Publications by authors named "P Purdy"
Computer-assisted sperm analysis (CASA) has become the predominant tool for assessing bull semen in AI programs. Despite such popularity CASA's ability to predict fertility has been limited, especially when emphasis is based on single motion characteristics. Our hypothesis is that numerical sets of CASA measures provide a more effective method to differentiate the potential fertilization capacity of bulls and that bulls can be clustered based on sets of CASA measures.
View Article and Find Full Text PDFArticle Synopsis
- A new method has been developed to directly introduce frozen embryonic gonadal germ cells (GGC) into sterile chicken hosts to help preserve chicken breeds and their genetic materials.
- The technique is particularly efficient using male gonads, but obtaining enough viable female gonads for breeding is challenging due to limited egg production in certain chicken breeds.
- A simplified culture method allows for high-purity GGC to be recovered from frozen 9.5-day-old embryonic gonads, supporting the biobanking of indigenous chicken breeds and potentially other bird species.
This study evaluated relationships among reproductive parameters and the bioclimatic indices: temperature and humidity index (THI), equivalent temperature index (ETI), black globe temperature and humidity index (BGTHI), and thermal comfort index (TCI), during the first 45 days of spermatogenesis (SP-45) and during the 15 days of sperm transit through the epididymis (STP-15) that preceded the reproductive assessments (ReA). Such information is useful in determining the optimal breeding season in Northeast Brazil. Santa Inês rams (n = 25) underwent two ReA in three periods of the year (D-P = dry; R-P = rainy and RD-P = rainy/dry transition), and the bioclimatic indices were calculated at the corresponding SP-45 and STP-15 timepoints prior to each ReA.
View Article and Find Full Text PDFNational animal gene banks that are responsible for conserving livestock, poultry, and aquatic genetic resources need to be capable of utilizing a broad array of cryotechnologies coupled with assisted reproductive technologies to reconstitute either specific animals or populations/breeds as needed. This capability is predicated upon having sufficient genetic diversity (usually encapsulated by number of animals in the collection), units of germplasm or tissues, and the ability to reconstitute animals. While the Food and Agriculture Organization of the United Nations (FAO 2012, 2023) developed a set of guidelines for gene banks on these matters, those guidelines do not consider applications and utilization of newer technologies (e.
View Article and Find Full Text PDFBackground: Non-surgical artificial insemination techniques for sheep may benefit from larger numbers of sperm in the insemination dose because the ewe cervix is convoluted and often cannot be traversed with an insemination gun resulting in deposition of the sperm at the os cervix.
Objective: To compare a range of sperm concentrations when cryopreserving semen from Santa Ines rams and determine the effects of this on post-thaw quality.
Materials And Methods: One ejaculate from each ram (n = 10) was diluted to four sperm concentrations to obtain the following groups: G-400, G-800, G-1200, and G-1600 x 10 sperm/mL.