Effect of breed, plane of nutrition and age on growth, scrotal development, metabolite concentrations and on systemic gonadotropin and testosterone concentrations following a GnRH challenge in young dairy bulls

Byrne, C.J.; Fair, Seán; English, A.M.; Urh, C.; Sauerwein, H.; Crowe, M.A.; Lonergan, P.; Kenny, David A.

doi:10.1016/j.theriogenology.2017.04.002

Cited by 31 publications

(18 citation statements)

References 64 publications

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“…Bulls fed the high-nutrition diet were younger at puberty and when they reached a SC of 28 cm than bulls fed the low-nutrition diet. In a similar study performed recently on Holstein-Friesian and Jersey bull calves between 3 to 49 weeks of age these results could be confirmed (Byrne et al, 2017). In addition, Dance et al (2015) noticed at 72 weeks, that bulls fed the highnutrition diet had greater paired testes weights.…”

Section: Effects Of Modifications In Nutrition Starting During the Insupporting

confidence: 76%

“…The estimated number of sperm produced by day in the bulls of the high-nutrition group was about 9% higher compared to the bulls of medium-nutrition group and about 30% higher than the number estimated in bulls of the low-nutrition group, while no differences in sperm quality were noticed depending on nutrition of the bulls (Dance et al, 2016). Overall, the results obtained by Dance et al (2015Dance et al ( , 2016 and Byrne et al (2017) are consistent with the studies from Brito et al (2007a, c, d), who modified the nutrition of beef bulls starting at the prepubertal period. All these studies provide clear evidence that nutritional modulation of bull calves before puberty has profound effects on reproductive development.…”

Section: Effects Of Modifications In Nutrition Starting During the Inmentioning

confidence: 66%

“…All these studies provide clear evidence that nutritional modulation of bull calves before puberty has profound effects on reproductive development. Because Dance et al (2015) and Byrne et al (2017) modulated the nutrition during the infantile and prepubertal periods, it is unclear, however, whether a nutritional modulation is required for both periods to obtain these effects on reproductive development or whether a shorter time interval would be as effective.…”

Section: Effects Of Modifications In Nutrition Starting During the Inmentioning

confidence: 99%

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Effects of nutrition on sexual development of bulls

Bollwein¹,

Janett²,

Kaske³

2017

Anim Reprod

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In the last decades a series of attempts have been made to improve reproductive performance of bulls via optimizing nutrition. Although an increase in energy uptake during the post-weaning period of calves led to a faster growing rate, it had no positive effects on sexual development. In contrast, a high-nutrition diet during the prepubertal period reduced the age at puberty of the bulls and increased the size/weight of the testis and the epididymal sperm reserves. This faster sexual development was associated with an increased transient LH peak, which seemed to be mediated by an increase in serum IGF-I concentrations. However, the exact mechanisms responsible for the interaction between nutrition and the subsequent development of calves are still not clear. Sexual development of bull calves depends not only on nutrition of the calves after birth but also on the feed intake of their mothers during pregnancy. A high-nutrition diet fed to the mother during the first trimester has negative effects on the reproductive performance of their offspring. In summary, growth, health and reproductive performance can be improved by nutrition, but further studies are necessary to obtain a better understanding about the mechanisms responsible for this phenomenon.

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Section: Effects Of Modifications In Nutrition Starting During the Insupporting

confidence: 76%

Section: Effects Of Modifications In Nutrition Starting During the Inmentioning

confidence: 66%

Section: Effects Of Modifications In Nutrition Starting During the Inmentioning

confidence: 99%

See 1 more Smart Citation

Effects of nutrition on sexual development of bulls

Bollwein¹,

Janett²,

Kaske³

2017

Anim Reprod

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“…The implications of an elevated feeding regimen on scrotal fat accretion and testicular thermoregulation have been reviewed (Kastelic, 2014). Whereas greater BW gain is generally mirrored by increased testicular growth, within breed (Byrne et al, 2017), the degree of scrotal fat required to adversely affect sperm production has not been well defined. Rearing strategies that consistently advance puberty and sexual maturation are required if the supply of semen from young elite sires is to meet demand, particularly within the context of seasonal breeding systems when inseminations are typically concentrated in a 6-to 8-wk period.…”

Section: Introductionmentioning

confidence: 99%

Plane of nutrition before and after 6 months of age in Holstein-Friesian bulls: I. Effects on performance, body composition, age at puberty, and postpubertal semen production

Byrne

Fair

English

et al. 2018

Journal of Dairy Science

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The aim of this study was to examine the effect of plane of nutrition (1) during the first 6 mo of life and (2) from 6 mo of age to puberty on early growth characteristics, age at puberty, and postpubertal semen production in Holstein-Friesian bulls. Holstein-Friesian bull calves (n = 83) with a mean (standard deviation) age and body weight of 17 (4.4) d and 52 (6.2) kg, respectively, were assigned to a high (Hi) or low (Lo) plane of nutrition for the first 6 mo of life. The Hi and Lo calves received 1,200 and 450 g of milk replacer, respectively; Hi calves were fed concentrate ad libitum and Lo were fed a maximum of 1 kg concentrate daily, and concentrate allowances remained the same after weaning. At 24 wk of age, bulls were reassigned within treatment to either remain on the same diet or to switch to the opposite diet until puberty, resulting in 4 treatment groups: Hi-Hi, Hi-Lo, Lo-Lo, and Lo-Hi. After puberty, all bulls were fed a moderate plane of nutrition until 60 wk of age; thereafter, the diet was ad libitum concentrates until slaughter at 72 wk of age. Bulls were weighed weekly before weaning and every 2 wk after weaning. Scrotal circumference (SC) was measured every 2 wk, beginning at 15 wk of age. Beginning at a SC of 24 cm, electro-ejaculation was carried out every 2 wk to establish the onset of puberty. Semen collection continued monthly after puberty. Thermal images of the scrotum were taken monthly from 28 to 36 wk of age. Scrotal skin thickness (SST) was measured monthly (from 16 wk of age to puberty) using a digital calipers. Bulls on the Hi diet had a higher scrotal temperature and SST at each time point than those on the Lo diet. Average daily gain (ADG) was greatest in Hi-Hi bulls, with Hi-Lo and Lo-Hi having similar ADG but both being greater than Lo-Lo. Bulls on the Hi diet pre-6 mo of age were younger at puberty, regardless of diet offered post-6 mo of age. Bulls offered a Hi diet post-6 mo were heavier at puberty. Neither scrotal temperature nor dietary treatment affected postpubertal semen production variables. In conclusion, a high plane of nutrition during the first 6 mo of age hastened the onset of puberty and the availability of saleable semen, regardless of plane of nutrition post-6 mo of age.

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“…Em touros, a liberação rítmica circadiana de testosterona não tem sido bem estabelecida, sendo que a secreção sérica de testosterona foi descrita como três a quatros picos espontâneos diários (Byrne et al, 2017). No entanto, estudos observaram maiores concentrações pela manhã, sem atribuírem este fato, ao ritmo circadiano da secreção de testosterona (Barbosa et al, 1991;Byrne et al, 2017). No presente estudo, não foi observado diferença entre os turnos durante as coletas discordando dos últimos autores.…”

Section: Resultsunclassified

Características de carcaça, órgão vomeronasal, concentrações séricas de testosterona e IGF-I em machos Nelore com ductos incisivos bloqueados

Emerick

Mahecha

Gonçalves

et al. 2019

Revista Brasileira De Ciência Veterinária

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Objetivou-se avaliar características quali-quantitativas da carcaça em machos Nelore, submetidos ao bloqueio dos ductos incisivos no período pré puberal. Além disso, objetivou-se avaliar as concentrações séricas de testosterona e do hormônio do crescimento semelhante a insulina do tipo I (IGF-I), e a arquitetura histológica do órgão vomeronasal (OVN). Trinta e quatro machos, no período pré puberal, foram divididos em três grupos experimentais: inteiros-animais controle sem qualquer procedimento (n = 11); bloqueados-animais com os ductos incisivos bilateralmente obstruídos (n = 10); castrados-animais com orquiepididectomia bilateral (n = 13). O OVN foi obtido no abate, ao final do experimento, para avaliação histomorfométrica. As coletas de sangue foram realizadas a cada três meses, em dois turnos (manhã e tarde), totalizando cinco avaliações. Observaram-se maiores (P<0,05) pesos corporais finais (inteiros = 494,1 ± 28,71; bloqueados = 500,6 ± 23,6 e castrados = 468,3 ± 21,8 Kg) nos inteiros e bloqueados. O acabamento da carcaça foi maior nos castrados (P<0,05) em relação aos inteiros e bloqueados, enquanto o rendimento de carcaça não apresentou diferenças entre os três tratamentos (P>0,05). Registrou-se redução da altura do epitélio neuro sensitivo do OVN nos bloqueados e castrados (P<0,05). Foi registrada menor concentração de testosterona nos bloqueados nas coletas quatro e cinco à tarde (P<0,05). Conclui-se que a obstrução dos ductos incisivos reduziu os estímulos sensoriais para o OVN, que por sua vez, promoveu alteração na concentração sérica de testosterona, sem alterar o ganho de peso dos animais, porém, não promoveu melhoria na qualidade da carcaça nas condições deste estudo.

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Effect of breed, plane of nutrition and age on growth, scrotal development, metabolite concentrations and on systemic gonadotropin and testosterone concentrations following a GnRH challenge in young dairy bulls

Cited by 31 publications

References 64 publications

Effects of nutrition on sexual development of bulls

Effects of nutrition on sexual development of bulls

Plane of nutrition before and after 6 months of age in Holstein-Friesian bulls: I. Effects on performance, body composition, age at puberty, and postpubertal semen production

Características de carcaça, órgão vomeronasal, concentrações séricas de testosterona e IGF-I em machos Nelore com ductos incisivos bloqueados

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