Department of Veterinary Sciences, Institute of Agricultural and Veterinary Sciences, University of Souk-Ahras, Souk Ahras, 41000, Algeria.
Laboratory of Science and Techniques for Living, University of Souk-Ahras, Souk Ahras, 41000, Algeria.
Int J Biometeorol. 2024 Dec;68(12):2515-2529. doi: 10.1007/s00484-024-02761-y. Epub 2024 Aug 19.
The present study investigates the susceptibility of two imported dairy cattle breeds to Algerian local climatic conditions, with a primary focus on heat stress (HS) and its repercussions on fertility traits. The dataset comprises 20,926 artificial insemination records involving 6,191 Prim'Holstein and 5,279 Montbéliarde cows. The animals originated from three distinct agro-ecological regions: littoral (L), semi-arid (SA), and arid (Ar), characterized by average annual Temperature-Humidity Index (THI) values of 75.2, 69.53, and 74.75, respectively. Logistic and linear regression models were performed to analyze the relationship between the THI on the AI day, season, and agro-ecological origin of the animals with the Conception Rate at 1st Artificial Insemination (CR 1stAI), Conception Risk (CR), Services per Conception (SPC), and reproductive period (RP). The results demonstrated a significant negative impact (P < 0.001) of THI > 72 compared to THI ≤ 72 on CR1st AI and CR for both cattle breeds (Prim'Holstein: -49.7% and - 17%, respectively; Montbéliarde: -20.7% and - 15%, respectively). Seasonal effects revealed a notably higher CR1stAI in winter and spring (≈ 25%) for Prim'Holstein and Montbéliarde cows compared to summer (19.41%) and autumn (19.12%), respectively. Furthermore, a reduced likelihood of conception at 1stAI and subsequent AI was observed during summer (0.839) and autumn (0.818) compared to winter for the Montbéliarde cows. Taking into account the littoral region as a reference, the likelihood of 1stAI success increased for both breeds in the SA region and decreased for the Ar region (P < 0.001). SPC increased for both breeds in THI > 72 categories (Prim'Holstein: 6.3%, Montbéliarde: 7.1%, P < 0.01), in the Ar region (Prim'Holstein: 30.9%, Montbéliarde: 26%, P < 0.001), and in the SA region (4%, P < 0.05) compared to the L region No significant seasonal effect on SPC was observed for either breed (P > 0.05). The RP increased in the THI > 72 category (Prim'Holstein: 4.1%, Montbéliarde: 7.4%, P < 0.001) and in the Ar region (Prim'Holstein: 122%, Montbéliarde: 73.4%) for both breeds. RP decreased in autumn compared to winter (Prim'Holstein: 15.3%, Montbéliarde: 8.4%). This study underscores the adverse impact of mild to severe heat stress (HS) and related factors (season, region) on fertility of Prim'Holstein and Montbéliarde cows under Algerian conditions, emphasizing the necessity for heat stress mitigation strategies, especially in adverse littoral humid and Saharan-arid environmental conditions.
本研究旨在调查两种进口奶牛品种对阿尔及利亚当地气候条件的敏感性，重点关注热应激（HS）及其对繁殖性能的影响。该数据集包含 20926 次人工授精记录，涉及 6191 头荷斯坦和 5279 头蒙贝利亚奶牛。这些动物来自三个不同的农业生态区：沿海（L）、半干旱（SA）和干旱（Ar），其平均年温度-湿度指数（THI）值分别为 75.2、69.53 和 74.75。使用逻辑和线性回归模型分析了授精当天、季节和动物的农业生态起源的 THI 与首次人工授精的受孕率（CR1stAI）、受孕风险（CR）、每配种受胎率（SPC）和繁殖期（RP）之间的关系。结果表明，THI>72 与 THI≤72 相比，对两种牛的 CR1stAI 和 CR 有显著的负面影响（P<0.001）（荷斯坦牛：分别为-49.7%和-17%；蒙贝利亚牛：分别为-20.7%和-15%）。季节性效应表明，荷斯坦牛和蒙贝利亚牛在冬季和春季的首次 AI 受孕率明显更高（约 25%），而在夏季（19.41%）和秋季（19.12%）较低。此外，蒙贝利亚牛在夏季（0.839）和秋季（0.818）比冬季的首次 AI 和后续 AI 的受孕可能性降低。考虑到沿海地区作为参考，两种品种在 SA 地区的首次 AI 成功率增加，而在 Ar 地区的成功率降低（P<0.001）。两种品种在 THI>72 类别中 SPC 增加（荷斯坦牛：6.3%，蒙贝利亚牛：7.1%，P<0.01），在 Ar 地区（荷斯坦牛：30.9%，蒙贝利亚牛：26%，P<0.001）和 SA 地区（4%，P<0.05）与 L 地区相比，首次 AI 受孕率的季节性效应不显著（P>0.05）。两种品种的繁殖期在 THI>72 类别中增加（荷斯坦牛：4.1%，蒙贝利亚牛：7.4%，P<0.001）和在 Ar 地区增加（荷斯坦牛：122%，蒙贝利亚牛：73.4%）。繁殖期在秋季比冬季减少（荷斯坦牛：15.3%，蒙贝利亚牛：8.4%）。本研究强调了轻度至重度热应激（HS）及其相关因素（季节、地区）对阿尔及利亚条件下荷斯坦牛和蒙贝利亚牛繁殖性能的不利影响，强调了需要采取热应激缓解策略，特别是在沿海潮湿和撒哈拉干旱的不利环境条件下。
