Associations between anogenital distance and measures of fertility in lactating North American Holstein cows: A validation study

Carrelli, J.E.; Gobikrushanth, M.; Corpron, McKenzie; Sandberg, W.; Rajesh, I.; Ahmadzadeh, A.; Oba, M.; Ambrose, D.J.

doi:10.3168/jds.2021-20827

Cited by 8 publications

(7 citation statements)

References 35 publications

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“…The distribution of short-and long-AGD cows within parity groups based on the 2 different AGD cut-points of 148 and 142 mm, and their corresponding mean, minimum, and maximum AGD are presented in Table 1. The mean (± SD) AGD in the present study was 142 ± 12.5 for all parities combined, which is 10 to 11 mm larger than previously reported for North American Holstein cows of mixed parities (Gobikrushanth et al, 2017;Carrelli et al, 2022). The reasons attributable to the increased AGD of cows in this herd may be the larger-than-average frame size of cows in this herd (personal communication from the herd manager) and lower-than-average herd replacement rate (27% vs. the provincial average of 47%) resulting in a greater proportion of third+ parity cows (49% vs. the provincial average of 35%).…”

Section: Descriptive Statisticscontrasting

confidence: 69%

“…Anogenital distance data from cows that were up to 14 d after calving and pregnant cows that were >180 d of gestation at the time of AGD measurement were excluded from all analyses. The early postpartum cows were excluded because of the possible influence of parturient trauma on AGD (Gobikrushanth et al, 2017) and cows >180 d of gestation at AGD measurement were excluded to avoid potential increase in AGD associated with gestational age (Rajesh et al, 2022). After applying these filters, data from 178 cows (55 primiparous, 123 multiparous) were used in the final analyses.…”

Section: Anogenital Distance Measurementmentioning

confidence: 99%

“…After applying these filters, data from 178 cows (55 primiparous, 123 multiparous) were used in the final analyses. Because AGD is a phenotype that is consistent through most physiological states and not affected by the stage of lactation in Holstein cows (Rajesh et al, 2022), one measurement was considered sufficient. All AGD measurements and estrus alerts (AAM data) were collected during the same lactation and the associations were evaluated retrospectively.…”

Section: Anogenital Distance Measurementmentioning

confidence: 99%

“…An inverse relationship was found, with the odds of pregnancy at first AI declining by 3.5% for every 1-mm unit increase in anogenital distance (P < 0.01). The data presented in this figure are a subset (<4%) of a larger data set reported elsewhere (Carrelli et al, 2022).…”

Section: Descriptive Statisticsmentioning

confidence: 99%

“…Although the inverse association between AGD and fertility in dairy cows first reported by Gobikrushanth et al (2017) has been confirmed by others in dairy cows (Akbarinejad et al, 2019;Grala et al, 2021;Carrelli et al, 2022), dairy heifers (Carrelli et al, 2021) and partially in beef cattle (Battista, 2019), the underlying physiological factors contributing to fertility differences between short-and long-AGD cattle have not been investigated. Determining the associations between AGD and estrous behavior characteristics, ovarian function and progesterone concentrations will help improve our understanding of the mechanisms at play.…”

Section: Introductionmentioning

confidence: 97%

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Anogenital distance is associated with postpartum estrous activity, intensity of estrous expression, ovulation, and progesterone concentrations in lactating Holstein cows

Madureira

Burnett

Carrelli

et al. 2022

Journal of Dairy Science

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The objectives of this retrospective observational study were to determine the associations of anogenital distance (AGD) with (a) postpartum estrous activity, (b) diameter of the preovulatory follicle, (c) intensity of estrous expression, (d) postestrus ovulation, (e) corpus luteum (CL) size, and (f) concentrations of progesterone at estrus and on d 7 after estrus. Lactating Holstein cows (n = 178; 55 primiparous, 123 multiparous) were enrolled into the study during the first postpartum week. All cows were continuously monitored by a pedometer-based automated activity monitoring (AAM) system for estrus. Postpartum estrous activity was assessed using the AAM estrus alerts, in which cows with at least one true estrus alert (i.e., a relative increase in steps from each cow's baseline detected by the AAM and the presence of at least one follicle >15 mm, a CL <20 mm, or no CL detected by ultrasound) by the first 50 d in milk (DIM) were considered to have commenced estrous activity. At the estrus alert >60 DIM, ovulation was determined by ultrasound at 24 h, 48 h, and 7 d after estrus, and blood samples were collected at estrus alert and on d 7 after estrus for progesterone analysis. The AGD was measured from the center of the anus to the base of the clitoris and classified as either short-or long-AGD using 2 cut-points of 148 mm (predictive of the probability of pregnancy to first insemination; short-AGD, n = 115; long-AGD, n = 63) and 142 mm (the median AGD; short-AGD, n = 90; long-AGD, n = 88). Regardless of the cut-point used, early postpartum estrous activity by 50 DIM (67 vs. 54%), duration of estrus (11.6 vs. 9.7 h), and preovulatory follicle diameter (20 vs. 19 mm) were greater in short-AGD than in long-AGD cows. Increased peak of activity at estrus in short-AGD cows (354 vs. 258% mean relative increase) was affected by an interaction between AGD and parity in which multiparous long-AGD cows had lesser relative increase in activity than primiparous cows (217 vs. 386%, respectively). Mean progesterone concentration at estrus was lesser in short-AGD (0.47 vs. 0.61 ng/mL) than in long-AGD cows. The ovulatory response at 24 h did not differ, but at 48 h (91 vs. 78%) and on d 7 after estrus (97 vs. 84%) it was greater in short-AGD cows. Although CL diameter on d 7 after estrus did not differ, short-AGD cows had greater progesterone concentration 7 d after estrus than long-AGD cows (4.1 vs. 3.2 ng/mL, respectively). In conclusion, greater proportions of short-AGD cows commenced estrous activity by 50 DIM, had larger preovulatory follicles, exhibited greater duration of estrus, had reduced progesterone concentration at estrus, had greater ovulation rates and progesterone concentration 7 d after estrus compared with long-AGD cows, with no difference in CL size between AGD groups. Because all the differences in physiological characteristics of short-AGD cows reported herein favor improved reproductive outcomes, we infer that these are factors contributing to improved fertility reported in short-AGD cows compared with lo...

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Section: Descriptive Statisticscontrasting

confidence: 69%

Section: Anogenital Distance Measurementmentioning

confidence: 99%

Section: Anogenital Distance Measurementmentioning

confidence: 99%

Section: Descriptive Statisticsmentioning

confidence: 99%