哺乳期经产母猪背膘变化对其繁殖性能的影响

<正>0前言母猪繁殖性能是影响猪场经济效益的重要指标之一,在一定程度上也反映了猪场的整体生产管理水平。膘情是一个衡量母猪体况的重要指标,它可以反映出母猪在不同生理阶段的营养状况和能量储备,并且影响母猪繁殖性能。母猪的膘情会受到生理阶段、饲料营养、生产管理、生产胎次、生长环境等因素的影响,膘情变化进而又会影响母猪的繁殖性能。背膘厚与母猪体内脂肪含量密切相关,可以有效反映母猪的营养储     

妊娠母猪体况的评定、研究与调控

背膘厚度是母猪整体膘情的一个反映指标,而母猪体况状态与其膘情密切相关。研究表明,妊娠母猪体况与其繁殖性能密切相关,妊娠母猪不同时期的背膘厚对其繁殖性能有一定的影响。因此,在母猪妊娠阶段,进行科学合理饲喂,控制好膘情,才能发挥其最大繁殖性能。文章综述了妊娠母猪体况评定方法、背膘厚对妊娠母猪繁殖性能的影响,在此基础上提出了妊娠母猪体况调整策略。     

后备母猪配种期背膘对产仔性能的影响

<正>母猪膘情体况与其繁殖性能密切相关,背膘是母猪体况的最直接反映。有研究表明后备母猪第一胎的产仔性能对后续胎次的繁殖表现具有重要意义,而后备母猪配种期背膘往往对头胎繁殖性能影响较大〔1〕。随着养猪业规模化、标准化的发展,一些规模猪场开始使用背膘仪对母猪背膘进行精确调控。本研究借助B超仪对规模猪场大约克后备母猪进行背膘测定,并对其头胎产仔性能进行统计,以期找出后备母猪配种期最适背膘范围,为指导后备母猪生产提供理论依据。     

背膘测定在养猪生产中的应用

正母猪在整个繁殖周期内随繁殖阶段的不同,体况也存在差异,依据不同繁殖目的保持适宜的体况,是保证其繁殖性能发挥的关键。背膘厚度可以有效反映母猪体况的变化,是母猪繁殖性能良好的预测指标,根据体况(背膘厚)调控妊娠母猪饲喂量,是实现母猪优质高效养殖的有效途径,因此母猪背膘厚度已成为衡量母猪体况的重要方法。近30年来母猪脂肪减少了50%,使繁殖母猪对营养变得更加敏感,在实际生产中根据母猪的生理阶段,制定相应的     

母猪背膘与繁殖性能的相关分析

正母猪的膘情是衡量其体况的一个重要指标,想达到更为高效的生产性能,就需在不同的生理阶段合理调节母猪的饮食,以调整背膘厚度,使母猪发挥出更好的繁殖性能。膘情是母猪机体体况的一个重要指标,它反映的是母猪在不同生理阶段的营养状况和体能储备。Cechova M和Wahner M等的研究表明,母猪的背膘厚和繁殖性能具有一定的相关性。因此在实际生产过程中,可以通过母猪     

二胎母猪配种至上产背膘增量对繁殖性能的影响

背膘厚是反映母猪体况的重要指标。通过调控母猪在不同阶段的饲料采食量、营养物质添加等,可改善母猪的膘情,提高饲粮营养消化率,减少饲料浪费,节约养殖成本。研究表明,二胎母猪配种背膘厚、上产背膘厚、配种至上产背膘增量均与产仔性能密切相关。二胎母猪配种背膘厚在14～16 mm,上产背膘厚在16～20 mm,可获得较高的产仔性能;背膘厚<13 mm或者>23 mm时,母猪繁殖性能不能高效表达。     

猪场,该如何控制母猪膘情?

正母猪膘情是衡量母猪个体优劣的重要指标,控制好母猪膘情是猪场是否能够盈利的一个关键点。而背膘厚度与体脂含量有直接关系,因此测定背膘厚已成为衡量母猪膘情的重要指标。那么,猪只各阶段的背膘多少时为宜呢?1后备母猪的膘情     

高产瘦肉型母猪分娩背膘厚度对其繁殖性能的影响

正背膘厚度是反映母猪身体脂肪的含量的关键指标,背膘厚度的降低意味着母猪对能量的盈亏十分敏感,而能量与繁殖表现密切相关,因此正确控制好种猪体况对于提高高产瘦肉型母猪繁殖力显得尤其重要。近年来随着瘦肉型种猪高度选育的发展,瘦肉型种猪的繁殖力逐步提升,但由于追求高瘦肉率,致使种猪的背膘过度降低。背膘厚度是反映母猪身体脂肪含量的关键指标,背膘厚度的降低意味着母猪对能量的盈亏十分敏感,而能量与繁殖表现密切相关,因此     

背膘厚度对母猪繁殖性能的影响

母猪体况在现代养猪业中占有非常重要的地位,反映母猪体况最为直接的指标就是背膘厚度。因此,控制母猪适宜的背膘厚度便成为生产管理的重要目标。猪只不同阶段的背膘厚度并不是孤立的,而是相互联系、互相影响的。母猪不同生长或生产时期背膘厚度与其繁殖性能存在相关性。文章重点分析了背膘厚度与母猪繁殖性状的相关性、不同时期背膘厚度对母猪繁殖性能的影响,旨在为确立母猪不同生理生产时期的适宜背膘厚度提供依据。     

律肝保对母猪繁殖性能影响的试验报告

母猪的繁殖性能受到疾病、营养、管理、品种、药物等因素影响,其中母猪的背膘厚度、是否便秘、是否泪斑、皮肤是否出血点直接影响母猪的繁殖性能。是否便秘、是否泪斑和皮肤是否出血点又可影响母猪的背膘厚度,而母猪膘情直接影响到母猪的体况,它反映的是母猪在不同生理阶段的营养状况和体能储备,因此在实际生产过程中,可通过母猪的背膘厚薄来粗略估计母猪繁殖性能,指导生产中母猪的饲养管理和营养调配,以提高生产水平,增加经济效益。     

妊娠期背膘厚对母猪产程及繁殖性能的影响

为优化母猪繁殖效率,探究妊娠期不同背膘厚对母猪繁殖性能和分娩产程的影响,本研究以广西某公司2 969头大白母猪和1 787头长白母猪为试验群体,收集2017年1月至2017年10月妊娠期3个阶段(妊娠30、80和107 d)背膘厚与分娩接产记录数据,分析背膘厚与分娩产程、总产仔数、产活仔数和初生窝重等性状的关系。研究结果表明,大白母猪分娩产程时间显著短于长白母猪(P<0.05),大白母猪总产仔数、产活仔数和初生窝重显著优于长白母猪(P<0.05)。在妊娠30 d时,背膘厚在18～20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大;背膘厚在18～20 mm组的长白母猪总产仔数和产活仔数最高。在妊娠80 d时,背膘厚≥20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大、产程最短;背膘厚在16～18 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较高、母猪产程较短。在妊娠107 d时,背膘厚在14～16 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大,但母猪产程与其他组差异不显著(P>0.05);背膘厚≥20 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较大。妊娠期背膘厚减少1～2 mm的大白母猪,其总产仔数和产活仔数最高,初生窝重较小,产程较长。而背膘厚减少>2 mm的长白母猪,其总产仔数和产活仔数最高,初生窝重较大,产程较短。上述试验结果说明,在母猪妊娠期间,合适的背膘厚可有效提高母猪繁殖性能和母猪分娩期间的福利水平。养殖场可以根据营养配方和猪群品种建立背膘数据库,通过精准饲喂将母猪背膘厚调整至最佳范围,同时合理控制妊娠期背膘变化。     

Identification of carcass and meat quality quantitative trait loci in a Landrace pig population selected for growth and leanness

The identification of QTL related to production traits that are relevant for the pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.     

Leptin: a metabolic signal affecting central regulation of reproduction in the pig

The discovery of the obesity gene and its product, leptin, it is now possible to examine the relationship between body fat and the neuroendocrine axis. A minimum percentage of body fat may be linked to onset of puberty and weaning-to-estrus interval in the pig. Adipose tissue is no longer considered as only a depot to store excess energy in the form of fat. Recent findings demonstrate that numerous genes, i.e., relaxin, interleukins and other cytokines and biologically active substances such as leptin, insulin-like growth factor-I (IGF-I), IGF-II and Agouti protein are produced by porcine adipose tissue, which could have a profound effect on appetite and the reproductive axis. Hypothalamic neurons are transsynaptically connected to porcine adipose tissue and may regulate adipose tissue function. In the pig nutritional signals such as leptin are detected by the central nervous system (CNS) and translated by the neuroendocrine system into signals, which regulate appetite, hypothalamic gonadotropin-releasing hormone (GnRH) release and subsequent luteinizing hormone (LH) secretion. Furthermore, leptin directly affects LH secretion from the pituitary gland independent of CNS input. Changes in body weight or nutritional status are characterized by altered adipocyte function a reduction in adipose tissue leptin expression, serum leptin concentrations and a concurrent decrease in LH secretion. During pubertal development serum leptin levels, hypothalamic leptin receptor mRNA and estrogen-induced leptin gene expression in fat increased with age and adiposity in the pig and this occurred at the time of expected puberty. In the lactating sow serum and milk leptin concentrations were positively correlated with backfat thickness and level of dietary energy fed during gestation as well as feed consumption. Although, these results identify leptin as a putative signal that links metabolic status and neuroendocrine control of reproduction, other adipocyte protein products may play an important role in regulating the reproductive axis in the pig.     

影响母猪繁殖性能的营养因素及调控措施

近年来随着中国养猪业不断规模化、集约化的发展,如何提高母猪的繁殖性能已成为养猪行业的热点。母猪的繁殖性能受遗传、营养、环境、健康状况等因素综合影响,其中营养因素是十分重要的因素之一。在母猪饲养管理的不同阶段采取一些简单可行的营养学方法,会显著提高母猪繁殖性能。作者在分析影响母猪繁殖性能的营养因素的基础上,提出了在母猪不同饲养阶段所采取的营养调控措施。     

Effect of Lactation Diet Fat Level on Sow and Litter Performance

The primary objective of this study was to determine the effects of supplemental dietary fat during lactation on sow BW, sow backfat thickness, sow feed consumption, litter size, and pig growth rate. Dietary treatments included 0, 3, 6, and 9% supplemental low acid yellow fat in a traditional corn-soybean meal basal lactation diet. A total of 160 Landrace and crossbred sows (approximately 40 per treatment) were included in the study. Sows fed 3 and 6% supplemental fat had greater (P<0.10) average backfat thickness at weaning. Sow weight change and feed consumption were inconsistent among dietary fat levels. Dietary fat level during lactation did not affect number of pigs born alive or number of stillborns. However, the 9% fat level was associated with more mummified pigs at birth. Number of pigs weaned was greater for the 0% supplemental fat than for the 9% fat level. The largest average pig weights at 21 (5.8±0.29 kg) and 28 (7.48±0.38) d of age were those from sows fed the 3% added fat diet. Sows with ≤25.4 mm backfat at farrowing had more pigs born alive (P<0.05), had less backfat at 21 and 28 d of lactation (P<0.05), and consumed more feed during wk 2 and 3 of lactation. Of all sows fed the control diet, sows with >25.4 mm backfat at farrowing consistently had heavier pigs throughout the lactation phase (P<0.05). Backfat loss during lactation was lower (P<0.05) for sows with ≤25.4 mm at farrowing within all dietary treatments. Consistent significant differences were not observed in sow weight loss or feed consumption between low and high backfat sows for each dietary treatment. Sow backfat loss during lactation is dependent on body condition at farrowing, in that, fatter sows at farrowing have greater backfat loss during lactation. Sows with ≤25.4 mm of backfat at farrowing responded to added dietary fat treatments and produced heavier pigs throughout the lactation period.     

The relationship of average backfat thickness of feedlot steers to performance and relative efficiency of fat and protein retention

Selection for growth and improved carcass merit has resulted in cattle that are variable in composition of gain during the finishing phase. This study assessed the relative performance among cattle with different levels of initial backfat thickness. It also exploited the ability to track carcass composition in the live animal with ultrasound estimates of backfat and marbling. A procedure was developed to partition and estimate relative efficiency of fat and protein gain. The trial periods were the last 43 or 50 d before slaughter and included 10 pens (average of 27 animals per pen) that ranged in average backfat thickness from 6.3 to 13.1 mm. There was no correlation (r2 = 0.0026) between average backfat thickness and G:F (g/kg of DMI). Correlations between average backfat thickness and ADG or DMI were also nearly zero (r2 = 0.0007 and 0.0042, respectively). Fat deposition from NEg was 3.98 times more efficient than protein deposition. Carcass backfat thickness was a poor predictor of carcass marbling score (r2 = 0.083), even though backfat thickness was an important predictor of the percentage of empty body fat (r2 = 0.807). The results indicate that a measure of backfat thickness on the live animal during the finishing phase is not an effective predictor of future feed efficiency. They also confirm that protein accretion is energetically expensive, and that using a single coefficient for predicting gain from NEg is valid regardless of whether gain is predominantly muscle or fat. These data document that there is little relationship between body composition and marbling score, which is contrary to models that assume a USDA quality grade target at a specified percent fat end point.     

江泉黑猪与杜长大三元杂交猪屠宰性能及肉质性状比较分析

为了解江泉黑猪的产肉和肉质特性,本试验选取在相同条件下饲养的100 kg左右的江泉黑猪阉公猪、母猪和杜长大三元杂交猪各10头按照相关规定进行屠宰和肉品质测定。对两种猪胴体指标（胴体重、胴体长、眼肌面积、背膘厚等）、肉质的物理指标（pH、肉色、大理石纹、滴水损失等）、常规化学指标（粗蛋白质、肌内脂肪、水分、灰分含量等）及江泉黑猪氨基酸含量进行了测定。结果表明,与杜长大三元杂交猪相比,江泉黑猪胴体瘦肉率较低,眼肌面积降低了30%左右（P<0.05）,而胴体背膘厚较高（P<0.05）。江泉黑猪在肉色、大理石纹、滴水损失、失水率、烹饪损失和肌内脂肪含量等指标上均显著优于杜长大三元杂交猪（P<0.05）,其中滴水损失、失水率和烹饪损失分别降低了约4.0%、3.1%和2.7%,肌内脂肪含量提高了约150.0%。由此可见,江泉黑猪在瘦肉产量上低于杜长大三元杂交猪,但在保水性、肌内脂肪含量、肉色、大理石纹等肉质指标上明显优于杜长大三元杂交猪,可为消费者提供品质优良的猪肉。     

A Comparative Study on the Carcass and Meat Quality Traits of Jiangquan Black Pig and DLY Pig

To further understand the germplasm characteristics of Jiangquan Black pig,100 kg Jiangquan Black pigs (10 barrows, 10 sows) and 10 Duroc×Landrace×Yorkshire (DLY) pigs under the same conditions were randomly selected to analyse the slaughter performance and meat quality according to related rules. After slaughtered,the carcass index (carcass weight, loin muscle area, carcass length and backfat thickness etc), meat quality physical indicators (pH, meat color, marbling, drip loss etc), gerneral chemical index (the contents of crude protein, intramuscular fat, moisture and ash etc) and the proportion of amino acids in Jiangquan Black pig were analyzed. The results showed that, Jiangquan Black pig carcass lean meat rate was relatively low, the loin muscle area was reduced by about 30% (P<0.05) compared with DLY pig, while the backfat thickness was higher than that of DLY pig (P<0.05). The meat color, marbling, drip loss, cooking loss, water loss rate index and intramuscular fat content of Jiangquan Black pig were significantly better than that of DLY pigs (P<0.05), the rate of water loss and drip loss and cooking loss were decreased by 4.0%, 3.1% and 2.7%, intramuscular fat content increased by 150.0%. Therefore, The lean yield of Jiangquan Black pig was less than DLY pig, but water retention property, intramuscular fat content, meat color, marbling, meat quality indexes were significantly better than that of DLY pig. In conclusion, Jiangquan Black pig could provide good quality pork for consumers.     

北京地区猪生长和繁殖性状边际效益的研究

本研究旨在估计北京地区猪生长和繁殖性状的边际效益.以差额法和系统分析法为基础建立农场模型,模拟商品猪群的生产过程,采集了北京地区多个具有代表性的猪场的数据,确定北京地区猪6个生长和繁殖性状的边际效益为:窝产活仔数(头)20.5元、达100kg体质量日龄(d)-0.3元、肥育期日增体质量(g·d-1)0.04元、饲料转化效率(kg·kg-1)-186.4元、胴体背膘厚(mm) 15元、母猪繁殖寿命(胎)1.8元.结果表明,市场价格的变化对性状边际效益的影响很大.     

Relationship between body fat and postweaning interval to estrus in primiparous sows

Twenty-two primiparous Yorkshire sows were used to determine whether a minimal threshold of body fat exists below which the return to estrus is delayed. A second objective was to examine the relationship between body fat and interval from weaning to estrus in restricted-fed sows. During lactation (28 d), sows received 7, 9, 11 or 13 Mcal of ME daily to produce a range of sow body fatness at weaning. Intake of all dietary essentials except ME was similar for all sows. Litter size was adjusted to 10 pigs for all sows by d 3 postpartum. Each day from weaning to estrus, sows received 110 kcal ME per kg metabolic body weight plus 1,359 kcal ME per sow. Body fat was estimated at weaning and at first postweaning estrus by deuterium oxide dilution. Last rib backfat depth was determined ultrasonically 24 h postpartum and at weaning. Irrespective of dietary ME intake, percentage body fat at weaning (R2 = .24; P less than .05) and first postweaning estrus (R2 = .03; P greater than .50) accounted for only a small portion of variation in interval from weaning to estrus. Likewise, loss of backfat depth during lactation was not an accurate predictor of interval from weaning to estrus (R2 = .24; P less than .05). The low coefficients of determination (less than .25) suggest that body fat is a minor controller of postweaning interval to estrus. In contrast, dietary ME intake during lactation accounted for the largest portion of the variation (R2; = .48; P less than .01) in postweaning interval to estrus. We conclude that timing of postweaning estrus in primiparous sows is not dependent on a minimal threshold of body fat. Furthermore, effects of lactational ME intake on the postweaning interval to estrus are more pronounced than the effects of body fat.