نتایج جستجو برای: breeding period
تعداد نتایج: 544398 فیلتر نتایج به سال:
Background: The sub-clinical carry-over effects of post-partum (PP) conditions and the problems independent of parturition may affect the cows’ performance during the breeding period. Aims: It was hypothesized that some mid-lactation cows may have compromised liver functions and calculating liver activity index (LAI; -1.5 to +1.5) may be helpful in detecting su...
Investigations were made into the body condition, energy metabolite and endocrinal changes of male green turtles Chelonia mydas prior to and during their vernal breeding period in the southern Great Barrier Reef. Prior to migration, breeding males exhibited a higher body condition index than non-breeding males. However, during the migratory reproductive period, breeding males lost significant b...
For land-breeding marine organisms such as seabirds, knowledge about their habitat use has mainly been gained through studies of breeding individuals that are constrained to return frequently to their breeding grounds. In this study we set out to measure whether: a) habitat selection in the non-breeding period predicts habitat selection in the breeding period, and b) whether breeding individual...
Taphozous longimanus (Hardwicke) is a continuous breeder as males show full spermatogenic activity throughout the year. Microscopic study of testis reveals that immature, pre-breeding and sexually active males occur round the year. The testis shows variations in its structure during the different stages of breeding activity. In the pre-breeding period, testis shows various stages of spermatogen...
Wild passerine birds (Passeriformes) from the northeastern part of the Czech Republic were examined for ectoparasites during the pre-breeding period in 2007. Two species of fleas of the genera Ceratophyllus and Dasypsyllus (Siphonaptera: Ceratophyllidae), and 23 species of chewing lice belonging to the genera Ricinus, Myrsidea, Menacanthus (Phthiraptera: Menoponidae), Brueelia, Penenirmus, and ...
This paper discusses when to start and stop breeding cows in their lactation. First, a review of the literature on the optimal voluntary waiting period (when to start breeding cows) shows that there is not much consensus on how long the economically optimal voluntary waiting period is. Secondly, the paper then describes a computer program that calculates the insemination value (IN$) for cows in...
One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed...
BACKGROUND Barn Swallows (Hirundo rustica) breed almost exclusively in the Northern Hemisphere. However, since the early 1980's, a small disjunct breeding population has become established in eastern Argentina, presumably by birds previously derived from those breeding in North America. Currently, it is unknown where these individuals go following breeding and how they have adjusted to a revers...
A total of 1474 and 1935 production and reproduction records of crossbred cattle and Murrah buffaloes from the year 1992 to 2012 were utilized in the present study to investigate breeding efficiency (BE) and various performance traits. Breeding efficiency was calculated using Wilcox and Tomar methods and Least –squares of Harvey model was used to study the effects of various non-genetic factors...
1. Understanding the interactions between different periods of the annual cycle in migratory animals has been constrained by our inability to track individuals across seasons. In seabirds, virtually nothing is known about how diet quality during the non-breeding period, away from the breeding grounds, might influence subsequent reproductive success. 2. We used stable nitrogen (delta(15)N) and c...
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