglets (rectal swab samples). Further samples were collected from 362 growing and 354 finishing pigs (rectal swab samples). Additionally, 56 feed and environmental samples were collected. During the slaughtering process, 122 pigs and their carcasses respectively, were sampled three times. Finally, 86 meat and minced meat samples were taken from 34 retail stores. Campylobacter spp. were isolated in sows (33.8 %), piglets (80.9 %), growing (89.2 %) and finishing (64.7 %) pigs. Yersinia spp. were detected in growing (15.2 %) and finishing (13.3 %) pigs only. After twelve hours of chilling neither Campylobacter spp. nor Yersinia spp. were detected. In raw meat samples, Campylobacter spp. were isolated from one liver sample and Yersinia enterocolitica from two meat samples. Common slaughter techniques and hygiene procedures may be effective tools to reduce the risk of contamination and recontamination of meat products since Campylobacter spp. and Yersinia spp. were found only sporadically in raw meat samples.     

Ionized calcium and total calcium in the blood of cattle, sheep, swine and horses of different ages, reproductive stages and uses]

Concentrations of ionized calcium (Cai) in blood and of total calcium (Ca(t)) in serum were determined in 99 cattle, 58 sheep, 74 pigs and 59 horses of different age groups and reproductive periods as well as kinds of use of the animals. The values of Cai in blood in the groups taken into account for comparison of species decreased significantly in the order dairy cows < ewes < sows < horses. In cattle and pigs, there were significant differences in the Cai-level, according to age with the youngest animals having the highest values. In cows from the fourth lactation onward, one day post partum (p.p.) the smallest concentrations were measured, differing significantly from animals in other reproductive periods. In ewes, the lowest values were estimated one week before parturition. The level of Cai in blood of sows decreased between day one and 6 weeks p.p. significantly. No significant differences could be demonstrated between the different groups of horses. With regard to the concentrations of total Ca, differences between the groups were not so clear as with Cai.     

The shedding of group A rotavirus antigen in a newly established closed specific pathogen-free swine herd.

A longitudinal study was undertaken in a newly established specific pathogen-free (SPF) swine herd to determine the dynamics of rotavirus antigen shedding in a closed swine facility. Pregnant SPF gilts which populated the herd, and their offspring, were monitored weekly for three consecutive lactations. Fecal samples were assayed for the presence of group-specific viral antigen by a solid phase immunoassay (ELISA). Results indicate that in the week prior to farrow, 35% of samples from gilts/sows contained rotavirus antigen. During nursing, 37% of the gilts'/sows' fecal samples also contained virus antigen. Over the course of three farrowings, every gilt/sow in the herd excreted virus antigen. Virus antigen was present in 25% of the samples tested from nursing pigs and in 70% of the samples tested from pigs in the postnursing period; 95% of the litters excreted virus antigen either while nursing or postweaning. Seasonal incidence in virus antigen excretion was noted with proportionally more suckling pigs virus antigen-positive in summer and proportionally more sows/gilts positive during winter. Diarrhea occurred only rarely in the sampled population. Although piglets shed rotavirus subclinically, ELISA positive feces from piglets of each lactation caused severe disease when fed to neonatal gnotobiotic pigs. Electropherotyping of these passaged viruses indicated minor variation in RNA banding patterns over time.     

Biologic quality of colostrum and calves from dairy cows injected with zinc during pregnancy]

The effects of an administration of the Zindep inj. preparation (Biotika) were evaluated in pregnant dairy cows as exerted on specific weight, total protein (TP) content, total immunoglobulin (IgC) and albumin (ALB) contents in colostrum. These parameters were also followed: calf's health, live weight, leucocyte (Lc) counts, T-lymphocyte (T-Ly) counts, contents of TPs, IgCs and ALBs in the blood serum of calves. Zinc concentrations were determined in colostrum, milk and calf blood serum. Our observations included 16 dairy cows in the seventh month of pregnancy in the second lactation and their calves in the winter feeding season. Eight experimental dairy cows were treated with the Zindep preparation in form of an injection to the neck muscles at a dose of 3 mg Zn/kg live weight in the mid-seventh month of pregnancy. Blood samples were taken from v. jugularis from all calves before their first drinking, on days 5, 15 and 30 of age. Colostrum, and/or milk samples were obtained by drawing of the colostrum or milk from the udder quarters within 60 minutes after parturition, on days 5 and 15 of lactation. Zn levels at birth were 16.48 +/- 2.67 mumol/l in experimental calves and 13.84 +/- 3.19 mumol/l in control calves. Zincaemia decreased slightly in both groups on days 5 and 15 of age, but it was insignificantly higher in calves coming from Zindep-treated dairy cows. Zn levels in the blood serum on the 30th day of age were 18.45 +/- 2.44 mumol/l in experimental animals and 15.73 +/- 3.11 mumol/l in control animals. Zn content in the colostrum of experimental cows was 2.40 +/- 0.42 mg/l and in the control it was 1088 +/- 0.52 mg/l (P < 0.05). On day 5 of lactation, Zn amounts in the milk of experimental dairy cows decreased to 0.95 +/- 0.12 mg/l and to 0.76 +/- 0.10 mg/l in the control (P < 0.01). Zn levels in the milk of experimental cows on day 15 of lactation were 0.95 +/- 0.13 mg/l and in the milk of control group they were 0.82 +/- 0.14 mg/l. Colostrum specific weight from zinc-treated cows was 1,067.86 +/- 0.75 g/cm3 and 1,056.8 +/- 13.53 g/cm3 in the control. TP and IgC concentrations were 137.81 +/- 38.11 g/l and 110.13 +/- 29.91 U ZST, respectively, in the colostrum of experimental group, and 105.98 +/- 32.02 g/l and 85.53 +/- 25.42 U ZST, resp., in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)     

The prevalences of Brachyspira spp. and Lawsonia intracellularis in Swedish piglet producing herds and wild boar population

The aim of the present study was to survey the prevalences of the enteric pathogens Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis in Swedish growing pigs and in the Swedish wild boar population and to relate these findings to clinical signs. The study included 105 randomly selected herds, constituting approximately one third of Swedish herds with a herd size of >100 sows. The herds were located all over the country. In these herds, growth promoters were not used and pigs sampled were not subjected to any medication. From each herd, samples were taken from 10 growing pigs aged 8-12 weeks, corresponding to approximately 2.5% of all growing pigs present in the herd at the sampling occasion. If possible, the samples were taken from pigs with diarrhoea. Forty-eight faecal samples and 71 rectal swabs were also taken from free-living wild boars (31 piglets, 19 growers and 21 adult animals) at shooting. The samples were analysed by culture and biochemical tests for the presence of Brachyspira spp. and by nested PCR for the presence of L. intracellularis. Brachyspira hyodysenteriae was not demonstrated in any sample. Brachyspira intermedia was detected in 22 samples originating from 15 herds, Brachyspira innocens/Brachyspira murdochii was detected in 370 samples from 82 herds and B. pilosicoli was detected in 134 samples originating from 34 herds. In 21 herds and in 534 samples, no Brachyspira spp. were detected. Lawsonia intracellularis was demonstrated in 285 samples from 50 herds. Further, 418 samples from conventional herds were negative with respect to L. intracellularis and in 345 samples the PCR had been inhibited. All samples from the wild boars were negative for Brachyspira spp., 12 of 48 samples were negative for L. intracellularis, and in 36 wild boar samples, the PCR was inhibited.     

Prevalence of antibodies to toxoplasma gondii in cattle and swine in the Netherlands: Towards an integrated control of livestock production

Summary

Serological surveys of the prevalence of antibodies against Toxoplasma gondii were carried out amongst swine and cattle in the Netherlands. Data were analysed according to the different categories of animals. The results show very low seroprevalences of Toxoplasma gondii in finishing pigs (1.8%) and in fattening calves (1.2%). In sows and dairy cattle, respectively, seroprevalences of 30.9% and 27.9% respectively, were found, demonstrating clearly the environmental infection pressure and illustrating the importance of housing and management in establishing low infection rates.

Substantially different seroprevalences were found between dairy cattle sampled in the North and in the South of the Netherlands (13.1% and 42.6%, respectively).

The infection rates in the samples from finishing pigs, fattening calves, and dairy cattle demonstrate that seroprevalences in individual farms or herds may differ considerably. Investigation of the factors involved can be useful in determining the causes of infection and for developing measures with regard to prevention. The very low seroprevalences in finishing pigs and fattening calves indicate, however, that the production of toxoplasma‐free meat may be well within reach in modern husbandry.

Since farm animals easily are infected, serological screening of individual farms or herds for the absence of T. gondii infection, as a part of the Integrated Quality Control programme, can be helpful in determining the quality of livestock production and in developing certain standards of hygiene for individual farms.     

Standardized ileal protein and amino acid digestibility by growing pigs and sows

Experiments were conducted to determine the effect of the physiological condition of swine on standardized ileal digestibility coefficients (SID). The apparent ileal digestibility coefficients were determined for crude protein and amino acids in six feed ingredients (corn, barley, wheat, soybean meal, canola meal, and meat and bone meal) in growing pigs and in gestating and lactating sows. Growing pigs and lactating sows were given free access to their diets, whereas gestating sows were allowed to consume only 2 kg of feed daily. The nonspecific (basal) endogenous losses of protein and amino acids were determined under similar feeding regimens after feeding a protein-free diet. The SID for crude protein and amino acids were calculated by correcting the apparent ileal digestibility coefficients for the nonspecific endogenous losses of protein and amino acids. With a few exceptions, there were no differences (P > 0.05) in the SID for crude protein and amino acids between growing pigs and lactating sows. Overall, gestating sows had higher (P < 0.05) SID for crude protein and all amino acids, except for tryptophan and aspartate, compared with growing pigs. Likewise, the SID of most amino acids obtained by gestating sows were higher (P < 0.05) than those obtained by lactating sows. Interactions (P < 0.05) between animals and diets were observed for gestating sows compared with growing pigs as well as gestating sows compared with lactating sows. As a consequence, it is not possible to extrapolate data from one feed ingredient to another. On most occasions, the lowest SID among the indispensable amino acids was calculated for threonine, valine, and lysine. It is concluded that gestating sows fed 2 kg of feed per day have higher standardized digestibility coefficients than do growing pigs and lactating sows given free access to their diets. This difference may be due to differences in daily feed intake rather than to the physiological status of the animals.     

Control of Isospora suis-induced coccidiosis on a swine farm

Results of a program designed to control neonatal porcine coccidiosis on a total confinement, farrow-to-finish swine farm are reported. The control program consisted of washing, phenol disinfection, and steam cleaning of farrowing houses and treatment of sows with amprolium HCl before and after farrowing. Before initiation of the control program, 88.9% of the sows examined in the farrowing house were negative for coccidian oocysts, 9.9% were positive for Eimeria spp, and 1.2% were positive for Isospora suis. Most pigs nursing on sows before initiation of the control program had diarrhea at 5 to 10 days of age, which led to dehydration and weight loss. Morbidity was high, and mortality was moderate. Composite fecal samples from these litters were all positive (100%) for I suis. After initiation of the control program, 99.6% of the sows examined in the farrowing house were negative for coccidian oocysts and 0.4% were positive for Eimeria spp. Clinical signs of coccidiosis were rarely present in nursing pigs examined after the control program was initiated; however, I suis was still present in 19.8% of the composite fecal samples from pigs examined. An association between oocyst production in sows and I suis infections in pigs was not found in the present study. Oocysts of Eimeria spp were not found in the feces from the pigs.     

Effect of feeding thyrotropin-releasing hormone to lactating sows

Two experiments were conducted to assess the effects of feeding thyrotropin-releasing hormone (TRH) during lactation on sows. In Exp. 1, sows were fed 0, 1, 10, 100 or 1,000 mg TRH on d 10.8 +/- .4 (mean +/- SE) after parturition. Blood samples were taken from sows every 30 min from -2 h to 8 h and at 10, 12 and 18 h from feeding. Consumption of 100 or 1,000 mg TRH increased mean serum concentrations of thyroxine (T4; P less than .001), 1,000 mg TRH increased growth hormone (GH; P less than .06) and 100 or 1,000 mg TRH increased prolactin (PRL; P less than .01), but insulin (INS; P greater than .10) was unaffected by TRH. Serum concentrations of T4 were elevated within 2 to 4 h after feeding TRH and remained elevated for 12 to 18 h. Concentrations of GH and PRL began to increase immediately after feeding 100 or 1,000 mg TRH and remained elevated for 6 and 8 h, respectively. In Exp. 2, sows were fed 0 or 200 mg TRH from d 111 of gestation to weaning at 27.1 +/- .3 d of lactation. Consumption of TRH elevated concentrations of T4 at all stages of lactation and increased respiration rate on d 10 and d 20, heart rate on d 20, and milk production on d 20 of lactation. Consumption of TRH did not influence number of pigs born, number born alive, survival rate during lactation, sow body weight, heartgirth, backfat depth, feed disappearance, or milk production on d 10 of lactation. Piglets nursing sows fed TRH were similar in weight to piglets nursing sows not fed TRH on d 0 and 5 of lactation, but they were heavier on d 10 (P less than .07), 15 (P less than .001), 20 (P less than .001) and 27 (P less than .0001). Sows fed TRH took longer (P less than .001) to return to estrus after weaning than control sows. Results indicated that feeding TRH elevated T4, GH and PRL and that feeding TRH for the duration of lactation increased milk production on d 20 of lactation and increased weaning weights, but it delayed estrus after weaning.     

Quantitative transmissible gastroenteritis virus shedding patterns in lactating sows.

To test the role of sows in spreading transmissible gastroenteritis (TGE), 11 sows were intravenously, intranasally, or intramammarily inoculated with virulent virus within 5 days of farrowing. Six of the sows were separated from their offspring, and 5 were allowed to nurse their litters. All sows became clinically ill with sign of anorexia, depression, and fever that persisted until postinoculation day 4 or 5. They shed virus through milk, nasal secretions, and feces, with individual variations occurring in degree and duration of shedding in the 1st week after inoculation. Of 40 pigs separately fed milk samples from the 6 inoculated sows, 19 pigs (47.5%) became sick in 24 to 40 hours, and virus was isolated from them at necropsy. Of 43 pigs in the 5 litters that nursed exposed dams, all became sick with typical signs of TGE, and 29 (67.4%) died in 2 to 9 days. Sows given the single intramammary inoculation of virus developed statistically significant higher levels of TGE virus-neutralizing antibodies than did sows inoculated intravenously or intranasally.     

The occurrence of Cryptosporidium parvum, Campylobacter and Salmonella in newborn dairy calves in the Manawatu region of New Zealand

AIM: To determine the occurrence of Cryptosporidium parvum oocysts, Campylobacter spp and Salmonella spp in faecal samples taken from newborn dairy calves on 24 dairy farms in the Manawatu region of New Zealand. METHODS: A cross-sectional study was conducted during the 2002 calving season. Faecal samples were collected from 185 newborn calves from a convenience sample of 24 dairy farms. The samples were tested microscopically for the presence of C. parvum oocysts, and bacteriologically for the presence of Campylobacter spp and Salmonella spp. RESULTS: Infections with C. parvum were identified in 33/156 (21.2%) calves from 10 farms. More than 10(6) oocysts/g (OPG) faeces were detected in calves from four farms. Campylobacter spp were isolated from 58/161 (36%) calves from 18 farms; in particular, C. jejuni subsp jejuni was isolated from 11/161 (6.8%) calves from seven farms. Salmonellae were not detected. CONCLUSIONS: Despite the short and concentrated calving pattern and the long interval between calving seasons characterising most dairy farms in New Zealand, C. parvum is widespread among calves. Campylobacter spp, especially C. jejuni, rapidly colonise the intestinal tract of newborn calves. RELEVANCE: This study provided an estimate of the ecological impact of newborn dairy calves with regard to the potentially zoonotic enteric pathogens most frequently isolated from human gastrointestinal infections in New Zealand.     

土种母猪和洋母猪的行为比较研究

为了比较广东大花白猪和蓝塘猪与大白、长白猪的哺乳期行为差异,分别选产后5~15d、带仔数为8~11头的5头土母猪与5头洋母猪,连续5d观察其在产仔限位栏内的行为表现。着重观察了母猪哺乳行为的引起、哺乳过程特征、母性行为、规癖行为和采食行为;研究结果表明,土母猪母性行为强、哺乳次数多4~5次、护仔性强,采食力不如洋母猪,小猪寄养换窝干扰母猪正常母性行为和哺乳。在此基础上讨论了土母猪和洋母猪对周围环境变化反应的敏感性。     

Oxytocin,prolactin and somatostatin in lactating sows: associations with mobilisation of body resources and maternal behaviour

The aim of the present study was to investigate how oxytocin, prolactin and somatostatin during nursings relate to maternal characteristics of sows. Undisturbed nursing behaviour and sow–piglet nasal contacts of 21 lactating sows were recorded on day 13 of lactation, and hormonal status was assessed during three successful nursings on day 14. Piglet and litter growth (days 8–15), sow weight loss (days 1–15) and catabolic state (measured as NEFA on day 7), as well as number of successful nursings on day 13 were used as measures of mobilisation of sow body resources. Nasal contacts and sow behaviour facilitating udder massage were used as measures of positive piglet-directed behaviours. Concentrations of oxytocin were higher, those of prolactin lower and those of somatostatin similar during nursings compared to samples taken 15 min after nursing. Oxytocin peaked during most nursings and prolactin increased gradually after nursings. Non-nursing oxytocin values were positively correlated with the proportion of sow-terminated nursings but not with other measures of piglet-directed behaviour. Non-nursing oxytocin concentrations were positively correlated with piglet weight gain and concentrations of oxytocin during nursings were correlated with NEFA and sow weight loss. Our results indicate that oxytocin might have more than merely an all-or-nothing function in triggering milk ejection. Oxytocin seems to be quantitatively related to efficiency of milk production, although the present study design does not allow for speculation on causal relationships.     

日粮中添加不同水平黄芪多糖对奶公犊生产性能的影响

本试验选择30头1月龄短途运输后奶公犊,随机分为A、B和C 3组,A和B组在日粮中分别添加5和10 g/(头·d)黄芪多糖,C组为对照组,不添加黄芪多糖,以探讨日粮中添加不同水平黄芪多糖对育肥奶公犊生产性能的影响。结果表明,日粮中添加5和10 g/(头·d)黄芪多糖均可显著提高奶公犊的采食量和日增重(P<0.05),降低腹泻频率,促进体尺指标发育。考虑成本等因素,建议生产上采用5 g/(头·d)黄芪多糖的添加量。     

Limitations of salivary and blood cortisol determinations in pigs

Blood and saliva samples were taken from groups of pigs maintained in intensive conditions. Multiple samples were taken from two unrestrained pregnant sows fitted with jugular cannulae. Single samples were taken from groups (mixed gilts and entire males; 70–90 kg) which were lightly exercised (7) or restrained (12). The rate of salivary secretion was low and collection of adequate samples took 5 min; in a number of pigs no saliva could be obtained.In order to stimulate salivary secretion, pigs (70–80 kg) were injected with pilocarpine nitrate (25 mg, subcutaneous) which produced a copious flow of saliva persisting for at least 15 min.Resting sows had higher mean levels of cortisol in plasma, ultrafiltrate and saliva than the other groups, which did not differ from each other. Within the pilocarpine group, males had a higher ultrafiltrate level of cortisol than females. In most instances salivary cortisol was significantly greater than ultrafiltrate cortisol.Ultrafiltrate and plasma cortisol were highly correlated (r=0.883) but this correlation was low in the presence of pilocarpine (r=0.260). Salivary cortisol was poorly correlated with either plasma (r=0.167) or ultrafiltrate cortisol (r=0.278) and the correlation with plasma was even lower following the administration of pilocarpine (r=0.086).It was concluded that salivary estimates of cortisol in the pig were not usefully correlated with levels of ultrafiltrate (free) cortisol.