Pregnancy Loss (28–110 Days of Pregnancy) in Holstein Cows: A Retrospective Study

Abstract

The objective of this retrospective study was to investigate the prevalence of pregnancy loss (PL; between 28–110 pregnancy days) and its relationship with factors: farm, year (2015–2018), season, artificial insemination (AI)-rank, parity, AI-type (fixed-time vs. oestrus-AI), previous PL, days in milk (DIM), fixed-time-AI protocol, AI-technician, bull, and semen-type (sexed vs. conventional). Data of 19,437 Holstein cattle AIs from eight Spanish farms were studied. Overall conception rate was 34.3% (6696/19,437) and PL 12.3% (822/6696). The PL was more likely to occur in primiparous (10.8%, odds ratio (OR) = 1.35; p = 0.04) and multiparous (15.3%; OR = 2.02, p < 0.01) than in heifers (PL = 6.9%, reference). Pregnancies achieved with AI after observed oestrus and natural breedings were associated with less PL than pregnancies after fixed-time-AI (12.7 vs. 11.9%; OR = 0.12, p = 0.01). First AIs related to higher PL than ≥2nd AIs (PL = 13.8% vs. 11.2; OR = 0.73, p < 0.01). The factors season, fixed-time-AI protocol, DIM, bull, AI-technician, or type of semen were not significantly associated with PL. Therefore, farmers and consultants should adapt their preventive strategies relating to PL, particularly, to the parity of the cattle.

The Effect of Stress on Reproduction and Reproductive Technologies in Beef Cattle—A Review

“…All these changes lower the fertilization rate and reduce the quality of any resulting embryos, increasing the risk of pregnancy loss and decreasing reproductive performance. This has been observed in beef cattle [ 152 ] and dairy cattle [ 153 , 154 ].…”

Supervivencia de la gestación en vacas Holstein asociada a la paridad y biotipo en Uruguay

“…Además, en la interacción de los biotipos y paridades, las HNA primíparas + multíparas presentaron un mayor riesgo de PDG (RR = 2,0; IC 95 %: 1,1 -3,7; P = 0,02) que las HNZ nulíparas. Este resultado nos lleva a considerar que la consistente selección generacional basada principalmente en la producción láctea del biotipo HNA, donde los altos niveles de producción de leche genera un mayor estrés metabólico (Fernández-Novo et al, 2020;Wiltbank et al, 2016) y una mayor pérdida de condición corporal en el posparto temprano (Fricke et al, 2022) en las primíparas y multíparas debido a…”

Noninfectious Causes of Pregnancy Loss at the Late Embryonic/Early Fetal Stage in Dairy Cattle

“…Remarkably, higher pregnancy loss rates were observed in the third and fourth parities of Simmental cows compared to those of heifers, primiparous cows, and cows in their second lactation [55]. In contrast, Fernandez-Novo et al [56] detected no effect of parity on conceptus mortality rates, reporting a 15% pregnancy loss rate in multiparous cows. However, losses as low as 3%-5% have been reported in primigravid animals [55,57,58].…”