The testing season affects red deer skinfold increase in response to phytohaemagglutinin

Red deer (Cervus elaphus) have a pronounced seasonality in their physiology. The aim of this study was to assess the effect of the season on red deer responsiveness to skin testing with the phytohaemagglutinin (PHA) mitogen. Study subjects included 270 farmed adult red deer (19 stags and 251 hinds). The skin testing was carried out between January 2009 and August 2010. The animals were injected intradermally with a 0.1 ml volume containing 250 μg of PHA diluted in phosphate buffered saline. The skinfold thickness was measured immediately prior to injection and 72 h after administration, always by the same person and with three repeats per measurement. Single effects of sex and time on skin test responsiveness were significant (p < 0.001) as well as their interaction (p < 0.001). In winter (January), and considering the average of two years, the skinfold increase in response to the intradermal injection of 250 μg PHA was 2.1 times larger in stags and 1.4 times in hinds than in summer (August). While stags had 1.3 times larger responses than hinds in winter, the inverse occurred in summer, with 1.1 times larger responses in hinds. We also evidenced a limited inter-annual variation of skinfold increase in response to PHA in red deer. These findings have important consequences regarding the interpretation of skin test results in the ante-mortem diagnosis of tuberculosis and paratuberculosis, at least in deer.     

Optimal dose and timing in phytohaemagglutinin skin-testing of deer

AIM: To establish the optimal dose of the mitogen phytohaemagglutinin (PHA) and the optimal time for measuring increased skin-fold thickness in red deer following intradermal injection, as an indicator of cell-mediated immune response. METHODS: Three doses (10, 50 and 250 microg) of PHA were injected intradermally in the right side of the neck, and phosphate buffered saline (PBS) was injected at a fourth site as a control, in 20 captive Iberian red deer (Cervus elaphus hispanicus) hinds. Skin-fold thicknesses were measured at 0, 12, 24, 36, 48, 60, 72, 84 and 96 h following injection. RESULTS: The highest dose of PHA tested (250 microg) resulted in a clear and long-lasting cellular response; increases in skin-fold thickness between 48 and 84 h post-injection varied minimally and response correlated positively with liveweight. No correlations with liveweight and no clear increases in skin-fold thickness occurred at the lower doses of PHA or the PBS. CONCLUSIONS AND CLINICAL RELEVANCE: This technique could be applied with minimal training and without specialised equipment in deer, for immunological and ecological research.     

Optimal dose and timing in phytohaemagglutinin skin-testing of deer

AIM: To establish the optimal dose of the mitogen phytohaem- agglutinin (PHA) and the optimal time for measuring increased skin-fold thickness in red deer following intradermal injection, as an indicator of cell-mediated immune response.

METHODS: Three doses (10, 50 and 250 µg) of PHA were injected intradermally in the right side of the neck, and phosphate buffered saline (PBS) was injected at a fourth site as a control, in 20 captive Iberian red deer (Cervus elaphus hispanicus) hinds. Skin-fold thicknesses were measured at 0, 12, 24, 36, 48, 60, 72, 84 and 96 h following injection.

RESULTS: The highest dose of PHA tested (250 µg) resulted in a clear and long-lasting cellular response; increases in skin-fold thickness between 48 and 84 h post-injection varied minimally and response correlated positively with liveweight. No correlations with liveweight and no clear increases in skin-fold thickness occurred at the lower doses of PHA or the PBS.

CONCLUSIONS AND CLINICAL RELEVANCE: This technique could be applied with minimal training and without specialised equipment in deer, for immunological and ecological research.     

不同生长阶段吉林梅花鹿血液生理生化指标分析

本试验通过研究吉林梅花鹿不同生长阶段血液生理生化指标的差异情况,旨在为梅花鹿的健康检测、疾病防治、育种等提供依据和参考。选取吉林省左家、双阳、东丰地区哺乳仔鹿93头（公37头,母56头）、育成鹿135头（公40头,母95头）、成年鹿130头（公42头,母88头）,共358头,进行13项血液生理指标、19项生化指标检测。结果显示：哺乳公鹿与哺乳母鹿各项指标总体上差异不大,仅红细胞系统指标、血糖、肌酸激酶具有显著性差异（P<0.05）;红细胞压积、红细胞平均体积、平均血红蛋白含量、平均血红蛋白浓度、碱性磷酸酶、乳酸脱氢酶在不同性别的育成鹿与成年鹿中差异极显著（P<0.01）。不同生长阶段公鹿天门冬氨酸氨基转移酶、前白蛋白、总胆汁酸、血糖等差异显著（P<0.05）,红细胞系统、肌酸激酶、钙、无机磷、肌酐等差异极显著（P<0.01）,白蛋白、淀粉酶差异不显著（P>0.05）;不同生长阶段的母鹿淋巴细胞总数、红细胞总数、中性粒细胞总数差异显著（P<0.05）,白细胞总数、红细胞系统指标、天门冬氨酸氨基转移酶、丙氨酸氨基转移酶、肌酸激酶、钙、无机磷等差异极显著（P<0.01）,谷氨酰转肽酶、总胆汁酸、白蛋白差异不显著（P>0.05）。以上结果说明,不同生长阶段、不同性别的梅花鹿血液生理生化指标存在较大变异,部分指标的差异可能与梅花鹿生茸、性别等生物学特性有关。对上述生理生化指标的测定,获得了不同性别的梅花鹿在不同生长阶段生理生化指标的参考范围,可为梅花鹿选种育种、疾病诊断、资源开发利用提供一定的参考,也可为野生东北梅花鹿资源保护和健康评估提供依据。     

Hematology of free-living marsh deer (Blastocerus dichotomus) from southeast Brazil.

This work reports basic hematologic values of a sample of a population of free-living marsh deer (Blastocerus dichotomus) living by the Paraná River in Southeast Brazil. Hematologic values are presented separately for male, female, and young animals as well as for anesthetized and nonanesthetized cervids. Nonanesthetized deer restrained by physical means had significantly higher erythrocyte indices and total leukocyte counts. Comparisons of blood parameters of anesthetized animals of different ages and gender differed slightly, with only two significant differences observed: young animals had significantly higher red blood cell counts than adult males and a lower blood total protein content when compared to adult females. Results indicate that two main reference ranges for blood values should be considered for marsh deer, for blood obtained from anesthetized or physically restrained individuals.     

Short interval intradermal skin testing in farmed red deer (Cervus elaphus) inoculated with Mycobacterium bovis

Two groups of 26 red deer (Cervus elaphus) were tuberculin skin tested for 41 weeks at three and six week intervals respectively, except at 17 weeks when the internal was two and five weeks. Seventeen weeks after the start of the experiment 36 deer were inoculated intratracheally with Mycobacterium bovis, and the remaining 16 were run in-contact. At six weeks post inoculation, 35 of the 36 inoculated deer reacted to the skin test with a mean skin thickness difference (STD) of 6.3 mm. In inoculated deer further testing led to a suppression of skin sensitivity which was significantly greater in the three-weekly tested group. There was no statistical difference in skin thickness response between 1 and 2 mg/ml bovine purified protein derivative (PPD). Of 454 tests on noninoculated deer (noninfected), 107 produced reactions. These reactions were small and 96% had a STD of less than 2 mm.     

Hematology in sika deer (Cervus nippon yesoensis Heude, 1884)

Blood samples were taken from 78 wild and 21 farmed sika deer (Cervus nippon yesoensis) using ketamine-xylazine sedation during their excited (82 deer) and resting (17 deer) states. Red cell count (RBC), hemoglobin (Hb), packed cell volume (PCV) and mean corpuscular volume (MCV) were significantly higher and mean corpuscular hemoglobin concentration (MCHC) was lower in excited deer than in resting deer. There was no significant difference in total leukocyte count (WBC) between excited and resting wild males, while a marked increase of WBC with neutrophilia was observed in excited wild females. RBC and PCV were significantly higher and MCH was lower in excited males than in excited females. In wild deer, WBC was significantly higher in females than in males, but there was no significant difference in WBC between farmed males and females. Sex differences in the hematological parameters were not observed in fawns (10 months).     

Sex and age differences in meat composition of Yeso sika deer (Cervus nippon yesoensis) reared for a short period after capture in the wild

Yeso sika deer captured in winter around Lake Akan in Hokkaido were reared for 8–10 months at Tokyo University of Agriculture in Abashiri. Six 1‐year‐old females and males and six 2‐year‐old or older (adult) females and males were slaughtered and their carcasses were processed. The chemical composition, mineral contents and fatty acid composition of the loin were measured. No marked influence of gender or age was noted in the chemical composition of loin. In the mineral contents, significant differences were noted. The potassium and sulfur contents were lower and the sodium content was higher in adult deer meat (P < 0.05, respectively) and the potassium content was higher in male deer meat (P < 0.05). Arsenic, cadmium or lead were not detected. In the unsaturated fatty acid, a significant interaction was detected (P < 0.05), and it was high in 1‐year‐old female deer meat and low in 1‐year‐old male deer meat. Significant gender or age differences were noted only in the mineral contents in the loin of deer reared for a short period after capture.     

Effects of preslaughter handling on the behaviour, blood biochemistry and carcases of farmed red deer

Eight groups of six red deer (four groups of males and four groups of females) were held overnight in an unfamiliar paddock, after which they were moved into a holding pen and slaughtered sequentially by stunning with a captive bolt pistol in a restraining pen. On entering the restraining pen, half the deer in each group were stunned immediately, but the other half were stunned after 10 minutes. Deer spent much of the initial period in the holding pen standing stationary in 'alert' postures, but became less alert over time. A significantly higher proportion of males than females were observed in alert 'head-up' postures in the restraining pen. Deer held in the restraining pen for 10 minutes had significantly higher plasma cortisol concentrations than those which were stunned immediately. Females had a significantly higher glycogen concentration postmortem in both the liver and semimembranosus muscle than males, and deer held in the restraining pen for 10 minutes had a significantly lower liver glycogen concentration than deer which were slaughtered immediately. Males had significantly higher semimembranosus muscle pHu values than females, although the differences were small, and of the 14 deer with pHu values above 6-0, 11 were males.     

阿拉善马鹿冬季肠道菌群组成的性别差异

肠道菌群对于动物消化及健康有着至关重要的作用,但在性别差异上的研究仍然有限。本研究通过高通量测序技术对贺兰山阿拉善马鹿(Cervus elaphus alashanicus)的20个粪便样本进行多样性分析,雌雄各半,并讨论性别因素对肠道菌群的影响。结果表明,阿拉善马鹿雌雄肠道菌群的多样性及结构均存在差异,且雌性肠道菌群的多样性更高。菌群构成的门水平上,雄性肠道菌群的优势菌门为厚壁菌门(Firmicutes 49.47%)和疣微菌门(Verrucomicrobia 14.21%),雌性肠道优势菌门为厚壁菌门(54.47%)和变形菌门(Proteobacteria 54.41%)。在属水平上,雌雄肠道菌群的优势菌属都为孢杆菌属(Sporobacter),含量为(雌性:6.79%,雄性:7.97%),拟杆菌属(Bacteroides),含量为(雌性:3.87%,雄性:4.42%),NMDS分析及LEfSe分析表明,性别因素对阿拉善马鹿雌雄肠道菌群的影响存在显著差异(P<0.05)。本研究表明性别因素对阿拉善马鹿冬季肠道菌群的多样性及构成存在影响,可为深入研究性别因素对阿拉善马鹿肠道菌群的影响提供依据。     

Comparison of concentrations of copper in plasma and serum from farmed red deer (Cervus elaphus)

AIM: To determine the relationship between the concentrations of Cu in plasma and serum in red deer, and to compare this relationship with those previously reported in cattle and sheep.

METHODS: Paired serum and heparinised plasma samples from 114 red deer from 10 herds (n=6-20 per herd) were analysed for concentrations of Cu. Samples were collected either at slaughter (n=84; eight herds) or by jugular venepuncture (n=30; two herds). Thirty-nine of the samples taken at slaughter were from adult hinds from four herds, while other samples were taken from 10–14-month-old males, except for one herd (10 samples) where an equal number of 8–9-month-old males and females were sampled. The effect of age, gender and herd on the relationship between concentrations of Cu in plasma and serum was assessed using univariate ANOVA. The individual results for concentrations of Cu in serum were compared with those in plasma, using limits-of-agreement plotting.

RESULTS: The mean concentration of Cu in plasma was not significantly different from that of serum (0.048; 95% CI=-0.14 to 0.24 µmol/L). There was no effect of age, sex or herd on this relationship.

CONCLUSIONS: In deer, there was no significant difference between concentrations of Cu in plasma and serum regardless of age, sex or herd of origin.

CLINICAL RELEVANCE: In contrast to the situation in cattle and sheep, the concentration of Cu in serum can be used interchangeably with that in plasma for the estimation of concentration of Cu in blood of red deer.     

Prevalence of Toxoplasma gondii antibodies in wild red deer, roe deer, moose, and reindeer from Norway

Serum samples from 4339 wild cervids collected in Norway were tested for antibodies against Toxoplasma gondii using the direct agglutination test. The association between seroprevalence and species, sex, age, and geographic region was investigated. Positive titers (> or =1:40) were found in 33.9% of 760 roe deer (Capreolus capreolus); 12.6% of 2142 moose (Alces alces); 7.7% of 571 red deer (Cervus elaphus); and 1.0% of 866 reindeer (Rangifer tarandus). The seroprevalences were significantly different between the species. There was a significant increase in prevalence with age in roe deer, moose, and red deer, except from yearling to adult in red deer. A significant age-sex interaction was found in moose, and the effect of age was most distinct for females. No association between seropositive animals and sex was found for roe deer and red deer. There were significant differences in prevalence between geographic regions in roe deer and male moose. A widespread exposure to T. gondii in Norwegian cervids is documented, and meat from Norwegian cervids, particularly roe deer, should be regarded a potential source of infection for humans.     

Sex-related macrostructural organization of the deer's brachial plexus

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.     

Unexpected high responses to tuberculin skin-test in farmed red deer: implications for tuberculosis control

Tuberculosis (TB) in deer is a serious zoonotic disease of worldwide distribution. Detection of infected animals is usually performed using single or comparative skin-testing (SST/CST), although false responses due to sensitization to other mycobacteria may occur, hampering diagnostic specificity. We describe the evolution of the responses to the SST, CST and to an in-house serological assay in a red deer farm subjected to regular TB testing in southern Spain in an attempt to understand the dynamics of possible non-specific reactions occurring under field conditions. We performed 2288 skin-tests and ELISAs in nine sampling periods between May 2009 and January 2011. In May 2010, a strong increase in skin fold thickness in response to avian purified protein derivative (PPD) (mean=4.0mm, 95% CI=3.5-4.5) and bovine PPD (mean=1.8mm, 95% CI=1.6-2.0) was observed in yearling deer hinds (n=150), compared to values recorded for the same individuals in November 2009 (avian PPD: mean=0.7 mm, 95% CI=0.6-0.8 and bovine PPD: mean=0.7 mm, 95% CI=0.6-0.7) and in January 2011 (avian PPD: mean=2.2mm, 95% CI=1.9-2.4 and bovine PPD: mean=1.1mm, 95% CI=1.0-1.2). Using SST, 54 animals (36%) of the yearlings tested in May 2010 would have been classified as positive reactors, while none of them was positive in the CST. The five animals with highest skin fold increases to mycobacterial antigens were culled and subjected to post-mortem analysis, which confirmed the absence of Mycobacterium tuberculosis complex (MTBC) infection but demonstrated the presence of environmental mycobacteria and closely related bacteria in four out of the five analyzed animals. Our results demonstrated how non-specific responses to mycobacterial antigens can adversely affect the specificity of TB diagnosis based on the SST. Thus, once TB infection has been ruled out using confirmatory techniques, application of comparative diagnostic tests is highly advisable to maximize test specificity and avoid the slaughter of false positive reactors.     

黑龙江林蛙繁殖期两性皮肤组织结构的差异比较

报道了繁殖期黑龙江林蛙皮肤及其腺体的显微结构特点及两性差别。研究发现：黑龙江林蛙雌雄个体在皮肤特定部位的表皮厚度和皮肤总厚度上存在显著差异;雌蛙各部位真皮致密层都比雄蛙相应部位的致密层厚,且有显著差别。雌雄性蛙色斑不仅存在两性差异,而且构成色斑的色素细胞数量雄蛙明显多于雌蛙;皮肤腺在组成类型和分布上雌雄也有差别,最明显的是雄蛙躯干的背、腹部存在有大量的特殊黏液腺,讨论了这种特殊的黏液腺在生殖行为中可能产生一些化学交流信号和辅助抱对作用。     

Motivations of Female Black Hills Deer Hunters

State fish and wildlife agencies are particularly interested in attracting female participation because of the potential to offset declining participation in hunting. Understanding female hunters’ motivations will be critical for designing effective recruitment and retention programs for women hunters. Although female participation in hunting is increasing, males still outnumber females by about tenfold. Gender differences in deer hunters were explored by comparing ratings of eight motivations (social, nature, excitement, meat, challenge, trophy, extra hunting opportunity, and solitude). Hunter types were defined by hunters’ selection of the most important motivation for why they like Black Hills deer hunting. Overall, females and males were relatively similar in their ratings of the eight motivations, and we found 85% gender similarity in the selection of the most important motivation. Women were slightly more motivated by the food aspect of the hunt while men placed slightly more value on the hunt as a sporting activity.     

The efficacy of the skin delayed-type hypersensitivity using a Brucellin prepared from a mucoid strain of Brucella abortus to detect brucellosis

Eight-hundred-and-ninety-six cattle belonging to herds officially designated Brucella-free, and 190 cattle belonging to infected herds were tested with the skin delayed-type hypersensitivity (SDTH) test, using brucellin (273) prepared from a mucoid strain of Brucella abortus. An increase in skinfold thickness > or = 2 mm was considered a positive SDTH test. The serum agglutination test, complement fixation test and bacteriological examination were used to confirm SDTH test results. Results show that 6 of the 896 uninfected cattle tested positive in the SDTH test, indicating a 99.3% specificity. Of the 44 cattle that tested serologically or bacteriologically positive, 33 tested positive in the SDTH test, indicating a 75% sensitivity. The value of the SDTH test was demonstrated by its ability to detect infection earlier than serological tests, and by confirming infection in cattle with ambiguous serological test results. An increase in skinfold thickness > or = 1 mm in cattle in suspected herds should not be ignored, as it may indicate specific sensitization. We recommend the use of the SDTH test in combination with serological tests for early diagnosis of brucellosis in cattle.     

The effect of Johne's vaccination on tuberculin testing in farmed red deer (Cervus elaphus)

AIM: To assess the degree of interference with bovine tuberculin testing in farmed red deer that vaccination of young deer with an oil-adjuvanted vs aqueous formulation of live attenuated Mycobacterium paratuberculosis Strain 316F vaccines would be likely to cause, and to compare immunological responses between vaccine formulations. METHODS: Five-month-old red deer (n = 45) were randomly allocated to three treatment groups of 15 animals, which received either no vaccine, a single 2-ml dose of an oil-adjuvanted formulation or two 2-ml doses, 6 weeks apart, of an aqueous formulation of live attenuated M. paratuberculosis Strain 316F vaccine injected subcutaneously (S/C) in the neck (Control, Oil-adjuvant Ptb, and Aqueous Ptb groups, respectively). Injection- site reactions were described and measured on Weeks 3, 6 and 9. Animals were weighed and lymphocyte transformation tests (LTT) and antibody enzyme-linked immunosorbent assays (ELISA) using avian, bovine and Johnin tuberculin were conducted on blood samples collected at Weeks 0, 6, 12, 15, 24, 27, 36 and 39. A bovine mid-cervical skin test (MCT) was applied at Week 12, and comparative cervical skin tests (CCTs) at Weeks 24 and 36. At Week 42, the animals were slaughtered at a commercial deer slaughter premises and subjected to rigorous meat inspection. RESULTS: Two animals were eliminated at the start of the trial due to a positive cross-reaction with bovine tuberculin in the initial LTT. Almost all animals reacted to the MCT at Week 12, with mean skin thicknesses of 3.9, 2.9 and 1.0 mm for the Oil-adjuvant Ptb, Aqueous Ptb and Control groups, respectively. When the CCT was conducted at Week 24, 2/15 Oil-adjuvant Ptb, 2/14 Aqueous Ptb and 1/14 Control animals were classified as CCT-positive to bovine tuberculin. By Week 36, all animals were CCT-negative. The Oil-adjuvant Ptb vaccination resulted in high persistent levels of antibody that reacted with bovine tuberculin, compared with negligible levels in the Aqueous Ptb group. Overall, a single dose of the Oil-adjuvant Ptb vaccine in deer stimulated a vigorous, cross-reactive immune response, evidenced by high LTT, skin-test and antibody reactions to bovine tuberculin, with both cell-mediated and humoral characteristics. By comparison, two doses of the Aqueous Ptb vaccine produced less cross-reactivity and a bias towards a cell-mediated response. The Oil-adjuvant Ptb vaccine resulted in moderate injection site lesions that were quite persistent, whereas the Aqueous Ptb vaccine resulted in smaller nodules that regressed more quickly. CONCLUSIONS: Vaccination of farmed deer with an oil-adjuvanted Johne's vaccine has the potential to cause significant interference with routine tuberculin skin testing. The cross-reactivity should decline with time and the CCT should be able to clear MCT-positives, but there is a risk of false-positives to the blood test for tuberculosis (BTB), due to high persistent levels of antibody. The CCT could be used as a primary skin test in vaccinated deer on some farms. The Aqueous Ptb caused fewer problems with skin testing and produced significantly less bovine antibody than the Oil-adjuvant Ptb, but stimulated persistent cell-mediated immune responses that may provide some protection against Johne's disease.     

Survey of permanent wound tracts in the carcases of culled wild red deer in Scotland

The number and sites of permanent wound tracts in the carcases of 943 wild culled red deer (Cervus elaphus) were recorded. During the peak period of the red deer rut there was a significant increase in the number of these tracts in the carcases, which was associated with a decrease from 89 per cent to 71 per cent in the probability of the first permanent wound tract also being the last (the terminal probability). There were significantly more permanent wound tracts in the carcases of one group (predominantly males) than in a second group (predominantly females and calves). In carcases with a single tract in the trunk, in which the heart and lungs were also examined, 80 per cent had tracts involving the heart and/or lungs, the recommended thoracic target organs. Tracts involving vital structures in the neck were also common, with 15.3 per cent of the carcases with a single permanent tract having damage limited to cervical structures.     

北京地区荷斯坦奶牛皮肤褶皱厚度与泌乳性能关系的研究

本研究通过测定荷斯坦奶牛肋部和颈部皮肤褶皱厚度,探究了皮肤褶皱厚度的影响因素及其与泌乳性能的关系。利用数显游标卡尺测量荷斯坦奶牛肋部和颈部皮肤褶皱厚度,评定奶牛体况,并收集皮肤褶皱厚度测量月份试验牛场的奶牛生产性能数据,共得到2 519头奶牛的数据用于分析。利用固定效应模型分析胎次、牛场、测定人、泌乳阶段、体况评分对奶牛皮肤褶皱厚度的影响,皮肤褶皱厚度对泌乳性能影响的分析模型中同样包括上述固定效应。结果表明胎次、牛场、测定人、泌乳阶段、体况评分对荷斯坦奶牛皮褶厚均有极显著影响（P < 0.01）,肋部皮肤褶皱厚度对泌乳性能无显著影响（P > 0.05）,而颈部皮肤褶皱厚度对日产奶量、乳脂率影响显著（P < 0.05）,颈部皮肤褶皱厚度对乳蛋白率、尿素氮无显著影响（P > 0.05）。颈部皮褶厚为7.20 mm的个体日产奶量最高;颈部皮褶厚为6.00 mm的个体,乳脂率最低。本研究进一步阐明了荷斯坦奶牛泌乳期内不同部位皮肤褶皱厚度的影响因素,并首次利用大群数据区分不同部位研究了皮肤褶皱厚度对泌乳性能的影响,为利用皮肤褶皱厚度提高奶牛管理效率提供科学依据。