Special Issue "Reproductive Physiology of Small Ruminants"

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Animal Reproduction".

Deadline for manuscript submissions: 28 February 2022.

Special Issue Editor

Dr. João Pedro de Sousa Santa Clara Barbas
E-Mail
Guest Editor
Instituto Nacional de Investigação Agrária e Veterinária, Quinta da Fonte Boa, 2005-048 Vale de Santarém, Portugal
Interests: small ruminants; reproduction physiology and biotechnologies; andrology; reproductive efficiency and methods; reproduction parameters; sperm cryopreservation (new extenders, tecniques, new methods, etc); Cervical artificial insemination

Special Issue Information

Dear Colleagues,

Small ruminants are the basis of many agro-ecologic systems and represent the principal revenues of many rural populations. They contribute to the fixations of populations in many areas where many agricultural systems are not possible due to poor-quality soils, insufficient water supply for irrigation, or the orography of the territory where the utilization of machinery is not possible. These systems are usually extensive but there are many areas where it is possible to select semi-intensive or intensive production systems. Additionally, small ruminants may produce milk, meat, and in some sheep breeds, wool of high quality. Native breeds usually produce products of high quality but are usually less productive than exotic breeds. Native breeds represent an irreplaceable genetic heritage which we must preserve, as a public obligation of all countries. Unfortunately major native breeds are endangered, and some of them are at risk of extinction. In some countries, some native breeds are already extinct.

Therefore, it is imperative to make great efforts to preserve native breeds. Additionally, some countries have been working for 20 years to increase the reproductive efficiency of their native breeds, which is the basis of any production system. It is also essential to increase the level of productivity—namely, milk and/or meat. We must increase and apply our knowledge about all factors that affect small ruminants’ productivity—namely, genetics, nutrition, reproduction, management, and health. Only with increased reproductive efficiency and higher productivity (milk and/or meat), alongside higher product quality, it is possible to sustainably increase revenues.

Reproductive efficiency is critical to economic viability for small ruminant exploitation. However, few producers take advantage of the available reproductive technologies (ARTs) associated with the genetic improvement that is essential to the economic sustainability of their exploitations. Today, in some countries, with the use of specialized breeds, nutrition, reproduction, and management techniques, we see increasing and sustainable levels of milk and meat productivity associated with better quality of their productions.

The use of estrous synchronization associated with artificial insemination schedules using refrigerated and frozen semen (goats) and refrigerated semen (sheep) has increased significantly since 20 years ago. In the last 10 years, more meat exploitation operations are using ARTs associated with genetic improvements to increase the productivity and quality of their products.

Other relevant factors include the preservation and improvement of small ruminant productivity. Preservation of male and female gametes determine steps. At present, the refinement of cryopreservation techniques is enabling the implementation of national germplasm banks. Additionally, frozen semen of the highest quality from high-quality genetic sires, associated with the improvement of artificial insemination programs, is steadily increasing in small ruminant exploitations. Therefore, the refinement and adequate implementation of ART technologies is essential.

The use of superior genetic males and the selection and utilization of assisted reproductive technologies (ARTs) are some of the determinant factors that we must consider to increase reproduction efficiency, productivity, and quality in the exploitation of small ruminants.

Dr. João Pedro de Sousa Santa Clara Barbas
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Animals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • reproductive efficiency
  • productivity
  • ART
  • gametes preservation
  • reproduction
  • sustainability
  • production systems

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
Effect of Body Condition Score, Treatment Period and Month of the Previous Lambing on the Reproductive Resumption of Melatonin-Treated Sarda Breed Sheep during Spring
Animals 2021, 11(7), 1898; https://doi.org/10.3390/ani11071898 - 25 Jun 2021
Viewed by 326
Abstract
Stakeholders place great emphasis upon rationalizing the management and rearing techniques which are utilized within sheep farms. The present study aimed to investigate factors which may improve the reproductive performance of melatonin-treated Sardinian sheep via a series of three trials. The first trial [...] Read more.
Stakeholders place great emphasis upon rationalizing the management and rearing techniques which are utilized within sheep farms. The present study aimed to investigate factors which may improve the reproductive performance of melatonin-treated Sardinian sheep via a series of three trials. The first trial (n = 100) investigated the effect of melatonin treatment alongside body condition score (BCS), the second trial (n = 150) investigated the effect of treatment alongside the date of treatment (treatment period) and the third trial (n = 150) investigated the effect of treatment alongside the previous lambing of the ewes. The findings indicated that melatonin is an effective tool for anticipating and improving the reproductive activity of in Sarda breed sheep during the springtime. Furthermore, to obtain optional results, melatonin implantation should be conducted in April, in ewes that have a BCS of >2.5 and that have passed their third month of lactation. Full article
(This article belongs to the Special Issue Reproductive Physiology of Small Ruminants)
Article
Sperm Behavior and Response to Melatonin under Capacitating Conditions in Three Sheep Breeds Subject to the Equatorial Photoperiod
Animals 2021, 11(6), 1828; https://doi.org/10.3390/ani11061828 - 18 Jun 2021
Viewed by 442
Abstract
In this study, we demonstrated that, in seasonal Mediterranean ovine breeds, supplementing the TALP medium with cAMP-elevating agents (the cocktail medium) is effective for achieving ram sperm capacitation, and that melatonin is able to regulate this phenomenon. We investigated the behavior under capacitating [...] Read more.
In this study, we demonstrated that, in seasonal Mediterranean ovine breeds, supplementing the TALP medium with cAMP-elevating agents (the cocktail medium) is effective for achieving ram sperm capacitation, and that melatonin is able to regulate this phenomenon. We investigated the behavior under capacitating conditions using the TALP and cocktail mediums, and the response to melatonin, of spermatozoa from three sheep breeds (Colombian Creole, Romney Marsh, and Hampshire) subject to the equatorial photoperiod, during the dry and the rainy seasons. The cocktail medium was able to induce sperm capacitation, assayed by chlortetracycline staining and phosphotyrosine levels, to a greater extent than TALP, without a higher loss of viability (membrane integrity and viable spermatozoa without phosphatidylserine (PS) translocation). The addition of melatonin at 100 pM or 1 µM in the cocktail medium partially prevented the decrease in viability without PS translocation and the increase in capacitated spermatozoa from all breeds, with no significant effect on phosphotyrosine levels. Differences between breeds and seasons were evidenced. This study shows that melatonin is able to exert direct effects on spermatozoa in ovine breeds under equatorial photoperiod conditions, as it does in seasonal breeds located in temperate regions. Full article
(This article belongs to the Special Issue Reproductive Physiology of Small Ruminants)
Show Figures

Figure 1

Article
Influence of Season and Liquid Storage at 16 °C on Beni Arouss Bucks’ Semen Quality
Animals 2020, 10(11), 1986; https://doi.org/10.3390/ani10111986 - 29 Oct 2020
Viewed by 552
Abstract
The study aimed at determining the effect of storage and season on fresh semen of Beni Arouss goats. Ejaculates were collected at monthly intervals from seven mature bucks and were extended at a final concentration of 800 × 106 spermatozoa. ml-1 [...] Read more.
The study aimed at determining the effect of storage and season on fresh semen of Beni Arouss goats. Ejaculates were collected at monthly intervals from seven mature bucks and were extended at a final concentration of 800 × 106 spermatozoa. ml-1 and stored at 16 °C for 24 h. Semen motility, viability and normal morphology were assessed at 0, 4, 8 and 24 h after collection. Motility and normal morphology parameters were recorded using computer-assisted sperm analysis (CASA) and viability was analyzed using eosin–nigrosin staining. As expected, motility, viability and normal morphology parameters showed a significant reduction within 24 h of storage and during all seasons (p < 0.05). However, semen collected in summer maintained a better quality after 24 h of storage at 16 °C than semen collected during the other periods (p < 0.05). In conclusion, the storage ability of Beni Arouss bucks’ semen stored at 16 °C was significantly higher during the summer. Full article
(This article belongs to the Special Issue Reproductive Physiology of Small Ruminants)
Show Figures

Figure 1

Review

Jump to: Research

Review
Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms
Animals 2021, 11(9), 2503; https://doi.org/10.3390/ani11092503 - 26 Aug 2021
Viewed by 233
Abstract
In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram [...] Read more.
In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock. Unfortunately, the selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic/reproductive evaluation, and/or health assessment or records. Therefore, it is important to establish integrative management practices to select the rams and ram lambs to be used in the breeding season. Among these practices are genomic testing, a comprehensive breeding soundness evaluation and assessment of health status and records of the males before the breeding season, to detect and correct potential issues. Full article
(This article belongs to the Special Issue Reproductive Physiology of Small Ruminants)
Show Figures

Figure 1

Back to TopTop