Effects of photoperiod during the dry period on cellular immune function of dairy cows
Effects of photoperiod during the dry period on cellular immune function of dairy cows
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DOI：
10.3168/jds.s0022-0302(04)73507-9
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发表时间：
2004-11-01
影响因子：
3.5
通讯作者：
Dahl, GE
中科院分区：
文献类型：
--
作者：
Auchtung, TL;Salak-Johnson, JL;Dahl, GE
最近的研究表明，牛暴露于光周期会影响免疫功能。本研究的目的是确定相对于接受长日照周期（LDPP；16 小时光照：8 小时黑暗）的奶牛，在干奶期对奶牛进行短日光周期（SDPP；8 小时光照：16 小时黑暗）处理是否会改变免疫功能。经产荷斯坦奶牛（n = 39）在产犊前 62 d 进行干燥，并接受光周期处理直至分娩；此后，将奶牛暴露在自然光周期下。在干奶期每周监测一般健康状况，并在干奶期和产犊时每月检查细胞免疫功能。从产犊前10天到产犊后2天测量催乳素和皮质醇的浓度。 LDPP 奶牛的围产期血浆催乳素激增 (54.6 ng/mL) 高于 SDPP (22.4 ng/mL)。相对于LDPP奶牛，SDPP奶牛在干奶期中性粒细胞趋化性和淋巴细胞增殖增强。在干燥期间，LDPP 和 SDPP 的中性粒细胞趋化性平均分别为 142.5 和 178.8 个细胞/孔。 LDPP 和 SDPP 奶牛在干奶期的淋巴细胞增殖率平均分别为 197.6% 和 326.5%。奶牛的生理特征没有受到干奶期处理的影响。然而，在分娩后 2 天内观察到治疗之间的差异。光周期管理对奶牛健康和福祉的潜在影响值得进一步研究。
Recent studies suggest that exposure of cattle to photoperiod can influence immune function. The objective of this study was to determine whether treatment of cows with short day photoperiod (SDPP; 8 h light: 16 h darkness) during the dry period alters immune function, relative to cows subjected to a long day photoperiod (LDPP; 16 h light: 8 h darkness). Multiparous Holstein cows ( n = 39) were dried 62 d before calving and exposed to photoperiod treatment until parturition; thereafter, cows were exposed to natural photoperiod. General health was monitored weekly during the dry period and cellular immune function was examined monthly during the dry period and at calving. Concentrations of prolactin and cortisol were measured from 10 d before calving to 2 d after calving. The periparturient prolactin surge in plasma was greater in LDPP cows (54.6 ng/ mL) than SDPP (22.4 ng/ mL). Relative to LDPP cows, neutrophil chemotaxis and lymphocyte proliferation were enhanced in SDPP cows during the dry period. Neutrophil chemotaxis averaged 142.5 and 178.8 cells/ well during the dry period for LDPP and SDPP, respectively. Lymphocyte proliferation during the dry period averaged 197.6 and 326.5% for LDPP and SDPP cows, respectively. Physiological characteristics of the cows were not affected by treatment during the dry period. However, differences between treatments were observed within 2 d of parturition. Potential implications of photoperiod management for cow health and wellbeing merit further investigation.