Field evaluation of a bioregulator containing live Bacillus cereus spores on health status and performance of sows and their litters

The efficacy of Paciflor, a bioregulator containing live Bacillus cereus CIP 5832 spores, was assessed in sows during late pregnancy and lactation, as well as in their piglets up to the growing phase. Two groups each of 30 pregnant gilts and sows received normal feed (T1 group), or feed with 85 g Paciflor per ton feed (T2 group), from 15 days prior to farrowing up to the end of the lactation period. Furthermore, 15 litters of the T1 group and 15 litters of the T2 group, were offered normal feed from the 5th to the 70th days of life (T1.1 and T2.1 groups, respectively), while the remaining 15 litters each of the T1 and T2 groups received the same feed but including Paciflor at a dose of 100 g/ton (from day 5 to day 49) and 50 g/ton (from day 50 to day 70). These pig litters were T1.2 and T2.2, respectively. No differences were seen between the T1 and T2 groups with respect to the clinical observations (loss of appetite, fever, mastitis, metritis and returns to oestrus, treatments applied, deaths, or removals to the slaughterhouse), gestation length, bodyweight of sows at farrowing or litter-size at birth. However, during lactation, the fat content of the dam's milk was increased (0.46% more fat), the body weight loss of sows was reduced and the number of weaned pigs per sow was increased (0.6 more pigs per litter) after administration of Paciflor (P < 0.05). Weaning to service interval was also reduced by 1 day (P < 0.05). Moreover, piglets receiving Paciflor with their feed (T1.2 and T2.2 groups) showed less incidence of scours and lower mortality compared to the untreated piglets (T1.1 and T2.1 groups), particularly those pigs originating from Paciflor-treated dams (T2.2 group) (P < 0.05). Despite the fact that no difference was seen between groups with regard to the amount of feed consumed, the feed conversion ratio of Paciflor-treated piglets (T2.2 and T1.2) was significantly improved compared to that of the untreated piglets (T2.1 and T1.1) (P < 0.05). With respect to weight gain, for the Paciflor-treated piglets, those born to Paciflor-treated mothers (T2.2) were 0.56 kg heavier than those born to untreated dams (T1.2) (P < 0.05). It is concluded that administration of Paciflor in dams during the end of pregnancy and during lactation, as well as to their offspring during suckling and the flat-deck period is beneficial for the survival and growth of the piglets.     

Evaluation of the influence of meloxicam and flunixin meglumine on the apoptosis of peripheral blood CD4+ and CD8+ T cells in calves

The aim of the study was to determine whether treatment with recommended doses of meloxicam or flunixin had an effect on the apoptosis of peripheral blood T lymphocytes in calves. The study was carried out on 4-5 months old calves (n = 24, 8 per group). Experimental animals were injected subcutaneously with a single dose of 0.5 mg x kg(-1) of meloxicam or intravenously with 3 doses of 2.2 mg x kg(-1) day(-1) of flunixin. The non-treatment animals served as control. Blood samples were taken at day 0 and at days 1, 2, 3, 5, 7 and 14 after the first NSAIDs injection. Apoptosis was determined by flow cytometry using Annexin V-PE/7-AAD staining. The kinetic analysis of apoptosis in the total lymphocyte population, as well as in the CD4+ and CD8+ subsets did not reveal significant differences in the frequency of early apoptotic cells between control and experimental groups throughout the period studied. Although, 24 h after administration of the first dose of NSAIDs, late-stage apoptosis/necrosis was significantly increased in the total lymphocyte population (the meloxicam group), as well as in the CD4+ (the meloxicam group and the flunixin group) and CD8+ (the flunixin group) subsets of T cells. However, this disturbance was transient, relatively poorly expressed and, thus, unlikely to be of clinical significance. Our results indicate that the use of meloxicam or flunixin in accordance with the recommended dosage regimen in cattle do not have a clinically significant influence on apoptosis of peripheral blood T cells.     

Clinical efficacy of meloxicam (Metacam) and flunixin (Finadyne) as adjuncts to antibacterial treatment of respiratory disease in fattening cattle

The clinical efficacy of two non-steroidal anti-inflammatory drugs (NSAIDs), meloxicam (Metacam 20 mg/ml) and flunixin meglumine (Finadyne), as adjuncts to antibacterial therapy in the treatment of acute febrile respiratory disease in cattle was compared. The randomised blind, positive controlled study was conducted under feedlot conditions in Mexico. Overall, 201 female cattle (weighing 220-250 kg) diagnosed with bronchopneumonia at the feedlot were recruited into the study. On Day 0 all animals were treated with 20 mg oxytetracycline/kg body-weight (Bivatop 200) by subcutaneous injection, in conjunction with either meloxicam (0.5 mg/kg subcutaneously, Metacam 20 mg/ml, n = 100), or flunixin meglumine (2.2 mg/kg intravenously, Finadyne, n = 101). According to label instructions, meloxicam was administered as a single dose, whereas flunixin meglumine could be administered daily for up to 3 consecutive days depending on the rectal temperature (with re-administration, if rectal temperature > or = 40.0 degrees C). Rectal temperature, respiratory rate, appetite, dyspnoea, coughing, nasal discharge and general condition were recorded on Days 0 (prior to treatment), 1, 2, 3 and 7 using a weighted numerical score. Scores were summed to generate a 'Clinical Sum Score' (CSS, range 7 to 24 points). Individual animal body weights were measured on Days 0 and 7. Nasal swabs were collected from 10 animals per treatment group on Day 0 for microbiological culture. Clinical parameters and the mean CSS showed no significant differences between treatment groups with mean CSS on Days 0 and 7 of 16.18 and 10.55 in the meloxicam group and 16.41 and 10.88 in the flunixin meglumine group. However, a significantly lower mean rectal temperature was measured in the meloxicam group on Day 2 (p < or = 0.01). No significant differences in mean body weights were found between groups. Repeated administration of flunixin meglumine was performed in 45% of the animals. No suspected adverse drug events related to treatments were reported. It is concluded that a single subcutaneous dose of meloxicam was as clinically effective as up to 3 consecutive daily intravenous doses of flunixin meglumine when used as an adjunctive therapy to antibacterial therapy in the treatment of acute febrile respiratory disease in feedlot cattle.     

Efficacy and pharmacokinetics of enrofloxacin and flunixin meglumine for treatment of cows with experimentally induced Escherichia coli mastitis

The efficacy of flunixin alone and together with enrofloxacin in treatment of experimental Escherichia coli mastitis was compared using six cows. The cross-over study design was used. Pharmacokinetics of flunixin and enrofloxacin were also studied in these diseased cows. The response of each cow was similar after the first and second challenge and the individual reaction seemed to explain the severity of clinical signs. The most important predictive factor for outcome of E. coli mastitis was a heavy drop in milk yield. Treatment with enrofloxacin and flunixin enhanced elimination of bacteria, but the difference from those receiving flunixin alone was not significant. Two cows, which had received no antimicrobial treatment (Group 1), were killed on day 4 postchallenge. One cow was killed after the first and the other after the second challenge. Cows receiving combination therapy produced 0.9 L more milk per day during the study period than cows which had only received flunixin (P < 0.05). Based on our findings, antimicrobial treatment might be beneficial in the treatment of high-yielding cows in early lactation. The absorption of enrofloxacin was delayed after subcutaneous administration, the mean apparent elimination half-life being about 23 h, whereas after i.v. administration elimination t(1/2) was only 1.5 h. The majority of the antimicrobial activity in milk originated from the active metabolite, ciprofloxacin, which could be measured throughout the 120-h follow-up period after the last subcutaneous administration. No differences were present in the pharmacokinetic parameters of flunixin between treatment groups: mean elimination half-life was 5.7-6.2 h, volume of distribution 0.43-0.49 L/kg and clearance 0.13-0.14 L h/kg. No flunixin or merely traces were detected in milk: one of the three cows had a concentration of 0.019 mg/L 8 h after administration.     

Effect of flunixin meglumine on surgical wound strength and healing in the rat

Forty male adolescent Sprague-Dawley rats were anesthetized and standardized ventral midline laparotomies and uniform-length gastrotomies and typhlotomies were performed. The visceral and abdominal surgically inflicted wounds were closed with 5-0 polypropylene and 4-0 nylon suture, respectively. The rats were allotted into 4 groups (10 rats/group); 2 groups were not given flunixin meglumine (controls) and 2 groups were given flunixin meglumine (1.1 mg/kg of body weight, IM, every 12 hours). On day 5 and again on day 14 after surgery, 1 control and 1 flunixin meglumine-treated group were euthanatized. Tensile strength of the skin and linea alba incisions was determined, using a computerized tensiometer. Gastric and cecal incision bursting strengths were determined, using a pressure manometer. Flunixin meglumine significantly (P less than 0.05) decreased the tensile strength of wounds in the skin and linea alba, but did not affect visceral bursting strength at day 5 after surgery. At day 14 after surgery, a significant difference in wound strength was not found between the flunixin meglumine and control groups in any of the tissues evaluated. Flunixin meglumine had an adverse influence on the inflammatory stage of wound repair, but not on the proliferative stage, when fibroplasia is a major factor in wound strength. Major histologic differences were not found in the incision wounds of flunixin meglumine-treated and nontreated control rats.     

饲喂频率对妊娠母猪背膘厚和繁殖性能的影响

[目的] 研究饲喂频率对妊娠母猪背膘厚和繁殖性能的影响。[方法] 挑选加系杜洛克经产母猪480头,配种时按照胎次（2~7胎）、背膘厚（11~22 mm）相近的原则随机将母猪分为T1组（每天饲喂1次）和T2组（每天饲喂2次）,两组每天等量饲喂。T1组母猪220头,饲喂时间为8：00;T2组母猪260头,饲喂时间为8：00和15：00,每次饲喂量为总量的一半,定位栏饲养。[结果] ①饲喂频率不影响妊娠56 d、开配-妊娠56 d的背膘厚（妊娠56 d背膘厚-开配背膘厚）（P>0.05）;T2组妊娠110 d（P=0.06）、妊娠56-110 d（P=0.09）背膘厚（妊娠110 d背膘厚-妊娠56 d背膘厚）有高于T1组的趋势。②饲喂频率对窝产总仔数、活仔数、死胎数、木乃伊胎数、初生窝重以及初生个体重均无显著（P>0.05）影响。③在三胎母猪中,T2组妊娠110 d（P=0.01）、妊娠56-110 d（P=0.04）背膘厚均显著高于T1组;五胎及以上母猪,T2组妊娠56-110 d（P=0.08）背膘厚有高于T1组的趋势。④饲喂频率不影响二胎母猪窝产总仔数、死胎数、木乃伊胎数、初生窝重以及初生个体重（P>0.05）,但二胎母猪中T2组活仔数有高于T1组的趋势（P=0.07）。[结论] 饲喂频率由每天两餐减少到每天一餐不会对母猪的繁殖性能产生不利影响。     

The effects of feeding grains naturally contaminated with Fusarium mycotoxins with and without a polymeric glucomannan adsorbent on lactation, serum chemistry, and reproductive performance after weaning of first-parity lactating sows

An experiment was conduced to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins such as deoxynivalenol on lactation, metabolism, and reproductive performance after weaning of first parturition sows and to evaluate the efficacy of a polymeric glucomannan mycotoxin adsorbent (GMA). Thirty-six Yorkshire sows were fed 3 diets (n = 12 sows/diet) from 91 +/- 3 d of gestation up to weaning on d 21 after farrowing. Diets included 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. The variables measured include ADFI, average daily BW change, serum biochemistry, milk composition, BW of litters at weaning, and weaning to estrus interval. The feeding of contaminated grains and contaminated grains + GMA reduced ADFI (P < 0.001). The feeding of contaminated grains resulted in weight loss (P = 0.007), as did the feeding of contaminated grains + GMA (P = 0.028), compared with controls, which underwent a small weight gain. There were no differences between the sows fed contaminated grains and those fed contaminated grains + GMA in average daily BW change. On the day of farrowing, total serum protein concentrations were lower for sows fed contaminated grains compared with controls (P = 0.038) and for sows fed contaminated grains compared with sows fed contaminated grains + GMA (P = 0.019). Seven days after farrowing, serum urea concentrations were lower for sows fed contaminated grains (P = 0.049) and contaminated grains + GMA (P = 0.048) compared with controls. Milk composition was not affected by treatments. There were no effects of diet on BW of litters at weaning or mortality of piglets during lactation. There was a trend for increased weaning to estrus interval in sows fed contaminated grains (P = 0.09) or contaminated grains + GMA (P = 0.08) compared with controls. It was concluded that the feeding of diets naturally contaminated with Fusarium mycotoxins to lactating sows reduces feed intake and increases BW losses. The weaning to estrus interval also tends to be longer in sows fed contaminated diets. Supplementing contaminated feed with GMA could counteract the reduction in serum protein and serum urea observed in sows fed contaminated feed.     

Reproductive performance of sows supplemented with dietary L-carnitine over three reproductive cycles.

The effect of L-carnitine supplementation during pregnancy and lactation on the reproductive performance of sows was studied in two separate trials over three reproductive cycles. Both trials were identical in design and conduct but were performed with different animals. The trials comprised of a total of 127 sows (trial 1) and 100 sows (trial 2) which were divided into control and treatment groups. All animals were fed individually and received basic feed mixtures with low native carnitine concentrations. The rations of the sows in the treated group were supplemented with 125 mg L-carnitine per head and day during pregnancy and 250 mg L-carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L-carnitine supplement. In the first trial, 212 litters were produced and evaluated for number and body weight of the animals, in the second trial, 173 litters were produced. L-carnitine supplementation significantly increased body weight gains of the sows between day 1 and day 85 of weaning. The number of born piglets, stillborn piglets and piglets fit for rearing was not influenced by dietary L-carnitine supplementation. However, L-carnitine supplementation significantly increased the weights of piglets and litters at birth, weight gains of litters during suckling and weights of litters at weaning. These effects of L-carnitine were seen in both trials; they were independent of the age of the sows and remained over three reproductive cycles in which the sows where continuously treated with L-carnitine. Overall, the study shows that dietary supplementation with L-carnitine during pregnancy and lactation improves the reproductive performance of sows over several reproductive cycles, independent of the age of the sows.     

Effect of feather meal as a source of valine for lactating sows

An experiment was conducted to evaluate feather meal as a source of Val in lactating sow diets. Sows (five farrowing groups; mean parity = 2.34) were allotted to one of two dietary treatments on the basis of ancestry, parity, and weight and date of d 110 of gestation. The treatment diets included 1) corn-soybean meal lactation diet (n = 40) or 2) corn-soybean meal lactation diet with 2.5% feather meal (n = 39). The diets were formulated on an equal Lys basis. All litters were adjusted to 10 pigs within 24 h after farrowing, and all sows weaned at least nine pigs. Sows were bled at 110 d of gestation and at weaning, and serum urea N was determined. Backfat thickness was determined ultrasonically at 110 d of gestation and at weaning. Serum urea N and backfat thickness at d 110 of gestation were used as covariates for serum urea N and backfat thickness at weaning, respectively. The litter response criteria (weaning weight, litter weight gain, and percentage survival) were not affected (P > .10) by feather meal. The sow response criteria (weaning weight, weight loss per day, weaning backfat thickness, change in backfat thickness, ADFI, and days to estrus) were not affected (P > .10) by feather meal. Sows fed feather meal had increased (P < .01) serum urea N and tended (P = .15) to have decreased sow weaning weight. Following the initial analysis of the data, the data set was split into two groups: 1) sows with litters gaining less than 2.17 kg/d (n = 19 and 20 for control and feather meal diets, respectively) and 2) sows with litters gaining more than 2.17 kg/d (n = 21 and 19 for control and feather meal diets, respectively). These two groups were analyzed separately. In sows with litters gaining less than 2.17 kg/d, the litter and sow criteria were not affected (P > .10) by treatment. In sows with litters gaining more than 2.17 kg/d, sow weaning weight was decreased (P < .04) and sow weight loss (P < .02) and serum urea N (P < .01) were increased in sows fed feather meal. Feather meal (as a source of Val) did not improve litter weight gain, but it increased serum urea N.     

A comparative study of the effects of meloxicam and flunixin meglumine (NSAIDs) as adjunctive therapy on interferon and tumor necrosis factor production in calves suffering from enzootic bronchopneumonia

The study was performed on 18 Black-and-White Lowland Breed calves with clinical signs of enzootic bronchopneumonia divided into three groups and respectively treated with oxytetracycline and meloxicam--Group I (9 animals); oxytetracycline and flunixin meglumine--Group II (3 animals); and oxytetracycline only--Group III (6 animals--control). The following observations were recorded before treatment (1st day) and two days later (3rd day): body temperature, the serum level of interferon (IFN) and tumor necrosis factor (TNF) as well as cytokine production by bronchoalveolar lavage (BAL) cells. The treatment of calves with a combination of oxytetracycline and meloxicam (Group I) and especially with oxytetracycline and flunixin meglumine (Group II) caused a significantly faster, in comparison to the control group, normalization of body temperature. Both drugs, meloxicam and especially flunixin meglumine, inhibited excessive TNF production in the organism (measured as the serum level of cytokine). Moreover, BAL cells isolated from calves treated with both NSAIDs were still able, ex vivo, to release TNF, in contrast to the control group (treated only with tetracycline) which lost the ability to produce TNF. The treatment of the calves with meloxicam and flunixin meglumine did not significantly influence the levels of IFN in sera but normalized ex vivo IFN production in BAL cells. These results suggest that the combination of meloxicam with an antibiotic or flunixin meglumine with an antibiotic which does not exert an immunosuppressive influence on the organism of calves suffering from enzootic bronchopneumonia is equally effective in the treatment of calves and superior to the antibiotic alone.     

Intermittent suckling: effects on piglet and sow performance before and after weaning

An experiment was conducted to study effects of intermittent suckling on creep feed intake and weight gain of litters. Loss of weight and backfat during lactation, as well as reproductive performance, were also measured. Batches of multiparous sows (Parity 1 to 12, 4.1 on average) were either suckled intermittently (IS, eight batches; n = 50) or continuously (control, eight batches; n = 62). Litters were weaned at 27 +/- 2 d of age, on average. Litter size (11.1 +/- 0.2 piglets, on average) was standardized within a batch within 3 d of birth. All litters had free access to creep feed and water from 1 wk of age onward. In the IS group, litters were separated from the sow for a period of 12 h/d (0930 to 2130), starting 11 d before weaning. Rectal ultrasonography was applied at d 3 after weaning to check the ovaries for follicle development or presence of corpora lutea. Creep feed intake by the litters during lactation was higher in IS litters than in control litters (686 +/- 57 vs. 314 +/- 42 g/piglet, P < 0.01). The distribution of creep feed intake shifted from a skewed one, with a majority of litters consuming less than 250 g/piglet in control litters, to a normal distribution, with an average creep feed intake of 500 to 750 g/piglet in IS litters. During the 7 d after weaning, creep feed intake in IS litters was also higher (281 +/- 15 vs. 204 +/- 9 g-piglet(-1) x d(-1), P < 0.01). The ADG of piglets during lactation was negatively affected by IS, resulting in lower weight at weaning (7,229 +/- 140 vs. 7,893 +/- 145 g/piglet, P < 0.05). During the 7 d after weaning, however, ADG was higher in IS litters (255 +/- 10 vs. 177 +/- 8 g-piglet-1 x d(-1), P < 0.01), and 7 d after weaning, the weights of the litters were similar (9,011 +/- 167 vs. 9,132 +/- 164 g/ piglet, P = 0.81). The IS litters that consumed little or no feed during lactation had an ADG after lactation that was higher than in control litters, with comparable creep feed intake during lactation: 204 vs. 136 g/d. Body weight loss by the sows during lactation was lower in IS sows (-10 +/- 2 vs. -16 +/- 1 kg, P < 0.05). A higher percentage of IS sows ovulated during lactation (22 vs. 3%, P < 0.01), and weaning-to-ovulation interval (excluding sows with lactational ovulation) was shorter in IS sows (4.7 +/- 0.2 vs. 5.3 +/- 0.2 d, P < 0.05). We conclude that IS increased creep feed intake during lactation, and that IS increased ADG after weaning, despite lower weaning weights. Ovulation during lactation was induced in 22% of the IS sows.     

Sows infected in pregnancy with porcine respiratory coronavirus show no evidence of protecting their sucking piglets against transmissible gastroenteritis

Eighteen litters of sucking piglets were challenged with one of two strains of transmissible gastroenteritis virus (TGEV). During pregnancy, their seronegative dams had been either inoculated intranasally with porcine respiratory coronavirus (PRCV), inoculated orally with TGEV or left untreated. On the basis of weight gain, clinical signs and survival, no differences in response to challenge was detected when piglets suckled by PRCV inoculated sows were compared with those suckled by uninoculated sows. Such a difference was evident when the litters of sows successfully pre-immunized with TGEV were compared with those of unicoculated or PRCV-inoculated sows. The possibility of transplacental transmission of PRCV was investigated in two litters born to sows that had been inoculated with this virus in late pregnancy. All sixteen live-born piglets were seronegative for the virus at birth and PRCV was not isolated from tissues taken from two stillborn piglets.     

Clinical evaluation of transmissible gastroenteritis virus vaccines and vaccination procedures for inducing lactogenic immunity in sows

Two federally licensed attenuated live transmissible gastroenteritis (TGE) virus vaccines (an IM vaccine and an oral-IM vaccine) and 1 nonlicensed nonattenuated live TGE virus vaccine were evaluated and compared in sows free of TGE virus-neutralizing antibodies. Litters from the sows were challenge exposed at 3 and 5 days of age, and results were combined according to the vaccine administered to the sows. The survivability of pigs suckling sows vaccinated with the nonattenuated vaccine was significantly (P less than 0.01) greater than that of pigs suckling sows vaccinated with the IM attenuated vaccine, significantly (P less than 0.05) greater than that of pigs suckling sows vaccinated with the oral-IM attenuated vaccine, and significantly (P less than 0.05) greater than that of pigs suckling sows that had not been vaccinated. The differences, however, between survivability of litters from sows vaccinated with the IM attenuated vaccine or the oral-IM attenuated vaccine and that of litters from the sows not vaccinated were not significant (P greater than 0.10). The nonattenuated TGE vaccine, although giving a higher level of protection than the attenuated vaccine, was eventually overwhelmed. Dexamethasone did not increase the incidence of diarrhea, and levamisole did not potentiate the lactogenic immunity in sows after given their first dose of the nonattenuated vaccine. Survivability in litters suckling sows that developed diarrhea after given their first dose of the nonattenuated vaccine was not greater than that in litters suckling sows that did not develop diarrhea. The best results were obtained when 3-day-old suckling pigs were challenge exposed with virulent TGE virus.     

The addition of ground wheat straw as a fiber source in the gestation diet of sows and the effect on sow and litter performance for three successive parities

A regional experiment was conducted at 8 experiment stations, with a total of 320 sows initially, to evaluate the efficacy of adding 13.35% ground wheat straw to a corn-soybean meal gestation diet for 3 successive gestation-lactation (reproductive) cycles compared with sows fed a control diet without straw. A total of 708 litters were farrowed over 3 reproductive cycles. The basal gestation diet intake averaged 1.95 kg daily for both treatments, plus 0.30 kg of straw daily for sows fed the diet containing ground wheat straw (total intake of 2.25 kg/d). During lactation, all sows on both gestation treatments were fed ad libitum the standard lactation diet used at each station. Response criteria were sow farrowing and rebreeding percentages, culling factors and culling rate, weaning-to-estrus interval, sow BW and backfat measurements at several time points, and litter size and total litter weight at birth and weaning. Averaged over 3 reproductive cycles, sows fed the diet containing wheat straw farrowed and weaned 0.51 more pigs per litter (P 相似文献   

The influence of suckling interval on milk production of sows

The objective of this study was to determine whether sow milk yield per gland could be increased by reducing the interval between suckles (suckling interval). Eighteen sows were allocated at their first farrowing to three treatments comprising litter sizes of 6 or 12 piglets or a cross-suckling treatment that was imposed to increase suckling frequency. The cross-suckled treatment comprised two groups of six piglets each. Each suckling group was allowed to suckle the sow during 30-min intervals each day between d 6 and d 28 of lactation. The suckling interval was shorter (P < .05) for cross-suckled sows than for sows suckling single litters of 6 or 12 piglets during early lactation (d 10 to 14) and late lactation (d 24 to 28). Average piglet growth rate between birth and 28 d of age was greatest (P < .05) for piglets in the single litters of six and lowest for piglets in the cross-suckled treatments. Single litters of 12 piglets had the highest (P < .05) litter growth rates, followed by the cross-suckled litters and then the single litters of six piglets. The concentration of lactose and fat in milk from sows remained relatively stable, although milk from the cross-suckled sows contained more protein in early lactation (P < .05). Milk yield of sows was not significantly increased (P > .05) by the cross-suckle treatment, although during early lactation, milk yield tended to be greater from sows in the cross-suckle treatment than from sows suckling single litters of six (8,920 g/d vs 7,819 g/d, P < .1). The concentration of DNA and total RNA and the RNA:DNA ratio in mammary glands was unaffected by treatment (P > .05). Sows with single litters of 12 piglets had the greatest total DNA in their udders (P < .05). However, individual gland weights were heavier (P < .05) in cross-suckled sows than in sows with single litters of 6 or 12 piglets. Increased suckling frequency seemed to play a role in increased mammary gland weight and milk production during lactation.     

大白猪哺乳期背膘损失对繁殖性能的影响

为了研究大白母猪哺乳期背膘损失对其繁殖性能的影响,试验选取大白母猪1 178头,统计6个胎次的总产仔数、产活仔数、健仔数、断奶窝重、断奶发情间隔、哺乳期背膘损失等性状,根据哺乳期的背膘损失情况将母猪分为6组：<0、0~1、1~2、3~4、5~6、>6 mm,以断奶窝重为协变量,利用最小二乘检验开展组间总产仔数、产活仔数、健仔数、断奶发情间隔等性状的差异显著性分析。结果显示,大白母猪6个胎次平均总产仔数、产活仔数、健仔数、断奶窝重、断奶发情间隔和哺乳期背膘损失分别为13.67头、11.51头、10.32头、65.90 kg、4.83 d和2.89 mm,大白母猪1~6胎产仔数在各组间存在显著差异（P<0.05）。综合全部6个胎次的结果可知,第4、5、6组间差异不显著（P>0.05）,但均显著高于第1、2、3组（P<0.05）;第4组总产仔数最高,达13.54头,比第1、2、3组分别高出1.90、2.29和1.63头（P<0.05）。虽然各胎次中各组间产活仔数和健仔数性状有时也出现显著差异,但综合分析6个胎次组间并未出现显著差异（P>0.05）。从断奶发情间隔性状来看,各组间均未出现显著差异（P>0.05）。结果表明,在大白猪生产中,将哺乳期母猪的背膘损失控制在3~4 mm可以获得更高的总产仔数。     

长大、PIC、混血母猪繁殖性状研究

对红河州某猪场长大母猪311窝、PIC母猪138窝及当地农村饲养混血母猪753窝的繁殖性状进行测定,探讨品种、胎次和分娩季节对母猪繁殖性状的影响。结果表明,品种因素对母猪产仔性能有显著影响,长大母猪和混血母猪的总产仔数、产活仔数、初生窝重、28 d校正断奶窝重均极显著高于PIC母猪（P〈0.01）,长大母猪和混血母猪间除初生窝重、初生个体重和28 d校正断奶成活率有极显著差异（P〈0.01）外,其它指标差异均不显著（P〉0.05）。胎次因素对母猪产仔性能产生显著影响,经产母猪显著高于初产母猪（P〈0.05）,长大、PIC母猪2~8胎、混血母猪3胎以上产仔性能较好,其中长大、PIC母猪以第4胎最佳。分娩季节对PIC、混血母猪的繁殖性状无显著影响（P〉0.05）,而对长大母猪的产活仔数有显著影响（P〈0.05）。     

The effect of salinomycin on certain blood parameters and milk quality of lactating sows

Twenty-five gilts and sows, after pregnancy confirmation using the ultrasonic method, were randomly divided and allocated to the following five experimental groups: SAL0 = negative controls, SAL20 = 20 mg salinomycin per kg of feed, SAL40 = 40 mg salinomycin per kg of feed, SAL60 = 60 mg salinomycin per kg of feed and SAL80 = 80 mg salinomycin per kg of feed. All animals remained under treatment for two consecutive breeding cycles. The sows were fed a home-mixed balanced feed during gestations and lactations. At the third, tenth and eighteenth day of each lactation, blood and milk samples were collected. Blood samples were analysed for cholesterol and total lipids and milk samples were analysed for the determination of the fat, lactose, protein, ash and totals solids concentrations. In all treated groups, cholesterol concentrations were significantly higher (P < 0.05) compared with the controls. Total lipid concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups in comparison with SAL0 and SAL20 groups, during both cycles. Milk fat concentrations were higher (P < 0.05) in treated groups than in the control group; the highest concentrations were observed at SAL40 and SAL60 groups. In all treated groups, concentrations of milk lactose were significantly higher (P < 0.05) than those observed in the negative control group. Milk protein concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups compared with the SAL0 group, but there was no significant difference in SAL20 and SAL80 groups in comparison with the SAL0 group. No significant differences were observed concerning milk ash concentrations between all groups. In all treated groups, concentrations of total solids were significantly higher (P < 0.05) in comparison with the control group; the highest concentrations were observed in the SAL40 and SAL60 groups. It is concluded that the use of salinomycin in sow diet, increases concentrations of blood triglycerides and cholesterol and improves the quality of milk, thus reflecting on higher weight gain and survival rate of suckling piglets.     

Lactational performance of first-parity transgenic gilts expressing bovine alpha-lactalbumin in their milk

The goal of this study was to determine whether the presence of the bovine alpha-lactalbumin transgene in first-lactation gilts enhances lactational performance and litter growth. Transgenic and sibling nontransgenic gilts were bred to nontransgenic boars. Litters were standardized to 10 piglets within 24 h of farrowing. Milk production was measured by the weigh-suckle-weigh method on d 3, 6, 9, and 12 of lactation. Bovine alpha-lactalbumin was present in the colostrum and milk of transgenic gilts throughout lactation. The expression of the transgene was associated with alterations in composition of mammary secretions, especially in early lactation. Lactose concentrations were greater (P < 0.05) in mammary secretions of transgenic gilts during the first 12 h postpartum compared with controls. In contrast, total solids concentration in mammary secretions from transgenic gilts were lower (P < 0.05) relative to controls during the first 6 h postpartum. Transgenic gilts produced more milk than controls on d 3, 6, and 9 of lactation (P < 0.01). By d 12, differences in milk production between transgenic and control sows were no longer different. Lactose intake by transgenic-reared litters was greater than lactose intake by control-reared litters on d 6 of lactation (P < 0.05). Total solids intake was significantly greater (P < 0.05) by transgenic-reared litters on d 3 and 6 compared to control-reared litters. The day x genotype interaction on litter weight gain after birth was highly significant (P = 0.011), with transgenic-reared litters gaining weight at a greater rate than control-reared piglets. Expression of the transgene was associated with increased milk production in lactating gilts and increased growth of transgenic-reared piglets. Increased lactose synthesis in response to the presence of the transgene may result in increased milk production in early lactation, leading to increased milk component intake by transgenic litters, and ultimately to increased growth of litters reared by first-parity transgenic gilts.     

The effect of a homologous bacterin given to sows prefarrowing on the development of Glässer's disease in postweaning pigs after i.v. challenge with Haemophilus parasuis serotype 5

The trial was carried out to evaluate the impact of maternal antibodies on the development of Gl?sser's disease after i.v. exposure of weaned pigs with a homologous serovar of Haemophilus parasuis (HPS). Two groups of weaned pigs were formed. Group one VI (n = 10): born to vaccinated sows, weaners i.v. challenged one week postweaning and euthanatized 14 days postweaning. Group two NVI (n = 10 wearners): born to non vaccinated sows, i.v. challenged one week postweaning euthanatized 14 days postweaning. One week postweaning all weaners were i.v. inoculated with HPS serovar 5. The following parameters were evaluated: clinical signs (depression, centralnervous signs, fever, lameness), macroscopic lung, pleura, peritoneum, liver and joint changes, and mortality. All trial sows were HPS seronegative prior to vaccination. The HPS vaccinated sows were proven seropositive on day 3 p.p. (values > 0.24), the non vaccinated ones were tested seronegative (values < 0.23). The progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused clinical and pathological signs. The majority of clinical signs as fever, depression, recumbency, lack of response to verbal stimuli and lameness showed significant (P < 0.05) milder clinical symptoms in VI than in NVI animals. Respiratory signs (P = .169) and involvement of the central nervous system as ataxia, muscular tremor, incoordination of hind legs and convulsions (P = 1) showed no significant differences between the groups. Except lesions of pericard (VI vs. NVI, P = .14) and pleura (VI vs. NVI, P = .14) there were significant (P < 0.05) macroscopic differences at necropsy in lung, liver, joints and cerebrospinal fluid between the offspring of vaccinated sows and the ones of non vaccinated dams. No HPS were isolated from the nasal mucosa of the pigs prior to inoculation. HPS serovar 5 was recovered at necropsy from the nasal mucosa of all pigs in both groups. One pig from group VI presented in all examined organs the presence of HPS serovar 5. The remaining animals in group VI revealed in lung, pericard, pleura, liver, joints and cerebrospinal fluid no presence of HPS. The rate of isolation between VI and NVI groups revealed a significant (P < 0.05) difference. All the survived piglets of group NVI showed positive ELISA titres against HPS serovar 5 (values > .24). The piglets that died or were euthanatized before the end of the study have not been subjected to ELISA serological testing. One piglet died in group VI before the end of the study. Non of the remaining animals in group VI showed seroconversion to HPS serovar 5. Implications: Vaccination of sows did not influence the colonisation of nasal mucosa, but progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused diseases.