Longitudinal monitoring of ovarian status in lactating Alpine goats during seasonal anestrus

This dataset describes the changes in the number of ovarian follicles ≥ 2 mm and corpora lutea in lactating primiparous and multiparous Alpine goats during the seasonal anestrus (February to September). All animals kidded in January, marking the start of the study, and were dried off at the end of August, shortly before its conclusion in September. The experiment consisted of two independent replicates, carried out in 2008 (n = 8) and 2009 (n = 8). The goats were housed in an open conventional barn and exposed to natural photoperiod. They were milked twice daily, at 08:00 and 17:00. The diet consisted of second- and third-cut alfalfa hay supplemented with 1.2 to 1.6 kg/day of concentrate depending on lactation stage. The concentrate was composed of soybean meal (200–300 g), dehydrated alfalfa (400 g), and maize (400–600 g). Ovarian status was assessed by transrectal ultrasonography using an Aloka SSD 500 scanner equipped with a 5‑MHz linear rectal probe (UST‑5820‑5). For each scanning session, all follicles ≥ 2 mm and visible corpora lutea were counted and measured separately for the right and left ovaries. In 2008, ultrasonography was performed once weekly from 7 February to 10 April (end of the breeding season), then three times per week during mid‑anestrus in weeks 16 (14, 16, 18 April), 23 (2, 4, 6 June) and 29 (15, 16, 18 July), and finally once weekly from 23 July to 1 October (end of anestrus). In 2009, scans were performed once weekly from 12 February to 4 March, then five times per week during mid‑anestrus in weeks 15 (6–10 April), 22 (25–29 May) and 26 (22–26 June), and once weekly from 30 July to 24 September. Ultrasound images were stored on magnetic tapes. Ovarian observations were recorded in real time on paper for each ovary and subsequently verified and corrected when necessary, using the video recordings before being entered into an Excel file. The video records are not included in the dataset. The dataset also provides individual animal information, including birth date, kidding date, age, and body weight, as well as a series of figures for data visualization.