Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Five experiments using a total of 4,470 pigs were used to determine the effects of dietary Cu and Zn source and finishing pig space allowance. Experiment 1 evaluated increasing dietary Zn from Zn hydroxychloride or ZnSO₄ for finishing pigs. Increasing dietary Zn up to 100 mg/kg Zn maximized ADG and HCW with the greatest response observed during the last 37 d period when ractopamine was included in the diet. Pigs fed diets with Zn hydroxychloride had greater HCW compared to those fed ZnSO₄. Experiment 2 evaluated increasing dietary Cu from either CuSO₄ or a 50:50 blend of CuSO₄:Cu-AA for finishing pigs. Pigs fed Cu from CuSO₄ alone consumed more feed and tended to have poorer feed efficiency than those fed a 50:50 blend of Cu from CuSO4:Cu-AA. Pigs fed a 50:50 blend of CuSO4:Cu-AA had improved HCW G:F but ADG was unchanged on a live and HCW basis. Experiments 3 and 4 evaluated increasing dietary Cu from tri-basic copper chloride or a Cu-chelate for nursery pigs. In Exp. 3, increasing Cu from Cu-chelate to 150 mg/kg Cu increased ADG and ending BW. Increasing Cu to 150 mg/kg Cu increased ADFI and improved G:F. Pigs fed Cu from Cu-chelate had greater ADG, ADFI and ending BW than those fed Cu from tri-basic copper chloride. In Exp. 4, increasing Cu to 225 mg/kg Cu increased ADG and ending BW. Because ADFI was unchanged, G:F tended to be improved as Cu level increased. There were no differences detected between Cu sources for growth performance. Experiment 5 was conducted to determine the effects of increasing space allowance by pig removal or gate adjustment during the finishing period. Pigs provided 0.91 m² had increased ADG compared with those allowed 0.63 m² with pigs from pens provided increased space intermediate. Pigs provided 0.91 m² had increased ADFI compared with pigs allowed 0.63 m² and those where a pig was removed; however, pigs from pens where the gate was adjusted were intermediate. As pigs grew to the minimum predicted space requirement and were subsequently allowed more space, performance was greater than those initially provided 0.61 m² but less than those allowed 0.91 m².

The effect of genotype and slaughter age on gonadal development, body development and the correlations between these measurements were studied in five pig genotypes (Genotype 1, Genotype 2, Genotype 3, Genotype 4 and Genotype 5) consisting of 112 gilts and 112 boars with initial live weights varying between 25 – 30 kg. The pigs were group-housed in commercial type grower houses and fed a diet consisting of 14 MJ/kg energy, 18 % CP and 1.1 % lysine during the growth period up to a live weight of 65 kg, followed by a diet consisting 13.5 MJ/kg, 16 % CP and 0.9% lysine from 65 kg to 90 kg and then a diet consisting of 13.2 MJ/kg, 15 % CP and 0.7% lysine from 90 kg onwards. Pigs were slaughtered at 116, 130, 144, 158, 172, 186, 200 and 214 days of age. Gonadal growth and development were measured in gilts (ovary length, ovary width, ovary thickness, ovary weight, ovary volume, follicle number, and size of the largest follicle), boars (testis length, testis width, testis weight and testis volume) and body development parameters (slaughter weight, warm carcass weight, carcass length, chest depth, dressing percentage and P2 backfat thickness) were compared. Differences between means were tested using breed, sex and slaughter age as fixed effects, while the relationships between gonadal and body development parameters were evaluated by means of correlation analysis. Genotype 5 had a significantly shorter ovary length than Genotype 4 and Genotype 2. Genotype 2 gilts also had heavier ovaries and larger ovary volumes than Genotype 5 gilts. In boars, Genotype 2 had significantly heavier testes weights than Genotype 5 boars. Genotype 5 boars also tended to have smaller testis volumes than Genotype 2 boars. In body development, Genotype 2 gilts and boars were superior to the Genotype 5 in terms of slaughter and warm carcass weights, while Genotype 3 seconded Genotype 2. The average P2 backfat thicknesses were 11.88 mm and 13.68 mm for boars and gilts respectively. Correlations between gonadal and body development parameters were low to moderate in the gilts (r = -0.305 to 0.555) and moderate to high in boars (r = 0.560 to 0.871). However, dressing percentage, follicle number and size of the largest follicle correlated poorly with all other measurements. It is concluded from the study that although Genotype 5 do not grow to the same size and at the same rate compared to the other genotypes, they appear to be the most suitable for the production of top quality pork in terms of its low backfat thickness. Genotype 5 pigs were also characterized with a slower gonadal growth and body development compared to Genotype 2 pigs. Results from this study suggest that selecting against backfat may delay gonadal development and sexual maturation in pigs. / Dissertation (MSc (Agric) Production Physiology)--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

In this study the effects of repeated antigen injections on total complement (C') and C'4 of guinea pig serum were investigated to determine if constant antigenic stimulation would show changes in the C' and C'4 titers. Attempts were also made to correlate any changes with variations in antibody titers during the repeated antigen injections.

The purpose of this paper is to report the results of studies on the aerobic, mesophilic intestinal flora of guinea pigs subjected to conditions similar to those encountered by man in spacecraft.

The principal purpose of this work was to determine the effect of immunized guinea pig serum upon the survival time of tumor infected mice, and to make a correlation between this effect and the complement titer.

<p>Sow litter sizes have been increasing over the years. Increasing litter sizes typically result in an increased duration of farrowing which can be detrimental to piglet survival due to the increased risk of <i>in-utero</i> asphyxiation. The cumulative effect of repeated contractions over extended time results in increased pressure on the umbilical cord. This causes an interruption of blood and oxygen to the piglet brain, increasing the risk of death. Although asphyxiation is the cause of the majority of stillbirths, piglets who are born alive can also suffer from <i>in-utero</i> asphyxiation. These piglets are considered to be of low vitality and are severely disadvantaged in regard to survival and growth. Different methods have been explored on ways to decrease farrowing duration, reduce stillbirths, and improve piglet survival, but the neonatal mortality rate is still rather high and is not decreasing. Therefore, new methods need to be investigated in the hopes of successfully decreasing the farrowing duration of sows.</p> <p>The first project aimed to shorten the farrowing duration and improve piglet survival in farrowing crates via the provision of nesting material and enriched piglet mats. There have been several studies on the effects of nesting material in farrowing crates, but most of those studies use materials that will fall through the slatted floors and block the liquid manure systems. The current study implemented the use of jute as the nesting material and proposed a novel way to present the material, by attaching it to the side of the crate, to prevent it from falling through the slatted floors and disrupting the manure systems. The enriched piglet mats were made from a microfiber material to promote homeothermy and reduce heat loss, thus potentially positively impacting piglet growth and survival. Twenty sows were randomly assigned to 1 of 2 treatments: 1) farrowing crate with jute nesting material (Nest; n = 10; 3 pieces of jute, each 40.6 cm x 21.6 cm) and two enriched piglet mats made from an acrylic board (28.0 x 86.4 cm) covered with a microfiber material, or 2) farrowing crate without nesting material (Control; n = 10) and 1 standard rubber mat (28.0 x 86.4 cm) for piglets. Sows had access to the jute material from approximately d 113 of gestation until they finished farrowing, while piglets had access to the mats for the first 3 d of age. Sow saliva was collected to measure Immunoglobulin A (IgA) and cortisol to assess stress on d -1, 0, 1, and 2, relative to farrowing, and a final sample at weaning (d 16.9 ± 0.18). Piglet plasma Immunoglobulin G (IgG) was collected from 4 piglets/litter at 48 h, 7 d, and weaning. Piglet skin temperature was measured from two piglets/litter using an infrared camera for 3 d after birth. Video was continuously coded for observations of jute-directed and crate-directed interactions. Nest sows performed less crate-directed behavior than Control sows (<i>P</i> = 0.02), while both groups performed the same amount of total nesting behavior (the sum of crate-directed plus jute-directed behavior) (<i>P</i> > 0.05). Cortisol tended to be less in Nest sows (<i>P</i> = 0.08), but there was no difference in IgA concentrations (<i>P</i> > 0.4). Nest piglets tended to be heavier on d 7 (<i>P</i> = 0.095), had greater IgG concentrations (<i>P</i> = 0.03), and greater skin temperatures (P = 0.02). There were no differences in farrowing duration or number of stillbirths (<i>P</i> > 0.7). </p> <p>The second study investigated the effects of a dietary supplement, 6.6% resistant starch (RS), on sow farrowing performance and piglet survival and vitality. Since RS has been shown to help stabilize blood glucose levels post-prandially, it was hypothesized that RS would decrease farrowing duration by improving the energy status of sows during farrowing. Forty-two sows were balanced for parity and randomly assigned to 1 of 2 treatments: standard lactation diet (n = 21) or diet containing RS (n = 21). Sow blood was analyzed for glucose concentrations at baseline, after 1 wk of being on their respective diets, and during farrowing. Blood glucose for RS sows increased between the beginning and end of farrowing while Control sow blood glucose decreased (P = 0.04). However, there were no other effects on sow blood glucose. Farrowing duration and number of stillbirths did not differ between treatments (P > 0.05). Piglet blood glucose concentrations for RS piglets tended to increase as the birth order increased, while blood glucose for the Control piglets tended to decrease. The other piglet vitality measures, assessed by blood lactate, pH, partial pressure of carbon dioxide (PCO₂), partial pressure of oxygen (PO₂), total carbon dioxide (TCO₂), bicarbonate (HCO₃), base excess (BE_ecf), and oxygen saturation (sO₂) did not differ between treatments (<i>P</i> > 0.05).</p> <p>In conclusion, farrowing duration was not successfully decreased by the provision of jute nesting material attached to the side of the farrowing crate or by supplementation of RS. However, the jute nesting material and enriched piglet mats did positively impact sow welfare and piglet measures to an extent, although this did not translate into improved piglet survival. The resistant starch supplementation seemed to impact sow glucose during farrowing, but not enough to impact farrowing performance or piglet survival or vitality. These results could be because the nesting treatment was not robust enough to allow sows to fully express their nesting behavior needs in order to impact farrowing performance, while the RS supplementation may have been too low of a dosage, not fed long enough, or a less effective type of RS. Novel ways to optimize sow farrowing performance and piglet survival are still needed.</p>

The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...

The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...

Electrophysiological studies of myenteric neurons in the guinea-pig antrum suggest that different neuroactive compounds are involved in synaptic transmission. It is not known what neurotransmitters and neuropeptides are present and to what extent they colocalize. Immunohistochemical stainings were performed on whole-mount preparations of the guinea-pig antrum. Immunoreactivity for neuron-specific enolase was used as a general marker and was set at 100%. There was no overlap between cholinergic and nitrergic neurons, resulting in two separate subpopulations. The presence of choline acetyltransferase immunoreactivity was used to identify the cholinergic subset, which accounted for 56% of the cells. Immunoreactivity for nitric oxide synthase, on the other hand, was displayed in 40.7% of the neurons. Substance-P immunoreactivity was present in 37.4% of the cells and vasoactive intestinal peptide and neuropeptide Y in 21.7% and 28.6%, respectively. Small subsets of neurons had immunoreactivity for serotonin (3.9%), calretinin (6.8%) and calbindin (0.5%). Colocalization studies revealed several subgroups of neurons, containing one or more of the screened markers. Though some similarity is found in the chemical coding of the antrum compared to that of the small intestine and the corpus, remarkable differences can be seen in the occurrence of some subpopulations. Cholinergic neurons are not as predominant as in other parts of the gut, serotonin presence is doubled and some vasointestinal-peptide-positive neurons express substance P. These differences might reflect the highly specialized function of the antrum; however, the exact role of these classes remains to be established.

In U.S. swine herds, sow removal rates due to death and voluntary and involuntary culling exceed 50% annually. This loss poses an economic problem for producers because the cost of acquiring replacement females is great. Although research has shown that crowding in the nursery has negative impacts on growth, research describing effects of crowding on subsequent reproductive performance and longevity in sows is lacking. This experiment was conducted to determine the impacts of crowding during the nursery phase of production on growth, physiology, and immunology in replacement gilts. Gilts (22.3 ± 3.2 d of age and 5.6 ± 0.6 kg BW) were subjected to floor space allocations of 0.15, 0.19, or 0.27 m2/pig during a 7-wk nursery period. Floor space allocations were achieved by altering the number of pigs per pen (14, 11, and 8 gilts/pen, respectively). As was expected, reduced floor space allowance in the nursery negatively affected growth performance although there was inconclusive physiological and immunological evidence to suggest that pigs were experiencing highly stressful conditions. Although feed intake was not measured, changes in blood counts and blood chemistry for gilts allowed reduced floor space were similar to other studies that reported negative effects of crowding on feed consumption. Further study of the gilts involved in this study will aim to determine if there are any links between the effects of crowding during the nursery and subsequent reproductive performance and longevity in the breeding herd. / Master of Science