The possible relationship between udder morphometric variables (UMVs), chemical quality (CHQ) of both colostrum (CA), and milk (MK), as affected by goat’s social rank (SR) (i.e., low-LSR, or high-HSR), was assessed. In late June, goats (Alpine–Saanen–Nubian x Criollo; n = 38; 25° N) were estrus-synchronized and subjected to a fixed-time artificial insemination protocol. Thereafter, in October, while a behavioral study was performed in confirmed-pregnant goats to define the SR classes (n = 15), live weight (LW), body condition (BCS), and serum glucose (GLUC) were registered on the last day of the behavioral study. The expected kidding date was 25 November. Both the UMVs (i.e., seven dates) and the CHQ (i.e., either one for CA and three times for MK) were collected across time (T). The UMVs involved udder perimeter (UDPER, cm), udder diameter (UDDIA, cm), left-teat (LTPER, cm) and right-teat perimeter (RTPER, cm), left-teat (LTLT, cm) and right-teat length (RTLT, cm), left-teat diameter (LTDIA, cm) and right-teat diameter (RTDIA, cm), and medium suspensory ligament (MSL, cm). The registered CHQ variables for both CA and MK were fat (FAT), protein (PRO), lactose (LAC), nonfat solids (NFS), freezing point (FP), and total solids (TS). The possible effect of SR, T, and the SR × T interaction upon the described response variables was tested. While LW favored the HSR goats (54.6 vs. 48.2 ± 1.7 kg; p < 0.05), neither BCS nor GLUC differed (p > 0.05) between SR. An SR × T interaction affected (p < 0.05) most UMVs (i.e., UDPER, MSL, LTLT, RTLT, LTDIA, and RTDI). UMV differences were associated with both changes across time and between SR. Whereas RTLT, LTDIA, RTDIA, and MSL showed their highest values one week prior to kidding, the largest UDPER values (p < 0.05) occurred within the week of kidding. Additionally, HSR goats showed increased values regarding UDPER, MSL, and LTLT. No differences (p < 0.05) between SR occurred regarding the CA-CHQ (i.e., FAT, PRO, LAC, NFS, FP, and TS). Still, an SR x T interaction affected (p < 0.05) the MK content of FAT, PRO, and NFS; while the largest values (p < 0.05) occurred on Day 7 postpartum, the other MK constituents decreased as the lactation advanced. Further, the HSR goats showed an enlarged MK-CHQ (i.e., FAT, PRO, and NFS). HSR goats merged some central behaviors such as aggressiveness, assertiveness, and supremacy to have primacy to feed access, augmenting their LW. Whereas said bodyweight advantage was not reflected upon in CA-CHQ, HSR goats augmented some morphological udder values (i.e., UDPER, MSL, and LTLT) and produced the best MK-CHQ (i.e., > FAT, > PRO, and > NFS) during early lactation. Therefore, both social rank (i.e., HSR goats), as well as the temporal transition stage from the last third of pregnancy to the first phase of lactation (i.e., time), operated as important modulators upon both udder architecture and milk quality in crossbred dairy goats under a dry-semiarid production system.

We evaluated the possible effect of maternal social rank (SR) concerning different morpho-physiological maternal indicators such as live weight (LWM, kg), body condition score (BCS, units), thoracic diameter (TD, cm), thoracic perimeter (TP, cm), and serum glucose content (GLU, mg dL⁻¹), upon the kid’s live weights (LWGK, kg) during the birth-to-weaning period. To define the SR [either high (HSR) or low (LSR)], a behavioral study was conducted on pregnant goats managed under semi-extensive conditions in northern arid Mexico (25° N; Alpine–Saanen–Nubian × Criollo; n = 15, 2–3 y/old) 30 days before the expected kidding date. The behavioral study was conducted during feeding time (i.e., 08:00, 13:00, and 17:00; 60 min test⁻¹, 180 min d⁻¹). The HSR goats showed higher values (p < 0.05) regarding prepartum, parturition, postpartum weights, and zoometric values. However, no differences (p > 0.05) between HSR and LSR goats occurred concerning the maternal serum glucose values, litter size, individual kid weights, or litter weights at weaning.

The objective of this research was to evaluate the effect of two doses of hCG (100 and 300 IU) administered at two different times after fixed-time artificial insemination (FTAI) on some response variables related to early fetal loss and total litter weight in goats during the reproductive transition period. Crossbred multiparous goats (n = 40) were subjected to an estrus induction protocol, subsequently inseminated, and randomly distributed into five experimental groups (n = 8): (1). G100-7, 100 IU hCG, 7 d post FTAI; (2). G100-14, 100 IU hCG, 14 days post FTAI; (3). G300-7, 300 IU hCG, 7 d post FTAI; (4). G300-14, 300 IU hCG, 14 days post FTAI; and (5). CONT, 0.5 mL of saline solution, 7 and 14 days post FTAI. The variables of corpus luteum area, embryonic implantation rate, embryonic efficiency index 1 and 2, conception rate, fertility rate, fecundity rate, fetal losses at days 30 and 45, total fetal losses, and the total weight of the litter favored G300-14. The use of hCG (300 IU) in the reproductive transition period is an effective reproductive strategy, reducing early fetal losses, improving embryonic efficiency, and increasing total litter weight, all of which are fundamental to the reproductive success of marginal goat production systems.