影响荷斯坦牛妊娠期长短的因素分析

[目的]为探究不同因素对荷斯坦牛妊娠期长短的影响,以期进一步改善奶牛繁殖性能.[方法]研究利用一般线性模型对江苏省某奶牛场2017-2019年20 589条产犊记录进行分析,探究不同胎次、产犊季节、犊牛初生重、犊牛性别及是否产双犊和是否使用性控冻精对荷斯坦牛妊娠期长短的影响.[结果]胎次、产犊季节、犊牛初生重、是否产双...     

影响荷斯坦牛产奶性能诸因素的分析

奶牛的产奶性能除受遗传因素影响外,在很大程度上还受各种环境因素的影响,这些遗传和环境因素主要包括牧场、年度、母牛的产犊月份、初产月龄、胎次及公牛组等。为了更准确地找出各影响因素对产奶性能的影响程度,本文对此进行了统计分析。　　　　　　　　１　材料与方法１．１　资料来源：本文资料取自于黑龙江省８５１１农场、８５０农场、香坊农场和大庆三环企业集团等１１个农牧场共２４个奶牛场１９８６～１９９５年间产犊奶牛的生产性能（３０５天产奶量、乳脂率、３０５天乳脂量）测定资料。共收集１９４头公牛的５４１２头女儿牛…     

影响荷斯坦牛产奶量差的因素分析

产奶量差是奶牛个体同一胎次前后2个泌乳月产奶量的差值,可准确反映产奶量变化情况。为探究影响荷斯坦牛产奶量差的因素,本研究收集整理了江苏省某大型奶牛场2015-2018年55 193头次荷斯坦牛生产性能测定记录,并利用最小二乘法分析胎次、测定年度、产犊季节、泌乳月4个因素对荷斯坦牛产奶量差的影响。结果显示:胎次、测定年度、产犊季节、泌乳月及其交互作用对产奶量和产奶量差均有极显著影响(P<0.01)。其中,不同胎次、测定年度和产犊季节的荷斯坦牛总产奶量在第2个泌乳月增加最快,产奶量差为8.79kg;头胎第6泌乳月、二胎第7泌乳月和三胎及以上第6泌乳月产奶量下降最大,产奶量差分别为-2.86kg、-4.59kg和-6.13kg;2015-2018年4个测定年度中,第10、第6、第7、第6泌乳月产奶量降低最大,产奶量差分别为-2.26kg、-4.98kg、-4.44kg和-3.56kg;春季产犊的荷斯坦牛第4泌乳月、夏季产犊的荷斯坦牛第12泌乳月、秋季产犊的荷斯坦牛第9泌乳月、冬季产犊的荷斯坦牛第6或第7泌乳月产奶量下降最大,产奶量差分别是-4.34kg、-4.71kg、-5.36kg和-5.40kg。此外,产奶量差与泌乳持续力呈极显著正相关(P<0.01),与产犊间隔呈显著正相关(P<0.05),与泌乳天数、高峰奶、乳脂率、蛋白率、305d产奶量呈极显著负相关(P<0.01)。因此,产奶量差作为衡量奶牛产奶量变化的指标之一,可为牧场进行科学饲养管理提供参考。     

黑龙江省中国荷斯坦牛繁殖性能调查及影响因素分析

奶牛的繁殖力对奶牛业生产的经济效益的影响很大,繁殖性能的好坏是奶牛能否正常发挥生产性能的前提,同时也关系到牛群的数量和质量。具有良好繁殖性能的牛群,其产奶水平高,牛群的周转速度和自然增长加快,牛群的质量也得以保证,相反,繁殖性能差的牛群,由于牛群周转...     

克拉玛依地区荷斯坦牛超排效果及影响因素的分析

本研究比较了不同年度、季节、超排方法、促卵泡素（FSH）的剂量、超排处理开始时发情周期天数及供体牛年龄对荷斯坦牛超排效果的影响。结果表明，秋季、冬季与夏、春季比较在采卵数和可用胚数方面差异极显著（P〈0．01）。改进方法与常规方法比较采卵数差异极显著（P〈0．01），可用胚数差异显著（P〈0．05），8．0mL、9．4mL、10．0mLFSH剂量之间各项指标均差异显著（P〈0．05）。而超排处理的年度、超排处理开始时发情周期天数及供体牛年龄对荷斯坦牛超排效果影响不显著（P〉0．05）。     

影响黑龙江省中国荷斯坦牛产奶性状的诸因素分析

奶牛的产奶性能除受遗传因素影响外,在很大程度上还受各种环境因素的影响,这些遗传和环境因素中主要包括母牛的产犊年龄、牧场、年度、产犊月份、胎次及公牛组（遗传组）等,为了更准确地找出各因素对产奶性能的影响程度,本文对此进行了统计分析,为奶牛场合理组织生产...     

江苏省中型牧场荷斯坦牛产犊间隔的影响因素分析

为探索胎次、初产月龄、产犊年度和产犊季节对荷斯坦牛产犊间隔的影响,本研究利用一般线性模型对江苏省某中型牧场2010—2018年胎次为2～8胎、产犊间隔为300～600 d荷斯坦牛的9 419条产犊间隔数据进行分析。结果表明:不同胎次、初产月龄、产犊年度和产犊季节对荷斯坦牛产犊间隔有显著影响(P<0.05)。其中,荷斯坦牛第4胎产犊间隔最大(394.72 d),第2胎产犊间隔最小(390.85 d);初产月龄在22月龄以下荷斯坦牛产犊间隔最大(404.71 d),初产月龄在23～30月龄产犊间隔无显著差异;2015年产犊的荷斯坦牛产犊间隔最大(400.17 d),2018年产犊的荷斯坦牛产犊间隔最小(369.52 d);夏季产犊的荷斯坦牛产犊间隔最大(417.11 d),春季产犊的荷斯坦牛产犊间隔次之(399.85 d),秋冬季节产犊的荷斯坦牛产犊间隔较小且无显著差异。由上可知,胎次、初产月龄、产犊年度、产犊季节均是影响荷斯坦牛产犊间隔的重要因素。     

影响中国荷斯坦牛SCS分布的因素分析

为探索影响中国荷斯坦牛乳中体细胞评分分布规律的因素,对我国东南沿海地区9个牧场2003年—2009年118471次奶牛群体改良(DHI)测定日记录进行了分析。结果表明:乳中体细胞数(SCC)为455.35×104个/mL,体细胞评分(SCS)为3.66。胎次、泌乳月和产犊季节显著影响乳中SCS的分布。随着胎次和泌乳月的增加,高SCS所占比例也逐渐增加,第3胎以上和第9泌乳月以后的奶牛有20%以上乳中SCS均高于6分(即大于56.5万个/mL)。春季产犊高SCS(≥6)所占比例最小(17.63%),夏季产犊比例最大(20.28%)。     

广西地区荷斯坦牛超数排卵效果分析

本研究在荷斯坦牛品种、年度、年龄、季节、FSH品牌及剂量、卵巢状态、超排方法等方面做了比较试验，结果表明不同品种和不同年度间的头均采卵数、头均可用胚胎数差异显著（P<0.05）。不同季节、不同FSH品牌及剂量、卵巢状态的头均采卵数、头均可用胚胎数和可用胚胎率差异均不显著（P>0.05）。     

热应激条件下荷斯坦牛血糖浓度特征及影响因素分析

为探究热应激条件下奶牛血糖浓度特征及其影响因素,本研究于2019年7月-2019年8月测定了北京地区2个规模化牧场的431头奶牛的血糖浓度,并收集了试验牛的生产性能测定记录,利用SAS 9.2软件的GLM过程分别分析环境温湿度指数、泌乳阶段、血液类型、胎次、妊娠状态及蹄病情况等因素对奶牛全血血糖和血浆血糖浓度的影响。结果表明,北京地区7-8月奶牛全血血糖和血浆血糖浓度分别为(3.78±0.33) mmol/L和(3.99±0.37) mmol/L;温湿度指数仅对全血血糖浓度有显著影响(P<0.05),泌乳阶段仅对血浆血糖浓度有显著影响(P<0.05),胎次和妊娠状态对两种血糖浓度均有显著影响(P<0.05),而瘤胃充盈度、血液类型、挤奶情况和蹄病情况等因素对两种血糖浓度均无显著影响;综上,奶牛血糖浓度对包括温湿度指数等在内的环境因素及生理因素的变化较为敏感,本研究可为牧场利用血糖浓度在一定条件下反映奶牛的热应激状况和提升牧场管理水平提供依据。     

Factors affecting the transfer of immunoglobulin G1 into the milk of Holstein cows

Immunoglobulin (Ig) G1 concentrations in milk from Holstein cows was measured to determine if transfer and concentration was influenced by production factors (lactation number, stage of lactation, daily milk production), milk composition (milk fat, protein, lactose, and total solids content) or by serum IgG1 concentration. Two hundred and ninety-nine Chinese Holstein cows were randomly selected from four herds containing a total of more than 1600 lactating animals. The concentration of IgG1 in the milk and serum was determined by ELISA.Milk IgG1 concentrations varied between 0.030 and 0.614 mg/mL and significantly correlated with lactation number, stage of lactation, daily milk production and somatic cell count. The IgG1 mass was found to highly correlate with lactation number, stage of lactation, daily milk production and milk protein content. Lactation number had the highest positive direct relationship with IgG1 concentration.     

Factors affecting plasma prolactin concentrations throughout gestation in high producing dairy cows

The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, Neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (PAG-1), progesterone and cortisol. Pregnancy was diagnosed by trans-rectal ultrasonography on Day 40 post-insemination and by palpation per rectum on Days 90, 120, 150, 180 and 210 or until abortion in aborting cows. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The study population was comprised of 73 non-aborting (54 Neospora-seropositive cows) and 20 aborting cows (all Neospora-seropositive) cows. In non-aborting cows, GLM repeated measures of analysis of variance revealed that lactation number and days in milk had no effect on plasma prolactin concentrations throughout gestation, whereas high plasma prolactin concentrations were significantly associated with high plasma levels of cortisol and PAG-1, with Neospora-seropositivity, positive photoperiod (increasing day length), twin pregnancy, and with low plasma progesterone concentrations. An interaction among plasma prolactin, plasma cortisol and milk production was observed in that plasma prolactin concentrations differed significantly throughout gestation and were highest in high-producing cows with high cortisol levels. In Neospora-seropositive non-aborting versus aborting cows, mean prolactin concentrations failed to differ on Days 40, 90, 120, 150 and 180 of pregnancy, whereas prolactin values were significantly lower (P = 0.03) in aborting animals on Day 210 of pregnancy. Our results indicate that a positive photoperiod and Neospora-infection lead to increased plasma prolactin concentrations throughout gestation. Reduced prolactin concentrations detected in Neospora-seropositive aborting cows compared to non-aborting animals suggests a protective effect of prolactin in N. caninum infection.     

Factors affecting the gestation period of pigs in Nigeria

Summary Gestation periods taken from 432 records on purebred Large White, Duroc, Hampshire and their crossbred sows at Fashola Stock Farm in the Oyo State of Nigeria were analysed to determine the effects of some factors on the trait. For Large White, Duroc, Hampshire and the crossbred sows the mean gestation periods were 113.2, 115.1, 114.5 and 112.8 days respectively. Overall least squares mean was 112.2 days with a standard deviation of 9.06 days. Litter size at birth, year of birth and breed × season interaction had very highly significant effects on length of pregnancy. Breed differences were significant (P<0.05) whereas parity and seasonper se did not seem to influence this trait. Effects of boars accounted for some 11.8% of the observed differences in the gestation periods of their litters. The heritability of the trait was estimated as 0.47±0.20 while the repeatability coefficient was 0.13. The data indicated a slight negative association between gestation period and litter size at birth.

---

Factores Que Afectan El Periodo De Gestacion De Cerdos En Nigeria

Resumen Se analizaron 432 registros de gestación de cerdos puros Large White, Duroc, Hampshire y de las hembras provenientes de cruces, en la Granja de Fashola, Estado de Oyo en Nigeria. Para las razas Large White, Duroc, Hampshire y los cruces, el promedio de gestación fue de 113.2, 115.1, 114.5 y 112.8 días respectivamente. El promedio total por cuadrado mínimo fue de 112.2 días, con una desviación estándar de 9.06 días. El número de lechones al nacer, año de nacimiento y la interacción de raza y estación tuvieron efectos significativos altos en la duración de la preñez. Las diferencias entre razas fueron significativas (P<0.05), mientras que los efectos entre razas similares y la estación del añoper se no parecieron tener mayor influencia. Algunos factores encontrados en los machos fueron responsables de 11.8% de las diferencias encontradas en los períodos de gestación. La heredabilidad de caracteres se estimó en 0.47±0.20, mientras que el coeficiente de repetibilidad fue 0.13. Los datos señalan una asociación negativa entre el período de gestación y el tamaño de la camada al nacer.

---

Facteurs Influencant Au Nigeria La Duree De La Gestation Chez Les Porcs

Résumé Une analyse a été faite à la ferme d'élevage de Fashola dans l'Etat d'Oyo au Nigeria, pour déterminer les effets de quelques facteurs sur la durée de la gestation en étudiant 432 gestations de truies de race pure Large White, Duroc et Hampshire et métissées. Pour l'ensemble de ces truies la durée moyenne de la gestation a respectivement été de 113,2; 115,1; 114,5 et 112,8 jours. La moyenne générale a été de 112,2 jours avec une déviation standard de 9.06 jours. Le nombre de produits à la naissance l'âge à la mise bas et l'interaction race x saison ont des effets hautement significatif sur la durée de la gestation. La différence entre les races a été significative (p<05 alors que le nombre de portées et al saison en soi ne semblent pas influencer ce caractère. L'influence des verrats intervient pour quelque 11,8 p. 100 sur cette durée lorsqu'elle concerne leurs produits. L'héritabilité de ce caractère a été estimée à 0,47±0,20 alors que le coefficient de repetabilité a été de 0,13. L'observation indique qu'il existe une association légèrement négative entre la durée de la gestation et le nombre de produits à la naissance.

     

Ultrasonographic monitoring of nuclear transferred fetal weight during the final stage of gestation in Holstein cows

Dystocia or stillbirth accompanied by Large Offspring Syndrome (LOS) occurs rather frequently in Holstein nuclear transferred calves. In regard to prophylaxes, nuclear transferred Holstein fetuses were monitored with ultrasonography during the final stage of gestation. Fetal weight was estimated weekly based on the fetal metacarpal width using ultrasonography. Fourteen Holstein cows pregnant with Holstein nuclear transferred fetuses were the subjects of this experiment. The fetal weight was estimated by measuring the fetal metacarpal width during the last month of gestation according to the expected date of parturition. Measurements were performed on a weekly basis. The ultrasound-estimated metacarpal width and body weight of 13 of the fetuses in the last week of gestation (30.2+/-2.2 mm, 50.0+/-4.7 kg) were similar to the actual measurement immediately after birth (30.0+/-2.1 mm, 51.2+/-5.5 kg). These results indicate that ultrasonographic monitoring within a week of parturition to is accurate for estimating fetal weight. Prediction of LOS with ultrasonography contributes to reliable a diagnostic method that minimizes syndrome-related gyneco-obstetric complications at parturition with the aid of appropriate treatments.     

Factors affecting calf mortality in Iranian Holstein dairy herds

The objective of this study was to document mortality reasons and risk factors for mortality in dairy calves in the northeast of Iran. This was a prospective cohort study of calves born on ten commercial dairy herds from 21 March 2009 to 20 March 2010. A total of 4097 live calves were followed for 90 days after birth. For each calf details of sex, parity of the dam, type of parturition and season of birth were recorded. The interval (in days) from the date of birth to the date of death and the reason for death was recorded for those calves that died before 90 days of age. A Cox proportional hazards model, including a frailty term to account for unmeasured herd-level effects was developed to quantify the effect of factors associated with time to death. Two hundred and sixty-six (6.5%, 95% CI: 5.8-7.3%) of the 4097 live-born calves died or were euthanised before 90 days of age. The most important reasons for death were digestive tract disorders (58% of all deaths, 95% CI: 52-64%) followed by respiratory diseases (13% of all deaths, 95% CI: 9-17%). Calves exposed to dystocia at birth had 2.09 (95% CI: 1.49-2.92) times the daily hazard of death compared with calves born from a normal calving. The daily hazard of death for calves born in the summer was 1.93 (95% CI: 1.41-2.64) times greater than the hazard for those calves born in the autumn. Inclusion of the herd-level frailty term had a significant effect on hazard estimates indicating that the study herds were heterogeneous in the distribution of unmeasured herd-level factors influencing calf survival. Our results show that diarrhoea is the most important cause of calf mortality in dairy herds in this area of Iran and that environmental and management factors affect calf mortality rate.     

Age, dose of FSH and other factors affecting superovulation in Holstein cows

Effects of age of donor and other factors on superovulation and production of transferable embryos were investigated. Data were obtained on 987 recoveries of embryos performed between November 1980 and June 1984 by Select Embryos, Inc. The 339 Holstein donors ranged in age from 1.8 to 17.8 yr. The effects of age of donor and dose of follicle stimulating hormone (FSH) were examined using regression analysis. For on-farm recoveries, numbers of embryos, rates of fertilization, quality scores of all embryos and numbers of transferable embryos decreased (P less than .01, P less than .001, P less than .05, P less than .01, respectively) with increasing age of donor. For in-clinic recoveries, numbers of embryos plus ova recovered were affected by age of donor, dose of FSH and the interaction of the two (P less than .05). Among older donors, increasing doses of FSH were associated with an increase in the number of ova plus embryos recovered. However, among younger donors, increasing doses of FSH had a negative effect. Numbers of embryos, rates of fertilization and numbers of transferable embryos decreased (P less than .05) with advancing age and increased (P less than .05) with increasing doses of FSH. Greater numbers of ova plus embryos were recovered when treatment with FSH was begun on d 10 or 11 as compared with d 7, 8, 9, 12, 13 or 14 (P less than .001). It was concluded that an increase in age of donor had a negative influence on the success of superovulation and the production of transferable embryos, and that the response to FSH was affected by age of donor.     

Prolonged gestation in two Holstein cows: transabdominal ultrasonographic findings in late pregnancy and pathologic findings in the fetuses

Prolonged pregnancy in cattle is a rare condition that is commonly accompanied with fetal adenohypophyseal hypoplasia. The final diagnosis is often challenging as breeding date error remains possible in virtually all situations. In this report, fetal wellbeing assessment is depicted in two Holstein cows suffered from prolonged pregnancy. Transabdominal ultrasonographic findings were compatible with healthy non-stressed fetuses. The clinical and pathologic findings encountered in both fetuses expelled after corticosteroid induction of parturition consisted of adenohypophyseal aplasia and hydronephrosis. Other nervous system anomalies (hydrocephaly or holocephaly) were observed. Tetralogy of Fallot was also found in one calf.     

Maize silage particle length modulates feeding patterns and milk composition in loose-housed lactating Holstein cows

This study analysed feeding patterns and feed selective consumption by loose-housed lactating dairy cows fed diets based on maize silage (MS) with different particle length (PL) to establish its effects on overall dry matter intake (DMI) and productive performance. Twelve multiparous Holstein cows were offered a total mixed ration (TMR) with three different PL of MS at harvesting (i.e., long, medium, and short). Results demonstrated greater numbers of day-time meals (i.e., 07:30–19:00 h) when PL was decreased from long to medium (P < 0.05). Night-time (i.e., 19:00–06:30 h) changes in the feeding pattern included an increased amount of feed per meal (P < 0.05) and a tendency to increase eating time per meal (P < 0.10) in cows fed the short-PL diet. Lowering the PL of MS also lowered the selective consumption against physically effective fibre larger than 1.18 mm (peNDF_> 1.18; P < 0.05) and in favour of fine particles (i.e., particles passing through 1.18 mm screen; P < 0.01). Decreasing PL of MS from long to medium and short increased daily DMI as well as the intake of energy and other nutrients contained in the diet including the amount of peNDF_> 1.18 (P < 0.01). The decrease in the PL of the diet also was associated with increased milk protein and lactose yield and milk urea nitrogen (P < 0.05). The actual milk yield and fat-corrected milk were not affected by the diet (P > 0.10). Although lowering of the PL tended to increase daily milk energy output (P < 0.10), the ratio between energy milk output and the energy intake was linearly decreased (P < 0.01), indicating a lower milk efficiency for the lower-PL diets. In conclusion, particle length of MS in a TMR has the potential to modulate circadian feeding patterns, selective consumption of the feed, daily DMI, and milk composition in high-producing dairy cows.