Neuroendocrine Basis of Seasonal Reproduction

Karsch, Fred J.; Bittman, Eric L.; Foster, Douglas L.; Goodman, Robert L.; Legan, Sandra J.; Robinson, Jane E.

doi:10.1016/b978-0-12-571140-1.50010-4

Cited by 354 publications

(337 citation statements)

References 75 publications

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“…These results showed that in female goats from subtropical Mexico, the photoperiod is a major environmental factor that controls the annual ovulatory activity. In the experimental group, the photoperiodic rhythm modified the seasonal pattern of ovulations observed in the control group exposed to natural light, a result consistent with those reported in Alpine does and Suffolk ewes (Karsch et al, 1984;Gebbie et al, 1999).…”

Section: Female Goatssupporting

confidence: 87%

Environmental and social cues can be used in combination to develop sustainable breeding techniques for goat reproduction in the subtropics

2011

Animal

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Goat breeds from subtropical latitudes show different annual reproductive cycles. Some of them display large seasonal variations in their annual breeding season, while others display a moderate seasonality or sexual activity all year round. This reproductive seasonality causes seasonality of milk, cheese and meat productions and, as a consequence, induces wide variation in producer incomes. To solve this problem and provide methods allowing producers to breed animals during the anestrous period and stabilize production all year round, it is necessary to have a deep knowledge of their annual sexual activity and to identify the environmental factors controlling the timing of the annual reproductive cycle. Then, it is possible to build on these knowledge sustainable breeding techniques adapted to the environmental, economic and social characteristics of the local breeding system. In this review, I will illustrate this strategy through the example of our experiments in subtropical goats. First, we determined the characteristics of the annual breeding season in both male and female goats. Second, we identified the photoperiod as the major environmental factor controlling the timing of this annual breeding season. Third, we used the photoperiod to stimulate indirectly the sexual behavior of does. Indeed, we used photoperiodic treatments to stimulate the sexual activity of bucks during the non-breeding season. These sexually active male goats were then used to induce and synchronize the estrous behavior and ovulatory activity of anestrous females in confined or grazing conditions by using the 'male effect'. Under subtropical conditions, these results constitute an original manner to control the reproductive activity of local goats using the photoperiod combined with the 'male effect.'

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Section: Female Goatssupporting

confidence: 87%

Environmental and social cues can be used in combination to develop sustainable breeding techniques for goat reproduction in the subtropics

2011

Animal

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“…The retina receives photoperiodic information, which follows a multi-step neural pathway to the pineal gland, where the message modulates the rhythm of melatonin secretion [14]. The duration of secretion differs between long and short days because melatonin is released at night, only.…”

Section: Seasonal Regulation Of Hypothalamic Activitymentioning

confidence: 99%

The effect of nutrition on the seasonality of reproduction in ewes

Forcada

Abecia

2006

Reprod. Nutr. Dev.

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-The beneficial effects of nutrition on reproduction in sheep have been described, particularly on ovulation rate. However, the relationships between nutrition and reproductive seasonality are not well known. This review will deal with the effects of body fat or food intake on sexual and hypothalamic/pituitary activity in sheep, mainly focused on Mediterranean genotypes. Although only severe malnutrition can significantly extend the length of the seasonal anestrous period, the level of fat reserves can play a significant role on reproductive seasonality delaying the onset of seasonal anoestrus, particularly on the Mediterranean environment. The effect of overfeeding on LH secretion has also been reported, specially at short term. Several experimental approaches have elucidated that both high body fat and food intake are able to modify the sensitivity of the hypothalamus to oestradiol negative feedback during seasonal anoestrus, with those effects being associated to a reduced amount of NPY mRNA and to an increase of plasma insulin, glucose and leptin concentrations, particularly in the late scenario. However, the highest receptivity to nutritional stimulation in terms of increasing LH occurs when ewes are subjected to a photoperiodic state of early anoestrus or late breeding season rather than under a photoperiod characteristic of the end of anoestrus or the beginning of the breeding season.sheep / nutrition / reproductive seasonality / gonadotropins

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“…doi:10.1017/S1751731117001045 animal and dramatically reduced sperm production in the male (Dacheux et al, 1981). This cycle, modulated by melatonin secretion, is under strong photoperiodic control (Karsch et al, 1984;Malpaux et al, 1997;Thiéry et al, 2002). In Europe, most domestic sheep breeds have a breeding season from late summer to early winter, leading to births occurring 5 months later from winter to early summer.…”

Section: Introductionmentioning

confidence: 99%

Animal Board Invited Review: Sheep birth distribution in past herds: a review for prehistoric Europe (6th to 3rd millennia BC)

Balasse

Tresset

Bălășescu³

et al. 2017

Animal

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In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminants' reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestors' remains to be written. This perspective echoes archaeologists' current attempts at reconstructing ancient pastoral societies' socio-economical organization. Information related to birth seasonality may be retrieved directly from archaeological sheep teeth. The methodology consists of reconstructing the seasonal cycle record in sheep molars, through sequential analysis of the stable oxygen isotope composition (δ 18 O) of enamel. Because the timing of tooth development is fixed within a species, inter-individual variability in this parameter reflects birth seasonality. A review of the data obtained from 10 European archaeological sites dated from the 6th to the 3rd millennia BC is provided. The results demonstrate a restricted breeding season for sheep: births occurred over a period of 3 to 4 months, from late winter to early summer at latitudes 43°N to 48°N, while a later onset was observed at a higher latitude (59°N). All conclusions concurred with currently held expectations based on present day sheep physiology, which, aside from the historical significance, contributes to the reinforcing of the methodological basis of the approach. Further study in this area will permit regional variability attributable to technical choices, within global schemes, to be fully reported.

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Neuroendocrine Basis of Seasonal Reproduction

Cited by 354 publications

References 75 publications

Environmental and social cues can be used in combination to develop sustainable breeding techniques for goat reproduction in the subtropics

Environmental and social cues can be used in combination to develop sustainable breeding techniques for goat reproduction in the subtropics

The effect of nutrition on the seasonality of reproduction in ewes

Animal Board Invited Review: Sheep birth distribution in past herds: a review for prehistoric Europe (6th to 3rd millennia BC)

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