<p>In recent years conservation of minor livestock breeds has been faced with numerous challenges attributed to decreasing national herd sizes, as well as differences in reproduction and growth. One such minor swine breed, the Large Black pig (LB), is increasingly attractive to small farmers due to their foraging abilities and carcass characteristics. Therefore, the LB pigs have been used in niche pork production systems which market pasture-raised pork products. The LB breed is critically endangered, maintaining a registered breeding population of less than 400 animals, with increasing prevalence of inbreeding and genetic drift. Therefore, the LB breed could benefit from a genetic importation to increase genetic diversity in a national herd with rapidly decreasing animal numbers. A genetic importation would require frozen semen to be brought in from another country for use in breeding U.S. pigs. Frozen-thawed semen (FTS) presents challenges for swine due to the reduced motile sperm cells which negatively impacts fertility. Therefore, the present study evaluated the utilization of FTS in a genetic importation for the LB pig. </p><p>A genetic importation occurred in 2016 where semen from the United Kingdom was used on various farms in the U.S. but resulted in zero piglets born. Therefore, 16 LB sows were donated to Purdue University for research into improving estrous and ovulation synchronization to facilitate FTS utilization. Four breeding replicates were performed where following 14 days of Matrix feeding, OvuGel® was administered at 144 h following last Matrix feeding (LMF) or 96 h in post-weaned sows and two FTS inseminations occurring at: 30 and 36 h, 17 and 23 h, 24 and 30 h, and 24 and 32 h after OvuGel® for replicates 1-4, respectively. Approximately 2.64±0.3 billion motile sperm cells per insemination were utilized in replicates 1-3 with American LB FTS, with replicate 4 utilizing 0.34±0.03 billion motile sperm cells of imported FTS. Follicle diameter (<i>P</i>=0.260), ovulation within 48 h of OvuGel® (<i>P</i>=0.411), and weight prior to breeding (<i>P</i>=0.681) did not influence conception rate, however expression of estrus was determined to significantly influence conception rate (<i>P</i>=0.043). Seventy-five LB piglets were weaned across the first three breeding replicates, with parity 2 sows observed to have larger litter sizes than parity 1 sows (<i>P</i>=0.066).</p> <p>Large Black and Duroc-sired (DS) crossbred pigs from replicates 1 and 2 farrowing were fed corn and soybean meal based finishing diets supplemented with (FIB) or without alfalfa and wheat middlings (CON). Following 6 dietary phases through finishing, 25 LB and 25 DS pigs were slaughtered at similar ages for digestive organ dissection and carcass measurements. Loin muscles were evaluated for fresh pork quality and instrumental color and tenderness. LB pigs had a reduced ADG (<i>P</i><0.0001) and G:F (<i>P</i><0.0001) compared to DS pigs. Pigs fed FIB resulted in reduced ADG (<i>P</i>=0.020) and reduced G:F (<i>P</i>=0.007). At slaughter LB pigs were 26.4 kg lighter than DS pigs (<i>P</i><0.0001), and pigs that were fed FIB had lighter live weights (<i>P</i>=0.002) than pigs fed CON. LB pigs had 28.5±1.3 cm² smaller longissimus muscle area (<i>P</i><0.0001), yielding 2.0 cm more 10^th rib back fat than DS pigs (<i>P</i><0.0001). CON pigs had heavier HCW (<i>P</i><0.0001) than FIB pigs, however FIB pigs had greater percent lean (<i>P</i>=0.015). LB pigs had significantly reduced percent lean than DS pigs (<i>P</i><0.0001). LB pigs had loins with reduced drip loss (<i>P</i>=0.009) and cooked shear force values (<i>P</i><0.0001). Overall, the growth and carcass composition of the pigs was most affected by genotype, and to a lesser extent than the type of diet fed. </p> <p>In conclusion, the genetic importation of LB semen was successful as ½ blood piglets were created for dispersal into the U.S. LB herd. Improvements in FTS utilization in this heritage breed contributed to the successful creation of live-born pigs. Additionally, growth and carcass information was obtained for LB breeders to use in understanding and marketing of this heritage breed of pigs.</p>

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Nitrogen is the most required mineral nutrient for almost all agricultural crops and the one that promotes maize yields mostly. Pastillation is a technology that allows blending urea with other mineral elements like sulfur and zinc homogeneously, aims at subsiding N losses, therefore enhancing the agronomic efficiency of the fertilizers. The aim of the first paper was to establish the recommendation of N rates and to evaluate the agronomic performance of pastille urea and its blend with sulfur and zinc, as well as commercial N sources sidedress applied to maize under the conditions of the Médio Sertão and Southern Sergipe. The experiments were carried out during the 2014 and 2015 seasons in both sites. The experimental design was Complete Blocks with 3 replications in split-plot arrangement with an additional Control treatment (TEST). In the plot 3 rates of N applications were tested: 75, 150 and 300 kg ha-1, while in the subplots the following products were evaluated: Pastille urea (UP), Pastille urea with elemental S (UP+S), Pastille urea with ammonium sulfate (UP+SA), Pastille urea with ammonium sulfate and elemental S (UP+SA+S), Pastille urea with ammonium sulfate and zinc sulfate (UP+SA+Zn), Prilled urea (UR) and Ammonium sulfate (SA). Leaf N and S contents as well as maize yield were evaluated to assess the agronomic performance of the products and to calculate the appropriate N recommendation. Economic assessments of the price for the commercial products and the corn grains allowed estimating the rate of maximum economic efficiency (DMEE). The greater the rate of N applied the higher leaf N content and grain yields of maize. Leaf S contents increased with increasing doses of S applied with the tested fertilizers. Yields with Ammonium sulfate were higher than UR, UP and UP+S in both seasons in Umbaúba (Acrisol) (Southern Sergipe). The DMEE for UR was 128 and 119 kg N ha-1 for Nossa Senhora das Dores (Acrisol) and Umbaúba, respectively. The recommended dose of SA was 119 kg ha-1, since it provided the greater incomes for both sites. In the second paper, the aim was to evaluate the agronomic performance and the losses of N through ammonia volatilization of N fertilizers sidedress applied to maize. Ammonia volatilization, leaf N content and maize yield were evaluated in all products tested in the first paper when applied at a rate of 150 kg ha-1 of N and in the TEST treatment. Three replications were used. All fertilized treatments showed higher leaf N contents and grain yields than TEST. The treatment SA showed yields higher than UP+SA+S. Of all N-NH3 lost by volatilization, 92.5% took place in the first 5 days after application. The UP+SA treatment reduced ammonia volatilization and did not differ statistically from SA and TEST. Leaf N content correlates positively and N volatilization negatively with grain yield. / O nitrogênio é o elemento mais requerido pela maioria das culturas e o que proporciona os maiores incrementos no rendimento do milho. O pastilhamento da ureia é uma tecnologia que permite a adição de outros elementos, como enxofre e zinco, e visa diminuir as perdas de N, e consequentemente melhorar a eficiência agronômica dos fertilizantes. No primeiro artigo, o objetivo foi a recomendação de doses de N e avaliação da eficiência agronômica da ureia pastilhada, e de suas complexações com enxofre e zinco, e fontes convencionais de N aplicados em cobertura na cultura do milho nas condições do Médio Sertão e Sul sergipanos. O delineamento experimental foi em blocos ao acaso, com 3 repetições, em esquema de parcelas subdivididas com tratamento adicional. As parcelas foram compostas pelas doses: 75, 150 e 300 kg ha-1 de N, e as subparcelas pelos fertilizantes: ureia pastilhada pura (UP), ureia pastilhada com S elementar (UP+S), ureia pastilhada com sulfato de amônio (UP+SA), ureia pastilhada com sulfato de amônio e S elementar (UP+SA+S), ureia pastilhada com sulfato de amônio e sulfato de zinco (UP+SA+Zn), ureia perolada (UR), sulfato de amônio cristal (SA), e o tratamento adicional testemunha (TEST). Foram avaliados o teor de N e S foliar, produtividade de grãos, e recomendadas doses de máxima eficiência econômica (DMEE). A adubação nitrogenada proporcionou maiores teores de N foliares, e produtividade de grãos, e estas variáveis aumentaram com o acréscimo das doses de N. Os teores de S foliares aumentaram com o incremento das doses de S. O SA proporcionou maior produtividade que a UR, UP e UP+S na média das safras no Argissolo Acinzentado. As DMEE para a UR foram de 128 kg ha-1 de N no Argissolo Vermelho-Amarelo, e 190 kg ha-1 de N no Argissolo Acinzentado. A dose indicada de SA foi de 119 kg ha-1 de N para ambos os solos, e este tratamento proporcionou as maiores rendas. No segundo artigo, o objetivo foi a avaliação da eficiência agronômica e as perdas por volatilização da amônia pela aplicação em cobertura no milho de fertilizantes nitrogenados convencionais e pastilhados, e em suas complexações com enxofre e zinco. Foram avaliados a volatilização da amônia, o teor de N foliar, a produtividade de grãos, e a relação entre estas variáveis. Os tratamentos avaliados foram UP; UP+S; UP+SA; UP+SA+S; UP+SA+Zn; UR e SA, todos na dose de 150 kg ha-1 de N, além da testemunha não adubada (TEST), com 3 repetições. Os tratamentos fertilizados apresentaram os maiores teores de N foliares e produtividade de grãos. O SA apresentou produtividade superior ao tratamento UP+SA+S. Do total de N-NH3 perdido por volatilização, 92,5% ocorreram até o quinto dia após a fertilização. A UP+SA reduziu a volatilização da amônia, não diferindo estatisticamente do SA e TEST. O teor foliar de N correlacionou-se positivamente, enquanto a taxa de volatilização, negativamente, com a produtividade de grãos. / São Cristóvão, SE