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Sex ratios that deviate from 1:1 have been observed in response to a number of stimuli. In this review we will discuss sex ratio biasing, and the evolutionary and molecular mechanisms thought to underlie this phenomena in mammals. The role of embryo quality will be discussed in relation to sex ratio modulation and epigenetic programing of the embryo. Sex ratio skewing has been studied in many species and several factors have been proposed as influencing secondary sex rat...

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bp0009rdr4 | (1) | REDR1986

Regulation of the secretion of FSH in domestic ruminants

Findlay J. K. , Clarke I. J.

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bp0009rdr12 | (1) | REDR1986

In-vitro fertilization of ruminants

First N. L. , Parrish J. J.

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bp0013cpr23 | Behavioural Aspects | CPR1989

Mechanisms mediating the stimulatory effects of the boar on gilt reproduction

Hughes P. E. , Pearce G. P. , Paterson A. M.

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bp0008rdr17 | Male Function and Spermatogenesis | REDR2014

Testicular function and fertility in bulls

Kastelic John P , Thundathil Jacob

Summary. Since one bull may be responsible for impregnating numerous cows, testicular function and fertility are of critical importance. Within this broad context, this review will focus on: the effects of nutrition on reproductive development; scrotal/testicular thermoregulation; breeding soundness; and sperm function/fertility. Bulls fed above-maintenance levels of energy and protein before 30 wk of age had increased luteinizing hormone pulse frequency, hast...

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bp0008rdr1 | Phylogenetics | REDR2014

Ruminant phylogenetics: A reproductive biological perspective

Silvia William J.

Summary. Phylogenetics is the study of evolutionary relationships among species. Phylogenies are based on the comparison of large numbers of characteristics among species. Traditionally, the field of phylogenetics was dominated by paleontologists so the characteristics studied were structural, often skeletal. The field of phylogenetics was revolutionized in the 1980s as scientists began using molecular data, first amino acid, then nucleotide sequences. This le...

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bp0008rdr11 | Peri-implantation: Conceptus-uterine Interaction | REDR2014

Consequences of interactions between the maternal immune system and the preimplantation embryo in cattle

Hansen Peter J

Summary. Using the cow, three questions related to the importance of the maternal immune system for the developing embryo are addressed: role of semen-induced inflammation for pregnancy establishment, regulation of preimplantation development by molecules that function as soluble mediators of immune cells, and immunological aspects of embryonic signaling by interferon-τ. Unlike rodents, there is no indication that semen modifies the physiology of the moth...

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bp0009rdr1 | (1) | REDR1986

Control of GnRH secretion

Clarke I. J.

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bp0009rdr16 | (1) | REDR1986

Short light cycles induce persistent reproductive activity in Ile-de-France rams

Pelletier J. , Almeida G.

Summary. European breeds of rams appear to be responsive to photoperiodic changes even though there are large differences between breeds in the timing and amplitude of endocrine (LH and testosterone) and gametogenetic variations before the sexual season. Light regimens such as 6-month light cycles or alternations of constant short and long days every 12–16 weeks are able to entrain the parameters of sexual activity. In these regimens in which the period ...

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bp0013cpr5 | Nutrition-Metabolism-Reproduction Interactions | CPR1989