A review of nutritional influences on reproduction in boars, bulls and rams

Brown, B. W.

doi:10.1051/rnd:19940201

Cited by 83 publications

(56 citation statements)

References 26 publications

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“…However, this type of diet should not have any advantage in the case of animals that are well developed and with higher intake ability, the use of a moderate energy diet perhaps being more adequate in order to avoid an excessive fatness and an adequate performance of future males for AI. Intensive feeding of young bulls can result in lowered reproductive performance probably due to an excessive fat deposition around the testis, which would hinder their correct thermoregulation, leading to a reduction in sperm production (for a review, see [31]). …”

Section: Discussionmentioning

confidence: 99%

Rearing management of rabbit males selected by high growth rate: the effect of diet and season on semen characteristics

et al. 2004

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-A total of sixty-six young males were used to evaluate the effect of low (L), medium (M) and high (H) concentrations of dietary digestible energy received during the rearing seasons (autumn and spring) on the performance and main semen characteristics of males for artificial insemination selected by a high growth rate. Males reared during the spring season presented a significantly higher weight at weaning than those reared during the autumn season (P < 0.001), and these differences were maintained until the end of the trial. The requirements of the males were easily covered as a general rule. In the autumn group, the males were unable to intake the digestible protein recommended only during their 3rd month of life, especially with low concentrate diets (P < 0.05). H males showed higher semen concentration and production during the autumn season, while L males showed a higher semen concentration and production than M males during the spring season, the H group showed intermediate values (P < 0.001). Males reared during the spring season showed significantly higher values of sperm concentration (P < 0.01) and production (P < 0.01). H males presented a lower percentage of spermatozoa with cytoplasmic droplets than the L group (P < 0.05) and the lowest values for sperm abnormalities during the autumn season, while the L group presented higher values for percentage abnormalities, especially during the last month controlled (P < 0.05). As a general rule, the main motility parameters controlled were not affected by the rearing diet received nor the season. These results seem to indicate that the management of rabbit males during the growing and rearing periods seem to significantly affect their subsequent performance and semen production.rabbit males / rearing / semen characteristics / dietary energy / season

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Section: Discussionmentioning

confidence: 99%

Rearing management of rabbit males selected by high growth rate: the effect of diet and season on semen characteristics

et al. 2004

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“…The roles of postnatal nutrition in progress towards puberty in male farm animals has been reviewed by Brown (1994). We will focus on mature animals for the remainder of this review, but we would like to acknowledge the major contributions in recent years from the laboratory of John Kastelic who have studied metabolic input into pubertal development of young bulls, and have clearly demonstrated that superior calfhood nutrition, probably through the action of metabolic hormones, promotes gonadotrophin secretion and thus testicular growth, and an earlier onset of spermatogenesis (see Barth et al, 2008).…”

Section: Foetal Life and Pubertymentioning

confidence: 99%

“…Most of the older literature describes experiments with young Bos taurus bulls that are up to 2 years old and post-pubertal but still growing rapidly (review Brown, 1994). In such animals, nutrition clearly affects testicular development and the production of spermatozoa in much the same way as it does in mature sheep and goats (Davies et al, 1957;Flipse and Almquist, 1961;Gauthier and Berbigier, 1982).…”

Section: Nutrition and The Production Of Spermatozoamentioning

confidence: 99%

Interactions between nutrition and reproduction in the management of the mature male ruminant

Martin¹,

Blache²,

Miller³

et al. 2010

Animal

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In mature male sheep and goats, changes in feed intake seem to have little effect on gonadal endocrine function but induce profound changes on sperm production. These outcomes are due to changes in size of the seminiferous tubules and in spermatogenic efficiency. Except with severe underfeeding, there are only minor changes in the endocrine function of the testis (testosterone production) unless season-long treatments are imposed. For cattle, nutrition clearly affects testicular development and the production of spermatozoa in young bulls, as it does in other species but, after the period of rapid growth has ended, there appears to be little or no response to nutrition. We are developing a clear picture of the metabolic signals, neuroendocrine processes and hormonal control systems that are involved, particularly for the mature male sheep. The energetic components of the diet, rather than protein, seem to be responsible, so we have envisaged a model of the relationship between energy balance and reproduction that has 4 'dimensions': genotype, structure (organs), communication (chemical and neural signals, nutrient sensing) and time (dynamics, metabolic memory, programming). We have linked these perspectives to 'resource allocation theory' and incorporated them into strategies for 'clean, green and ethical animal production'. In contrast to the clear outcomes with respect to spermatogenesis, the effects of nutrition on sexual behaviour are more difficult to define, perhaps because the behaviour is affected by a complex mix of physiological factors and because of flawed methods for quantifying male behaviour. For example, sexual behaviour is compromised by severe feed restriction, but male sexual behaviour requires intensive motor activity so a decline in libido could be caused by general weakness rather than specific nutritional limitations. The interaction between sexual activity and feeding behaviour also complicates the issue under field conditions. At the other end of the scale, overweight males can show reduced sexual success because they have difficulty courting and mounting. For this reason, exercise can enhance the fertilising capacity of rams. This will be important in extensive mating systems where males need to assemble and guard a harem and then mate many times for several weeks. For artificial insemination centres, there seems to be very few data on the nutritional management of males, but problems with overfed animals appear to be a risk. Future research should concentrate on the intra-testicular systems mediating the effects of nutrition on the production of spermatozoa.

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“…Η θετική επίδραση της αυξημένης χορήγη σης ενέργειας στον όγκο και το βάρος των όρχεων και στην παραγωγή σπέρματος είναι διαπιστωμένη (Oldham et al 1978, Murray et al 1990, Brown 1994. Δεν είναι, όμως, ακριβώς γνωστό ποιο ποοοοτό αύ ξησης δίνει τα πλέον επιθυμητά αποτελέσματα.…”

Section: αποτελεσματαunclassified

The feeding of rams on farms of the "Macedonia" Cooperative of Chios sheep breeders

Valergakis¹,

Gelasakis

Oikonomou

et al. 2017

J Hellenic Vet Med Soc

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The aim of this study was to verify the adequacy of ram rations in intensively reared flocks of the Chios breed. Data were collected from the 66 farms of the "Macedonia" Cooperative of Chios Sheep Breeders and were evaluated using requirements published by INRA and NRC. Statistical analysis was performed using analysis of variance. Ram requirements for net energy lactation, digestible protein, absorbable calcium and absorbable phosphorus were greatly exceeded. Farm classification in three groups (A, Β and C, 26,15 and 25 farms, respectively), based on net energy offered during maintenance (100%, 122% and 154% of requirements, respectively), showed that there was considerable area for improvement; the use of large quantities of concentrates is unjustified. Location, considerable on-farm feed production and zero grazing were associated with farm classification in group C. Rations used during the pre-breeding and the breeding periods offered 40-50% more net energy than required. Protein requirements were greatly exceeded (200-250%); alfalfa hay was the basic roughage and soybean and other oilseed meals (10% and 5%, respectively) were included in the concentrates. Calcium requirements were greatly exceeded as well. However, 1 out of 4 farms was providing inadequate amounts of phosphorus during maintenance. Moreover, adequate amounts of vitamins and trace minerals were offered by 37.9% of farms only, during maintenance. This situation was improved during the pre-breeding and the reeding periods (54.5% and 74.2%, respectively), but it was still far from desirable. It was estimated that balanced rations would decrease annual ram feeding expenses by at least 20€. At the same time, incidences of elevated body condition scores and their detrimental effects on ram fertility and some diseases, like urolithiasis, would be greatly reduced.

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A review of nutritional influences on reproduction in boars, bulls and rams

Cited by 83 publications

References 26 publications

Rearing management of rabbit males selected by high growth rate: the effect of diet and season on semen characteristics

Rearing management of rabbit males selected by high growth rate: the effect of diet and season on semen characteristics

Interactions between nutrition and reproduction in the management of the mature male ruminant

The feeding of rams on farms of the "Macedonia" Cooperative of Chios sheep breeders

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