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Body adiposity is generally considered the most pertinent factor in puberty attainment; however, recent data suggests that pre-pubertal reproductive tract development may be altered by dietary sugar consumption. Two experiments were conducted to delineate the direct effects of fructose on the maturation of the pre-pubertal reproductive tract and fertility. At three weeks of age, forty gilts were placed on one of five dietary treatments (n=8) containing 15% fat (FAT), 35% fructose (FRU), both fat and fructose (HFHF), or two different controls: one standard industry (IND) diet meant to result in optimal lean growth and a second diet to account for the reduced lysine (LYS) intake in the treatment diets. Body weights did not differ amongst any of the five treatments on the day of sacrifice (P=0.32). As a percentage of BW, total reproductive tracts were heavier in fructose fed gilts (1.3±0.1 v. 0.8±0.1%; P=0.01) compared to non-fructose gilts. In the second experiment, starting at 130d of age, gilts were checked twice daily for puberty attainment. Gilts that attained puberty were artificially inseminated (AI) on their third estrous cycle. On gestational day 38±3, pregnant gilts were harvested for reproductive tract collection. Fewer fructose fed (FRU and HFHF) pigs became pregnant than non-fructose fed (IND, LYS, and FAT) gilts (25% v. 75% respectively; P=0.03). All HFHF gilts failed to become pregnant. Placental weights were greater in LYS fetuses than FAT fetuses (79.07 ± 6.55g v. 47.26 ± 6.45g, respectively, P= 0.04). Taken together, these results demonstrate that fructose consumption increases reproductive tract size, but that reproductive capabilities are reduced. / Master of Science

The primary objective of this study was to investigate the effect of dietary fiber on methanogenic diversity and community composition in the hindgut of indigenous Chinese Lantang gilts to explain the unexpected findings reported earlier that Lantang gilts fed low-fiber diet (LFD) produced more methane than those fed high-fiber diet (HFD). In total, 12 Lantang gilts (58.7±0.37 kg) were randomly divided into two dietary groups (six replicates (pigs) per group) and fed either LFD (NDF=201.46 g/kg) or HFD (NDF=329.70 g/kg). Wheat bran was the main source of fiber for the LFD, whereas ground rice hull (mixture of rice hull and rice bran) was used for the HFD. Results showed that the methanogens in the hindgut of Lantang gilts belonged to four known species ( Methanobrevibacter ruminantium, Methanobrevibacter wolinii , Methanosphaera stadtmanae and Methanobrevibacter smithii ), with about 89% of the methanogens belonging to the genus Methanobrevibacter . The 16S ribosomal RNA (rRNA) gene copies of Methanobrevibacter were more than three times higher ( P <0.05) for gilts fed LFD (3.31×10 9 copies/g dry matter (DM)) than gilts fed HFD (1.02×10 9 copies/g DM). No difference ( P >0.05) was observed in 16S rRNA gene copies of Fibrobacter succinogenes between the two dietary groups, and 18S rRNA gene copies of anaerobic fungi in gilts fed LFD were lower than ( P <0.05) those fed HFD. To better explain the effect of different fiber source on the methanogen community, a follow-up in vitro fermentation using a factorial design comprised of two inocula (prepared from hindgut content of gilts fed two diets differing in their dietary fiber)×four substrates (LFD, HFD, wheat bran, ground rice hull) was conducted. Results of the in vitro fermentation confirmed that the predominant methanogens belonged to the genus of Methanobrevibacter , and about 23% methanogens was found to be distantly related (90%) to Thermogymnomonas acidicola. In vitro fermentation also seems to suggest that fiber source did change the methanogens community. Although the density of Methanobrevibacter species was positively correlated with CH 4 production in both in vivo ( P <0.01, r =0.737) and in vitro trials ( P <0.05, r =0.854), which could partly explain the higher methane production from gilts fed LFD compared with those in the HFD group. Further investigation is needed to explain how the rice hull affected the methanogens and inhibited CH 4 emission from gilts fed HFD.

The administration of raw soybeans to the diet of prepubertal gilts had no effect (p>0.05) on age to puberty, number of corpora lutea, or embryos present. Also, the number of pigs farrowed live and 28d litter weights did not differ between gilts consuming the raw soybean diet and gilts consuming the control diet. There was a reduction (p<0.05) in the number of pigs weaned in the group consuming the raw soybeans but no differences (p>0.05) in weaning weights. Gilts fed the raw soybean diet had a reduction (p=0.05) of hot carcass weights compared to gilts consuming the control diet but exhibited no differences for other carcass parameters measured. Thermal imaging was able to differentiate gilts in estrus versus diestrus. Gilts in estrus had greater (p<0.05) surface area temperatures than gilts in diestrus.

The shift to group-housing of the breeding herd makes it difficult to manage animals individually. To maximize sow longevity and reproductive performance, gilts must be bred on second heat weighing between 135 and 160 kg. As gilts are typically fed ad libitum (AD), they often exceed targeted breeding weights, leading to structural and other problems resulting in culling at early parities. Thus, utilization of an electronic sow feeder (ESF) enables caretakers to manage animals individually in group-housing situations, by allotting predetermined amounts of feed. The specific objectives of this study were to: 1) to determine the effects of AD or restricted (RS) feeding bases (FB) on growth and sexual development in replacement gilts using an ESF; 2) to determine the growth and reproductive responses to gonadotropins in gilts fed on either AD or RS feeding bases using an ESF; and 3) to ascertain the effects of short-term increases in feed allowances on growth and sexual development in previously feed-restricted gilts using an ESF. Gilts employed in all studies were acclimated to an ESF (ACCUTEAM, Osborne Industries, Osborne, KS) beginning at 150 d of age, during a 10-d training period. Across all experiments, treatments were assigned at 160 d of age. In experiments 1 and 2, gilts received feed on either AD (5.00 kg/d) or RS (2.72 kg/d) bases. In the first study, estrus detection began at 160 d of age. In experiment 2, gilts assigned to receive gonadotropins were treated at 170 d of age, with estrus detection beginning the next d. Gilts fed on the RS basis were observed to have improved feed conversion efficiency compared to AD-fed gilts in experiments 1 and 2 (both P < 0.01); and flushed gilts in experiment 3 had G: F similar to RS gilts. Average daily gain was not affected by FB in the first and third experiments, however AD-fed gilts gained weight at a faster rate (P = 0.02) than RS gilts in experiment 2. Gilts fed AD consumed their allotments across more meals than those fed RS. Age at puberty onset was not affected by FB in any of the experiments. Further, P.G. 600 did not hasten the onset of puberty, irrespective of FB in experiment 2. In experiment 3, ovulation rate was numerically greatest for flushed gilts, and was significantly greater than RS gilts (P = 0.05). The ovulation rate for flushed gilts was similar to AD gilts. Across all experiments, feed disappearance was observed to decrease as AD-fed gilts approached estrus. In this series of experiments, FB did not alter puberty onset, however ovulation rate was increased when gilts were allocated short-term increases in feed allowances. Further, utilizing an ESF may augment current industry estrus detection methods by monitoring feeding behavior. / Doctor of Philosophy / On commercial swine operations in the U.S. sow removal rates due to death and culling exceed 40% annually. On average, sows are culled at parity 3 or 4, while at least this many parities are required before investment costs are recouped. Gilts are typically fed AD until BW of 135 kg are attained by approximately 200 d of age. Oftentimes, gilts fed on AD basis exceed targeted breeding weights, leading to structural and other problems resulting in culling at early parities. To improve sustainability and competitiveness of pork production systems, the industry must focus on proper gilt management practices to facilitate successful entry into the breeding herd and increase longevity and lifetime performance as sows. A series of 3 experiments were conducted to evaluate different feeding bases on growth and sexual development in gilts. The first experiment evaluated the impact of AD or RS feeding on growth and sexual development in gilts using an ESF. Age at puberty was not different in limit-fed gilts. Limit-fed gilts also grew at a similar rate accompanied with improved feed conversion compared to AD fed gilts. Results from this experiment indicate that gilts can be limit-fed prior during the period around puberty until entering the breeding herd without negative impacts to growth or sexual development. In the second experiment, the same feeding bases were utilized, but within feeding basis groups, gilts either received or did not receive treatment with exogenous gonadotropins. Age at puberty was similar, regardless of feeding basis or gonadotropin treatment. Feed conversion was improved in limit-fed gilts, however daily gain was improved for gilts receiving feed AD. Results from this experiment imply that limit feeding gilts has no negative impacts on sexual development, but daily gain is reduced. In the third experiment, previous feeding bases were used, and a third, nutritional flushing, was also studied, when gilts received AD feed 7 d after first estrus. Flushed gilts had feed conversion like that of limit-fed gilts with daily gain similar to that of AD gilts. Gilts which were flushed had ovulation rates which were similar to gilts receiving feed AD but was greater compared with limit-fed gilts. Results indicate that flush feeding can achieve daily gain similar to ad libitum feeding and feed conversion similar to limit-feeding, while improving ovulation rate compared to limit-feeding. Across all studies, feed disappearance decreased for AD fed gilts as they neared estrus. Overall, using an ESF allows for precise feeding of replacement gilts and allows producers to implement various feeding strategies across multiple animals on an individual basis. Monitoring feed behavior with an ESF may enhance current estrus detection practices.

The aim of the thesis was to analyse the reproductive parameters of the CLW and CLWxCL sows group in selected breeding group (CLW - Czech Large White, CL - Czech Landrace). Sows, compared to gilts, had more all born piglets born after 100 services (by 118 piglets more after 1st insemination and 116 piglets more after all inseminations). The CLWxCL sows gave birth to 0.10 more all born piglets and 0.21 live piglets more. The highest number of piglets, all and live, was born in the 4th parity. The correlation coefficients between the age at the 1st service and the number of all resp. live-born piglets were low. Only 0.1 live piglets were born to CLW sows with weaning to service interval (WSI) from 5 days compared to WSI to 4 days. In CLWxCL sows, more live-born piglets showed sows with WSI to 4 days compared to sows with WSI from 5 days. The difference was higher, namely 0.8 piglet (P < 0.05). In the case of CLW and CLWxCL sows was confirmed a statistically significant difference in the number of live-born piglets between the sows with a gestation length from 116 days, up to 114 days and 115 days. Most of the piglets were born after AMD 74 boar and the lowest number after AMD 101 boar.

The work deals with the analysis of some conditions to increase the level of piglets in factory farms. In addition to the genetic material used in crossing the farm, there is really important material support: good nutrition, breeding environment and nursing care. All these requirements were fullfilled in evaulated plant. In the breeding herd, were revealed a significant effect of early estrus and early pregnancy rate in the interval weaning of piglets. The obtained data showed that the percentage is not significantly different farrowing in sows and gilts. The number of live born piglets is no significant difference in sows and gilts. That's why is advantagous to continuously include gilts in basic herd and early replacement of saws according to their health status and number of past litters. Return breeding of sows should be at the annual breeding 23 to 25 piglets per sow.

O objetivo do estudo realizado no Laboratório de Pesquisa em Suínos, da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Pirassununga – SP, foi verificar os efeitos combinados de gonadotrofinas exógenas, (eCG e LH) e flushing sobre a duração e dispersão da manifestação do primeiro e segundo estros, ciclicidade das fêmeas, número de ovulações, viabilidade embrionária e freqüência de cistos ovarianos. Foram utilizadas 72 marrãs pré-púberes da linhagem Pen Ar Lan NAIMA®, com idade média de 157,49±5,01 dias, e 96,65±7,70kgs de peso, distribuidas em quatro tratamentos, em arranjo fatorial, com e sem flushing , e com e sem hormônio. A ração utilizada continha 16% de PB e 3.286,73 kcal/kg ME. A partir do 7º dia do primeiro estro, induzido com hormônio, as fêmeas do tratamento com flushing receberam 50% de incremento da mesma ração. No 16º dia, após o primeiro estro, as marrãs no tratamento hormonal receberam aplicação de 600 UI de eCG (Novormon®) e 2,5 mg de LH (Lutropin®), 72 horas após. Todas as marrãs foram expostas ao macho duas vezes ao dia, a partir do 10º dia e inseminadas ao segundo estro com sêmem heterospérmico contendo 4 x 109 espermatozóides. Ao abate, realizado no 5º dia após a inseminação, os genitais foram colhidos para exame dos ovários e coleta dos embriões. Não se observou interação entre os fatores. Os efeitos analisados em separado, não evidenciaram diferença significativa no Número de ovulações (14,28±5,06 vs 13,47±5,57 com e sem Flushing e 14,60±5,78 vs 13,23±4,83 com e sem Hormônio, respectivamente, P>0,05), na freqüência de cistos ovarianos (22,86% vs 11,11%, com e sem Flushing e 15,15% vs 18,42%, com e sem Hormônio, respectivamente,. P>0,05), na Manifestação do 2º estro (85,71% vs 91,43% com e sem Flushing e 90,63% vs 86,84% com e sem Hormônio, respectivamente, P>0,05), no Peso Final (115,35±8,23 vs 111,56±8,30kg, com e sem Hormônio, respectivamente, P>0,05), na Espessura de toucinho (10,0±2,0 vs 10,2±1,8mm com e sem Hormônio, respectivamente, P>0,05), e na Duração dos estros (57,68±20,02 vs 59,68±14,76 horas, com e sem Hormônio e 57,75±14,99 vs 59,62±19,43 horas, com e sem Flushing, respectivamente, P>0,05). Constatou-se diferença significativa na Viabilidade embrionária (11,55±4,81 vs 8,50±5,32 embriões viáveis, com e sem Flushing e 8,39±5,66 vs 11,25±4,58 embriões viáveis, com e sem Hormônio, respectivamente P=0,02), indicando valor superior para o tratamento com Flushing e inferior no grupo com Hormônio. No Peso final (117,48±9,82 vs 109,28±7,57kg, com e sem Flushing, respectivamente, P=0,0001) e na Espessura de toucinho (10,7±2,2 vs 9,5±1,9kg, com e sem Flushing, respectivamente, P=0,03) o valor superior ficou para o grupo com Flushing. Concluiu-se no estudo a não interação dos efeitos, entre os fatores Hormônio e Flushing . O uso das gonadotrofinas (eCG e LH) reduziu a dispersão de manifestação do segundo estro, sendo efetiva a sua sincronização. O emprego do Flushing no primeiro ciclo estral em marrãs influenciou positivamente a viabilidade embrionária e na associação do eCG e LH mais Flushing não notou-se efeito interativo, identificando-se diminuição da viabilidade embrionária, pela ação hormonal. / The objective of this study, held at the Swine Research Laboratory of the School of Veterinary Medicine and Zootechnology of the Univ. of São Paulo in Pirassununga, São Paulo, was to verify the combined effects of exogenic gonadotropin (eCG and LH) and flushing on the duration and dispersion of the manifestation of initial and second estruses, cyclicity of females, number of ovulations, embryonic viability, and frequency of ovarian cysts. Used for the experiment were 72 pubertal gilts of Pen Ar Lan NAIMA® lineage, with an average age of 157.49±5.01 days, and weight of 96.65±7.70kg. They were distributed in four treatments in a factorial arrangement, with and without flushing, and with and without hormone treatment. The feed used contained 16% CP and 3,286.73 kcal/kg ME. Starting on the seven day of the first estrus, induced with homone, the females with flushing treament received a 50% increase in the amount of the same type feed that they had been receiving. On the sixteenth day of the first estrus the gilts that received hormone treatment were given 600 UI of eCG (Novormon®) and 2.5 mg of LH (Lutopin®), 72 hours later. All the gilts were exposed to boar twice at day, starting on the tenth day and inseminated during the second estrus with heterospermic semen containing 4 x 109 spermatozoon. At slaughter on the fifth day after insemination, the genitals were removed to examine the ovaries and collect the embryos. Interaction between the factors were not observed. The effects that were analyzed separately did not show significant differences in the number of ovulations (14.28±5.06 vs 13.47±5.57 with and without flushing, and 14.60±5.78 vs 13.23±4.83 with and without hormones, respectively, P>0.05), in the frequency of ovarian cysts (22.86% vs 11.11%, with and without flushing and 15.15% vs 18.42% with and without hormones, respectively, P>0.05), during the second estrus (85.71% vs 91.43% with and without flushing and 90.63% vs 86.84% with and without hormones respectively, P>0.05), at final weight (115.35 ± 8.23 vs 111.56 ± 8.30kg, with and without hormones, respectively, P>0.05), in the backfat (10.0±2.0 vs 10.2±1.8mm with and without hormones, respectively, P>0.05), and in the duration of the estruses (57.68±20.02 vs 59.68±14.76 hours, with and without hormones and 57.75±14.99 vs 59.62±19.43 hours, with and without flushing, respectively, P>0.05). A significant difference was found in embryonic viability (11.55±4.81 vs 8.50±5.32 viable embryos, with and without flushing and 8.39±5.66 vs 11.25±4.58 viable embryos with and without hormones, respectively P=0.02), which indicated higher numbers when treated with flushing and lower numbers when treated with hormones. At the final weight (117.48±9.82kg vs. 109.28±7.57kg with and without flushing respectively, P=0.0001) and in the backfat (10.7±12.2 vs 9.5±1.9kg, with and without flushing, respectively, P=0.03) flushing resulted in a higher number. It is concluded in this study that there is a lack of interactive effects between treaments with hormones and flushing. Utilization of gonadotropins (eCG e LH) reduced the dispersion of the second estrus within an effective synchronization. The utilization of flushing in the first estrous cycle in gilts gave positive results as regards to embryonic viability. The association of eCG and LH, plus flushing did not show an interactive effect, and a reduction was identified in embryonic viability based the action of hormones.

O estudo objetivou avaliar num programa biotécnico aplicado a uma granja comercial, os feitos combinados, emprego de gonadotrofinas e aplicação do \"flushing\". As gonadotrofinas empregadas na indução e sincronização do estro à puberdade em marrãs, aliado a ciclicidade até o 4º estro, correspondeu à aplicação ou não da combinação hormonal, 600 UI de eCG (Novormon®, Syntex S. A., Argentina) e após 72 horas, 2,5mg de LH porcino (Lutropin®, Vetrepharm Canadá Inc., Canadá). O \"flushing\" alimentar ou esquema alimentar adotado na granja, foi empregado no ciclo estral que antecedeu a primeira inseminação artificial, ocorrida aos 220 dias de idade das fêmeas. Os parâmetros analisados foram: taxa de concepção (TC), taxa de parto (TP), taxa de aproveitamento (TA) e tamanho de leitegada (TL), sendo esse último representado pelo número de leitões nascidos totais (NT), nascidos vivos (NV), natimortos (NM) e mumificados (MM). Foram utilizadas 119 leitoas híbridas, num delineamento experimental inteiramente casualizado em arranjo fatorial 2x2. O tratamento com hormônio mostrou percentual significativamente maior de fêmeas que manifestaram estro até o 5° dia de início da indução, em comparação com o tratamento somente com o estímulo do macho, 18,33% vs. 5,08%, respectivamente (P=0,0249). No intervalo seguinte de 18 - 30 dias após a indução, considerando variação do ciclo estral de 18 a 25 dias, a combinação hormonal revelou percentual significativamente maior comparado com o estímulo natural do macho, 48,33% vs. 16,94%, respectivamente (P=0,0003). Nos intervalos subseqüentes as diferenças não foram significativas. Não foi detectada interação significativa para os efeitos combinados gonadotrofinas e \"flushing\". Na análise das características em separado, não houve diferença significativa na taxa de concepção para os tratamentos combinação hormonal e estímulo do macho (96,23% vs. 94,00%, respectivamente), e tratamentos com \"flushing\" e esquema alimentar da granja (95,92% vs. 94,44%, respectivamente). Na taxa de parto, os percentuais embora não tenham revelado significância, mostraram diferenças numéricas, sendo o maior valor numérico representado pelo tratamento com hormônio em comparação com o macho, 92,45% vs. 80,00% respectivamente (P=0,0653). Quanto à taxa de aproveitamento das fêmeas, considerando a indução aos 153 dias de idade das marrãs até o parto, da mesma maneira evidenciou-se diferença numérica mostrando o tratamento com hormônio percentual maior em comparação com macho, 81,67% vs. 67,80%, respectivamente (P=0,0815). Não houve diferença significativa nos tratamentos relacionados à aplicação do \"flushing\" e esquema alimentar da granja, 70,00% vs. 79,66%, respectivamente. Não foi evidenciada diferença significativa quanto ao total de nascidos, nascidos vivos, natimortos e mumificados, para os dois fatores. Destacou-se diferença numérica de 0,75 leitões a mais no total de nascidos para o tratamento com hormônio, não havendo diferença significativa quando considerado o fator \"flushing\". A analise econômica feita pelas observações obtidas no presente estudo, considerando taxa de aproveitamento do parto e total de nascidos, destaca benefício financeiro apresentado através do valor presente líquido (VPL) para a combinação hormonal de $1.862,75, enquanto que o tratamento que utilizou indução somente com o macho, revelou um VPL negativo de $2.845,55. Conclui-se que houve efeito positivo das gonadotrofinas (eCG e LH) na indução e sincronização do estro à puberdade o qual pode ser associado, na menor dispersão da ciclicidade das marrãs até o quarto estro, no menor número de fêmeas descartadas até o primeiro parto e na vantagem econômica com base na taxa de aproveitamento das fêmeas até o parto e total de leitões nascidos. / The objective of the study was to investigate in a biotecnical program applied in a commercial breeding unit, the effects of the gonadotrophins (eCG and LH) on puberty estrus inductions and synchronization in gilts followed by their ciclicity. The investigation included the use of flushing on preceding oestrus cycle to first artificial insemination (IA). The traits analised were: conception rate, farrowing rate, the percentage of animals that started the experimental period and stayied to first farrowing, and litter size. The experiment used 119 hybrid gilts on 153 days of age. The experimental design was entirely random in a factorial arrangement 2x2. One factor corresponding to the gonadotrophin (H) application or the male (M) induction only. The hormonal treatment utilized a combination of 600 UI of eCG (Novormon®, Syntex S. A., Argentina) and 72 hours lates, 2,5 mg of LH (Lutropin®, Vetrepharm Canadá Inc., Canadá). The other factor corresponds to the flushing application in a restriction - ad libitum regimen (R) or a flushing application based on a lactation diet offered in an ad libitum regimen in the breeding unit (B). This factor was applied in the oestrus cycle that preceded first artificial insemination, occurring at 220 days of age. Our results identified,18,33% hormonal treatment of females showing apparent estrus compared to 5% in treatment that used only the male induction. From 18 to 30 days after induction, considering the estrus interval variation about 18-25 days, the hormonal treatment showed significant percentage more than the male induction (48,33% vs. 16,94%, respectively). In the following intervals the differences weren\'t statiscally significant. The cumulative percentuals until 30 days and 90 days periods, the values were 71,67% vs. 69,49% and 91,67% vs. 94,92%, respectively, for hormonal treatment and male induction. There wasn\'t significant interation for reproductive traits. There wasn\'t significant difference on the conception rate, when you considered the factors separately, hormonal treatment (H) and male (M) induction (96,23% vs. 94,00%, respectively) and flushing (R) and the regime adapted in the breeding unit (B) (95,92% vs. 94,44%, respectively). While the farrowing rate hasn\'t showed significance, there was umerical differences in favour of hormonal treatment against male induction (92,45 %vs 80,00%, respectively) (P=0,0653). Considering the period since induction (153 days of age) until parturition, the percentual of hormonal treatment group was superior compared to the male induction group (81,67% vs. 67,80%, respectively) (P=0,0815). However, the percentual was some flushing (R) and the regimen assumed in the breeding unit (G) (70,00% vs. 67,80%, respectively). There wasn\'t significant difference related to total born, born alive, stillborn and mummified fetus on both factors. It is important to emphasize the numerical differences of 0,75 total born piglets in favor of the hormonal groups. There wasn\'t any difference on the flushing factor. The economical analyses, considering the period since induction until parturition and total born piglets suggested a financial benify to the hormonal treatment compared to the male induction.