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Master of Science / Department of Animal Sciences and Industry / Jeffrey S. Stevenson / We hypothesized that pregnancy outcomes may be improved by inducing luteal regression, ovulation, or both before a control CO-Synch + CIDR program (100 mcg GnRH i.m. [GnRH-1] and insertion of a progesterone-impregnated intravaginal controlled internal drug release [CIDR] insert on d -10, 25 mg PGF2alpha (PG) i.m. and CIDR insert removal on d -3, and 100 mcg GnRH i.m. [GnRH-2] and timed AI [TAI] on d 0) in suckled beef cows. This hypothesis was tested in 2 experiments, in which cows were treated with either PG or PG + GnRH before initiating a control CO-Synch + CIDR program to increase the proportion of cows starting the program in a low (< 1 ng/mL; Exp. 1) or high (≥ 1 ng/mL; Exp. 2) progesterone status, respectively. Blood was collected before each injection for later progesterone analyses. In Exp. 1, cows at 9 locations (n = 1,537) were assigned to either: (1) control or (2) PrePG (same as control with a PG injection on d -13). The PrePG cows had larger (P < 0.05) follicles on d -10 and more (P < 0.05) ovulated after GnRH-1 than controls (60.6 vs. 36.5%). Incidence of estrus between d -3 and 0 was greater (P < 0.05) for treated multiparous cows than multiparous controls and treated and control primiparous cows (74.1 vs. 64.3, 58.6, and 59.1%, respectively). In Exp. 2, cows at 4 locations (n = 803) were assigned to: (1) control (same as Exp. 1) or (2) PrePGG (same as control with PG injection on d -20 and GnRH injection on d -17. Cows with BCS > 5.0 or ≥ 70 d postpartum at TAI were more (P < 0.05) likely to become pregnant than thinner cows or those with fewer days postpartum. Treated cows in both experiments were more (P < 0.05) likely than controls to have luteolysis after initial PG injections and reduced (P < 0.05) serum progesterone. In both experiments, pregnancy rates at d 35 did not differ between treatment and control; however, cows classified as anestrous before d -10, but with elevated progesterone on d -10, had increased (P < 0.05) pregnancy outcomes than remaining anestrous cows with low progesterone concentrations. In summary, luteal regression and ovulation were enhanced by treatments before the 7 d CO-Synch + CIDR program; however, pregnancy per TAI was not improved.

The objective of the thesis was to analyse the reproductive traits of sows on a particular farm with regard to the method used, as observed during the period of one year. The highest rate of live-born piglets per the first litter (12.4) was reached in nucleus breeding. Regarding the mating method, the highest number of piglets born in the first litter (12.7) was reached through natural mating, followed by intrauterine insemination (12.3) and cervical insemination (11.6). During the one-year period, the rate of successful conception at first service was 83.3 per cent of sows in case of intrauterine insemination, 80.6 per cent of sows in case of natural mating and 79.2 per cent of sows in case of cervical insemination. When calculating the number of all born piglets per 100 inseminations, it was found out that 1 028 piglets were born in case of intrauterine insemination, 1 026 piglets in case of natural mating and only 921 piglets were born in case of cervical insemination, that is 107 (or 105) less. The highest number of born piglets (11.8) was reached in sows serviced when they were 256270 days old, followed by sows serviced when 241255 days old (11.1 piglets). With the gestation length under 114 days, the sows farrowed 1.2 piglets more than when the gestation length was over 115 days. With the weaning-to-conception interval under 5 days, the sows farrowed more (12.4) piglets than with the weaning-to-conception interval lasting over 6 days, which resulted in only 11.9 piglets being born.

The goal of this work is to determine necessary economic and organizational measures for introducing goat insemination in Czech Republic. As the current number of goats is 14 402 head, 23 044 doses are needed for their successful insemination. These doses would be produced from 14 brood billy-goats. Supposing investment costs to establish the insemination station, are estimated at 3 220 000CZK. The period to repay them would be 4 years and 340 days according to the assumed calculated prices of insemination doses. The distribution and sale of insemination doses would be arranged by breeding organizations under an agreement with the intended insemination station. The assumed selling price of 1 insemination dose to final customer could be 230,8 CZK during the 1st year. The price includes a fee of 100 CZK for the realisation of insemination.This price would be gradually reduced to 199 CZK (6th year).

This study was designed to : 1) Determine the effects of fresh vs frozen semen at a high inseminate dosage (lOOxl06sperm) contrasted to their effects at a conventional dosage (20xl06 sperm) on accessory sperm per ovum and 2) Evaluate the relationship between accessory sperm number per embry%vum and fertilization status/embryo quality if accessory sperm number were affected by treatment. In this study semen from four bulls routinely giving a minimum of 700/0 morphologically normal and 600/0 motile sperm cells were used. Ejaculates of these bulls were split and prepared for use as fresh and frozen semen at either 100xl06 or 20xI06 cells per dose in.5 mL French straws. Half of the total semen filled straws were frozen in liquid nitrogen at -196°C and half were stored at 5°C for 4 days after collection and used as unfrozen. Cows in standing heat were inseminated with fresh or frozen semen at either high (IOOxl06 sperm) or conventional dose (20xl06 sperm). Ova/embryos were recovered non surgically on day 6 after breeding. Accessory sperm were counted in the recovered embryos/ova after partial digestion with Pronase followed by compression of the embryo/ovum with a cover slip. From 129 inseminations to normally cycling cows, 98 embryos/ova were recovered. To reduce male effects, embryos/ova used were randomly balanced across treatments, by ejaculate within bull for evaluation of frozen vs fresh semen (n = SO) and by bull for evaluation of high vs low dosage treatments (n = 76). No difference (P > 0.05) in accessory sperm was observed for fresh vs frozen semen at either the high or low dosage. The mean accessory sperm values for fresh high dose (n=21), frozen high dose (n=21), fresh low dose (n= 19), and frozen low dose (n= 19) were 26.S1±30.23 (SD), 36.05±44.74 (SD), 29.37± 55.97 (SD) and 30.l6± 70.18 (SD) respectively. When data for embryos/ova resulting from fresh and frozen semen were pooled within dosage, a significant difference was observed between the median accessory sperm values for high and low doses of semen (P < .05). Mean ± SD and median values for accessory sperm were: 37.8± 38.3 and 27.5; 28.9± 62.8 and 3.0, for the high and low dose, respectively. Increasing accessory sperm number by the higher dosage improved the fertilization status/embryo quality (P < .05). Percentage unfertilized ova, degenerate embryos and embryos classified poor to fair and good to excellent were: 3, 5, 24, 68; and 21, 16, 18, 45, for the high and low dose, respectively. Overall, embryos/ova classified good to excellent, poor to fair, degenerate and unfertilized had median accessory sperm values of 18, 9.5, 5.5 and 0, respectively. However, the lack of accessory sperm in unfertilized ova was significantly different from excellent-good quality embryos (P < .05). / Master of Science

Orientador: Frederico Ozanam Papa / Banca: João Carlos Pinheiro Ferreira / Banca: Alício Martins Junior / Resumo: A despeito das inúmeras variáveis que influenciam direta e indiretamente a fertilidade das fêmeas bovinas, a qualidade das amostras seminais exerce um papel importante na determinação das taxas de concepção dos programas de inseminação artificial. Os objetivos dessa pesquisa foram comparar a efetividade de dois diluidores de criopreservação de sêmen bovino no processamento de amostras seminais apresentando diferentes concentrações espermáticas em relação aos índices de congelabilidade determinados laboratorialmente (Experimento I) e as taxas de concepção proporcionadas por cada metodologia quando utilizada em programas de inseminação artificial em tempo fixo (IATF) em bovinos (Experimento II). No Experimento I foram utilizados 14 ejaculados de diferentes touros da raça Nelore. Cada ejaculado foi fracionado em oito alíquotas iguais, submetidas a criopreservação com os diluidores Tris-gema de ovo-frutose (meio TRIS) e MKA nas concentrações de 12, 25, 50 e 100 milhões de espermatozóides totais por mililitro de meio, formando oito grupos experimentais em função das variáveis diluidor e concentração. As amostras foram descongeladas a 46 ºC por 20 segundos, avaliando-se os padrões de motilidade através do método computadorizado (CASA), integridade de membrana plasmática (IMP), resistência ao teste de termorresistência rápido (TTR) e taxa de recuperação e IMP após seleção espermática pela técnica de swim-up. Para o Experimento II foram selecionados sete touros utilizados no Experimento I, obtendo-se um ejaculado de cada animal por eletroejaculação...(Resumo completo, clicar acesso eletrõnico abaixo) / Abstract: Although there are many variables which directly or indirectly influence female bovine fertility, the quality of sperm samples plays a important role in the determination of conception rates in artificial insemination programs. The aim of the present study was to compare the efficiency of two bovine semen extenders for sperm freezing with different spermatic concentrations in the freezability determined by lab tests (Experiment I), and conception rates after fixed time artificial insemination (FTAI; Experiment II). In Experiment I 14 ejaculates of different Nelore bulls were used. Each ejaculate was splitsampled in to eight equal parts and then submitted to cryopreservation with Tris-egg yolk fructose (TRIS) and MKA extenders, at concentrations of 12, 25, 50 and 100 millions spermatozoa per milliliter forming eight experimental groups. The samples were thawed at 46 ºC for 20 seconds, and the following parameters were evaluated: sperm motility and movement (by computer-assisted semen analysis - CASA), sperm membrane integrity (SMI), resistance to the fast thermoresistance test (TT), recovery rate and sperm membrane integrity after sperm selection through swim-up technique. Seven of 14 bulls used in Experiment I were selected for Experiment II, and semen was collected from each of the animals by electroejaculation. The seven ejaculates obtained were mixed (semen pool) and cryopreserved, thus forming eight experimental groups according to the freezing extenders and sperm concentrations/straws: TRIS 12, 25, 50 and 100, and MKA 12, 25, 50 and 100...(Complete abstract, click electronic address below) / Mestre

Call number: LD2668 .T4 1936 S21

Call number: LD2668 .T4 1985 B74 / Master of Science

Master of Science / Department of Animal Sciences and Industry / Jeffrey S. Stevenson / Our objective was to determine the optimal time to inseminate artificially cows following the standard CO-Synch protocol that also included a progesterone-releasing intravaginal controlled internal drug release (CIDR) insert. Lactating females from 3 Kansas locations were utilized. Crossbred Angus cows (n = 212) from the Agriculture Research Center in Hays (ARCH; location 1); Angus-Hereford crossbred cows (n = 249) from the Kansas State University Cow-Calf Unit (location 2); and purebred Angus, Hereford, and Simmental cows (n = 144) from the Kansas State University Purebred Beef Unit (location 3) were used in this study. Cows within each location were blocked by parity and assigned randomly within blocks to be artificially inseminated (AI) at 4 different times after the PGF2[Alpha] injection of the protocol: 48, 56, 64, or 72 h. Pregnancy diagnosis occurred at 32 and 63 d after insemination. Blood samples were collected 9 to 10 d and just before the first GnRH injection. Radioimmunoassays were performed on the blood sera samples to determine progesterone concentrations. Progesterone concentrations determined that approximately 60% of cows were cycling at the initiation of the study. A difference in cyclicity was observed with regards to age as well as body condition score. Pregnancies per AI (P/AI) at d 32 varied according to location and cycling status. Pregnancy loss between d 32 and 63 also was greatest for cows inseminated at 48 and 72 h. As pregnancy rates at d 63 increased with the 56- and 64-h treatments, pregnancy loss decreased. A significant difference in calving interval was detected among treatments, the shortest calving interval at 56 h. Results indicated that in most situations, the 56- and 64-h treatments presented the most desirable outcomes. The 56-h treatment presented the greatest number of P/AI for younger cows (≤ 3 yr), but for older cows, inseminations anytime 56 h or later produced the most P/AI. Overall pregnancy rates at d 63 were greatest for the 56-h treatment, with the fewest pregnancy losses. Given the interactions that seem to exist among location, cycling status, and age, further work is necessary to better define these relationships with the applied protocol.

M. Tech. Agriculture / South African unimproved indigenous goats are disease tolerant, able to survive on harsh conditions such as extreme temperatures and poor vegetation. It is therefore, important to include this breed in breeding objectives during this time of climate change and when animals are resistant to antibiotics. However, these goats are under threat of extinction and very little information on their reproductive status is recognized. In order to improve or maintain South African unimproved indigenous goats, basic science concerning male fertility, semen quality and production should be investigated to conserve genetic materials for future breeding. Conflicting results have been reported concerning the effect of semen collection techniques on buck sperm quality. Longevity of sperm following semen collection is a major limitation to use fresh semen for artificial insemination in rural communities where majority of South African unimproved indigenous bucks are kept. Extenders such as Tris, egg yolk and cow skimmed milk have been used to prolong the survivability of buck sperm in other countries, but contradictory results have been reported concerning which extender is more suitable for buck semen. Egg yolk based extenders have been used mostly in buck semen compared to Tris or cow skimmed milk based extenders. The purpose of the study was to compare semen collection techniques on South African unimproved indigenous goat semen, and the utilization of indigenous chicken egg yolk for preserving South African indigenous buck semen.