Transient stray voltage: Is it detrimental to growth performance,health status and welfare of market pigs?

The effects of transient stray voltage associated with an alternating current were evaluated in growing-finishing pigs from 9 to 22 weeks of age. Seventy-two pigs were assigned to 9 blocks of 8 animals each. In each block, the following treatments were randomly distributed: a constant voltage differential created between the feeder or drinker and the metallic floor (woven wire), at a level of 0 volt plus 2-volt pulses (0 V–2 V), 2 volts plus 3-volt pulses (2 V–5 V), 5 volts plus 3-volt pulses (5 V–8 V), and a control treatment without any voltage differential (0 V–0 V). The constant voltage was applied 24 h per day. The pulses of 3 s duration were in the form of an increase in the amplitude of the constant 60-Hz signal. One pulse appeared every 20, 40 and 100 s during the hour following feed distribution and every 60, 120 and 300 s during the rest of the day. The animals were fedad libitum and received fresh feed twice per day. Once during the 2-week periods at 9–10, 13–14, 17–18 and 21–22 weeks of age, the behaviour of the pigs was recorded during the hour following the two daily feed distributions. Animal weights and blood samples were taken every 2 weeks, from 9 to 21 weeks of age. No significant effect of transient stray voltage on any of the variables measured for the feeding, drinking, sitting or lying activities was found (p>0.05). At 9–10 weeks of age, the number of rooting bouts was higher for the 5 V–8 V treatment (p=0.03) and the number of events of butting the penmate was higher for the 2 V–5 V treatment (p=0.05). Although the water and feed intake did not differ between treatments (p0.39), the average daily gain of the control group was lower than that of treated groups (p=0.04) at 9 and 10 weeks of age, while the pigs submitted to a 2 V–5 V treatment had a higher daily gain than the pigs in the other treatment groups (p=0.05) at 17 and 18 weeks of age. Finally, the frequency of gastric ulceration and the metabolic profile were not affected by the treatments (p>0.05) except for the CO₂ and total protein concentrations (p0.04), where treatment effects were inconsistent among ages. Consequently, under the experimental conditions of the present study, no major impact of transient stray voltage on the health, growth or welfare of fattening pigs was observed.     

Effect of drinker type and sound stimuli on early-weaned pig performance and behavior

Early-weaned pigs appear to be highly motivated to engage in motor patterns associated with nursing, which is thought to lead to the development of abnormal ingestive behaviors. If performance of these behaviors is related to sucking motivation, then the normal stimuli associated with nursing should stimulate pigs to perform these abnormal behaviors, specifically belly nosing. The goal of this study was to determine whether belly nosing could be affected by sow nursing vocalizations and whether the style of the drinker device influenced early-weaned pig behavior. Over six trials, 352 Yorkshire pigs were weaned at 15 d and assigned to pens (n = 44) of eight pigs based on litter, weight, and sex. Four pens in each of two rooms were outfitted with either a water nipple drinker or a drinker bowl. Rooms either had recorded sow vocalizations broadcast at hourly intervals or no sound (control). Pig behaviors were videotaped in a sample of pens (n = 32) on d 0, 1, 2, 5, 9, 11, 13, 16, and 18 after weaning. On d 0 to 2, pigs were observed continuously for feeding and drinking behaviors. On d 5 to 18, pigs were observed by scan sampling every 5 min for time budgets. Pigs with drinker bowls had higher apparent feed intakes during the first 2 d after weaning (P = 0.024), whereas they spent less time engaged in drinking behavior (P = 0.001). This coincided with an overall lower water use (P = 0.001) than that of pigs with nipple drinkers. Pigs with bowl drinkers also spent less time belly nosing than those with access to a nipple drinker (P = 0.012). Pigs in the sow vocalization treatment tended to have a higher ADG (P = 0.075), whereas they spent less time performing feeding behavior (P = 0.064). However, there was no effect of sow nursing grunts on belly nosing. These results suggest that there is a complex relationship between feeding, drinking and sucking, and belly nosing is not controlled by the same external stimuli as sucking. Because drinker type and the motor patterns that it accommodates affect belly nosing, it may be that the internal stimuli associated with nursing, such as the actual act of sucking, play a large role in the development of abnormal oral-nasal behaviors.     

Effect of drinker type on water intake and waste in newly weaned piglets

During the first few days after weaning, pigs often experience BW loss as they adapt to eating solid food. During this time period, they are also known to drink excessively and develop abnormal oral behavior such as belly nosing. The excessive drinking may stem from the piglets' attempt to satiate hunger through gut fill from a familiar ingestive source. Gut fill through water intake may affect the establishment of feeding behavior. Using drinker devices other than the standard nipple drinker may ease the piglets' transition at weaning by facilitating the initiation of feeding and preventing the development of behavioral problems such as excessive drinking and belly nosing. In this experiment, we examined the effect of drinker type on water and food intake, growth rates, and belly nosing in newly weaned piglets. Eighteen pens of 15 piglets each (270 piglets total) were weaned at 18.1 +/- 0.1 d of age and housed in pens containing 1 of 3 drinker devices (standard nipple, push-lever bowl, and float bowl). Piglets' water and feed intake, water use, BW, and behavior were examined on a pen basis through 2 wk after weaning. Piglets with nipple drinkers wasted more water than the other piglets (P < 0.001; float, 295 +/- 70 mL x pig(-1) . d(-1); nipple, 1,114 +/- 63 mL x pig(-1) . d(-1); and push-lever, 186 +/- 63 mL x pig(-1) . d(-1)), whereas piglets with float bowls consumed less water than the other piglets (P < 0.001; float, 475 +/- 81 mL . pig(-1) x d(-1); nipple, 870 +/- 76 mL x pig(-1) . d(-1); push-lever, 774 +/- 76 mL x pig(-1) . d(-1)). Drinker type affected feeding behavior (P = 0.02); piglets with push-lever bowls spent less time at the feeder than the other piglets, although no difference was detected for feed intake (P = 0.64) or overall ADG (P = 0.16). Piglets with push-lever bowls also tended to perform less piglet-directed nosing behavior than piglets with the float bowl (P = 0.04). Piglets appear to use more water during the first 2 d after weaning with certain drinker devices. However, piglets do not appear to attain satiety through water consumption because most of the water used during the first few days after weaning is wasted. This excessive drinking and water wastage can be abated through the use of push-lever drinkers without negative implications for feed intake or growth rates.     

Exposure variability of fosfomycin administered to pigs in food or water: Impact of social rank

The objective of this study was to document the effect of social ranking on the internal exposure of pigs to an antibiotic (fosfomycin) administered either in food or in drinking water. Signs of aggression were recorded at the feeder and drinker. The interindividual variability explained by the social rank was even greater when the test antibiotic was given in food despite the fact that the water consumption was less variable than the food intake. The range of plasma concentrations after administration of fosfomycin either in food or drinking water leads to a number of pigs in the treated group being exposed to rather low and highly variable concentrations of fosfomycin and not able to maintain adequate plasma concentrations above the typical minimum inhibitory concentration (MIC). Social rank clearly influences the level of exposure of pigs to fosfomycin both in food and drinking. However, its administration in drinking water is likely to be the best option to optimize antibiotic efficacy.     

Behavior and reproductive performance by stalled breeding females on a commercial swine farm

The behavior of stalled females pigs was observed to investigate the relations between behavior and reproductive performance. A commercial farrow-to-finish farm equipped with a computerized recording system with approximately 300 female pig inventories was visited three times to observe three postural behaviors (lying, standing, and sitting) and three stereotypies (vacuum chewing, drinker playing, and bar biting) of stalled females at 15-min intervals for 6 h (25 times including 0 min of one zero-time sampling) after feeding. Relative frequencies (%) of the postural behaviors and the stereotypies for 6 h were expressed as a percentage of a total of 25 time observations. Statistical models for reproductive performance included each behavior, parity, and day of visit. Among 609 pregnant females observed at our three visits, the means in relative frequencies (%) of lying, standing, sitting, vacuum chewing, drinker playing, and bar biting for 6 h were 60.1 +/- 0.91, 32.3 +/- 0.87, 7.60 +/- 0.44, 12.7 +/- 0.65, 0.4 +/- 0.06, and 0.2 +/- 0.50%, respectively. Among 514 farrowed females of the 609 pregnant females, the means of total pigs born, pigs born alive, pigs born dead, birth litter weights, pigs weaned, and adjusted 21-d litter weights were 12.3 +/- 0.13, 11.2 +/- 0.12, 1.1 +/- 0.06, 17.1 +/- 0.18 kg, 10.3 +/- 0.08, and 68.1 +/- 0.40 kg, respectively. Females showing a high relative frequency (> or = 36%) of vacuum chewing during gestation produced fewer (P < 0.05) total pigs born (11.7 +/- 0.38 vs. 12.6 +/- 0.22) than those showing no vacuum chewing. No relationships were found between vacuum chewing and other performance measurements such as pigs born alive, pigs weaned, and adjusted 21-d litter weights. Neither postural behavior nor the other stereotypies were related to reproductive performance. The farrowing rate was not related to any postural behavior and stereotypy in logistic regression mixed models. This study suggests that a subpopulation of females exists on commercial farms that frequently exhibit vacuum chewing and give birth to fewer total pigs. High frequency of vacuum chewing in those females may be indicative of their suboptimal reproductive performance.     

Water requirements of liquid-fed heavy pigs: Effect of water restriction on growth traits,animal welfare and meat and ham quality

Reducing water waste, and therefore the total volume of manure produced, is one of the ways to lower the environmental impact of intensive pig farming. The aim of this trial was to verify whether the absence of additional fresh drinking water could compromise the production traits or behaviour of liquid-fed heavy pigs. Sixty animals (initial BW 78 kg) were divided into two experimental groups, both fed a liquid diet (water-to-feed ratio 3:1 w/w). All pens were equipped with nipple drinkers; one of the groups had permanent access to fresh water (working drinkers—WD), whereas the other group had no water supply except that delivered with food (dry drinkers—DD). The pigs were housed in temperature- and humidity-controlled rooms. They were brought to a weight of 160 kg and then slaughtered. Hams were dry-cured according to the directives for Parma ham production. No significant differences (P>0.05) were observed between the experimental groups with respect to growth parameters (ADG and FCR), behavioural traits, blood parameters or the qualitative traits of carcasses (dressing out, lean meat yield, backfat thickness), meat (pH, colour, WHC, fatty acid composition of subcutaneous fat and tenderness) and cured hams (weight losses, sensory properties, chemical composition and oxidative status). With respect to drinking behaviour, a low number of visits to the drinker were recorded for both groups and data seem to indicate a high amount of water wasted by pigs provided with additional water delivery by nipple drinkers. Liquid feeding did not suppress drinkers use or drinker manipulation in both groups.     

Effect of environment on Pekin duck behaviour and its correlation with body condition on commercial farms in the UK

1.?Forty-six flocks of commercially-reared Pekin ducks were studied to determine the effects of housing system and environment on the behaviour of farmed ducks and its correlation with physical condition. Houses differed predominantly in their ventilation, drinking, feeding and brooding systems, and were indicative of systems currently in use in the UK.

2.?At 41 d of age ducks spent 1?5% of the time feeding, 6?7% drinking, 4?2% rooting and 15?5% dry preening. They spent large amounts of time relatively inactive, 43?5%, or performing comfort behaviours, 17%. On average 4?6% of their time was spent walking and only 1?8% wet preening.

3.?A greater proportion of the maximum number of ducks able to use the drinker at any one time used the trough; nipple use was least and Plasson use intermediate. The proportion of ducks wet preening was not affected by drinker type but increased with increasing drinker space (mm/bird).

4.?Duck behaviour was little affected by commercial production system and was influenced more by environment, age and physical condition. Activity at an older age incorporated more of the behaviours associated with thermal comfort (panting) and maintenance of plumage condition (dry and wet preening). These behaviours increased with increasing temperature, relative humidity and atmospheric ammonia. Poor walking ability was correlated to increased frequency of panting, reduced activity at the drinker, and longer resting bouts.     

Hepatic corticosteroid-binding globulin (CBG) messenger RNA expression and plasma CBG concentrations in young pigs in response to heat and social stress

Plasma cortisol, porcine corticosteroid-binding globulin (pCBG), hepatic CBG expression, and other physiological and behavioral measures of stress were studied in pigs in response to elevated temperature in conjunction with establishing a social hierarchy. Twenty-four crossbred pigs were weaned at 25 d of age (three or six pigs from six sows) and housed in littermate groups at 23 +/- 2 degrees C. At 57 d of age (d 0), animals were weighed and placed under general anesthesia for collection of blood (10 mL) and liver (approximately 100 mg) samples. On d 1, three unacquainted pigs of similar BW (23 +/- 1 kg) from different litters were allotted to each of eight nursery pens within two environmentally controlled rooms (12 pigs per room). From d 1 to 7, one room was maintained at 23 +/- 2 degrees C (CON) and the other at 33 +/- 2 degrees C (HEAT). Both rooms were kept at 23 +/- 2 degrees C from d 8 to 14. Animals were videotaped for 72 h beginning on d 1 and 8 to document behavioral changes in response to room temperature. The social hierarchy of pigs within each pen was based on fight activity recorded on d 1 to 3. Blood and liver tissue were collected again on d 7 and 14. The ADG for HEAT pigs increased (P < 0.05) over d 8 to 14 compared with d 1 to 7. In contrast to CON pigs, HEAT pigs displayed increased (P < 0.01) drinking but decreased feeding and lying in contact with other pigs from d 1 to 3, and similar drinking and feeding but increased (P < 0.01) lying with contact behaviors from d 8 to 10. With the exception of subordinate pigs exhibiting less (P < 0.05) frequent standing/walking behavior than the dominant or intermediate pigs on d 1 to 3, frequency of behaviors for both recorded time periods did not differ among pigs due to social status, regardless of treatment. The concentration of plasma haptoglobin in HEAT pigs on d 7 compared with d 0 increased (467 vs. 763 mg/L; P < 0.05), whereas cortisol and pCBG decreased (274 vs. 235 nmol/L and 11.4 vs. 9.9 mg/L, respectively; P < 0.05) as a result of treatment. The free cortisol index (total cortisol/pCBG) was greater (P < 0.05) in HEAT pigs on d 14 than on d 0 or 7. Hepatic CBG mRNA level was not affected by treatment. On d 14, HEAT pigs had plasma cortisol, pCBG, and haptoglobin concentrations similar to those of CON pigs. These results indicate that measured behavioral and physiological responses were not related to social status, and decreased circulating levels of cortisol and pCBG in pigs following a 7-d exposure to elevated temperature may not be determined by hepatic CBG mRNA expression.     

Experimental model of enterotoxigenic Escherichia coli infection in pigs: potential for an early recognition of colibacillosis by monitoring of behavior.

The hypothesis that altered behavior is a sign for an early recognition of disease was tested. The experiment was conducted to evaluate the behavioral patterns of pigs in a model of postweaning colibacillosis. Twenty-five weaned pigs (from a herd that was previously found to be highly susceptible to F4⁺ Escherichia coli strains) were randomly assigned into 5 groups, kept in isolated pens under the controlled ambiental conditions. One day after weaning, the pigs from three groups were intragastrically inoculated (via orogastric tube) with either F4ac⁺ (1466 or 2407) or F4⁻ (1467) nonenterotoxigenic E. coli (non-ETEC) strains, respectively. The pigs from the fourth group were inoculated with F4ac⁺ ETEC strain M1823 and the remaining 5 pigs that received broth containing 1.2% sodium bicarbonate were kept as noninoculated controls. The pigs were examined daily and the frequency and duration of their behavioral patterns, such as eating, drinking, lying, standing, urinating, defecating, rooting and playing were monitored for 300 h during a period of 10 days. In this model, three conditions were also observed in F4-susceptible pigs: (1) acute fatal diarrheal disease; (2) moderate diarrhea and weight loss and (3) no diarrhea and weight loss. The incidence (both frequency and duration) of defecating was significantly higher (P<0.05) in pigs inoculated with F4ac⁺ ETEC strain M1823 as compared to that of noninoculated (control) pigs. Pigs inoculated with F4ac⁺ non-ETEC strain 1466 had a significantly lower frequency of eating (P<0.05) and frequency/duration of drinking (P<0.05) than did the controls. The 1466-inoculated pigs, had an increased diarrhea score, but frequency/duration of defecating was not significantly different. Pigs inoculated with F4ac⁺ non-ETEC strain 2407 spent more time in lying (P<0.05) than did noninoculated pigs. Conversely, the pigs that received F4⁻ non-ETEC strain 1467 laid shorter (P<0.05) and ate/drank less frequently (P<0.05) than the controls. It was concluded that the changed occurrence of defecating and eating in pigs that were inoculated with either F4ac⁺ ETEC (M1823) or non-ETEC (1466) strain, respectively, was consistent with the pending clinical disease, i.e. postweaning colibacillosis.     

Effect of liquid whey feeding on fecal microbiota of mature and growing pigs

The effect of liquid whey feeding on fecal bacteria and their metabolites was assessed in five pregnant sows and 66 growing pigs. Sows were fed a control diet for 4 weeks (control period) followed by the same diet but with whey feeding (5 L/day/pig) for 4 weeks (whey period). One group of growing pigs was given 267 L of whey per pig (whey group), while the other group was not (control group). In both cases, liquid whey was given separately from control diet. Sows in the whey period had feces showing lower pH, lower ammonia concentration, and larger population sizes of total bacteria, lactobacilli and bifidobacteria. The bacterial gene library analysis indicated that Mitsuokella and Megasphaera were more frequently detected, while Clostridium disporicum were detected less frequently in the whey period. Feces from whey‐fed growing pigs showed lower pH than that from control pigs in the early stage of growing. Also, larger populations of total bacteria, lactobacilli and bifidobacteria were recorded in the whey group. From the bacterial gene library analysis, the detection frequency of Lactobacillus reuteri tended to be higher in the whey group. These results indicate that whey feeding influences the hindgut microbiota of pigs, possibly leading to a fermentation shift that is favorable for animal health.     

Effect of verapamil on cardiac chronotropic response to vagal stimulation in neonatal pigs

The effects of verapamil on the chronotropic response to vagal stimulation in young pigs anesthetized with sodium pentobarbital (30 mg/kg of body weight, intraperitoneally) was evaluated. After bilateral vagotomy, the administration of verapamil (loading dose of 100 micrograms/kg, followed by 2 micrograms/kg/min infusion) resulted in a significant (P less than 0.05) reduction in heart rate (HR) and mean arterial blood pressure. Cardiac frequency responses to vagal stimulation were obtained by stimulating the distal end of the right vagus nerve at selected frequencies (5, 10, 15, and 20 Hz) with supramaximal voltage (10 to 15 V) and constant duration (2 ms). The HR was measured after 15 s at each level of stimulation. The slopes of decrease in HR to the frequency of vagal stimulation were significantly (P less than 0.05) reduced after verapamil as compared with its controls. After atropine (0.5 mg/kg), the vagally induced tachycardia was partially attenuated by verapamil, but was completely eliminated by beta blockade with propranolol (1 mg/kg). These findings indicated that verapamil may influence the parasympathetic control of the heart in young pigs.     

Influence of sarcoptic mange and cold and ambient temperature on blastogenic responses of lymphocytes and serum cortisol concentrations of pigs

Blood samples from sarcoptic mite-infested pigs were evaluated for effects of mite infestation and cold and ambient temperatures on lymphocyte blastogenic responses and for effects of mite infestation on serum cortisol concentrations. In experiment 1, sarcoptic mite-infested and noninfested pigs were housed in cold (5 to 15 C fluctuating) and thermoneural (25 C) environmental chambers for 5 weeks. Differences were not observed (P greater than 0.10) in blastogenic responses to phytohemagglutin or pokeweed mitogen between lymphocytes from infested and noninfested pigs on postinfestation days (PID) 7, 21, 28, and 35 in either environmental chamber. When lymphocytes from noninfested pigs were cultured with sera from infested pigs, alterations of blastogenic responses were not detected. Cortisol values were higher (P less than 0.05) in sera from sarcoptic mite-infested pigs, compared with those from noninfested pigs, at 4 PM on PID 14 and 4 AM and 10 AM on PID 15. Cortisol values were higher (P less than 0.05) in sera obtained at 10 AM on PID 14 and at 10 AM on PID 15 from pigs housed in cold chambers, compared with those from pigs housed in thermoneutral chambers. Interactive effects between sarcoptic mite infestation and cold ambient temperatures were not observed. At 4 AM on PID 15 (experiment 2), cortisol values were higher (P less than 0.05) in sera of infested pigs, compared with those in noninfested pigs. Seemingly, sarcoptic mange in pigs did not alter mitogen-induced lymphocyte blastogenic responses, but did increase serum cortisol concentrations, indicating that sarcoptic mange may be a stressor in pigs.     

Monitoring chromosome mutations in large-scale breeding operations

The frequency of chromosomal aberrations and exchanges of sister chromatids (SCEs) in peripheral lymphocytes was studied in 65 pigs from five large breeding herds. Four groups comprised fattened pigs and the fifth group consisted of sows from a large multiplier breeding herd. During the investigation, the dust from the sites was analyzed for the presence of zinc, lead, cadmium, mercury, aflatoxin B1, PCB, DDT, and lindane. The average frequency of aberrant cells (AB.B) in the pigs of group I was 3.85 +/- 1.60%, in group II 2.10 +/- 1.52%, in group III 5.01 +/- 2.1%, in group IV 3.50 +/- 1.58%, and in group V 6.20 +/- 3.21%. The cytogenetic finding corresponded to the differences in the amount of foreign substances found in the dust on the premises where the animals of all groups were kept. The average frequency of the SCEs was 7.00 +/- 1.10 (I), 6.51 +/- 0.89 (II), 6.92 +/- 0.72 (III), 7.10 +/- 0.85 (IV) and 7.06 +/- 1.47 (V) per one cell. Statistically significant differences in the numbers of AB.B. were recorded between groups II and I, II and IV, I and III, IV and V (p less than 0.05) and between groups II and III, II and V (p less than 0.01). There was no statistically significant difference in the frequency of SCEs. The determination of the frequency of chromosomal aberrations can be used for the hygienic control of the degree of exposure of pigs to mutagens.     

Synthetic maternal pheromone stimulates feeding behavior and weight gain in weaned pigs

One hundred and forty-four pigs were used to determine the effects of a putative synthetic maternal pheromone on behavior and performance of weanling pigs. Each pen of weaned pigs contained three pigs that were given free access to water and feed. Pigs were videotaped in time lapse for 48 h after weaning and weekly body weights and feed disappearances were recorded for 4 wk. Treatments included: a) control (vehicle applied), b) 30 mL of synthetic pheromone applied to the feeder, or c) 10 mL of synthetic pheromone applied to each of three pigs' snouts. Pigs exposed to the synthetic pheromone spent more (P < 0.05) time with their heads in the feeder and less (P < 0.05) time drinking, lying down, or engaged in agonistic behaviors than control pigs. Pigs exposed to the synthetic pheromone were more (P < 0.05) active during the 48-h period of video taping than control pigs. Pigs exposed to the synthetic pheromone (either on the feeder or their snout) had increased (P < 0.01) average daily gain (ADG) and better (P < 0.01) feed:gain ratio than control pigs over the 28-d postweaning period. In conclusion, the putative synthetic pheromone, applied once at weaning, stimulated apparent feeding behaviors, and reduced fighting and apparent drinking behaviors during the first 48 h after weaning. ADG and feed:gain ratio were improved by application of the putative synthetic pheromone either directly on the feeder or when painted on the pigs' snouts. Olfactory signals can modulate adaptation to the postweaning environment in ways that may improve pig performance and welfare.     

Epidemiological associations between characteristics of registered broiler chicken flocks in Canada and the Salmonella culture status of floor litter and drinking water

A Canada-wide flock management survey of 294 randomly selected commercial broiler chicken flocks was conducted during 1989-1990. The prevalence of flocks that yielded Salmonella from cultures of floor litter or drinking water, and the prevalence of floor litter samples that yielded Salmonella, were significantly associated (p < 0.05) with the age of the flock and the region of Canda in which the flock was located. Culture of Salmonella from the drinking water was significantly associated (p < 0.05) with the type of drinker used, the dead bird disposal method, and the region of Canada in which the flock was located. There was a significantly greater risk (p < 0.05) of contamination of drinking water with Salmonella from trough drinkers (odds ratio = 7.99) and plastic bell drinkers (odds ratio = 6.10) than from nipple drinkers. No significant associations were found between pest control, restrictions on visitors, clean-out methods, or water sanitization and the culture of salmonellae from floor litter or drinking water.     

饲喂模式对猪生长性能、养分消化率和肠道微生物组成的影响

本试验旨在探究不同饲喂模式对猪生长性能、养分消化率和肠道微生物组成的影响。选择120头平均初始体重(26.0±0.4)kg的生长猪(公、母各半),按体重和性别随机分为自由采食组(FA)和限制饲喂频率组(每天饲喂3次,M3),每个处理10个重复,每个重复6头猪,试验期共28 d。结果表明:M3组平均日采食量和耗料增重比均显著低于FA组(P<0.05);饲喂模式的改变对养分表观全肠道消化率无显著影响(P>0.05);M3组血浆尿素氮和游离脂肪酸水平显著低于FA组(P<0.05),而胰岛素水平显著高于FA组(P<0.05);饲喂模式对猪粪便微生物组成有一定影响,在门水平上,M3组拟杆菌门丰度显著低于FA组(P<0.05),柔膜菌门和疣微菌门丰度显著高于FA组(P<0.05);在属水平上,M3组Prevotellaceae_UCG-003、Ruminococcaceae_UCG-010、Ruminococcaceae_NK4A214_group、Rikenellaceae_RC9_gut_group和Coprostanoligenes_group的丰度显著高于FA组(P <0.05),而Selenomonas、Roseburia、Prevotella_2、Prevotella_7、Prevotella_9、Anaerovibrio和Alloprevotella的丰度显著低于FA组(P<0.05)。综上,饲喂模式对生长猪养分消化率无显著影响,限制饲喂频率可改变肠道微生物组成并改善生长猪饲料报酬。     

Therapeutic effects of various concentrations of lincomycin in drinking water on experimentally transmitted swine dysentery

Three experimental studies were conducted in 232 growing pigs (8 to 12 weeks old) to evaluate the therapeutic effects of various concentrations of lincomycin in drinking water, against swine dysentery experimentally transmitted, by oral inoculation or by contact-commingling exposure. Four or 5 concentrations of lincomycin were used in each experiment (132, 66, 33, 16.5 or 0.0 mg/L of drinking water). Medication was initiated 7 to days after exposure and was continued for 6 to 10 days. Both methods of exposure were capable of transmitting the disease successfully. A more marked dose response was noticed in pigs inoculated orally than in pigs that were exposed by contact. All concentrations of lincomycin were effective for the treatment of swine dysentery by oral or by contact exposure. At the smaller concentration of 16.5 mg/L of drinking water, lincomycin was less effective for treating the disease than it was at greater concentrations. The suggested optimal concentration was 33 mg of lincomycin/L of drinking water for the treatment of swine dysentery.     

Role of feeding in the treatment of dogs with pancreatic degenerative atrophy

Fourteen dogs with pancreatic degenerative atrophy (PDA) were fed their original diets or a special diet for 2 periods of 4 weeks to compare the severity of clinical signs in relation to different types of diet. During the first period, the dogs were given ordinary food, and in the second period, the dogs were given only the special diet that consisted of a commercial moderate-fat, low-fiber, highly-digestible food. In addition, equal amounts of pancreatic enzymes were added into the food during highly-digestible food. In addition, equal amounts of pancreatic enzymes were added into the food during both periods. The owners were given a questionnaire covering 9 typical signs of PDA. They were asked to assess the severity of signs daily for the 2 periods using a scale provided with the questionnaire. The general well-being of the dogs was significantly (p less than 0.05) better during the period when the dogs were fed a special diet. Of the individual clinical signs associated with PDA the severity of flatulence, borborygmi, volume of faeces and frequency of defecation were significantly (p less than 0.05) decreased on the special diet. There were no significant differences in appetite, drinking, colour and consistency of the faeces or in coprophagy between the 2 feeding periods. The costs of the special diet were almost double compared to the ordinary diets.     

Effect of the composition of the ration during the dry period on fertility and milk production of Holstein cows in Israel

In each for of kibbutzin herds located in Israel the dry cows were divided in two feeding groups. The experimental group, in totally 266 cows, obtained only oat, barley or wheat hay ad libitum, whereas the control group (n = 253) was fed additionally mix or silage up to four kg dry matter. The cows in the control group responded in the following lactation with a 1.3 kg higher average FCM per day (p = 0.02) and with a 1.7 kg higher maximum FCM (p = 0.01) in comparison to the experimental group. The differences between the experimental and control group in A. I.-parameters days open, conception rate on first insemination and percent problem cows were rather small. However, the frequency of retained placenta and ovary cysts was significantly (p less than 0.05) higher in the control group than in the experimental group. In one herd the influence of body condition between the end of lactation, dry period and 50-80 days p.p. as well as the change of body weight between the end of lactation and calving on milk production and fertility could be evaluated. A decrease of one body condition score unit between the dry period and 50-80 days p.p. was associated with an increase of FCM by 2.01 kg (p less than 0.01), a decrease of the conception rate by 21% (p less than 0.05) and an elongation of the days open by 23.6 days (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)