Risk factors for stillbirths in two swine farms in the south of Brazil

We evaluated stillbirth risk factors in two commercial swine farms of the Rio Grande do Sul State (south of Brazil). The study was conducted during 1 month in Farm A and during 2 months in Farm B, both during 1999. Data for all farrowings that occurred during the study period were recorded (101 for Farm A and 373 for Farm B), without interference in the farm management. In Farm A, 39% of all litters born during the period of interest had stillborn piglets and the stillborn risk for piglets was 12%. In Farm B, 25% of all litters had stillborn piglets whereas the stillborn risk was 2%. Variables considered as potential risk factors for stillbirths were: parity (1, 2–3, 4+); breed (purebred or crossbred); sow body-condition (normal or fat); use of oxytocin during parturition (yes or no); obstetric intervention through vaginal palpation (yes or no); farrowing duration (<4 or ≥4 h); mummified fetuses (yes or no); total litter size (<12 or ≥12 piglets); and litter birth weight (<11 or ≥11 kg). All stillborn piglets had their classification validated by necropsy. In multivariable logistic-regressions, the cases were the litters having at least one stillborn piglet. In Farm A, litters having at least 12 pigs and in which oxytocin was used during the parturition had 20.8-times-higher odds of stillborn occurrence. In Farm B, litters from sows having parity ≥4 had 2.2-times-higher odds of stillborn occurrence than litters from parity 2 to 3 females, litters having ≥12 pigs had 2.0-times-higher odds of a stillborn piglet than smaller litters and farrowings in which vaginal palpation was performed had 8.0-times-higher odds. Farrowing room management to minimize stillborn risk should target higher-parity females, large litters and optimization of practices of obstetric interventions.     

Impacts of a modified farrowing pen design on sow and litter performances and air quality during two seasons

The impacts of using a modified farrowing pen (MOD) on the performance of sows and their litters and on ambient air quality over a hot and a cool season were evaluated. Primiparous Yorkshire × Landrace sows farrowed either during the months of February and March (thermoneutralily, TN) or June and July (heat-stress, HS). Temperatures within each season were controlled to 21 and 29 °C, respectively, for TN and HS. Animals from each group were assigned to a standard farrowing crate (STD; TN, n = 17; HS, n = 16) or a MOD pen (TN, n = 19; HS, n = 19). The MOD pen consisted of a STD crate with a 1.5 × 1.6-m comfort zone in the back, equipped with rubber floor mats, a feeder and a nipple waterer. Litter size was standardized to 10 or 11. No creep feed was provided and piglets were weighed weekly. Sows were weighed on days 2 and 22. Feed intake of sows was monitored daily, a milk sample was obtained on day 21 for compositional analyses and jugular blood samples were collected on days 2 and 21 to measure prolactin, IGF-I and urea. Sows consumed less feed (3.4 vs. 4.7 ± 0.1 kg/day, P < 0.001) in a hot than in a cool season and, at 29 °C, sows in MOD pens consumed more feed (3.9 vs. 3.0 ± 0.2 kg/day, P < 0.01) than sows in STD pens. Sow lactation weight loss was greater (− 26.4 vs. − 19.1 ± 1.9 kg, P < 0.05) for sows in STD than MOD pens in a hot season. The reduction in prolactin concentrations from days 2 to 22 of lactation tended to be greater (P = 0.08) in a hot season for sows in STD pens. Concentrations of urea and IGF-I increased as lactation advanced (P < 0.01) and IGF-I was lower for HS compared to TN sows on both days (P < 0.01), whereas urea was greater for HS sows on day 2 only (P < 0.01). Milk DM was less in a hot than in a cool season (P < 0.01). Average piglet weight gain was reduced in a hot compared to a cool season during the second week of lactation (P < 0.05) and this reduction was less in MOD than STD pens during the third week of lactation (P < 0.01). During a hot season, even though not significant, average weight gain of piglets from days 2 to 21 of lactation was reduced by 6.0% in MOD pens compared to 9.7% in STD pens.     

Effect of floor cooling on performance of lactating sows during summer

Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17 °C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8 °C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8 °C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P < 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P < 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P < 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P < 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.     

Effects of chilled drinking water on the performance of lactating sows and their litters during high ambient temperatures under farm conditions

Heat stress has detrimental effects on lactating sows and their litters, including decreased feed intake and milk production in sows and decreased weight gain in their offspring. It also increases respiration rate, rectal temperature, and weaning to estrus interval in sows. This study was conducted to investigate the effects of chilled water (CW) on the performance of lactating sows and their litters exposed to high ambient temperatures for 21 days. Ninety multiparous sows (Yorkshire × Landrace; parity range: 2 to 5) and their litters (Yorkshire × Landrace × Duroc) were divided into 3 blocks (30 each). Sows and their litters within each block were randomly assigned to one of the three treatment groups (n = 10 each). Each group was provided with drinking water at 10, 15, or 22 °C (control) under farm conditions where ambient temperature above 25 °C was consistent during the experimental period. Sows on CW (both 10 and 15 °C) consumed more feed and water than did control (P < 0.01) and higher estimated milk production compared with control (P < 0.01), but had lower rectal temperature and respiration rate compared with control (P < 0.01). Mean weaning weight (P < 0.01) and average daily gain (P < 0.01) of litters in CW groups were higher than those in control group. There were no differences in the measured variables, with the exception of the respiration rates, between the two CW treatment groups. These results suggest that CW may improve the performance of sows and their litters exposed to high ambient temperatures and the 15 °C water, from an energy viewpoint, may be more effective.     

Relation between reproduction performance and indicators of feed intake, fear and social stress in commercial herds with group-housed non-lactating sows

Group-housing of non-lactating sows is becoming increasingly widespread in commercial sow herds in European countries as a result of changed legislation. Group-housing may lead to individual variation in feed intake, stress and fear, which may impair the reproduction performance. However, whether the individual variation in feed intake and the level of stress and fear under commercial conditions is severe enough to impair the reproduction performance is not known. In a detailed farm study including 14 herds with different layouts the relations between various indicators of feed intake, stress and fear and reproduction performance were studied based on 553 focal sows. Twelve percent of all mated sows were re-mated and average litter size was 14.8 born piglets per litter. Chance of pregnancy (P < 0.05) and litter size (P = 0.08) correlated positive with back fat gain from weaning to 3 weeks after mating. Sows eating in less than 20% of all observations at feeding had significant higher risk of returning to oestrus compared to sows eating more frequently. Number of skin lesions correlated positively (P = 0.07) with interval from weaning to first mating. No relations between reproduction performance and lying behaviour, aggressions after mixing or the outcome of three fear tests were found. The results indicate that the unintended individual variation in feed intake in sows group-housed in commercial herds may be large enough to affect the reproduction performance. This calls for management initiatives to reduce unequal feed intake in group-housed sows.     

Between-breed variability of stillbirth and its relationship with sow and piglet characteristics

Litter characteristics at birth were recorded in 4 genetic types of sows with differing maternal abilities. Eighty-two litters from F(1) Duroc x Large White sows, 651 litters from Large White sows, 63 litters from Meishan sows, and 173 litters from Laconie sows were considered. Statistical models included random effects of sow, litter, or both; fixed effects of sow genetic type, parity, birth assistance, and piglet sex, as well as gestation length, farrowing duration, piglet birth weight, and litter size as linear covariates. The quadratic components of the last 2 factors were also considered. For statistical analyses, GLM were first considered, assuming a binomial distribution of stillbirth. Hierarchical models were also fitted to the data to take into account correlations among piglets from the same litter. Model selection was performed based on deviance and deviance information criterion. Finally, standard and robust generalized estimating equations (GEE) procedures were applied to quantify the importance of each effect on a piglet's probability of stillbirth. The 5 most important factors involved were, in decreasing order (contribution of each effect to variance reduction): difference between piglet birth weight and the litter mean (2.36%), individual birth weight (2.25%), piglet sex (1.01%), farrowing duration (0.99%), and sow genetic type (0.94%). Probability of stillbirth was greater for lighter piglets, for male piglets, and for piglets from small or very large litters. Probability of stillbirth increased with sow parity number and with farrowing duration. Piglets born from Meishan sows had a lower risk of stillbirth (P < 0.0001) and were little affected by the sources of variation mentioned above compared with the 3 other sow genetic types. Standard and robust GEE approaches gave similar results despite some disequilibrium in the data set structure highlighted with the robust GEE approach.     

养殖规模对不同胎次母猪生产力的影响

为了比较不同规模猪场不同胎次母猪繁殖力的高低,本研究采集了106家不同规模猪场母猪的详细生产数据。按母猪实际存栏头数将猪场划分为<1 000、1 000~5 000、5 000~10 000和≥10 000头4个规模,分析不同规模猪场母猪1~9胎次活仔率、健仔率、畸形仔率、死胎率、木乃伊率、断奶活仔率及窝均产总仔数、窝均产活仔数、窝均产健仔数、窝均产死胎数、窝均断奶活仔数、窝均出生个体重、窝均出生窝重等相关繁殖指标的差异。结果表明,在胎次相同的情况下,猪场活仔率、健仔率和断奶活仔率随着饲养规模的扩大呈逐渐升高的趋势,而畸形仔率、死胎率和木乃伊率则呈相反趋势。母猪实际存栏头数≥10 000头的猪场1~7胎次（第4胎除外）的活仔率、健仔率和断奶活仔率均显著高于<1 000头猪场（P<0.05）,而与其他两个规模猪场差异不显著（P>0.05）。母猪存栏数<1 000头的猪场1、2、3、5、7胎次的死胎率显著高于其他3个规模猪场（P<0.05）。各个胎次的窝均产总仔数、产活仔数、产健仔数、畸形仔数、死胎数、木乃伊数、出生窝重都随着猪场饲养规模的扩大呈逐渐降低的趋势。<1 000头的猪场第2、3胎的母猪窝均产总仔数、产活仔数、产死胎数、窝均断奶活仔数、窝均出生窝重均显著高于其他3个规模猪场（P<0.05）。综上,养殖规模对不同胎次母猪生产力均产生较大影响,中大规模猪场（≥1 000头）的母猪繁殖力整体上低于小规模猪场（<1 000头）,但仔猪的体况和成活率要优于小规模猪场。     

Mammary development and milk production in the sow: Effects of udder massage, genotype and feeding in late gestation

The primary aim of the study was to investigate whether post-ejection udder massage 1–2 weeks pp (post partum) had an effect on the amount of mammary tissue and milk production in the domestic sow.

The nursing behaviour of 35 primiparous LYL or YLY sows and their litters was followed on days 7 and 14 pp. The milk production was measured by the weigh–suckle–weigh method of the whole litter on days 11 and 18 pp. After weaning on day 28 pp, the sows were slaughtered and the mammary tissue excised and weighed.

No significant correlations were found between the duration of post-ejection udder massage and the subsequent milk production. LYL sows had more mammary tissue (P < 0.05) and their piglets spent more time performing post-ejection udder massage compared to the YLY sows (P < 0.01). Individual variation was found in the proportion of time that the sows were lying on either their right or left side. The weight of the mammary tissue from the left side was positively affected by the amount of udder massage (pre- and post-ejection massage) that the sows had received while lying on the right side relative to the amount that she had received while lying on the left side on day 7 pp (P < 0.01).

In conclusion, the intensity of udder massage influenced the amount of mammary tissue at slaughter. The genotype of the sow affected the expression of nursing behaviour and milk production. No connection was found between post-ejection udder massage and the measures of milk production 1–2 weeks pp. Finally, feeding during the last half of gestation affected the nursing behaviour.     

Impacts of a freedom farrowing pen design on sow behaviours and performance

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10 cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P>0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.001). Crushing mortality was higher among piglets in farrowing pens (P<0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P>0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P>0.05). Sows in freedom farrowing pens were found to be more protective of their piglets.     

Effect of rearing environment and age on gut development of piglets at weaning

Outdoor reared pigs are reported to be larger at weaning than indoor reared pigs and respond better to the weaning process. This may be due to enhanced gut development associated with increased size. Eighty sows were allocated to either indoor or outdoor farrowing on the basis of size, parity and past performance. Resulting litters were weaned at either 4 or 6 weeks of age. On days 26 and 40 of age, 40 (10/treatment) and 20 piglets (10/treatment still unweaned) were killed to measure intestinal morphology. Data were analysed as a 2 × 2 factorial using the GLM procedures of Minitab 12.2. Pigs reared outdoors were larger than those reared indoors at both weaning ages, pigs weaned at 6 weeks were heavier than those weaned at 4 weeks, 8.4 versus 7.4 kg at 4 weeks and 12.9 versus 10.5 kg at 6 weeks respectively (± 0.25, P ≤ 0.001). There were no differences in small intestine size relative to body weight due to rearing environment and no differences in gut morphology. When corrected for body weight, 6 week pigs had heavier small intestines than 4 week pigs, 0.39 (± 0.010) versus 0.34 (± 0.007) g/cm length, respectively (P ≤ 0.001). Six week unweaned pigs had similar villus heights to 4 week unweaned pigs but wider villi (P < 0.05) and deeper crypts, for example, at the 25% site crypt depths were 236 and 193 μm (± 7.7/5.5) respectively (P < 0.001). Hence increased piglet size due to outdoor rearing did not advance gut maturation whereas increased piglet size due to age did influence maturation of gut structure.     

Microbial activity in the gut of piglets: I. Effect of prebiotic and probiotic supplementation

Four groups of six 21 days-old piglets were used to evaluate the effect of a prebiotic or probiotic on the intestinal fermentative activity. In each group, piglets received one of the following diets: basal diet (C); basal diet supplemented with xylo-oligosaccharide (C-XOS); basal diet supplemented with Saccharomyces cerevisiae (C-SC); and basal diet supplemented with xylo-oligosaccharide and S. cerevisiae (C-XOS + SC).

The short chain fatty acids in the colon of piglets were decreased with the inclusion of S. cerevisiae in the diet (P < 0.01). The xylanolytic activity was higher (P < 0.05) in the small intestine of piglets fed C-XOS + SC diet, but no significant differences were found in the caecum and colon. In the caecum contents, the cellulolytic activity was increased (P < 0.05) by the C-XOS and C-SC diets, but remained similar when the diet was supplemented with the two additives combined.     

Urogenital diseases and their effect on reproductive performance in high-parity sows

In a Slowakian indoor pig production unit (2423 sows), from June to December 2002 all culled sows with excessive vulval discharge at culling, and with vulval discharge and periparturient disease in their previous history were subjected to retrospective lifetime production analysis. The sows were assigned to nine groups according to parity (parity 1-9). Average total litter size, average live-born litter size, average stillbirth rate, average mummy rate, and average litter weaning weight were evaluated retrospectively for all births. Non-culled sows represented the control animals. The percentage of animals with periparturient disease and vulval discharge in their history differed between parities. Parity 2, 3, and 4 sows had a significantly lower percentage of vulval discharge and periparturient disease in their history than sows of other parities. Compared to parity 1-6 sows, parity 7-9 sows had significantly lower (P < .001) conception rates, farrowing rates, and adjusted farrowing rates. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had a significantly larger (P < .001) lifetime average total born and live-born litter size. Compared to parity 1-3 and 7-9 sows, parity 4-6 sows had a significantly lower (P < .001) rate of stillbirths over all parities. No differences in mummy rates were detected between the sows of different parities. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had significantly higher (P < .001) weaning litter weights over all parities. Sows without a history of vulval discharge and periparturient disease had higher (P < .001) production levels in parity 7-9. IMPLICATIONS: The present results indicate that parity markedly influences the production level of sows that have a history of periparturient disease and vulval discharge.     

Impact of rank position on fertility of sows

The investigations were carried out with 484 sows from two farms (farm A: housing the sows in small groups of 8 animals each, farm B with a large group of 100 sows) and a total number of 982 inseminations. The number of agonistic interactions was registered for each sow during 48 h after mixing soon after weaning the piglets at farm A. The individual rank place in the social hierarchy was calculated on the basis of wins and defeats and the sows were divided in high and low ranking sows. At farm B the rank position was estimated on the basis of the daily feeding order at two electronic feeding stations (first half of the sows in the feeding order = high ranking, second half = low ranking). Additionally, the following parameters were recorded for each sow: parity, genotype, farrowing rate and litter size (total and alive born piglets). The analysis showed that sows with a high rank position had a significantly higher farrowing rate (88.8%) compared to group-mates with low rank places (82.8%, p = 0.051) (farm A). Sows with a high rank position reached a significantly higher litter size of total born piglets (12.66, 16.14 piglets per litter respectively) than the low-ranking group-mates (12.13, 14.83 piglets/litter respectively — farms A and B). When mixing sows, the time and the conditions (e.g. group size, space allowance per sow) have to be considered to prevent the negative influence of low rank order on fertility.     

Altrenogest Treatment Associated with a Farrowing Induction Protocol to Avoid Early Parturition in Sows

This study investigated the effect of altrenogest treatment on the farrowing development of sows, and birth weight (BW) and piglet survival until the third day of life. Three control groups were used: (i) sows that farrowed spontaneously before 114 day of gestation (CONT <114); (ii) sows that spontaneously farrowed at ≥114 day of gestation (CONT ≥114); (iii) sows that farrowed at ≥114 day with cloprostenol treatment (CONTCLOPR). Other sows were treated with altrenogest (Regumate^®) for 3 days (days 111, 112 and 113 of gestation): one group gave birth spontaneously (ALT) and the other group received altrenogest until day 113 and cloprostenol on day 114 (ALTCLOPR). There were no differences (p > 0.05) in farrowing duration, BW, coefficient of variation (CV) of BW, stillborn piglets, mummified foetuses, percentage of light piglets and survival until Day 3 between sows with and without cloprostenol treatment, in both control (CONT ≥114 vs CONTCLOPR) and altrenogest‐treated sows (ALT vs ALTCLOPR). Further comparisons were performed taking into account three groups: sows with early delivery (CONT <114 – farrowing before 114 days of gestation; n = 56), sows with longer gestation (CONT ≥114 – with and without cloprostenol treatment sows; n = 103) and ALT sows (with and without cloprostenol treatment; n = 105). Gestation length of CONT ≥114 and ALT sows was similar (p > 0.05), but higher than in CONT <114 sows. There were no differences (p > 0.05) between groups in farrowing duration, CV of BW, and percentages of stillborn piglets and mummified foetuses. Sows of CONT <114 group had a larger litter size and a lower BW than sows of the other two groups (p < 0.05). Sows of CONT <114 group had a higher percentage of lighter piglets and a lower piglet survival rate (p < 0.05) than ALT sows. In conclusion, altrenogest treatment proved to be an efficient method to avoid early parturition in 3–5 parity sows resulting in heavier piglets at birth.     

Stillbirth in the pig in relation to genetic merit for farrowing survival

The objectives of this study were to analyze the incidence of different categories of stillborn piglets in relation to genetic merit for farrowing survival of sows and litters and to analyze relationships of total number of piglets born per litter, average BW of the litter, and within-litter variation in BW with genetic merit for farrowing survival of sows and litters. Records of 336 purebred litters, produced by 307 first-to eighth-parity sows, were collected on a nucleus farm in Brouennes, France. Breeding values for farrowing survival were estimated for sows (EBVfs_maternal) and litters (EBVfs_direct) using a large data set from which information obtained in the current study was excluded. For each litter, BW, number of stillborn piglets (classified as nonfresh stillborn, prepartum stillborn, intrapartum stillborn, and postpartum stillborn), and number of live-born piglets were recorded. Birth weights of stillborn piglets were lower than BW of live-born piglets (P < 0.0001), except for prepartum stillbirths. The total number of stillborn piglets per litter and the number of stillborn piglets in each category decreased with increasing EBVfs_maternal (P < 0.01). An increase in EBVfs_direct was also associated with a decrease in the total number of stillborn piglets per litter (P < 0.01). This decrease was due to a decrease in the number of nonfresh, prepartum, and postpartum stillborn piglets but not to a decrease in the number of intrapartum stillborn piglets. Probabilities of stillbirth in relation to EBVfs_maternal were higher than probabilities of stillbirth in relation to EBVfs_direct. Total number of piglets born decreased with increasing EBVfs_direct (P = 0.0003), but was not related to EBVfs_maternal. Average BW of the litter (P < 0.0001) and within-litter variation in BW (P = 0.05) decreased with increasing EBVfs_maternal but were not related to EBVfs_direct. Selection for the maternal genetic component of farrowing survival seems a better strategy than selection for the direct genetic component. Selection for the maternal genetic component of farrowing survival reduces stillbirth in all categories and does not affect litter size.     

The change of nursing for oestrus induction (biostimulation): Effect of contact between rabbit doe and its young

This study focused on the effects on subsequent reproductive traits of females and development of the current litter as a result of different contact between the rabbit doe and its progeny when a temporary doe–litter separation was used for biostimulation. Immediately after parturition and adjusting to eight young per litter, multiparous Pannon White rabbit does (n = 400) were divided into five groups based on parity, doe condition, and weight of litter and the kits. Rabbits in the control group (C) nursed freely up to weaning at 35 days of age. In the group following local farm practice (F) using a metal-plate for separation, females nursed once a day (8 am to 9 am) for the first 14 days of lactation and freely afterwards. In three biostimulation groups, there was a change from free to once a day nursing before insemination (i.e. controlled nursing at 8, 9 and 10 days) provided with a wire-mesh separation (BW: permits visual, olfactory, and acoustic contact); using a metal-plate for separation (BM: no visual but possible olfactory, acoustic and vibration contact); or with taking the litter with the nest-tray 5 m away from the doe's cage (BN: there is no contact at all) and returning to free nursing just after AI (at 11 days in the morning) up to weaning. The type of separation exerted a significant influence on oestrus and subsequent kindling of does. Comparing C, F, BW, BM and BN groups, sexual receptivity (30.4, 45.4, 24.0, 25.6, 43.0%, respectively; P < 0.05), fertility (74.4, 84.2, 80.8, 80.3, 89.5%; P < 0.05) and kindling rates (71.1, 85.5, 76.9, 77.3, 88.2%, respectively; P < 0.05) improved in F and BN groups. The total number of kits born (10.0, 10.3, 10.5, 10.4, 9.55, respectively; P = 0.392) and kits born alive per litter (9.25, 9.65, 9.59, 9.83, 9.03, respectively; P = 0.607) were not affected, but newborn kit weight was numerically less in the BW group (69.7, 67.5, 65.5, 67.6, 67.3 g, respectively; P = 0.166). Growth rates of current progeny up to weaning were higher and identical in C and BM but less in F and BN groups (27.5, 25.6, 27.1, 27.3, 26.7 g/day, respectively; P = 0.001). However, the total weight of 70-day-old rabbits per doe did not differ significantly (17.51, 17.53, 17.54, 16.81, 15.81 kg, respectively; P = 0.271). On the whole, the production of the F, BM and BN groups was superior to that of the control and BW groups since subsequent kindling results improved without a significant reduction in slaughter rabbits per doe from current litters.     

Space allowance for dry, pregnant sows in pens: body condition, skin lesions, and performance

Different floor space allowances for dry, pregnant sows in pens were evaluated to determine the impacts of space on sow performance, productivity, and body lesions during 2 consecutive farrowings. Treatment groups of 5 sows/pen were assigned to 1.4, 2.3, or 3.3 m(2) of floor space/sow or of 5 sows in individual stalls (1.34 m(2)). The experiment consisted of 6 replications (blocks 1 to 6), and within each block measurements were recorded for 2 consecutive pregnancies and farrowings. A total of 152 sows were measured at 1 farrowing, and 65 of those sows were measured at the successive farrowing (n = 217 records). Performance traits were BCS, BW, backfat (BF), days until rebred, and proportion culled. Litter traits were number of piglets born alive, male:female ratio, and proportions of stillborn, mummified, or dead piglets after birth. Litter performance measures were mean piglet BW and gain and litter BW. Lesion scores were assessed for several body regions. There were treatment and parity effects and interactions for several traits. An interaction of space treatment and parity occurred for sow mean BW, d-110 BW, BF, litter size, and litter and piglet BW and gain, with most effects in parity 2, 3, and 4 sows. Space affected sow mean (P < 0.001) and d-110 BW (P < 0.05) and mean BF and adjusted BF (P < 0.001); sows in pens at 相似文献   

Effect of intramuscularly administered beta-carotene on reproductive performance in sows

The present study investigated the effects of intramuscularly administered beta-carotene on reproductive parameters in female pigs. A total of 216 multiparous sows were observed from weaning of their litters until the next farrowing. On the day of weaning, the animals were allocated to two groups. Sows of the treatment group were injected with 70 mg beta-carotene both at the day of weaning and after the last insemination, sows of the control group were left untreated. For all sows, intramuscular injection of beta-carotene resulted in a significant increase of the total number of piglets born per litter by 1.2 (p < 0.05). When sows were divided by parity, beta-carotene treatment in second parity sows increased the total number of piglets per litter (beta-carotene 13.7 +/- 1.2, control 11.2 +/- 3.7, p < 0.01) and the number of piglets born alive (beta-carotene 12.0 +/- 2.7, control 10.0 +/- 3.4, p < 0.05). No such effect was seen in sows of third or higher parity. No other reproductive parameters were affected by beta-carotene supplementation. Tolerability and safety of the administered preparation were good. No side effects related to the medication were observed. The effect of beta-carotene on reproduction is thus affected by parity of the sows. This effect seems to be exerted mainly during early pregnancy and is most likely beta-carotene-specific and independent from its role as a vitamin A precursor.     

Colostrum yield and litter performance in multiparous sows subjected to farrowing induction

The consumption of colostrum at a low level can compromise the survival and growth of piglets. Therefore, this study aimed to evaluate the effect of farrowing induction on colostrum yield, IgG concentration and the survival and performance of piglets until the weaning. Sows of parity 3 to 7 were assigned into two groups: Control (n = 48), sows with spontaneous farrowing; and induction (n = 48), sows induced to farrow on day 114 of gestation with a PGF₂ analogue. Colostrum and blood samples were collected from the sows, at farrowing and 24 hr later. Blood samples from the piglets were collected at 24 hr after birth. The performance of the piglets was evaluated in a subsample of 28 litters from each group. All piglets were weighed at 7, 14 and 20 days of age. The farrowing length, the number of piglets born alive, stillborn piglets, weight at birth, litter weight at birth and colostrum yield were not significantly affected (p > .05) by farrowing induction. There was no difference between the groups (p > .05) in the percentage of sows with obstetric interventions. Serum IgG concentration, in both sows and piglets, and colostrum IgG concentration were similar between the groups (p > .05). Furthermore, survival rate, piglet weight and litter weight at 7, 14 and 20 days of age were also similar between the groups (p > .05). Therefore, it can be concluded that the farrowing induction performed on day 114 of gestation does not affect the colostrum yield, the IgG concentration in colostrum and serum of piglets, and the litter performance until the weaning.     

Herd-level risk factors for infectious diseases in Swedish dairy calves aged 0-90 days

The effect of environmental factors and management routines on the risk of diarrhoea, respiratory disease and other infectious diseases was investigated in 3081 heifer calves 0–90 days old in 122 Swedish dairy herds. The farmers kept records on cases of diseases in their heifer calves and in addition, project veterinarians clinically examined all calves every 2–3 months. At each visit, the veterinarians also measured the ammonia concentration and relative air humidity in the housing facilities for the calves. The cleanliness of the animals and their environment was recorded as a measure of the hygienic status of the farm. The presence or absence of draught (i.e. wind velocity > 0.5 m/s) was recorded twice during the study period. The effect of these factors, as well as the placing of the calf pens, the nature of the pen walls, air volume per animal, management factors (such as the status of the caretaker and feeding routines) and presence or absence of a bovine viral diarrhoea virus (BVDV) infection in the herd, was evaluated by means of a two-level variance component logistic model. The placing of calf pens along an outer wall was significantly associated with the risk of diarrhoea (odds ratio (OR): 1.92, P < 0.01). The risk for respiratory disease was significantly associated with an ammonia concentration below 6 ppm (OR: 0.42, P < 0.05) while the odds ratio for moderately to severely increased respiratory sounds was significantly associated with a BVDV infection in the herd (OR: 2.39, P < 0.05) and draught (OR: 3.7, P < 0.02). Absence of draught was significantly associated with the risk for infectious diseases other than diarrhoea and respiratory disease (OR: 0.42, P < 0.01).