仔猪初生重对后期生长发育的影响

据报道，初生重低于0．9kg的仔猪死亡率可达％呢，初生重在1．35－1．552g范围死亡率可下降至18％，1．8kg以上存活率可88％。另外，初生重低50％的仔猪断乳重低16．62％。本文旨在通过分析不同品种初生重的仔猪后期生长发育情况，探讨初生重大小对断奶重、60日龄重的影响规律，并对不同品种仔猪的生长发育进行比较。1背景资料和研究方法1．1本研究资料选自某种猪场1993－1996年长白和杜洛克母猪产仔哺育记录。1．2该种猪场按照工厂化生产工艺流程组织生产，猪舍按空怀一妊娠舍、分娩一保育舍、出售猪舍顺序排列，根据其生产特点与要求，分…     

提高仔猪初生重的技术措施

影响母猪繁殖率的制约因素很多,其中仔猪初生重小是一个关键因素,也是影响猪场经济效益的关键因素。本文简述了仔猪初生重的意义、提高仔猪初生重的技术措施。     

初生仔猪均匀度和窝内平均重的影响因素分析

本研究旨在揭示固定效应(产活仔数、分娩胎次、配种季节以及妊娠天数)对初生仔猪均匀度和窝内平均重的影响程度和变化规律,为种猪的生产和选育提供数据支撑和理论依据。选取华东某国家生猪核心育种场3 663条大白猪繁殖数据进行分析。结果表明:产活仔数、分娩胎次和配种季节对初生仔猪的均匀度和窝内平均重均有显著影响,妊娠天数只对窝内平均重有显著影响,而对初生仔猪均匀度影响不显著;产活仔数越多,2胎后分娩胎次越多,初生仔猪均匀度越差、窝内平均重越小;秋季配种的母猪其出生仔猪均匀度最好但窝内平均重最小;妊娠天数越长的仔猪窝内平均重越大,但过长和过短的妊娠天数都不利于初生仔猪的均匀度。     

仔猪初生重对断奶窝重的影响

提高猪的增重速度首先要从仔猪初生重、断奶重抓起 ,要取得仔猪窝重高的结果 ,除了抓好泌乳母猪的饲养管理、发挥母猪良好的泌乳性能外 ,做好仔猪补料、抓旺食、过好断奶关及疾病的预防工作是关键。1　试验材料与方法1 .1　试验猪随机选用 1 8窝“杜长上”初生仔猪 ,饲养 3 5日龄断奶。泌乳母猪、仔猪分别用申兰集团饲料厂生产的泌乳母猪料和乳猪料。母猪产前一周进产房待产 ,母猪采用高床单体限位栏 ,两侧为仔猪活动空间并配有保暖小间。1 .2　试验猪的饲养管理1 .2 .1　对临产前母猪后躯、乳房部位及分娩床面用0 .1 %高锰酸钾溶液擦拭消毒…     

提高仔猪初生重的综合技术措施

影响养猪生产的因素很多，而仔猪初生重的大小是影响母猪生产性能的一个重要因素。本文从饲养母猪的环境，组建合理母猪群，母猪适宜的初配期，加强母猪的饲养、营养饲料及添加剂的补充，合理的免疫程序等来提高仔猪初生重，继而提高仔猪成活率，增加养猪经济效益。     

影响母猪产仔数和仔猪初生重的因素

繁殖率是反映母猪繁殖力和猪场生产管理水平的重要经济参数。通常衡量母猪群生产性能的指标是每头母猪每年提供的断奶仔猪数,主要有两部分组成,即年母猪产仔窝数和母猪每窝的断奶仔猪数。据生产实践,有许多因素影响着母猪的生产性能,包括遗传因素、环境因素、饲养管理因素等。饲养母猪,只有年产仔窝数多,     

仔猪初生体重与生产性能的关系

<正>1 初生体重与断奶前的成活率 大量的调查研究表明,仔猪的初生体重与早期断奶是否成功有很大关系。初生体重影响断奶前的成活率。一般来说,初生体重越小,断奶前的仔猪死亡率越高。 法国Caugant等(1993)的一篇研究报告表明,初生重小于1kg的仔猪,哺乳阶段死亡率达36％,l.0～1.5kg时降至8％,1.5～2.0kg时仅为5％。 在争抢和保卫自己吮乳位置的争斗行为中,体重往往是决定仔猪胜负的决定性因素,况且体重大的仔猪体温调节能力明显强于弱小者。体重小的仔猪,其体内能量贮备少,活动力、御寒力和耐饥力均低于体重大的仔猪,竞争乳头能力也弱,且易被压死和冻死。     

仔猪初生重及断奶重对成活率的影响

影响猪场生产指标和经济效益的主要因素是仔猪成活率,其与仔猪初生重及断奶重密切相关,因此探究仔猪初生重及断奶重与成活率之间的关系,对猪场淘汰仔猪具有参考价值。本研究以四川阆中大北农桥楼猪场二元母猪所产500头仔猪为试验对象,记录、整理和分析仔猪初生重、21日龄断奶重、21日龄成活率及70日龄成活率。结果表明：仔猪初生重呈正态分布,体重过小、过大的数量较少;体重≤1.0kg的仔猪21日龄成活率较低,体重>1.3kg的仔猪21日龄成活率均在95%以上;21日龄断奶重较大仔猪的70日龄成活率较高,5.5～6.0kg的仔猪最为理想。因此,建议四川阆中大北农桥楼猪场适当淘汰初生重≤1.0kg的仔猪,提高经济效益。     

初生仔猪死亡的因素分析及应对措施

综合国内外的相关报道,从遗传、营养、管理、环境和疾病五个方面揭示影响初生仔猪成活率的因素,提出应对措施,为养猪生产提供借鉴与参考。     

能量对低出生体重仔猪死亡率、断奶重和初乳摄入量的影响

文章探讨了能量补充对低出生体重仔猪的死亡率、断奶体重、日增重及初乳摄入量的影响。处理组选择22头母猪所产的306头活仔猪,其中极低出生体重(<1 kg)72头,低出生体重(1~1.2 kg)77头,分别于出生时和出生后8~12 h口服能量补充剂。对照组选择24头母猪所产的340头活仔猪,其中极低出生体重81头,低出生体重74头。结果显示:能量补充较对照组显著降低了极低出生重仔猪哺乳3 d的死亡率(P <0.05),有降低低出生重仔猪死亡率的趋势(P=0.07)。总的来说,能量补充剂有降低仔猪哺乳3 d死亡率的趋势(P=0.06)。能量补充较对照组对极低出生重仔猪哺乳7和21 d存活优势率显著提高了4.04和3.59倍(P <0.05)。对照组较处理组显著提高了仔猪的断奶重(P <0.05)。对照组与处理组对仔猪的日增重、初乳摄入量及出生产量的影响均无显著差异(P> 0.05)。处理组母猪初乳产量在数值上比对照组低(P> 0.05),但处理组母猪初乳产量均匀性在数值上较对照组好。综上所述,能量补充通过为极低出生体重仔猪直接提供能量而不是通过提高初乳的摄入量来降低其断奶前的死亡率。     

影响疫苗免疫效果的因素

免疫接种是预防动物发生传染病的主要手段，但并不是所有经过疫苗接种的动物都能达到预期的免疫效果。疫苗接种后机体产生的免疫应答是一个极其复杂的生物学过程，许多因素都会影响机体免疫力的产生。本文着重从疫苗、动物和环境三个方面分析影响免疫效果的因素，     

非遗传因素对多胎细毛羊初生重和断奶重的影响

本研究旨在分析影响多胎细毛羊出生重和断奶重的因素,为优质多产细毛羊的选育奠定基础.利用SPSS19.0软件对多胎细毛羊羔羊的初生重和断奶重进行了描述性统计分析,并利用SAS9.2软件的GLM(最小二乘方差分析)程序对新疆科创畜牧繁育中心2009-2019年多胎细毛羊1 567条产羔记录分析出生年份、出生月份、性别和母羊...     

Passive immunization in neonatal piglets in natural rearing--effects of birth order, birth weight, litter size and parity

603 neonatal piglets (German Landrace) were investigated for passive immunization affected by birth order, birth weight, litter size and parity. Concentrations of immunoglobulins in the blood serum of piglets on the first day of life served as measure for passive immunization. Blood samples were drawn at 12, 18 and 24 hours post partum. Quantitative measurements of immunoglobulin classes were carried out by radial immunodiffusion. There was a significant effect of birth order, because of the rapid changes in colostrum composition between onset of birth and the last piglet of each litter. The effect of birth weight was only partly significant and different for the immunoglobulin classes. There was no significant effect of litter size on passive immunization. Parity had a significant positive effect on IgG- and IgA-concentrations in sow's colostrum with litter two to six, parity 1 and 2 lead to highest IgM concentrations in the blood serum of piglets.     

影响蛋壳质量的因素及预防措施

蛋鸡养殖中把蛋壳质量归结为蛋壳重、蛋壳强度、蛋壳颜色等,在实际生产中,蛋壳质量的中心问题是蛋壳破损率(可达5%～7%)和褐壳蛋蛋壳颜色变浅的问题.许多因素影响和控制蛋壳质量,如蛋鸡的品种、日龄、环境、疾病、饲养管理、营养水平等,本文就影响蛋壳质量的原因及预防措施作以综述.     

影响牛乳中脂肪含量因素及提高措施

牛乳中的脂肪含量--乳脂率,是衡量牛乳质量的重要指标之一.乳品厂家在牛乳收购过程中因脂肪含量低而降价收购或拒收的现象普遍存在.而牛乳中的乳脂率,又受多种因素的影响发生较大变化,一般含量在3%～5%.     

Genetic study of individual preweaning mortality and birth weight in Large White piglets using threshold-linear models

Individual records from 49,788 Large White piglets were used to evaluate preweaning mortality and its relationship with birth weight (BW). Preweaning mortality included farrowing mortality (TM) was also divided into stillbirth (SB), early (EM), late (LM) and total (ELM) preweaning mortality. Farrowing mortality was also studied as a sow's trait as number of piglets born dead (NBD). Threshold-linear models were used via MCMC. Traits included (1) TM-BW, (2) SB-ELM-BW, (3) SB-EM-LM and (4) NBD-ELM-BW. Model for BW included parity number, litter size, sex, contemporary group (farm-farrowing year-month), litter, and direct and maternal additive genetic effects. For mortality traits, litter effect was of the nursing litter for cross-fostered piglets (4.9%). Models for SB (2, 3) and NBD (4) excluded the effect of sex. In Model 3, BW was fitted as covariable for EM and LM. Estimates of direct and maternal heritability for BW were 0.03–0.06 and 0.14–0.19; and for mortality traits 0.03–0.12 and 0.08–0.12. Direct-maternal correlations were negative for all traits. Genetic correlations between all mortality traits were positive. Results confirmed the importance of BW for the genetic evaluation of piglet mortality. Early mortality is a good candidate for improvement of TM because of larger heritability and high genetic correlations with other mortality traits. It is most efficient to treat SB at sow level and preweaning mortality at the piglet level.     

Relationships among steroid hormone levels in newborn piglets,birth weight,placental weight,vitality of offspring and litter size

Blood estrone sulfate (E₁S), estrone (E₁), estradiol (E₂) and progesterone (P₄) in newborn piglets were measured to clarify the relationships among birth and placental weight, vitality of offspring and litter size. First, the association between vital status (normal, weak and stillborn) from 165 newborn piglets of 18 litters and steroid concentrations; second, steroid concentrations from 152 newborn normal piglets and litter size; and third, steroid content in fetal placenta from 50 newborn normal piglets of six litters and litter size, were investigated. In the normal group, the birth and placental weight were significantly higher than those in the other groups. Blood E₁S levels in the stillborn group were significantly lower, whereas E₁, E₂ and P₄ were significantly higher compared to the normal group. Blood and placental E₁S levels in the small litter group were significantly higher than those in the other groups. However, there was no significant difference among the three litter size groups in the levels of steroid hormones in maternal blood. These results indicate that vitality of newborn piglets is related to E₁S concentration of neonate, to birth weight and placental weight. However, steroid hormone concentrations of newborn piglets were greatly affected by the number of littermates.