饲喂鲜草紫花苜蓿对母猪生产性能的影响

通过对即将配种的母猪(A处理)、距分娩期1个月的怀孕母猪(B处理)、距分娩期2个月的怀孕母猪(C处理)饲喂紫花苜蓿鲜草,研究紫花苜蓿鲜草对母猪生产性能的影响。试验结果表明,母猪采食紫花苜蓿后,其仔猪的初生重、断奶窝重及断奶成活率极显著提高(P<0.01)。在饲试阶段,饲喂紫花苜蓿可以降低全价料的用量,其中A处理试验组母猪采食紫花苜蓿可减少38kg/头,其次是C处理。根据当前仔猪市场价格,A、B、C处理的试验组毛收入均高于对照组,分别高出672元/窝、48元/窝、336元/窝。综合饲养成本,母猪从配种前至断奶全程饲喂鲜草紫花苜蓿比只饲喂一段时间的经济效果更显著。     

不同饲喂模式对妊娠母猪生产性能的影响

近年来,国家对生猪养殖的大力扶持使得规模化的大型养猪场不断出现,养殖效益也在不断增加。然而,在猪场的经营管理中,母猪的繁殖性能尤为重要,也关系着猪场的经济效益。本试验旨在研究两种饲喂模式对母猪生产性能的影响。试验分为对照组和试验组2个处理,每个处理40个重复,每个重复1头猪:对照组饲喂模式,怀孕85~94日龄饲喂3.5 kg妊娠母猪饲料;怀孕95~115日龄饲喂3.8 kg哺乳母猪饲料;分娩当天饲喂1.5 kg哺乳母猪饲料;试验组,配种~怀孕94日龄饲喂2.2 kg妊娠母猪前中期饲料;怀孕95~108日龄饲喂3.8 kg妊娠母猪后期饲料;怀孕109~112日龄饲喂3.2 kg围产母猪饲料;怀孕113日龄饲喂2.5 kg围产母猪饲料;怀孕114日龄饲喂2.0 kg围产母猪饲料;怀孕115日龄饲喂1.5 kg围产母猪饲料;分娩当天饲喂1.0 kg围产母猪饲料。结果表明:(1)对照组与试验组(不同饲喂模式)饲喂的母猪,仔猪初生窝重、初生活仔数、20 d窝重、20 d窝头数均为差异显著。试验组仔猪初生窝重显著提高27.32%,初生活仔数显著提高20.45%,20 d窝重显著提高72.42%,20 d窝头数显著提高49.92%。(2)试验组仔猪28 d断奶窝重显著提高57.85%,仔猪28d断奶头数显著提高47.23%,断奶后10 d窝重显著提高51.81%,断奶后10 d头数显著提高45.57%。(3)试验组断奶后7 d发情母猪日均采食量显著提高7.53%,断奶后母猪发情天数显著降低23.62%。试验组饲喂模式,在动物生产性能方面具有明显优势。同时,在母猪配种初期做到了合理限饲,规范减料、加料,同时有效解决了母猪便秘的问题。     

添饲杂交狼尾草对母猪繁殖性能的影响

为研究饲喂杂交狼尾草对母猪繁殖性能的影响,选用长大二元杂种妊娠母猪123头,根据各组母猪胎次（2～6胎）、上一胎生产成绩、配种日期、健康状况、体况等一致的原则分成4组,分别为29、33、30、31头,杂交狼尾草的添加量分别为0、0.25、0.5和0.75kg/d;并每组随机选6头在妊娠30d、110d和产后5d固定采血,分别测定血清中孕酮、催产素和泌乳素的含量。结果表明,添加杂交狼尾草可提高母猪分娩率、降低难产比例,提高总产仔数、健仔数和仔猪初生重;可提高18日龄育成仔猪数、仔猪个体重,显著提高仔猪18日龄窝重、窝增重和窝日增重;但对受胎率和返情率有不利影响。妊娠30d孕酮、110d催产素和产后5d泌乳素的含量均随着杂交狼尾草添饲量的增加而上升,0.75kg/d添饲组比对照组分别提高了2.25ng/mL、177.77pg/mL和3.11ng/mL。本研究范围内,0.75kg/d杂交狼尾草添饲量较有利于改善母猪的繁殖性能。     

乳酸菌素对母猪繁殖性能及哺乳仔猪生长性能的影响

为探究饲料中添加乳酸菌素对母猪及哺乳仔猪的影响，试验选择健康状况良好、预产期相近、胎次相近（3～6胎）的20头母猪，按完全随机设计法分为对照组和试验组，每组10个重复，每个重复1头母猪，试验期54 d。对照组饲喂基础日粮，试验组饲喂基础日粮+0.25 g/kg的乳酸菌素。结果表明：与对照组相比，试验组母猪在重胎期及哺乳期的采食量均较高（P>0.05）；试验组母猪的窝产仔数、窝产活仔数、窝产健仔数、初生总窝重、健仔重及母乳中的免疫球蛋白含量有所增加（P>0.05）；母猪日粮中添加0.25 g/kg的乳酸菌素不影响母猪粪便中的微生物（乳酸菌、大肠杆菌及产气荚膜梭菌）、断奶后的发情情况及哺乳仔猪粪便中的免疫球蛋白含量。因此，哺乳母猪料中添加0.25 g/kg乳酸菌素可提高重胎期和哺乳期母猪的采食量，改善母猪的产仔情况，提高母猪乳汁中的免疫球蛋白A(IgA)与免疫球蛋白G(IgG)的含量，降低仔猪的死胎率、弱仔率及腹泻率。综上，哺乳母猪料中添加0.25 g/kg乳酸菌素可改善母猪的繁殖性能，提高哺乳仔猪的生长性能。     

夏季不同饲喂方式对两广小耳花猪哺乳母猪生产性能的影响

本试验旨在研究夏季不同饲喂次数和料水比对两广小耳花猪生产性能的影响,选择48头两广小耳花猪哺乳母猪,分为4组,每组12头母猪。4个处理组的饲喂方式分别为饲喂2次/d和料水比为1∶2.5(对照组)、饲喂2次/d和料水比为1∶3.5、饲喂3次/d和料水比为1∶2.5、饲喂3次/d和料水比为1∶3.5。监测母猪从产后至断奶25 d的采食量、仔猪生长性能以及环境温湿度等指标。结果表明:饲喂3次/d与2次/d母猪的日平均采食量分别为3.33、2.41 kg,哺乳期间母猪平均总采食量前者较后者高23 kg/头;哺乳仔猪平均断奶窝重分别为32.35、29.14 kg,窝增重前者较后者高3.17 kg/窝。综上,通过增加饲喂次数和选择与人工作息时间不一致的时间点饲喂可以提高哺乳母猪的采食量,但需要智能化自动化饲喂设备相配套。     

不同饲喂模式对哺乳母猪生产性能的影响

本试验旨在研究不同饲喂模式对哺乳母猪生产性能的影响.选择胎次、 膘情相近的健康母猪60头饲喂相同日粮,随机分为2组,每组30个重复,每个重复1头母猪.对照组采用人工投料模式饲喂,处理组采用哺乳母猪下料器模式饲喂.试验21天后,检测其生产性能.结果表明:与对照组相比,处理组哺乳期母猪平均日采食量提高0.92 kg/天,断奶窝重增加6.88 kg/窝,断奶活仔数提高0.58头/窝,泌乳期母猪背膘损失减少0.63 mm.结论:采用母猪下料器饲喂模式有利于提高哺乳期母猪的采食量,改善母猪的泌乳性能,减少母猪背膘损失,增加仔猪断奶头数,提高仔猪断奶重.     

母猪妊娠期饲粮中添加L-肉碱对其生产性能的影响

为研究母猪妊娠期饲粮中添加L-肉碱对其生产性能的影响,试验采用单因子设计,选取配种时间相近的长大母猪30头,随机分为3组,每组10个重复,每个重复1头母猪,对照组饲喂基础饲粮,试验1组饲喂基础饲粮+L-肉碱100 mg/kg、试验2组饲喂基础饲粮+L-肉碱200 mg/kg。妊娠母猪基础饲粮分为妊娠0～90 d和91 d至分娩两个阶段配制,都采用玉米-豆粕型饲粮。试验结果表明,母猪妊娠期饲粮中添加L-肉碱100 mg/kg和200 mg/kg能显著提高仔猪初生重及母猪窝产仔数和窝产活仔数,有效降低窝产弱仔数。     

母猪日粮中添加不同硒源对其乳硒及仔猪健康状况影响的比较

为了研究补硒对硒从母猪转运到仔猪的影响,试验对哺乳母猪饲粮中不补充硒或分别以亚硒酸钠、酵母硒形式补充0．3mg／kg硒,高于NRc对饲粮硒的推荐量（0．15mg／kg）。未强化硒的玉米一豆粕型基础饲粮为阴性对照组,饲粮中含有较高的内源性硒（Se：0．20～0．23mg／kg）。52头母猪从分娩前60d饲喂到哺乳第14d。分别在分娩前60d、30d、分娩当天、产后14d,从每个处理组选择6头母猪采血,测定血清硒浓度。收集分娩后12h内的初乳,及哺乳第14d的乳汁。在仔猪出生和断奶（14d）当天,从每窝仔猪中选择5头（每个处理组12窝仔猪）采血,混合血清,检测硒、免疫球蛋白G的浓度,及谷胱甘肽过氧化物酶的活性。各处理组母猪在妊娠期间的血清硒水平下降;哺乳期间逐渐增加。分娩时,饲喂酵母硒（P〈0．06）的母猪血清硒浓度高于没有补硒的母猪。与饲喂亚硒酸钠的母猪相比,饲喂酵母硒的母猪其初乳和常乳（第14d）中硒浓度增加（P〈0．01）。与饲喂基础饲粮组相比,酵母硒组仔猪在出生时血清硒浓度增加（P〈0．01）。14日龄仔猪血清硒浓度在各个处理组间没有差异。仔猪血清IgG和谷胱甘肽过氧化物酶活性不受饲粮硒源的影响。给妊娠和哺乳母猪补充0．3mg／kg有机硒或无机硒,窝产死胎数减少。但是,只有饲喂有机硒（酵母硒）的母猪,仔猪出生时血清硒水平更高。有机硒组母猪初乳和14d常乳中硒浓度增加程度高于无机硒组。     

不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究

试验设计4个处理3个重复,开展不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究。4个处理为：处理Ⅰ（CK）只饲喂肥育猪的基础日粮,处理Ⅱ为基础日粮＋浇灌沼液的牧草浆0.25kg/头.d,处理Ⅲ为基础日粮＋浇灌沼液的牧草浆0.5kg/头.d,处理Ⅳ为基础日粮＋浇灌沼液并加施尿素的牧草浆0.5kg/头.d。结果表明,处理Ⅱ、Ⅲ、Ⅳ平均日增重分别比处理Ⅰ提高了22.4g,40.4g和48.4g,料肉比分别比处理Ⅰ降低了4.62%、3.96%和7.26%,每头猪效益分别比处理Ⅰ提高了26.0元、34.3元和44.6元,猪肉氨基酸含量也比处理Ⅰ有不同程度的提高,尤其以添加增施尿素的牧草浆后,肥育猪的日增重、料肉比和经济效益都最好。     

小母猪及经产母猪管理手册(续完) 附录7:妊娠后期提高饲喂水平对于仔猪初生重的影响

一群224头的母猪(康贝尔22和康贝尔29)(头胎母猪72头、2胎母猪24头、3胎母猪36头以及4胎或以上母猪92头),该母猪群在分娩前14 d分组,并分别按3种饲喂方案中的一种进行饲喂,以确定妊娠后期增加喂料量对提高仔猪初生重及窝仔重的有效性。将商品猪场同一周、同一批次配种的小母猪和经产母猪随机分为3组,按3种喂料方式(每日增加喂料量:0、0.91kg、1.82 kg)中的一种进行饲喂。饲喂试验猪要符合母猪胎龄和体况评分要求。分娩前14 d开始按试验规定的喂料量饲喂妊娠母猪。分娩前两天,试验母猪转入产房,在此,改用哺乳料,饲喂量减至每天1.82 kg,直到分娩。妊娠日粮配方中赖氨酸总量达到0.55%,所有其他的营养成分均达到或超过NRC(1998)要求。分娩时按窝称量每头仔猪吃奶前的个体初生重。所有非试验母猪分娩后称量吃奶后的仔猪总窝重。所有的记录均应把死胎和木乃伊胎儿纳入分析范围,结果组与组之间总产仔数和活仔数差异不显著。窝仔重、产活仔总重、仔猪个体重和死胎个体重在经产母猪(2胎或以上)之间差异不显著。不管如何,日喂料量增加1.82 kg的头胎母猪组与日喂料不增加的头胎母猪相比,窝仔重明显重,差异显著(P=0.019),分别为18.7 kg∶16.1 kg;同样,活仔总重也明显重,差异显著(P=0.030),分别为16.6 kg∶15.1 kg。此外,日喂料量增加1.82 kg的头胎母猪组与日喂料不增加的头胎母猪相比,活仔个体初生重明显要重,差异显著(P0.001),分别为1.438 kg∶1.312 kg。基于这些数据,从妊娠100 d到分娩前,头胎母猪日喂料量增加1.82 kg,可以提高仔猪初生重,但对经产母猪,无助于提高其仔猪初生重。     

Effects of Dextrose Plus Lactose in the Sows Diet on Subsequent Reproductive Performance and within Litter Birth Weight Variation

Effects of dextrose plus lactose in sow’s feed were tested on subsequent reproductive performance and within litter birth weight variation. During the last week of gestation and lactation, sows were either fed a commercial lactation diet (Control: C), or an isocaloric diet containing 25 g/kg dextrose plus 25 g/kg lactose (Treatment: T). In the subsequent weaning‐to‐oestrus interval (WEI), all sows received the same amount of a commercial feed, but T sows were supplemented with 150 g dextrose plus 150 g lactose per day. Weight and backfat changes were recorded as well as litter characteristics during the treatment period and the subsequent parity. No significant effect of treatment was found on the subsequent reproductive performance, including the number of piglets born, although the number of live born piglets was 0.51 larger (p = 0.31) and weight of the live born piglets was 84 g higher in the T sows (p = 0.07) than in the C sows. When sows were categorized in sows with 12 or less and more than 12 total born piglets in the previous litter, treatment of sows with dextrose plus lactose resulted for the group with 12 or less piglets in a strong increase in subsequent total born piglets (13.97), whereas in the untreated sows the subsequent litter size was 11.89. In the group with more than 12 total born piglets, no effect of treatment was found (interaction between previous litter size and treatment p = 0.03). The within litter variation in birth weight in the subsequent litter was numerically lower in the T sows. We concluded that the use of dextrose and lactose during lactation and WEI seems to enhance litter size in sows with low previous litter size and seems to have the potential to reduce the within litter variation in birth weight.     

Influence of different phosphorus levels and phytase supplementation in gestation diets on sow performance

A total of 104 sows of different parities were studied. They were fed four diets with different phosphorus (P) levels during gestation for two reproductive cycles, while the same diet was fed during lactation. The aim was to decrease the total P level in the diet during gestation and to evaluate the effect on sow performance. The gestation treatments were low P (LP-; 3.7 g P/kg feed), low P with phytase (LP+, Ronozyme P; 765 FTU/kg feed), medium P (MP; 4.5 g P/kg feed) and high P (HP; 6.0 g P/kg feed). Daily feed allowances were 2.6 kg during gestation and 9.2 kg during lactation. Number of born piglets and piglet mortality were higher (p < 0.05) in the LP treatments than in the MP and HP treatments. No difference (p > 0.05) in the numbers of live-born piglets, piglet birthweights, sow weights or piglet weight gains was found between the treatments. Phosphorus level in sow milk was the highest (p < 0.05) in the MP treatment, while no effects (p > 0.05) of treatment were found on milk Ca levels, P and Ca levels in serum of sows and piglets, nor on the analysed mineral, fat and protein contents of piglets. The estimated average requirement of P for the entire gestation period was 4.4-4.5 g/day. In conclusion, a reduction of dietary total P content during gestation did not result in negative effects on sow or piglet performance. This suggests that it should be possible to lower the dietary P content for gestating sows, compared with earlier recommendations, and thereby reduce the environmental P pollution.     

Post-farrowing stress management in sows by administration of azaperone: effects on piglets performance

This study examined the impact of a single dose of azaperone administered to sows at the end of farrowing on piglet weight gain and mortality during the lactation period. Two hundred fifty-two sows (JSR hybrid) housed in a conventional farrowing crate system were assigned to either a treatment or a control group. The parities of the sow were between 1 and 6. The differences between live birth weight and weight at weaning were recorded for 3,093 individual piglets. Serum concentrations of IgG of 485 piglets also were recorded during tail docking. Median and interquartile range (IQR) were 5.1 (2.9 to 9.5) mg·mL(-1) in the control group and 5.6 (3.1 to 12.1) mg·mL(-1) in the azaperone group (P > 0.05). Litter size was 13.0 (11 to 15) total born piglets and birth weight was 1.28 (1.05 to 1.52) kg. Weaning weight for the control group was 5.64 (4.73 to 6.54) kg compared with 5.78 (4.79 to 6.71) kg for the azaperone treated group (P = 0.005). Daily BW gain differed significantly (P = 0.001) between the 2 groups, 205 g for the controls, compared with 214 g for the azaperone group. There were no significant differences between piglet mortality rates (17% and 20%). Azaperone applications to sows tended to have a positive effect on productivity. Effect was greatest in the primiparous sows and declined with increasing parity. This may have been due to both physiological and behavioral differences between the sows as they experienced increasing numbers of gestations, farrowings, and lactation periods.     

日粮中使用NUTRI-PAL对夏季初产母猪繁殖性能的影响

试验以20头妊娠90d的初产母猪(长白×大白)为试验动物,研究日粮中使用5%Nutri-Pal对其繁殖性能的影响。试验分对照组及5%Nutri-Pal试验组。结果表明:与对照组相比,试验组母猪的采食量略有提高(P>0.05),窝产活仔数增加0.55头、初生窝重增加1.57kg、断奶后7d内发情率提高了22.3%,弱仔、死胎、木乃伊的比例均有不同程度的下降,但母猪窝总产仔数、断奶到发情的间隔无显著差异(P>0.05)。仔猪15日龄窝重、断奶窝重比对照组分别提高了3.53kg和5.56kg,死亡率下降了37.57%。结果显示,日粮中使用5%Nutri-Pal能促进夏季初产母猪的繁殖性能。     

Effect of dietary supplementation of oregano essential oils to sows on colostrum and milk composition, growth pattern and immune status of suckling pigs

This study evaluated the effects of supplementing sow diets with oregano essential oils (OEO) during gestation and lactation on sow colostrum and milk composition and on the growth pattern and immune status of suckling pigs. A total of 70 second-parity sows were randomly assigned to 1 of 2 gestation dietary treatments within 24 h after service: control (CON) or CON + 250 mg/kg of OEO (OREG). In lactation, sows were again assigned to either the CON or OREG dietary treatment. Thus, the lactation treatments were CON-CON, CON-OREG, OREG-CON, and OREG-OREG. Colostrum and blood samples were collected from 6 sows per lactation dietary treatment. Thymus lymphocyte (T lymphocyte) subpopulations (γδ, cluster of differentiation 8, and 32 cluster of differentiation 4) were enumerated in blood and mammary secretions along with IGF-1, IgG, and IgA concentrations. Piglet growth rate were determined from 18, 17, 17, and 18 litters from the CON-CON, CON-OREG, OREG-CON, and OREG-OREG lactation dietary treatments, respectively. Growth rates were determined in 630 piglets, and piglets were individually identified and weighed on 1, 5, 9, 12, 16, and 19 d of age. Oregano essential oil supplementation during gestation or lactation had no effect (P > 0.05) on GE, CP, GE:CP, GE:fat, and IGF-1 in sow milk. Reductions of the fat percentage in milk on d 7 (P < 0.05) and d 14 (P = 0.07) were found in sows supplemented with OEO during lactation compared with those in the CON treatment. Milk from sows supplemented with OEO during lactation had the greatest number of T lymphocytes compared with those in the lactation CON treatment on d 14 of lactation (P < 0.01). The number of T lymphocytes in milk was greater for sows in the CON-OREG treatment compared with those other treatments on d 14 of lactation (P < 0.05). Energy intake was greater on d 1 to 5 in piglets from sows fed OEO during gestation than those from sows in the CON treatment (P < 0.05). A trend (P = 0.10) for greater milk intake was observed in piglets from sows supplemented with OEO during gestation compared with those from sows in the CON treatment. Similarly, a tendency for an increase in ADG on d 1 to 5 was found in piglets from sows supplemented with OEO during gestation compared with those from sows in the CON treatment (P = 0.10). Insulin-like growth factor-1 at birth and on d 7 and 14 of lactation did not differ among piglets from sows assigned to the different dietary treatments. Oregano essential oil supplementation of sow diets did not affect (P > 0.05) immunoglobulin concentrations in piglets after suckling. Supplementing sow diets with OEO during gestation or lactation did not affect (P > 0.05) the T lymphocytes, percentage of T-lymphocyte subpopulations, and natural killer cell activity of piglets during lactation. Supplementing sow diets with 250 mg/kg of OEO during gestation and lactation did not affect the growth potential of and immune responses in suckling piglets.     

Dietary fiber for pregnant sows: influence on sow physiology and performance during lactation

This study was conducted to investigate the effects of feeding sows a bulky diet during gestation on their physiological and metabolic adaptations during the peripartum period, and to determine how these effects may relate to sow and piglet performances. From d 26 of gestation until farrowing, gilts were fed diets that contained 2.8 or 11.0% crude fiber (control and high-fiber diets, respectively, n = 9/group). Daily feed allowance provided the same amount of DE daily (33 MJ of DE/d). Throughout lactation, sows were allowed to consume a standard lactating sow diet ad libitum. Litters were standardized to 12 piglets beyond 48 h after birth. On d 105 of gestation, a jugular catheter was surgically implanted. Preprandial blood samples were collected from d 109 of gestation to the day after farrowing and on d 4, 18, and 26 of lactation. Meal tests and glucose tolerance tests were performed on d 109 of gestation and d 4 and 18 of lactation. During gestation, BW and backfat gain did not differ between treatment groups. During lactation, sows fed the high-fiber diet ate an average of 0.94 kg/d more than control sows (P < 0.02). Piglets born from sows fed the high-fiber diet grew faster than piglets from control sows (P = 0.03). Body weight and backfat losses did not differ between the 2 treatment groups. Sows fed the high-fiber diet during gestation had lesser concentrations of leptin before farrowing than control sows (P < 0.01). Leptin concentrations were negatively correlated with feed intake during lactation (P < 0.05). The prepartal increase in prolactin concentrations tended to be greater in sows fed the high-fiber diet than in control sows (P < 0.1). Preprandial concentrations of glucose, NEFA, lactate, and IGF-I fluctuated over time without significant treatment effect. Glucose half-life was shorter in late gestation than during both stages of lactation, but did not differ between sows in the 2 groups. In late gestation, the postprandial increases in glucose and insulin were delayed, and smaller, after a high-fiber meal than after a control meal. During lactation, glucose and insulin profiles after a standard meal did not differ between sows from treatment groups. In conclusion, the greater appetite of lactating sows fed a high-fiber diet during gestation does not seem related to changes in glucose and insulin metabolism and may be partly due to decreased secretion of leptin. The greater feed consumption was accompanied by a faster growth rate of piglets without sparing effect on maternal body reserves.     

糖蜜对不同比例苎麻杂交狼尾草混合青贮发酵品质的影响

为探讨糖蜜对不同比例苎麻杂交狼尾草混合青贮发酵品质的影响,本试验设计7个苎麻（Boehmeria nivea L.）和杂交狼尾草（Pennisetum americanum×P.purpureum）混合比例,按原料鲜重计,各比例分别为100：0（R100）,70：30（RP73）,60：40（RP64）,50：50（RP55）,40：60（RP46）,30：70（RP37）和0：100（P100）。每个混合比例设计对照组（CK）和糖蜜处理组（M）。结果表明：添加糖蜜显著（P<0.05）降低青贮料的pH值、氨态氮含量、乙酸含量和丁酸含量,显著（P<0.05）提高青贮料的干物质含量和乳酸含量。杂交狼尾草比例的提高,也能够一定程度上提高青贮的发酵品质。生产中,使用糖蜜时,推荐调制RP73苎麻和杂交狼尾草混合青贮;无糖蜜时,推荐调制RP55苎麻和杂交狼尾草混合青贮。     

Effect of dietary L-carnitine supplementation on growth performance of piglets from control sows or sows treated with L-carnitine during pregnancy and lactation

Previous studies showed that supplementation of sows' diets with L-carnitine increases body weights of their piglets at birth. This study was performed to investigate whether piglets of sows treated with L-carnitine differ in their growth potential from that of piglets of untreated control sows after weaning. It was also investigated whether supplementation of piglets' diets with L-carnitine improves their growth after weaning. In two trials, piglets of the first litters of primiparous sows (trial 1) and the second litters of the same sows (trial 2) were divided into four groups: group 1, piglets of control sows, fed a control diet; group 2, piglets of control sows fed a diet supplemented with 30 mg L-carnitine/kg; group 3, piglets of L-carnitine-treated sows, fed a control diet; group 4, piglets of L-carnitine-treated sows fed a diet supplemented with 30 mg L-carnitine/kg. Mean initial body weights of the piglets of the four groups were identical. They were 8.5 kg in trial 1 and 12.5 kg in trial 2. Diets were fed ad libitum over a period of 35 days. Piglets from sows treated with L-carnitine did not differ in body weight gains, feed intake and gain : feed ratio from those of control sows. In trial 1, piglets supplemented with L-carnitine had higher body weight gains (p < 0.005) and showed a tendency towards a higher gain : feed ratio (p = 0.09) than piglets fed the control diets. In trial 2, no significant difference in these parameters emerged between piglets fed the diet supplemented with L-carnitine and those fed the control diet. In conclusion, this study shows that dietary L-carnitine treatment of sows does not improve the growth potential of their piglets after weaning under the conditions of equal initial body weights. The study also shows that L-carnitine supplementation of their diets improves the growth performance in light piglets of primiparous sows.     

Effect of L-carnitine supplementation on performance parameters in gilts and sows

The effect of L-carnitine supplementation during pregnancy and lactation on performance parameters of sows was studied. The trial comprised a total of 127 sows (40 gilts, 87 mature sows) which were divided into a control and a treatment group. All animals were fed individually and received basic feed mixtures for pregnancy and lactation with low carnitine concentrations (gestation diet: 4.7 mg/kg feed, lactation diet: 12.5 mg/kg feed). 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. L -carnitine supplementation resulted in higher sow liveweight gains between day 1 and day 85 of pregnancy. The number of piglets per litter and the number born alive did not differ between the control sows and those treated with L -carnitine. However, the L -carnitine-supplemented sows produced only half as many non-viable piglets as the control animals. Moreover, litter weight and mean birth weight of piglets from L -carnitine-treated sows were higher than in the control sows. This effect was more marked in gilts (+8% higher litter weight, +9% higher piglet weight) than in sows (+7% and +6%, respectively). Piglets from sows whose ration was supplemented with L -carnitine showed higher liveweight gains during the suckling period (+12% for gilts, +4% for sows), which is why litter weights post weaning were also higher among the sows treated with L -carnitine than in the control sows (+14% for gilts, +10% for sows). Overall, the study shows that dietary supplementation with L -carnitine during pregnancy and lactation improves the reproductive performance of sows.     

Riboflavin requirement of lactating swine

Twenty-five crossbred gilts and 25 crossbred sows were used in an experiment to estimate the riboflavin requirement of lactating swine. During gestation the females were fed a 12% crude protein, corn-soybean meal diet that was marginal in riboflavin content, i.e., 2.3 mg/kg. After farrowing, litter size was equalized across lactation diets within each parity category. The basal, 14% crude-protein corn-soybean meal lactation diet was supplemented to provide five levels of dietary riboflavin: 1.25, 2.25, 3.25, 4.25 and 5.25 mg/kg. Five gilts and five sows were fed each dietary treatment. Each dam was provided her assigned diet ad libitum during the 24-d lactation; piglets were not provided supplemental feed. The erythrocyte glutathione reductase activity coefficient (EGRAC), an indicator of riboflavin status, was measured on blood samples obtained from the dams and their piglets on d 1 and d 24 postpartum. On d 1, the mean EGRAC of gilts was slightly higher than that of sows, while piglet EGRAC was similar regardless of maternal age. On d 24 gilts and their piglets had higher average EGRAC (P less than .01) than did sows and their piglets. Thus, there was a treatment x dam age interaction (P less than .05). Lactation performance criteria gave further evidence of similar treatment x age group interactions. Gilts fed the diet containing 1.25 ppm riboflavin had higher piglet mortality, consumed less feed and lost more weight (P less than .05) for each criterion than did sows fed the same diet. Despite these observations, the broken-line estimates of the riboflavin requirement, based on EGRAC, for gilts and sows were 16.3 and 16.2 mg/d, respectively. The EGRAC values for piglets closely paralleled those of their dams regardless of treatment, suggesting that there is no mechanism to protect the nursing piglets from a maternal dietary deficiency of riboflavin.