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Simple Summary: In the arid lands of Northern Mexico, there are several dairy cattle clusters managed under intensive production systems and fed completely with mixed rations, yet 3–5% feed rejection of the total ration offered has been reported. This surplus feed retains a high nutritional value which could be used to improve the reproductive efficiency of goats managed under marginal–extensive schemes. Therefore, we visualized an interesting research opportunity based on the circular economy approach. We hypothesized that a short-term supplementation with feed leftovers from dairy farms (i.e., intensive system) will increase the reproductive outcomes of rangeland managed goats (i.e., extensive system), trying to promote the circularity/connectedness between two highly discordant production systems. Our study intended to elucidate this working hypothesis. Based on a circular economy approach, we evaluated the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) on the reproductive performance of crossbred/rangeland goats (i.e., extensive system) in arid Northern Mexico. During the deep-anestrous season (i.e., March–April, 25° North), multiparous goats (n = 38) with a similar body weight (BW) and body condition score (BCS) were randomly assigned to two groups: (1) supplemented group (SG; n = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg), receiving 400 g goat d−1 of dairy-cow-feed leftovers prior to grazing; and (2) non-supplemented group (NS; n = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg). Both groups were directed to the rangeland for a period of ≈8 h. While the experimental period lasted 36 d, the experimental breeding considered 11 d (d0–d10). The anovulatory status of goats was ultrasonographically confirmed on days −20, −10, and −1 prior to male–female interaction. Previously, bucks were separated for 3 weeks from the experimental females and received exogenous testosterone every third day (i.e., 50 mg i.m.) prior to mating. With respect to the response variables, namely BW, BCS, blood glucose levels (BGLs), estrus induction (GIE, %), latency to estrus (LTE, h), estrus duration (ED, h), and luteal tissue volume (LTV, mm), no differences (p > 0.05) occurred between experimental groups. However, the response variables, namely goats ovulating (GO, %; 78.9 vs. 47.3), total number of corpuses luteum (TNCL, n; 27 vs. 13), ovulation rate (OR, n; 1.42 vs. 0.73), multiple ovulation (MO, %; 73.3 vs. 55.5), and pregnancy rate on d 36 (PRd36, %, 68.4 vs. 36.8), favored (p < 0.05) the SG over the NS goats. Our results demonstrate that connecting the circularity of two divergent ruminant production systems (i.e., cow-intensive and goat-extensive) by using dairy cows' feed leftovers as a targeted supplementation strategy in anestrous goats under a marginal-rangeland production system enhanced out-of-season reproductive outcomes (i.e., ovulation rate and pregnancy rate), thus benefiting marginal goat producers and their families. [ABSTRACT FROM AUTHOR]

Simple Summary: The main dairy area of the country is in the arid central north of Mexico (25° NL). It is characterized by a dry climate with high temperatures, where dairy cattle are subject to prolonged periods of heat stress (HS). Due to this, through the THI and the year's seasons, the effect of HS upon milk production, feed-to-milk efficiency, and cow comfort was evaluated in 2467 Holstein–Friesian cows between 2016 and 2019 in an intensive dairy management system. Total milk production decreased as THI increased, while milk composition also suffered changes due to HS. The percentage of cows in production and cows' lying time exhibited a visible drop from a THI of 68–71. Differences were also observed across seasons, with the highest milk production values in Winter and Spring and the lowest in Summer. In the same way, lying time differed among seasons, with a longer resting time in Winter and less time in Summer. Finally, the potential economic burden that HS caused at the producer and industry-market levels and its impact on nutrient and alimentary security at the societal level were also quantified. The possible effect of heat stress (HS), measured with the temperature–humidity index (THI) across seasons of the year (SY) upon milk production (MP), feed-to-milk efficiency (FME), and cow comfort (CC) was assessed in Holstein–Friesian cows in northern-arid Mexico. Data from 2467 cows (2146 milking and 321 dry) were recorded across SY [spring (SP), summer (SM), autumn (AT), and winter (WN)] between 2016 and 2019 in an intensive dairy farm located in the Comarca Lagunera (25° NL) with large fluctuations regarding ambient temperature and solar radiation. The THI was stratified into four classes: non-HS, <68; light HS, 68–71; moderate HS, 72–76; and intense HS, ≥77. The considered response variables were Milk production: both on a farm basis (totMP) and on a cow basis (cowMP); Nutritional efficiency: dry matter intake (DMI, kg); Feed conversion efficiency (FCE, kg) and energy-corrected milk (ECM, kg); Percentage of milking cows: (MC%); and Cow comfort: lying time (LT, h). Analyses of variance for unbalanced data were performed through "R". Both totMP and cowMP differed (p < 0.05) as HS increased; the largest values (i.e., 77,886 L and 35.9 L) occurred at lower THIs (i.e., <68 and 68–71) while the milk production fell (i.e., 66,584 L and 31.7 L) with the highest THIs (i.e., ≥77). Not only feed-to-milk efficiency (i.e., DMI, FCE, and ECM) but also the MC% exhibited a similar trend; a visible drop (p < 0.05) occurred from a THI of 68–71 onwards. Furthermore, the LT declined as the THI augmented, from 10.6 h at <68 to 8.5 h at ≥77. Moreover, differences (p < 0.05) also arose across seasons; TotMP, cowMP, DMI, FCE, and ECM revealed their largest (p < 0.05) values in WN and SP, halfway ones in AT, with the lowermost figures in SM. In the same way, cow comfort differed (p < 0.05) among seasons, with diverse lying times (h); WT, 10.5; AT, 10.20; SP, 9.3 h; and 8.8 in SM. Finally, the potential economic burden that HS caused at the producer (USD 233.2 million) and industry-market levels (USD 311.1 M), as well as its impact upon nutrient and alimentary security at the society level (i.e., 311 M milk liters and 195,415.82 Gcal), were also quantified. [ABSTRACT FROM AUTHOR]

Simple Summary: The effect of social rank (i.e., low or high) in adult Dorper rams on sexual behavior, body condition score, seminal quality, and whole blood count was evaluated. The high-social-ranked Dorper rams displayed more sexual behaviors compared with low-social-ranked rams. In parallel, high-social-ranked rams had a higher body condition score and a larger ejaculate volume compared with low-social-ranked rams; they also showed an optimal health and wellness status, reflected by the whole blood count. Such behavioral, metabolic, sexual, seminal, and health advantages shown by the high-social-ranked Dorper rams must be taken into account to avoid reproductive failures. While there is still limited evidence on the role that social rank plays in out-of-season reproductive success, this study helps to better comprehend how social dominance is associated with male-to-male competitiveness, male-to-female sexual behavior, seminal quality, and blood cell components, and how their interaction with each other modulates and even determines out-of-season reproductive success in Dorper rams. Dorper rams (n = 24) were evaluated during the sexual resting season to determine their social rank (SR), either high (HSR) or low (LSR), under intensive management conditions in northern Mexico (25° N). Aggressive behaviors were quantified during male-to-male interactions, and appetitive and consummatory sexual behaviors during male-to-female interactions. Morphometric, live weight (LW), and body condition score (BCS) were recorded. During the early reproductive season, male-to-female behaviors were newly itemized simultaneously by seminal quality and quantity sampling. Finally, the dependent variables of the hemogram components were also quantified. Neither LW (61.25 ± 2.4 kg) nor morphometric variables differed between SR groups. However, BCS (2.25 vs. 2.66 u), sexual behaviors (i.e., approaches: 59.6 vs. 21.73 n, mating with ejaculation: 77.7 vs. 42.86 %, latency to ejaculation: 16.6 vs. 143.07 s), ejaculate volume (0.57 vs. 0.23 mL), and hemogram components favored the HSR rams (p < 0.05). Moreover, in their first male-to-female interaction, >50% of the LSR rams failed to display any sexual activity. HSR rams displayed a greater number of threatening behaviors, managing to displace LSR rams when exposed to estrus ewes during the male sexual resting season; more sexual behaviors; and an increased seminal volume in a non-live weight-dependent fashion. [ABSTRACT FROM AUTHOR]

Simple Summary: Standardized induction and synchronization treatments and AI timing are used in goats, despite the fact that physiological differences can be linked to the breed, which could compromise the achievement of the AI programs in autochthonous breeds. However, few, if any, studies have been carried out to explore the reproductive physiology in the autochthonous breeds, in contrast to the commercial breeds. We studied the periovulatory hormone-release in Payoya goats, an autochthonous, endangered Spanish breed, and some differences were detected between the pregnant and non-pregnant goats. We observed a lower LH peak in those goats that failed to get pregnant, whilst other periovulatory hormones showed a similar release pattern in both groups. The results suggest that the LH peak should be favored to increase the success of fixed-time artificial insemination programs, and further studies should be conducted to understand the cause of this diminished LH release during the preovulatory surge. Sexual activity in domestic goats is positively influenced by reducing the photoperiod. Various protocols have therefore been developed in goats for the induction and synchronization of estrus during those months in which their sexual activity is reduced. The present observational study evaluates the periovulatory hormonal profile in Payoya goats (n = 24), during a non-favorable photoperiod (i.e., spring), being treated for estrus induction. The treatment comprised the vaginal insertion of sponges impregnated with progestogen (fluorogestone acetate, FGA), together with cloprostenol and equine chorionic gonadotrophin (eCG), 48 h before the end of the treatment. When the treatment ended, the plasma concentrations of the LH, FSH, progesterone and estradiol were determined. The goats were inseminated 46 h after the sponge withdrawal, and a pregnancy diagnosis was carried out 40–45 days after the insemination. Various parameters were monitored, such as the peaks of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol, and their respective intervals, in reference to the time of the sponge withdrawal. The conception rate was 62.5%, and the kidding rate was 50%. The results record the hormonal release pattern after the estrus synchronization treatment based on the FGA, and the differences between the pregnant and non-pregnant goats. The findings suggest that the LH peak produced after the estrus synchronization treatment, both in terms of the amplitude and the time of increment, is involved in the reproductive failure detected. [ABSTRACT FROM AUTHOR]

Simple Summary: The potential effect of social rank [R] (high—HSR; medium—MSR; low—LSR) in anestrus goats subjected to an estrus induction protocol (EIP) primed with progesterone (P4) and receiving a differential equine chorionic gonadotropin (eCG) dose [D] (D100 vs D350) upon some reproductive outcomes in crossbred dairy goats under intensive stall-fed conditions was evaluated. Response variables included estrus induction (EI, %), latency to estrus (LAT, h), duration of estrus (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n). Most of the response variables were positively affected by social rank, favoring to the HSR goats (i.e., EI %, DUR h, OVU %, OR n, and CLS cm). In addition, increased OR and PREG occurred in the HSR + D350 group, while D350 increased LS, irrespective of R. Interestingly, since no differences regarding LAT, DUR, OVU, CLS, PREG, and KIDD occurred between D350 and D100, the obtained values support the use of a reduced level of exogenous hormones to induce and generate out-of-season reproductive efficiency. We evaluated the possible role of the social rank [R] (i.e., low—LSR, middle—MSR, or high—HSR) in anestrus goats exposed to a P4 + eCG [D] (i.e., 100 or 350 IU) estrus induction protocol (EIP). Adult, multiparous (two to three lactations), multiracial, dairy-type goats (Alpine–Saanen–Nubian x Criollo goats (n = 70; 25°51′ North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrus status while the R was determined 30 d prior to the EIP. The variables of estrus induction (EI, %), estrus latency (LAT, h), estrus duration (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n) as affected by R, D, and the R × D interaction, were evaluated. While OVU and CLS favored (p < 0.05) HSR (96% and + 1.04 ± 0.07 cm), an increased (p < 0.05) LS occurred in D350 vs. D100 (2.06 ± 0.2 vs. 1.36 ± 0.2); neither R nor D affected (p > 0.05; 38.5%) KIDD. However, EI, LAT, DUR, OR, and PREG were affected by the R × D interaction. The HSR group had the largest (p < 0.05) EI % and DUR h, irrespective of D. The shortest (p < 0.05) LAT occurred in D350, irrespective of R. While the largest (p < 0.05) OR occurred in HSR and MSR within D350, the HSR + D350 group had the largest PREG (p < 0.05). These research outcomes are central to defining out-of-season reproductive strategies designed to attenuate seasonal reproduction in goats. [ABSTRACT FROM AUTHOR]

Simple Summary: We evaluated the potential supplementation effect of protein enriched Opuntia cladodes, the flat leaf-like steam of cactus species (PEO), upon changes of blood metabolites, estrus induction, estrus latency, and ovulation rate in anestrous goats exposed to sexually active males. We observed that PEO positively influenced reproductive outcomes without changes in blood metabolites. Our results highlight the importance that bio-fortified Opuntia cladodes supplementation exerts on anestrous goats exposed to the male effect as an option to improve not only the out-of-season reproductive efficiency of goats but to enhance the sustainability of marginal, extensive and semi-arid goat production systems. The effect of protein enriched Opuntia cladodes supplementation upon changes of serum total protein, urea, cholesterol, glucose as related to estrus induction (EI%), estrus latency (EL, h), and ovulation rate (OR, units) in adult anestrous goats exposed to the male effect was evaluated. In late April, anestrus goats (n = 45, 25° N) homogeneous regarding live weight (LE; 43.8 ± 1.6 kg) and body condition score (BCS; 2.3 ± 0.1 units) were randomly assigned to: (1). Protein-enriched Opuntia (PEO; n = 15; 29.8% CP, 2.2 Mcal ME kg−1), (2). Non-enriched Opuntia (NEO; n = 15; 6.4% CP, 2.1 Mcal ME kg−1), and (3). Control (CON; n = 15). NEO and PEO goats were individually supplemented with cladodes (160 g d−1; 0900–1000 h), thereafter all groups grazed in a marginal rangeland (1000–1800 h). Neither LW (p > 0.05) nor BCS (p > 0.05) differed among groups, yet an increased (p < 0.05) EI % (100, 57, 42 ± 0.16%), EL h (62, 60, 32 ± 4.2 h), and OR (1.33, 0.71, 0.43 ± 0.23 units) occurred in PEO and NEO vs. CONT, respectively. However, neither blood metabolites differed among groups nor a treatment x time interaction occurred. Peri-breeding protein enriched Opuntia cladodes supplementation of anestrous goats exposed to active males increased (p < 0.01) reproductive outcomes during the non-breeding season. [ABSTRACT FROM AUTHOR]