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de Sá Geraldo A, Pinto PHN, da Silva Carvalho AB, da Costa MMCP, Santos JDR, Taira AR, Cosentino IO, de Figueiredo BRR, Balaro MFA, Ungerfeld R, Brandão FZ. Reproductive seasonality of hair rams under tropical conditions: an alternative for non-seasonal lamb production? Trop Anim Health Prod 2023; 56:4. [PMID: 38051439 DOI: 10.1007/s11250-023-03848-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023]
Abstract
Reproductive seasonality limits the periods of breeding on the year and, therefore, productive output. However, some breeds appear as probably non-seasonal. The aim of the study was to characterize the seasonal pattern of Santa Inês rams, including an ultrasound characterization of the reproductive tract, testosterone concentrations, and semen characteristics. Fifteen Santa Inês rams remained in a grazing system with concentrate supplementation, and measurements of the reproductive tract and ultrasound evaluation (biometrics and pixel intensity) of the testicles and accessory sex glands were monthly recorded. Computerized seminal evaluations were also performed monthly, and serum testosterone concentration was measured every 15 days. Body weight and condition remained stable throughout the year. In general, reproductive traits varied along the year and reached maximum values during autumn and minimum in spring. Despite that, as fresh semen remained with enough quality to breed all along the year, seasonality does not appear as a limiting factor to breed along the year. Therefore, Santa Inês rams can be used for all-year-round breeding or for crossbreeding when rams from other breeds decrease their fertilizing ability.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Rodolfo Ungerfeld
- Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de La República, Ruta 8 Km 18, 13000, Montevideo, Uruguay
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Ledezma-Torres R, Sánchez-Dávila F, Rodríguez-Miranda D, Luna-Palomera C, Grizelj J, Vázquez-Armijo J, López-Villalobos N. Sexual performance and semen quality of pubertal lambs treated with different weaning methods. Arch Anim Breed 2022; 65:259-265. [PMID: 36035875 PMCID: PMC9399914 DOI: 10.5194/aab-65-259-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 06/27/2022] [Indexed: 11/26/2022] Open
Abstract
The objective of this study was to determine the effect of the
weaning method on lamb stress, body weight, sexual behavior, and semen
quality of Saint Croix male lambs. The present study was carried out during
the late spring and summer of 2018 in the northeast of Mexico. Sixty male
lambs born as twins or triplets (3.2 ± 0.6 kg birth weight) and
weaned at 60 d of age (19.21 ± 1.8 kg weaning weight) were divided
into two weaning methods: complete separation from the dams (CS; the lambs
were moved to a pen that was at 500 m of distance from the dams) and
separation with contact from the dams (SCD); the lambs were physically
separated by a steel mesh that prevented the lambs from having the
possibility of sucking milk from their mothers, but they maintained
permanent visual and auditory contact. Cortisol levels were determined
3 d before and 7 d after weaning. Lambs were evaluated as 3-month-old lambs for sexual behavior and semen quality for 9 weeks. The
effects of the weaning method (M), week (W), and the interaction M × W were
significant on body weight and cortisol levels (P<0.001). The SCD
lambs had higher cortisol levels at 3, 5, and 7 d after weaning than CS
lambs (P<0.001). The CS lambs had higher body weight during the
first 4 weeks after weaning than SCD lambs (P<0.001). The weaning
method had no effect on scrotal circumference, sexual behavior, and semen
quality traits, except for progressive sperm motility, being better for the
lambs that were completely separated (P<0.05). The results from
this study show that complete separation of lambs and ewes at weaning is an
effective method to reduce lamb stress and improve lamb growth after
weaning, but it did not have long-term effects on sexual behavior and semen
quality of Saint Croix male lambs.
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Affiliation(s)
- Rogelio Alejandro Ledezma-Torres
- Universidad Autónoma de Nuevo León, Facultad de Medicina Veterinaria
y Zootecnia, Posgrado Conjunto FA-FMVZ, General Escobedo, CP
66050, Mexico
| | - Fernando Sánchez-Dávila
- Universidad Autónoma de Nuevo León, Facultad de Agronomía,
Posgrado Conjunto FA-FMVZ, Laboratorio de Reproducción Animal, Unidad
Académica Marín, Marín, CP 66700, Mexico
| | | | - Carlos Luna-Palomera
- Universidad Juárez Autónoma de Tabasco, División Académica de Ciencias Agropecuarias, Villahermosa, Tabasco, CP 86280, México
| | - Juraj Grizelj
- Universidad de Zagreb, Facultad de Medicina Veterinaria, Zagreb, Croatia
| | | | - Nicolás López-Villalobos
- Universidad Autónoma del Estado de
México, Centro Universitario Temascaltepec, Temascaltepec,
CP 51300, Mexico
- School of Agriculture and Environment, Massey University, Palmerston North
4442, New Zealand
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Sánchez-Dávila F, Lombardo J, Freitas-de-Melo A, Bernal Barragán H, Ungerfeld R. Singleton or twin male lambs: Effects on their reproductive development. Anim Reprod Sci 2021; 231:106797. [PMID: 34175553 DOI: 10.1016/j.anireprosci.2021.106797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 10/21/2022]
Abstract
Because intrauterine environment differs between twins and singletons, twin-born lambs are often studied when effects of fetal programming are evaluated. In sheep, fetal programming might have effects on reproductive physiology and behavior after sexual maturation. The aim of this study was to compare sperm output and sexual behavior in developing singleton- or twin-born lambs of similar body weight. Singleton lambs (n = 12) and twin (n = 9) male-male lambs were used. From 5.4 until 9.1 months of age, body weight, scrotal circumference (every 3-4 weeks), sexual behavior (every 14 days) and semen characteristics (every 28 days) were evaluated. In the third ejaculate, singleton lambs ejaculated a larger volume of semen than twins (P = 0.03). Considering a pool of the three ejaculates, twin lambs ejaculated semen with a greater sperm concentration than singleton lambs (P = 0.015). There was an interaction between group and time to the onset of courtship behavior (P = 0.02) and a tendency for an interaction in the number of mount attempts (P = 0.052). Singleton-born lambs, during the first evaluation period began courtship behavior earlier than twin-born lambs (P < 0.0001). In conclusion, there were only slight differences in semen and sexual behavior between male ram lambs born as singletons or twins with similar weight. Male ram lambs born as singletons initiated the courtship behavior earlier than twins during the first sexual behavioral evaluation period, ejaculated a larger volume of semen in the third consecutive ejaculate, and there was a lesser sperm concentration in the three ejaculates.
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Affiliation(s)
| | - Jesus Lombardo
- Universidad Autónoma de Nuevo León, Posgrado Conjunto, Mexico
| | - Aline Freitas-de-Melo
- Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | | | - Rodolfo Ungerfeld
- Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay.
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