Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
Rev. Ciencia Agraria (2024). Vol. 3 No. 2 pp. 7-24
Revista Ciencia Agraria
www.cienciaagraria.com
ISSN: 2955-8085 ISSN-L: 2955-8085
Editada por:
Instituto Universitario de Innovación Ciencia y Tecnología Inudi Perú
ORIGINAL ARTICLE
Comparative evaluation of the reproductive capacity of male goats in feedlot
Evaluación comparativa de la capacidad reproductiva de machos cabríos en confinamiento
Avaliação comparativa da capacidade reprodutiva de machos caprinos em confinamento
Emanuel Cordeiro da Silva
1
Federal Rural University of Pernambuco, Recife - Dois Irmãos, Brazil
https://orcid.org/0000-0003-3314-0168
emanuel.isaque@ufrpe.br (correspondence)
Eduarda da Silva Fontain
Cabanha Severino, Belo Jardim - Pernambuco, Brazil
https://orcid.org/0009-0005-0823-9280
eduarda.carvalho88@outlook.com
DOI: https://doi.org/10.35622/j.rca.2024.02.001
Received: 20/06/2024 Aceppted: 19/09/2024 Published: 23/09/2024
PALABRAS CLAVE
caprinos, eficiencia
reproductiva, índices
RESUMEN. El presente trabajo fue realizado con base en los datos y registros zootécnicos de una
propiedad de caprinos y ovinos en la ciudad de Belo Jardim, Agreste de Pernambuco. Con la
información sobre tres machos cabríos, se obtuvieron los datos de las hembras preñadas y
aquellas que llevaron el embarazo a término, además de las crías nacidas vivas y mortinatos. A
1
Bachelor degree in Animal Science from the Federal Rural University of Pernambuco, Brazil.
KEYWORDS
goats, reproduction,
reproductive efficiency,
reproductive indices,
selection.
ABSTRACT. The present work was carried out based on data and zootechnical records from a goat
and sheep property in the city of Belo Jardim, Agreste of Pernambuco. With information on three
male goats, data were obtained on the pregnant females and those that carried the pregnancy to
term, in addition to live births and stillbirths. Based on this data, the Chi-square statistical analysis
and Fisher's test were used to verify the reproductive efficiency of the male goat on the reproductive
indices of the females, using the Systat 13 software. The results showed no significant differences
between the evaluated males concerning their service capacity, according to the records of a
breeding season during the years 2021, 2022, and 2023. This allowed the determination of the
percentage of reproductive indices for each male and, with this, to proceed with selecting the most
viable breeder for the herd or, if necessary, proceed with disposal. On the other hand, the equal
environmental conditions for the males determined that only one showed significant results
concerning the reproductive indices of the females. Meanwhile, significant differences were
observed between the males during the breeding seasons of 2021 and 2023, but there was a
significant effect among the males in the 2022 breeding season (P<0.05). Concluding that the
evaluation of reproductive capacity and reproductive indices are important tools in the selection of
breeding males.
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
8
reproductivos,
reproducción, selección.
partir de estos datos, se utilizó el análisis estadística Chi-cuadrado y el test de Fisher para la
comprobación de la eficiencia reproductiva del macho cabrío sobre los índices reproductivos de
las hembras, donde se utilizó el software Systat 13. En los resultados, no se observaron diferencias
significativas entre los machos evaluados con respecto a su capacidad de servicio, según los
registros de una estación reproductiva durante los años 2021, 2022 y 2023. Esto permitió
determinar el porcentaje de los índices reproductivos de cada uno y, con eso, proceder seleccionar
al reproductor más viable para el rebaño o si es necesario proceder al descarte. Por otro lado, las
condiciones ambientales igualitarias, para los machos, determinaron que apenas uno demostró
resultados significativos sobre los índices reproductivos de las hembras. Mientras que, se
observaron diferencias significativas entre los machos en las estaciones reproductivas de 2021 y
2023, pero hubo efecto significativo entre los machos en la estación reproductiva de 2022
(P<0.05). Concluyendo que la evaluación de la capacidad reproductiva y los índices reproductivos
son herramientas de gran importancia en la selección de machos reproductores.
PALAVRAS-CHAVE
caprinos, eficiência
reprodutiva, índices
reprodutivos,
reprodução, seleção.
RESUMO. O presente trabalho foi realizado com base nos dados e registros zootécnicos de uma
propriedade de caprinos e ovinos na cidade de Belo Jardim, Agreste de Pernambuco. Com as
informações de três bodes, foram obtidos os dados das fêmeas prenhas e daquelas que levaram a
gestação até o final, além das crias nascidas vivas e natimortos. A partir desses dados, utilizou-se
a análise estatística do Qui-quadrado e o teste de Fisher para comprovar a eficiência reprodutiva
do bode sobre os índices reprodutivos das fêmeas, onde foi utilizado o software Systat 13. Nos
resultados, não foram observadas diferenças significativas entre os machos avaliados em relação à
sua capacidade de serviço, segundo os registros de uma estação reprodutiva durante os anos de
2021, 2022 e 2023. Isso permitiu determinar a porcentagem dos índices reprodutivos de cada um
e, com isso, proceder à seleção do reprodutor mais viável para o rebanho ou, se necessário,
proceder ao descarte. Por outro lado, as condições ambientais igualitárias para os machos
determinaram que apenas um apresentou resultados significativos sobre os índices reprodutivos
das fêmeas. Enquanto isso, foram observadas diferenças significativas entre os machos nas
estações reprodutivas de 2021 e 2023, mas houve efeito significativo entre os machos na estação
reprodutiva de 2022 (P<0.05). Concluindo que a avaliação da capacidade reprodutiva e dos índices
reprodutivos são ferramentas de grande importância na seleção de machos reprodutores.
1. INTRODUCTION
In the goats, just as in other mammals of zootechnical interest, the peak reproduction depends on internal
fertilization of a female gamete (secondary ovocyte) by a male gamete (spermatozoid). Therefore, it is necessary
that the male and female are in close contact and have a strong motivation to carry out copulation, that is, that
the male has the ability to mount the female and that she is receptive (Fabre-Nys e Gelez, 2007; Da Silva,
2021ab).
The reproductive and service capacity of male goats is related to determinant parameters such as sexual
behavior, spermatic quality, etc. (Cadena-Villegas et al., 2021).
The social environment of domestic goats, for the most part, is artificially controlled, that is, controlled by man
(Silva et al., 2022). Nevertheless, aspects such as hierarchy and individual relationships can also have a direct
and/or indirect effect on reproduction and sexual behavior in a way that is not controllable by men (Ungerfeld,
2021). That said, it is important to know the socio-sexual context considered normal for the species in which
reproduction is inserted to understand the relationships of animals under controlled conditions, that is, animals
in feedlot (Fabre-Nys, 2000; Schleske and Vásquez, 2014).
The sexual performance is generally referred to as the male goat's natural ability to massively mate a given
number of females in a relatively short period of time (Robertson et al., 2020). This ability depends on the
combination of sexual desire or motivation (libido), physical coordination, strength, endurance and nutritional
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
9
status of the animal (Fabre-Nys, 2000). A buck considered sterile is easily identified after mount, however, those
who present reduced fertility cause serious problems and cause economic losses to breeders and the artificial
insemination (AI) industry (Mocé et al., 2022).
The conducting behavioral observations in young male goats in goat herds can provide a basis for identifying
and selecting males with greater sexual performance (Schleske and Vásquez, 2014). Additionally, the exposure
of young males to females in estrus or heat tends to reduce the sexual performance problems and, thus, the
efficiency of males in tests of service capacity can be improved, as occurs in other species, such as the bovine.
A peremptory problem in different production systems is the inadequate selection of a male to be used as a
breeder (Carneiro et al., 2023). Therefore, it is possible that when recording the libido or sexual motivation of
males in goat production units, it will be possible to select animals that, after puberty, are possible breeders and
successfully achieve sexual maturity, being able to contribute to improving efficiency reproduction of the
production unit (Scheleske and Vásquez, 2014).
To mitigate the possible possibilities of errors, it is necessary to evaluate the various aspects of the future
reproductor: such as the male's libido in contact with females in estrus, as well as the quality of his semen
(Carneiro et al., 2023). The libido and seminal quality are two distinct characteristics and do not always present
analogous data, since such characteristics are governed by different mechanisms (Nájera et al., 2023), that is, a
caprine may have high libido, but its semen can present low sperm viability.
Another test that accurately reveals the reproductive capacity of males is the mount directed to a group of females
and the subsequent farrowing, which involves spending time and money; for this reason, it is desirable to have
available simple tests that allow rational prediction of the reproductive capacity of an adult buck (Schleske and
Vásquez, 2014). Although the male's fecundity depends on several factors such as: 1) spermatozoids production,
2) viability and fertilization capacity of gametes, 3) libido and, finally, 4) the ability to mount, copulate or mate.
The establishment of some behavioral tests, combined with the quality of the semen, as well as the possibility
of recording some indices allows us to evaluate the reproductive aptitudes of each male goat.
In some studies, a test was carried out to measure sexual behavior for 10 minutes in a group of one year old
male goats and tested six months later. Nevertheless, both times of the year were not compared, therefore, it is
not possible to know whether the animals improved, worsened or maintained their behavior and libido
throughout the reproductive seasons (Nuraine et al., 2021).
Given this scenario, the present study aims to evaluate the service capacity in a group of 3 male goats at full
sexual maturity, with the purpose of covering receptive females and, with the recording of the data obtained,
determine the percentage of some reproductive indices, especially fertility, which can be used to select breeders
in production units and, therefore, contribute to improving the reproductive performance of the herd.
2. METHOD
The present study was carried in Cabanha Severino - Sheeps and Goats Creator in Serra do Vento, Belo Jardim,
Pernambuco, Brazil, which is geoFiguraically located at 8º13’55’’ South and 36º20’56’’ West at 643 m altitude.
According to Alvares et al. (2013) the climate is classified as BSh or hot semiarid tropical, or driest of tropical,
with an average annual temperature of 18.5 ºC minimum and 28 ºC maximum, with average mensal precipitation
of 32.4 mm, with 72% rain in summer and autumn and 28% in winter and spring (Climatempo, 2024).
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
10
For the study, a group of 3 adult male goats with an average of 18 to 24 months of age, at full sexual maturity,
with an approximate weight of ±50 kg, housed in stalls of approximately 20 m2, covered, with water clean and
fresh, and feed ad libitum composed of Tifton-85 hay and commercial concentrate with 15% crude protein (CP)
and 65% total digestible nutrients (TDN) and a forage: concentrate ratio of, more or less, 40:60 according to Da
Silva (2021c). A group of 15 females in estrus was used for each male.
The study was developed with the aid of records of breeding and births for the years 2021, 2022 and 2023. The
mount station between males and females lasted 30 days and each male was exposed to 15 multiparous adult
females in a specific paddock for the breeding season willing with cover, water, feed and pasture, with an
approximate area of 1.8 ha.
The males remained inside the stalls where they were provided with the necessary food to meet their basic needs
based on Da Silva (2021c), of which the ration was composed of cassava zest, soybean bran and vitamin-mineral
premix, in addition to Tifton-85 hay and concentrated in appropriate quantities according to Da Silva (2021c)
(Table 1). Remained daily in a stable environment, sometimes in the company of other males where dominance
behavior occurred between them.
Table 1
Bucks nutrition requirements, feeds and ration composition
Requirement
DMI (kg·day
-1
)
CP (%)
TDN (%)
0,85
15,0
65,0
Feeds composition
CP (%)
TDN (%)
Tifton-85, hay
11,7
56,5
Cassava, zest
2,8
82,0
Soy, bran
45,0
73,0
Ration composition
Ingredients
Quantity (%)
CP (%)
TDN (%)
Tifton-85, hay
43,5
5,10
24,58
Cassava, zest
31,4
0,88
25,77
Soy, bran
20,1
9,02
14,65
Vitamin-mineral, core
4,0
-
-
Salt
1,0
-
-
Total
100
15,00
65,00
Requirement
100
15,00
65,00
Note. NRC (2007); Da Silva (2021c).
The direct fertility or service capacity of a male was considered to be the number of females calved between the
number of females covered or that were exposed to a male during the 30-day mount season.
Semen samples from the 3 males were obtained using the Walmur artificial vagina, 2020, heated to 37 ºC to
avoid thermal shock, and were immediately incubated in a water bath at 37 ºC. The samples were evaluated for
ejaculate volume, sperm concentration, mass motility (MM), and percentage of motile, live and dead
spermatozoids (Rocha et al., 2015). An aliquot of semen was diluted (1:400) in formaldehyde saline solution
buffered (0.54% NaCl, 0.62% Na2HPO4, 0.13% KH2PO4, 5% formaldehyde, pH 7.4) (Evans and Maxwell, 1987)
and evaluated in a Neubauer chamber to estimate spermatic concentration. A drop of semen was positioned on
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
11
a slide and evaluated for MM, with a scale between 0 and 5 being assigned under optical microscopy (100x).
Another drop of semen was positioned, diluted (1:1) with PBS pre-heated to 37 ºC and covered to evaluate the
percentage of motile sperm, under optical microscopy (400x) (Maxwell et al., 1996).
The data were analyzed using the chi-square method, Tukey test and Fisher's exact test to compare the
proportions between males and lambings, using the Systat 13 statistical package (Chicago, Illinois, 2015).
(Siegel, 1998).
The variables evaluated were fertility, natality, mortality, twinning, trigemelarity, simple parturitions and
reproductive efficiency. Fertility was the variable used to determine and compare the service capacity of males.
The birth records for the years 2021, 2022 and 2023, according to data from the zootechnical bookkeeping for
reproductive records, are summarized in Table 2.
Table 2
Reproduction form for recording births in Cabanha Severino
2021
Number of the goat
Date
Type of parturition
Sex
Birth weight (kg)
Number of buck
Birth status
CS-c06
01/15/2021
Triple
Male
-
1
Dead
Male
3,8
Female
3,5
CS-c08
01/15/2021
Doble
Female
1,9
1
Male
3,2
CS-c09
01/15/2021
Doble
Male
3,2
1
Male
3,0
CS-c10
01/15/2021
Simple
Male
2,5
1
CS-c11
01/15/2021
Doble
Male
4,0
1
Female
2,6
CS-c13
01/17/2021
Doble
Female
2,9
1
Male
-
Dead
CS-c14
01/17/2021
Triple
Male
2,6
1
Male
3,9
Male
3,1
CS-c17
01/18/2021
Doble
Female
3,4
1
Male
3,8
CS-c18
01/18/2021
Simple
Female
2,9
1
CS-c19
01/18/2021
Simple
Male
4,8
1
CS-c20
01/18/2021
Simple
Female
3,8
1
CS-c24
02/20/2021
Simple
Male
4,3
1
CS-c25
02/20/2021
Simple
Male
3,0
1
CS-c28
03/10/2021
Doble
Male
2,4
1
Female
4,0
CS-c30
04/25/2021
Doble
Male
3,6
1
Female
3,3
CS-c31
04/27/2021
Doble
Female
3,7
1
Male
3,1
CS-c35
04/27/2021
Simple
Male
2,7
1
CS-c40
04/28/2021
Doble
Male
3,8
1
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
12
Female
3,7
CS-c45
05/01/2021
Doble
Female
4,2
1
Female
3,7
CS-c60
05/04/2021
Simple
Male
3,7
1
CS-c61
05/04/2021
Doble
Male
3,3
1
Female
2,8
CS-c62
05/04/2021
Doble
Male
3,3
1
Female
2,9
CS-c80
05/08/2021
Doble
Male
3,0
3
Female
2,9
CS-c81
05/08/2021
Doble
Male
3,4
3
Female
3,0
CS-c82
05/08/2021
Simple
Male
4,0
3
CS-c83
05/09/2021
Doble
Male
3,1
3
Female
2,6
CS-c84
05/09/2021
Simple
Male
4,4
3
CS-c85
05/09/2021
Simple
Female
4,1
3
CS-c86
05/11/2021
Doble
Male
3,3
3
Male
4,0
CS-c87
05/12/2021
Doble
Male
3,3
3
Male
4,1
CS-c88
05/20/2021
Simple
Male
3,8
3
CS-c90
05/20/2021
Simple
Female
3,5
3
CS-c95
05/20/2021
Simple
Female
3,6
3
CS-c99
05/20/2021
Simple
Male
4,8
3
2022
Number of the goat
Date
Type of parturition
Sex
Birth weight (kg)
Number of buck
Birth status
CS-c14
01/26/2022
Doble
Male
3,1
2
Male
3,1
CS-c10
01/26/2022
Simple
Male
3,3
2
CS-c11
01/26/2022
Doble
Male
3,1
2
Female
3,0
CS-c13
01/27/2022
Doble
Female
3,0
1
Female
3,0
CS-c61
01/27/2022
Simple
Female
3,2
2
CS-c24
01/27/2022
Doble
Male
3,0
2
Male
3,2
CS-c17
02/05/2022
Doble
Female
2,8
2
Female
2,2
CS-c29
02/05/2022
Doble
Female
2,9
1
Male
3,1
CS-c30
02/05/2022
Simple
Male
3,3
1
CS-c32
02/09/2022
Simple
Female
3,0
1
CS-cDUDA
02/09/2022
Doble
Female
3,0
2
Dead
Female
3,1
CS-c31
02/15/2022
Doble
Female
2,9
2
Female
2,7
CS-c40
02/15/2022
Simple
Male
3,3
1
CS-c45
02/16/2022
Doble
Female
2,7
2
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
13
Male
3,0
CS-c60
02/26/2022
Doble
Male
3,1
2
Male
3,1
CS-c62
02/26/2022
Doble
Female
3,0
1
Female
3,6
CS-c80
03/01/2022
Doble
Female
3,1
1
Male
3,1
CS-c82
03/01/2022
Simple
Male
3,2
1
CS-c83
03/01/2022
Doble
Male
2,7
1
Dead
Female
2,5
CS-c84
03/05/2022
Simple
Male
3,2
1
CS-c85
03/05/2022
Doble
Male
3,1
1
Female
3,2
CS-c87
03/09/2022
Simple
Female
3,2
1
CS-c88
03/09/2022
Simple
Female
3,2
1
CS-c95
03/10/2022
Simple
Male
3,5
1
CS-c99
03/10/2022
Doble
Male
3,0
1
Male
2,9
2023
Number of the goat
Date
Type of parturition
Sex
Birth weight (kg)
Number of buck
Birth status
CS-c10
01/05/2023
Triple
Male
4,6
2
Female
-
Dead
Female
3,0
CS-c11
01/05/2023
Simple
Female
3,4
3
CS-c13
01/05/2023
Simple
Male
3,0
3
CS-c14
01/05/2023
Simple
Male
2,8
2
CS-c16
01/05/2023
Simple
Male
3,5
3
CS-c18
01/06/2023
Simple
Male
3,8
3
CS-c29
01/06/2023
Doble
Male
3,0
3
Male
2,5
CS-c30
01/07/2023
Simple
Male
4,1
3
CS-c31
01/07/2023
Doble
Male
2,8
3
Male
3,2
CS-c32
01/07/2023
Doble
Male
2,6
2
Female
2,5
CS-c38
01/08/2023
Simple
Male
3,5
2
CS-cDUDA
01/08/2023
Doble
Female
2,6
2
Female
2,5
CS-c40
01/11/2023
Simple
Male
4,6
2
CS-c42
01/11/2023
Doble
Female
2,7
3
Male
3,2
CS-c45
01/11/2023
Simple
Female
2,0
3
CS-c50
01/13/2023
Doble
Male
3,6
2
Male
3,0
CS-c55
01/13/2023
Triple
Male
3,1
2
Male
2,5
Female
1,9
CS-c60
01/15/2023
Doble
Female
2,5
2
Male
2,6
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
Esta obra está bajo una licencia internacional Creative Commons Atribución 4.0.
14
CS-c62
01/15/2023
Doble
Male
2,7
3
Male
2,7
CS-c65
01/20/2023
Simple
Male
3,8
3
CS-c70
01/22/2023
Simple
Female
3,2
2
CS-c80
01/25/2023
Simple
Female
3,1
2
CS-c81
01/28/2023
Simple
Male
3,7
1
CS-c82
01/28/2023
Doble
Male
3,2
2
Female
3,0
CS-c83
01/29/2023
Triple
Male
3,7
2
Male
-
Dead
Male
2,8
CS-c84
02/02/2023
Doble
Female
3,0
1
Female
2,6
CS-c85
02/02/2023
Simple
Female
3,8
1
CS-c87
02/02/2023
Simple
Male
3,8
1
CS-c88
02/02/2023
Doble
Male
3,1
1
Male
3,0
CS-c89
02/03/2023
Simple
Female
-
1
Dead
CS-c90
02/06/2023
Simple
Male
3,7
1
CS-c91
02/06/2023
Simple
Male
3,7
1
CS-c92
02/10/2023
Doble
Female
3,0
1
Female
3,2
CS-c95
02/10/2023
Simple
Female
-
1
Dead
CS-c98
02/15/2023
Simple
Female
3,7
1
CS-c99
02/16/2023
Simple
Male
4,3
1
The reproductive indexes were calculated based on data of Lima et al. (2016), Sousa (2018) e Maia and Nogueira
(2019):
1) Fertility rate:
𝐹𝑒𝑟𝑡𝑖𝑙𝑖𝑡𝑦 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑎𝑟𝑜𝑢𝑠
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑒𝑥𝑝𝑜𝑠𝑡
𝑥 100
2) Natality rate/prolificity:
𝑁𝑎𝑡𝑎𝑙𝑖𝑡𝑦 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡 𝑘𝑖𝑑𝑠 𝑡𝑜𝑡𝑎𝑙 𝑏𝑖𝑟𝑡ℎ 𝑥 100
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑡
𝑃𝑟𝑜𝑙𝑖𝑓𝑖𝑐𝑖𝑡𝑦 =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡 𝑘𝑖𝑑𝑠 𝑡𝑜𝑡𝑎𝑙 𝑏𝑖𝑟𝑡ℎ
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑡
3) Mortality rate:
𝑀𝑜𝑟𝑡𝑎𝑙𝑖𝑡𝑦 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡 𝑘𝑖𝑑𝑠 𝑏𝑖𝑟𝑡ℎ 𝑑𝑒𝑎𝑑
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡 𝑘𝑖𝑑𝑠 𝑡𝑜𝑡𝑎𝑙 𝑏𝑖𝑟𝑡ℎ
𝑥 100
4) Gemelarity rate:
𝐺𝑒𝑚𝑒𝑙𝑎𝑟𝑖𝑡𝑦 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑒𝑚𝑒𝑙𝑎𝑟 𝑝𝑎𝑟𝑡𝑢𝑟𝑖𝑡𝑖𝑜𝑛𝑠
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑡
𝑥 100
5) Trigemelarity rate:
𝑇𝑟𝑖𝑔𝑒𝑚𝑒𝑙𝑎𝑟𝑖𝑡𝑦 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑟𝑖𝑔𝑒𝑚𝑒𝑙𝑎𝑟 𝑝𝑎𝑟𝑡𝑢𝑟𝑖𝑡𝑖𝑜𝑛𝑠
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑡
𝑥 100
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Comparative evaluation of the reproductive capacity of male goats in feedlot
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15
6) Simple parturitions:
𝑃𝑎𝑟𝑡𝑢𝑟𝑖𝑡𝑖𝑜𝑛𝑠 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑖𝑚𝑝𝑙𝑒 𝑝𝑎𝑟𝑡𝑢𝑟𝑖𝑡𝑖𝑜𝑛𝑠
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑡
𝑥 100
7) Reproductive efficiency:
𝑅𝐸 (%) =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡 𝑘𝑖𝑑𝑠 𝑤𝑒𝑎𝑛𝑒𝑟 𝑙𝑖𝑣𝑒
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑎𝑡𝑠 𝑒𝑥𝑝𝑜𝑠𝑡
𝑥 100
3. RESULTS
The results of seminal characteristics of breeders in the three mount seasons are found in Table 3.
Table 3
Seminal characteristics of bucks during reproductive season
Buck 1
RS
EV (mL)
SC
(millions/mL)
MM
(0-5)
MS
(%)
LS
(%)
DS
(%)
2021
0,75
a
825
a
3,5
a
68
a
73
a
27
a
2022
0,85
a
817
a
3,5
a
70
a
75
a
25
a
2023
0,88
a
801
b
3,0
a
60
b
67
a
33
b
Buck 2
RS
EV (mL)
SC (millions/mL)
MM
(0-5)
MS
(%)
LS
(%)
DS
(%)
2022
0,68
a
830
a
3,7
a
70
a
68
a
32
a
2023
0,71
a
827
a
3,5
a
71
a
72
b
28
b
Buck 3
RS
EV (mL)
SC (millions/mL)
MM
(0-5)
SM
(%)
LS
(%)
DS
(%)
2021
0,71
a
836
a
3,2
a
72
a
65
a
35
a
2023
0,75
a
830
a
3,5
a
75
a
70
b
30
b
Note. RE: reproductive season; EV: ejaculate volume; SC: spermatozoid concentration; MM: massal motility; SM:
spermatozoids motile; LS: live spermatozoids; DS: dead spermatozoids. Different letters between lines indicate
significant difference P<0.05 by chi-square and Tukey tests.
It is noted that male 1 was the only one to be present in the 3 mount seasons, therefore, depending on the wear
and age of the animal, it is possible to obtain, for example, an increase in the volume of the ejaculate, however
smaller concentration sperm, mass motility and motile and live spermatozoids and an increase in the number of
dead spermatozoids (Figure 1).
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Comparative evaluation of the reproductive capacity of male goats in feedlot
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Figure 1
Evaluation of seminal characteristics of buck 1
Note. EV: ejaculate volume; SC: spermatozoid concentration; SM: spermatozoids motile; LS: live spermatozoids;
DS: dead spermatozoids.
The evaluated and calculated reproductive indices, according to the records of the 2021, 2022 and 2023 mount
seasons present in Table 2, are found in Table 4.
Table 4
Reproductive indexes of the evaluated herd, according to mount season
2021
Reproductive
parameter
Buck 1
Buck 2
Buck 3
Goats exposed
30
-
15
Pregnant goats
22
-
12
Fertility rate (%)
73,33
a
-
80,00
a
Natality rate (%)
172,72
-
141,67
Prolificity (goat kids/goat)
1,73
-
1,42
Mortality rate (%)
5,26
-
0,00
Gemelarity rate (%)
54,55
-
41,67
Trigemelarity rate (%)
9,09
-
0,00
Simple parturitions (%)
36,36
-
58,33
Reproductive efficiency (%)
120,0
-
113,3
2022
Reproductive
parameter
Buck 1
Buck 2
Buck 3
Goats exposed
15
15
-
Pregnant goats
15
10
-
Fertility rate (%)
100,00
a
66,67
b
-
Natality rate (%)
146,67
180,00
-
Prolificity (goat kids/goat)
1,47
1,80
-
Mortality rate (%)
4,55
5,56
-
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Gemelarity rate (%)
46,67
80,00
-
Trigemelarity rate (%)
0,00
0,00
-
Simple parturitions (%)
53,33
20,00
-
Reproductive efficiency (%)
140,0
113,3
-
2023
Reproductive
parameter
Buck 1
Buck 2
Buck 3
Goats exposed
15
15
15
Pregnant goats
12
13
11
Fertility rate (%)
80,00
a
86,67
a
73,33
a
Natality rate (%)
125,00
184,62
136,36
Prolificity (goat kids/goat)
1,25
1,85
1,36
Mortality rate (%)
13,33
8,33
0,00
Gemelarity rate (%)
25,00
38,46
36,36
Trigemelarity rate (%)
0,00
23,08
0,00
Simple parturitions (%)
75,00
38,46
63,64
Reproductive efficiency (%)
86,67
146,67
100,00
Note. Different letters between lines indicate significant difference P<0.05 by chi-square and Tukey tests.
Service capacity test over time
As mentioned above, fertility rate was used to assess the service capacity of males in the present study;
therefore, based on the data in Table 4, the service capacity test in 2021 between males 1 (73.33%) and male
3 (80.00%) did not show a significant difference in terms of direct fertility considered as the number of goats
that gave birth. The results can be seen in Table 4 and Figure 2. The percentage of fertility was not significant
among this group of males and, therefore, there were no statistical differences in fertility values, considering a
P value greater than 0.05 (P>0.05).
Figure 2
Fertility percentage of bucks group in reproductive station of 2021
Note. NS não significativo P>0,05, teste qui-quadrado e Tukey.
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Comparative evaluation of the reproductive capacity of male goats in feedlot
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In the 2022 mount season, there was a significant difference between male 1 (100.00%) and male 2 (66.67%),
thanks to the chi-square and Tukey tests it was determined that male 1 had a percentage of higher fertility at
P<0.01, compared to male 2 (Figure 3); thus determining the good reproductive performance of male 1 in the
years 2021 and 2022.
Figure 3
Fertility percentage of bucks group in reproductive station of 2022
Note. DS diferença significativa P<0,01, teste qui-quadrado e Tukey, com um grau de liberdade.
As for the 2023 mount season, the percentage of fertility was not significant between male 1 (80.00%), male 2
(86.67%) and male 3 (73.33%), thanks to chi-square and Tukey tests it was determined that the percentage of
fertility showed no significant difference between males this year and, therefore, there were no statistical
differences in fertility values (Figure 4).
Figure 4
Fertility percentage of bucks group in reproductive station of 2023
Note. NS não significativo P>0,05, teste qui-quadrado e Tukey.
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Comparative evaluation of the reproductive capacity of male goats in feedlot
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Fertility comparison of each male over time
When we compared the fertility of males across the different mount seasons, that is, the reproductive seasons
evaluated, it was noted that at the time of mount, that is, at the time of service of male 1, in the years 2021
(73.33%), 2022 (100%) and 2023 (80%), the percentage of fertility showed a significant difference according
to the chi-square and Tukey tests; therefore, it was determined that male 1 had a higher fertility percentage at
P<0.06 (Figure 5).
Figure 5
Fertility percentage of buck 1 in the three breeding seasons
Note. DS diferença significativa P>0,06, teste qui-quadrado e Tukey.
Regarding the service of male 2 in the years 2022 (66.67%) and 2023 (86.67%), the fertility percentage did not
show a significant difference using the chi-square and Tukey tests; therefore, it was determined that there is no
relevance in the direct fertility rate of male 2 at P>0.05 (Figure 6).
Figure 6
Fertility percentage of buck 2 in the three breeding seasons
Note. NS diferença não significativa P>0,05, teste qui-quadrado e Tukey.
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Comparative evaluation of the reproductive capacity of male goats in feedlot
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Finally, in relation to the service of male 3 in the years 2021 (80%) and 2023 (73.33%), the fertility percentage
did not show a significant difference using the chi-square and Tukey tests; therefore, it was determined that
there is no relevance at P>0.05 (Figure 7).
Figure 7
Fertility percentage of buck 3 in the three breeding seasons
Note. NS diferença não significativa P>0,05, teste qui-quadrado e Tukey.
4. DISCUSSION
As for the service capacity observed in the group of males in the present study, they behaved in a similar way.
The exception to this behavior was male 1, who performed this behavior more frequently throughout the years
2021, 2022 and 2023, which can be configured as a greater motivation or sexual libido. This behavior was
also observed in the study by Singh et al. (2023) when assessing the sexual behavior of a group of male goats
exposed to female goats in heat and evaluating the reproductive capacity of both males supported by
reproductive records of the number of females covered, pregnant and calved.
Galián Arnaldos et al. (2021) also observed similar behavior and corroborate the results in an evaluation with
males of breed Murcian at different ages. These results can be influenced and be directly related to the age of
the male, since male 1 is already an adult and has greater experience as he was used in all breeding seasons
and his behavior and libido patterns are already well defined. AMJAD et al. (2021) and Galián Arnaldos et al.
(2021) also corroborate the statement that the age of the male and his experience in reproductive life have a
direct influence on his service capacity and, consequently, on reproductive indexes.
Appetitive sexual behaviors have already been studied and evaluated in other studies, such as in Cardelas
(2010) which evaluated young bucks exposed to different male: female ratios and the relationship that seminal
quality has on the reproductive capacity of males; as well as Schleske and Vásquez (2014) in observing the
sexual conduct of adult bucks. These authors found similar results for pre-copulatory conducts.
Pereyro (2016) and Sánchez-Dávila et al. (2018) carried out similar studies with the males used in this study;
however, the goats were still considered young and the results they obtained were different from the present
study, since in this study the results among males were similar in terms of service capacity based on the
results obtained. This condition was possible given the age of the males and the time of year in which the
Rev. Ciencia Agraria
Vol. 3. No. 2 (2024) pp. 7-24
Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
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21
mount season is more favorable for the animals to express their reproductive potential, this fact was
corroborated by Amoah et al. (1996) in a study with female goats, as well as by Santos et al. (2016).
For example, male 1, being the male with older age and reproductive experience, was able to have 30 females
to be mated by him and, thus, a higher percentage of fertility was obtained, which was significant compared to
the others males for which there were no significant results, performing the chi-square and Tukey statistical
tests, which resulted in a higher fertility percentage of P<0.06 for male 1 and P>0.05 for males 2 and 3. This
similar situation was found by Delgadillo et al. (1997) in a study with male goats from tropical and subtropical
zones.
In analysis, it can be stated that such a configuration is due to the sexual indices that, during the first stage,
the males went through a period of learning, upon which the sexual behavior improved during the exposure
of the males a number of times to the females continuously or not and that it is independent of other factors
such as the time of year, which, in semi-arid conditions, there is no interference from the photoperiod in goat
reproduction (Dias and Veloso, 2020). On the other hand, sexual indices also made it possible to highlight
males with lower performance or reproductive potential over time, which can be discarded as breeders based
on the results obtained; therefore, the direct fertility or fertility rate it is a parameter to be considered when
choosing a breeder or when discarding males intended for reproduction.
5. CONCLUSIONS
The service capacity and fertility percentage are reliable tools to select a breeding male in general terms, but
it is necessary to evaluate other characteristics such as seminal quality, fertility indexes, etc. which are tools
that help us select one or more animals that can serve as breeders for the herd and, therefore, assist in
choosing and maintaining the best animals with excellent reproductive characteristics.
The learning and obtaining of experience is a requirement of great importance for males to develop adequate
sexual behavior, and for their level of reaction or service efficiency to improve with each mount and in a short
period of time.
It is advisable to keep animals in stable environments that offer well-being, in addition to meeting their essential
nutritional needs to ensure that their behavior is not affected. Males must be kept in separate stalls to avoid
dominance and hierarchy of just one animal, thus avoiding possible aggression that could put others at risk,
thus affecting their physical integrity and, consequently, their behavior and reproductive efficiency.
The service capacity helps us predict whether a male has superior reproductive capacity, excellent or deficient,
but it must be complemented by a fertility test to ensure the accuracy of its high reproductive efficiency,
favoring the herd's indices and, finally, in the number of animals available for slaughter or replacement.
Conflicto de intereses / Competing interests:
Los autores declaran que no incurrieron en conflictos de intereses.
Rol de los autores / Authors Roles:
Emanuel Cordeiro da Silva: Conceptualización, metodología, software, validación, curación de datos, análisis formal,
investigación, recursos, escritura – borrador original, escritura – revisión y edición, visualización, supervisión,
administración del proyecto, adquisición de fondos
Eduarda da Silva Fontain: Conceptualización, escritura – borrador original, escritura – revisión y edición,
visualización, supervisión, administración del proyecto, adquisición de fondos
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Comparative evaluation of the reproductive capacity of male goats in feedlot
Emanuel Cordeiro da Silv; Eduarda da Silva Fontain
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22
Fuentes de financiamiento / Funding:
Los autores declaran que no recibieron financiamiento para la realización de la investigación.
Aspectos éticos / legales; Ethics / legals:
Los autores declaran no haber incurrido en aspectos antiéticos, ni haber omitido aspectos legales en la realización de
la investigación.
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