Poczynek Milaine, Nogueira Larissa de Souza, Carrari Isabela Fonseca, Carneiro Jorge Henrique, Almeida Rodrigo de
Department of Animal Science, Universidade Federal do Paraná, Rua dos Funcionários 1540, Curitiba 80035-050, Paraná, Brazil.
Animals (Basel). 2023 Feb 8;13(4):596. doi: 10.3390/ani13040596.
This study aimed to evaluate the impact of body condition score (BCS) at calving, parity, and the calving season on the performance of dairy cows and their offspring. Data from 521 Holstein cows that calved a female calf and had their BCS evaluated at calving from a single commercial farm located in Southern Brazil were used. Cows were categorized into five BCS classes: class 1: <3.0 ( = 19), class 2: 3.0-3.25 ( = 134), class 3: 3.5-3.75 ( = 160), class 4: 4.0-4.25 ( = 142), and class 5: >4.25 ( = 66). Data were also categorized by calving order (primiparous and multiparous dams) and by calving season. The study was designed as a prospective cohort study. Variables with normal distribution were analyzed by the MIXED procedure of SAS, while binary outcomes were analyzed by the GLIMMIX procedure of SAS. Daughters from primiparous dams were born lighter (39.1 ± 0.42 vs. 41.4 ± 0.29 kg, < 0.01), but they had the same weights as the daughters from multiparous cows at weaning (121.5 ± 1.67 vs. 120.4 ± 1.58 kg, = 0.20). As expected, primiparous cows showed lower ( < 0.01) 305-day milk yields than multiparous ones: 8633 ± 363 vs. 10,761 ± 249 kg, respectively. Regarding the calving season, cows that calved in the winter were the most productive ones, and those that calved in the fall had lower milk yields ( = 0.01). Calves born in the winter were heavier at birth ( < 0.01), calved younger ( = 0.04), and produced more milk at first lactation ( = 0.03). The BCS class had an impact ( < 0.01) on calf birth weights; daughters from Class 1 cows (BCS < 3.0) were lighter (38.0 ± 1.0 kg) than the calves from Class 5 cows with a BCS > 4.25 (41.9 ± 0.57 kg). Calves from dams with a BCS < 3 (Class 1) had a 31.8% culling rate until weaning, while calves from cows with a BCS of 3.0-3.25 (Class 2) had a 9.6% culling rate ( = 0.12). These results suggest that maternal and environmental factors, such as calving season and parity, in addition to the dams' body condition score at calving, are associated with different offspring performances.
本研究旨在评估产犊时的体况评分（BCS）、胎次和产犊季节对奶牛及其后代生产性能的影响。使用了来自巴西南部一个商业农场的521头荷斯坦奶牛的数据，这些奶牛产下了雌性犊牛，并且在产犊时进行了BCS评估。奶牛被分为五个BCS等级：1级：<3.0（n = 19），2级：3.0 - 3.25（n = 134），3级：3.5 - 3.75（n = 160），4级：4.0 - 4.25（n = 142），5级：>4.25（n = 66）。数据还按产犊顺序（初产和经产母牛）和产犊季节进行了分类。该研究设计为前瞻性队列研究。正态分布的变量通过SAS的MIXED过程进行分析，而二元结果通过SAS的GLIMMIX过程进行分析。初产母牛的女儿出生时体重较轻（39.1 ± 0.42 vs. 41.4 ± 0.29 kg，P < 0.01），但在断奶时它们与经产母牛的女儿体重相同（121.5 ± 1.67 vs. 120.4 ± 1.58 kg，P = 0.20）。正如预期的那样，初产母牛的305天产奶量低于经产母牛（P < 0.01）：分别为8633 ± 363 vs. 10761 ± 249 kg。关于产犊季节，冬季产犊的奶牛生产性能最高，秋季产犊的奶牛产奶量较低（P = 0.0）。冬季出生的犊牛出生时较重（P < 0.01），产犊时年龄较小（P = 0.04），并且在第一次产奶时产奶量更多（P = 0.03）。BCS等级对犊牛出生体重有影响（P < 0.01）；1级奶牛（BCS < 3.0）的女儿比BCS > 4.25的5级奶牛的犊牛轻（38.0 ± 1.0 kg）。BCS < 3（1级）的母牛所生犊牛在断奶前的淘汰率为31.8%，而BCS为3.0 - 3.25（2级）的母牛所生犊牛的淘汰率为9.6%（P = 0.12）。这些结果表明，除了产犊时母牛的体况评分外，诸如产犊季节和胎次等母体和环境因素与后代的不同生产性能相关。
