Estimates of feed produced by pasture were obtained from pasture investigations at the Tidewater Field Station from 1949 through 1953, Dry lot groups of pigs similar to those fed on pasture and fed similar rations were used to estimate total concentrates necessary for maintenance and gain of pigs on pasture. Feed production of each pasture was estimated from the difference between concentrates consumed by the pigs on that pasture and total concentrates for similar performance in dry lot. Estimates for 1949 and 1950 were based on the regression of feed consumption on average daily gain of pigs fed in dry lot. Weight of the animals was not considered in computing these estimates, In 1952 and 1953 the regression of feed consumption on weight was the basis for estimates when pigs were fed at the high level of nutrition, end feed required per pound of gain above maintenance for similar weight pigs was the basis for estimates, when pigs were fed at the low level of nutrition. Direct comparisons were made between pigs fed in dry lot and on pasture at the high level of nutrition, since feed consumption and weight were similar, This was not the case with pigs fed in dry lot and on pasture at the low level of nutrition. Feed consumption was the same but average daily gain differed significantly. Since the low level of nutrition provided slight gain for pigs in dry lot, it was necessary that this gain be subtracted from the total gain made by pigs on pasture. The net gain was assumed to be the direct result of the pasture, The feed required per pound of gain above maintenance was calculated and multiplied by the net gain (gain made from pasture), the product being an estimate of the feed replacement value of the pasture lot. Estimations were calculated on a per acre basis. A summary by years of the feed replaced by the pasture is shown in Table 15. This summary indicated that a more consistent estimate was obtained when weight of the animals was included in estimating expected feed consumption, Exceptions to this occurred in 1952 and 1953 when pigs were self-fed on ladino clover. In 1952, the estimated feed replacement value of the pasture, when pigs were provided supplement, was 584 pounds, while in 1953 the estimate was 93 pounds. When supplement was not included in the ration, the feed replaced by the pasture was 26 and 903 pounds for 1952 and 1953, respectively. / Master of Science

Three hundred and twelve feeder pigs, six lots of 52 pigs each (52 pounds) were used to study the response of five antibiotic supplementations in a commercial hog finishing operation. Lot one received neomycin 80 grams per ton, lot two Bacitracin MD (40 grams per ton), and lot three no antibiotic o Lots four, five and six received SP-250 for 10 days (five pounds per ton). After termination of SP-2S0, lot four received neomycin (80 grams per ton), lot five bacitracin MD (40 grams per ton) and lot six no antibiotic. At the end of the 9l-day feeding period, the first draft of hogs) which included all hogs weighing approximately 200 pounds, was removed for slaughter. A second draft of hogs was slaughtered 14 days later, the remaining hogs in each lot were all removed 32 days later. The supplementation of SP-250 (lots 4, 5 and 6) for 10 days increased (P .01) the ADG by 0.2 pounds over control, Neomycin and Bacitracin MD did not affect the ADG. Combinations of SP-250 and Neomycin or Bacitracin MD produced gains similar to those of SP-250 alone. Carcass length was measured from the first rib to the aitch bone, also average chilled carcass weight and dressing per cent were obtained at the packing plant. Feed intake did not appear to be affected by any of the treatments. Feed efficiency appeared to be improved by SP-250 due to the greater gains. The overall mean live weight at slaughter also had a tendency to be greater for lots 4, 5, and 6. There was essentially no difference among lots I, 2, and 3 or among lots 4, 5, and 6 in live weight at slaughter. Mean slaughter weights were 220 lbs. and 212 lbs. for those supplemented with SP-250 and those not, respectively. Chilled carcass weights of pens 4, 5, and 6 evidenced the slightly greater live weights as compared to lots 1, 2, and 3. The treatments had no effect on dressing % or carcass length. Those lots receiving SP-2S0 tended to have slightly thicker back fat. / Master of Science

The major objectives of this research were to examine whether copper (Cu) exerts its growth promoting actions systemically, to assess the role of feed intake in Cu-stimulated growth and to investigate the effect of Cu on the growth control system. An economical and convenient bioassay system using non-fusing myogenic BC₃H₁ cells and a MITT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide ) cell proliferation assay was developed, which measures serum mitogenic activity, an indicator for blood growth factor activity. The potential use of a previously reported cobalt-copper antagonism in reducing tissue Cu deposition in pigs fed high Cu diets was evaluated in two experiments using a total of 192 pigs. Feeding 150 or 300 ppm of inorganic cobalt (Co) as Cobalt Chloride reduced Cu deposition in the kidney, but failed to reduce Cu deposition in the liver and brain as reported in rats. Dietary Co of 150 ppm was found to be detrimental to weanling pigs. Therefore, inorganic Co feeding is of limited use in studying Cu-stimulated growth. The effect of intravenously injected Cu on growth was studied in two experiments with a total of 89 pigs. Amounts of Cu injected were calculated to simulate varying absorption rates in pigs fed 250 ppm of dietary Cu. Injecting appropriate amounts of Cu (calculated using digestibility of 5 % in Exp. 1 and 2-4 % in Exp. 2) promoted growth by 12-31 % (P < .05). Copper injections also stimulated serum mitogenic activity. Pituitary growth hormone (GH) mRNA was not significantly affected by Cu injections. This study suggests that Cu may stimulate growth systemically, without acting in the gastrointestinal tract as proposed by the antimicrobial hypothesis. The importance of feed intake in Cu-stimulated growth was examined in two experiments with a total of 138 pigs. Pair-feeding (Exp. 1) and restricted feeding (Exp. 2) were used to equalize the feed intake of pigs fed high Cu diets to that of pigs fed basal diets. Both experiments showed that Cu-stimulated growth was greatly reduced when Cu-fed pigs were restricted to have the same amount of feed as the control, which indicates that enhancing feed intake is an important part of the growth promoting mechanism of Cu. Copper feeding also enhanced serum mitogenic activity and increased pituitary GH mRNA concentration, independently of feed intake. This suggests that Cu feeding also affects the growth control system directly. In Exp. 2, Cu-lysine (providing 200 ppm dietary Cu) was found to be more effective than Cu sulfate in promoting growth. This benefit of Cu-lysine was largely from an increase in feed intake. This research demonstrated that Cu is able to promote growth systemically; and identified the importance of feed intake and the growth control system for Cu-stimulated growth, which opens new areas for future research. / Ph. D.

Crossbred pigs 3 to 4 weeks of age were randomly assigned from outcome groups based on weight and sex to one of four dietary treatments either with or without added soybean oil or hulls. Nursery air quality was evaluated by measuring the concentrations of ammonia, carbon dioxide, settled dust, suspended particle size, and by microbiologically culturing air samples. Weekly performance data was also collected. ADG was unaffected by dietary treatment. ADFI was increased when soybean hulls were added to the ration with the difference being significant in trials 1 and 2 and over-all. Adding soybean oil to the ration produced slightly lower feed intakes over all trials but was not significant. Rations with added soybean oil reduced F/G, whereas, the addition of soybean hulls increased F/G for over-all trials. The response to soybean oil was less when soybean hulls were added. A comparison of rations 1 and 4 showed only slight differences in ADG, ADFI and F/G. The addition of soybean oil resulted in a 47% reduction in settled dust for trials 1 and 2 combined, and a 45% reduction for trial 3. Mean bacterial colony counts for each week and over-all for trial 3 were lower when soybean oil was added to the ration. Ammonia and carbon dioxide concentrations were not affected by dietary treatment. From the results of this experiment, the addition of soybean oil to starter diets improved nursery air quality and performance in some cases, however, gas concentrations were not different. / Master of Science

Call number: LD2668 .T4 1978 G74 / Master of Science

published_or_final_version / Zoology / Doctoral / Doctor of Philosophy

Orientador: Dirlei Antonio Berto / Banca: Ricardo de Oliveira Orsi / Banca: Marcos Livio Panhoza Tse / Banca: Valdomiro Shigueru Miyada / Banca: Messias Alves da Trindade Neto / Resumo: A nutrição exerce influência na modulação do sistema imune e na melhoria da resistência dos animais à infecção, visto que os nutrientes são necessários para a multiplicação celular durante a resposta imune e síntese de moléculas relacionadas à comunicação celular. Dois experimentos foram conduzidos com leitões desmamados aos 21 dias de idade e submetidos ao desafio com 150 μg kg-1 PV de lipopolissacarídeo (LPS) de Escherichia coli sorotipo 055:B5. Objetivou-se avaliar efeitos da adição de beta-glucanos originários da levedura Saccharomyces cerevisiae (0 e 300 ppm) em dietas com densidade nutricional baixa e elevada (3300 e 3450 kcal de EM kg-1) sobre o desempenho (Experimento I) e morfometria intestinal (altura de vilosidades: AV, profundidade de criptas: PC, relação AV:PC e área das placas de Peyer: PP) e peso de órgãos (fígado, timo e baço) dos leitões (Experimento II). No experimento I foram utilizados 96 leitões em delineamento de blocos ao acaso (oito repetições), em esquema fatorial 2 x 2 (2 níveis de beta-glucanos x 2 densidades nutricionais), enquanto no segundo experimento, 40 leitões foram distribuídos em delineamento de blocos ao acaso (cinco repetições) com arranjo fatorial dos tratamentos 2 x 2 x 2 (2 níveis de beta-glucanos x 2 densidades nutricionais x 2 épocas de abate: uma semana antes da primeira inoculação com LPS e uma semana após a segunda inoculação com LPS). Nos experimentos foram realizadas análises estatísticas dos dados utilizando o procedimento GLM (Experimento I) e análise multivariada (Experimento II) do SAS, sendo as médias comparadas pelo teste de Bonferroni P(<0,05). A dieta de baixa densidade nutricional sem beta-glucanos proporcionou maior (P<0,05) AV e AV:PC do duodeno e jejuno. Não foram observados efeitos (P>0,05) dos beta-glucanos e da densidade nutricional da dieta no desempenho, PC do jejuno e na área... (Resumo completo clicar acesso eletrônico abaixo) / Abstract: Nutrition influences the modulation of the immune system and improves the resistance to infection, because the nutrients are required for cell proliferation during the immune response. Two experiments were conducted with piglets weaned at 21 days old and immunologically challenged with 150 μg kg-1 BW lipopolysaccharide of Escherichia coli serotype 055:B5 to evaluate the effects of two levels of beta-glucans (0 and 300 ppm) of yeast Saccharomyces cerevisiae and two levels of nutrient density (3300 and 3450 kcal ME kg-1) on growth performance (Experiment I) and intestinal morphometry (villus height: VH, cript depth: CD, VH:CD, Peyer's patches area: PP) and organs weight (liver, spleen and thymus) of weanling pigs (Experiment II). In Experiment I, 96 weanling pigs were randomly assigned in a complete block design in a 2 x 2 factorial arrangement (2 levels of beta-glucans: 0 and 300 ppm, and 2 levels of nutrient density: 3300 and 3450 kcal ME kg-1) with 8 replications per treatment and 3 pigs per pen. In Experiment II, 40 weanling pigs were randomly assigned in a complete block design in a 2 x 2 x 2 factorial arrangement with the same levels of beta-glucans and nutrient density of experiment I at two slaughter moments with 5 replications per treatment and one pig per pen. Data were analyzed in accordance with GLM procedure (Experiment I) and multivariate procedure (Experiment II) by SAS, and the treatment means were compared by Bonferroni test (P<0.05) in both experiments. The low nutrient density diet without beta-glucans had higher (P<0.05) VH and VH:CD in duodenum and jejunum. No differences concerning levels of beta-glucans and nutrient density were observed (P>0.05) on growth performance, and CD in jejunum neither in PP ileal area. The addition of beta-glucans and high nutrient density diets are not viable for pigs from 21 to 59 days of age, once no effects were observed on growth... (Complete abstract click electronic access below) / Doutor

Orientador: Aleksandrs Spers / Banca: Dirlei Antonio Berto / Banca: Rodolfo Nascimento Kronka / Banca: Romualdo Shigueo Fukushima / Resumo: Embora os suínos apresentem limitada capacidade em degradar material fibroso, é possível utilizar fontes fibrosas na ração de determinadas categorias animais, como por exemplo suínas em fases pré-púbere e púbere, devido à necessidade de moderado ganho de peso neste período. Por ocasião do primeiro cio útil (terceiro cio fisiológico), as fêmeas devem apresentar valores mínimos de 110 kg de peso corporal e 1,8-2,0 cm de espessura de toucinho. O objetivo desta pesquisa foi o de determinar os efeitos causados pelo emprego de 0; 6,6; 13,2 e 19,8% de fibra em detergente neutro (FDN), na ração basal de fêmeas suínas em fase pré-púbere e púbere (marrãs). As concentrações de FDN na ração, foram obtidas através da inclusão de 0, 10, 20 e 30 % de feno de "coast cross" (Cynodon dactylon), respectivamente. Foram utilizadas 20 marrãs puras e mestiças, das raças Landrace e Large White, com peso e idade médias iniciais de 52,85 kg e 110 dias, em um experimento em blocos casualizados, com cinco repetições/tratamento. Em relação às características de desempenho animal, o incremento de FDN na ração de marrãs, promoveu respostas lineares (P<0,01) no ganho diário de peso (0,675; 0,607; 0,525; 0,483 g/d); no peso corporal por ocasião do primeiro cio útil (118,0; 114,0; 102,2; 98,2 kg); na conversão alimentar (3,6; 4,0; 4,7; 5,3); e resposta quadrática (P<0,05) na espessura de toucinho (3,28; 3,34; 2,82; 1,74 cm). No referente à idade de ocorrência do primeiro cio útil, não houve registro de efeito significativo (P>0,10) sobre esta característica, a qual apresentou valor médio de 203 dias. A digestibilidade dos componentes dietéticos foi influenciada pela presença de fibra dietética na ração das marrãs. A adição de FDN promoveu resposta linear (P<0,01) na digestibilidade da matéria seca... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Although swines show limited capability in degrading fiber, it is possible utilization of feeds in the diet of some animal categories such as gilts. These animals need to gain moderate weight during this period that precede breeding and by the time females exhibit their third physiological heat, they have to weight a minimum of 110 kg and have at least 1.8-2.0 cm of subcutaneous fat. The objective of this research was to assess the effects caused by utilization of 0; 6.6; 13.2 and 19.8 % of neutral detergent fiber (NDF) in the basal diet of gilts. These concentrations of NDF were obtained through inclusion of 0; 10; 20 and 30 % of coast-cross hay (Cynodon dactylon), respectively. This trial was conducted with 20 pure and crossbred Landraceand Large White females with average weight of 52.8 kg and 110 days old. The experimental design employed was a completely randomized block design with five repetitions per treatment. Increasing concentration of NDF in the diet of gilts led to linear response (P<0.01) on the daily weight gain (0.675; 0.607; 0.525; 0.483 g/d); on the body weight by the onset of the third physiological heat (118.0; 114.0; 102.2; 98.2 kg); on the feed efficiency (3.6; 4.0; 4.7; 5.3); and quadratic response (P<0.05) on the subcutaneous fat thickness (3.28; 3.34; 2.82; 1.74 cm). However, no significance was found (P>0.10) on the third physiological heat onset age which average 203 days. Nutrient digestibility was also affected by addition of hay to the basal diet. Dry matter digestibility had linear response... (Complete abstract click electronic access below) / Doutor

Orientador: Roberto de Oliveira Roça / Coorientador: Dirlei Antonio Berto / Banca: Luiz Edvaldo Pezzato / Banca: Marcos Livio Panhoza Tse / Banca: Messias Alves da Trindade Neto / Banca: Nikolas de Oliveira Amaral / Resumo: Esta pesquisa teve como objetivo avaliar a digestibilidade dos nutrientes, balanço de nitrogênio e desempenho de suínos nas fases de crescimento e terminação alimentados com dietas contendo milho híbrido comum e geneticamente modificado. Foram realizados dois experimentos: digestibilidade aparente das rações contendo híbridos de milho comum e transgênicos, e desempenho de suínos nas fases de crescimento e terminação alimentados com transgênicos. O delineamento do experimento da digestibilidade aparente foi em blocos (DBC) com quatro tratamentos, sete repetições, totalizando 28 animais mestiços (LD x LW) com peso médio inicial de 50 ±1,1 kg, sendo a unidade experimental o animal; e o desempenho teve delineamento em blocos casualizados (DBC) com três tratamentos e dez repetições totalizando 60 animais mestiços, machos castrados e fêmeas (LD x LW) com peso médio inicial de 30 ±2,2 kg, sendo a unidade experimental a baia contendo dois animais. Os tratamentos do experimento digestibilidade foram: R1- ração basal (referência) contendo milho híbrido variedade 2B587®; R2- 60% da R1 e 40% do milho híbrido comum variedade 2B587®; R3- 60% da R1 e 40% do milho híbrido transgênico 2B587Hx® e R4- 60% da R1 e 40% do milho híbrido transgênico 2B707Hx®. Os tratamentos do experimento de desempenho foram: D1- ração contendo milho híbrido comum variedade 2B587®; D2- ração contendo milho híbrido transgênico variedade 2B587Hx® e D3- ração contendo milho híbrido transgênico variedade 2B707Hx®. Os dados obtidos foram analisados utilizando-se o software estatístico SAS. Não foram observadas diferenças entre os milhos híbridos comuns em relação aos transgênicos para os parâmetros de digestibilidade dos milhos e variáveis de desempenho (P > 0,05). Foram encontrados efeitos sobre o balanço de nitrogênio e digestibilidade das rações (P < 0,05), ... / Abstract: This research aimed to evaluate nutrient digestibility, nitrogen balance and performance of pigs in the growing and finishing phases. They were fed with diets containing hybrid common corn and genetically modified corn. Two experiments were conducted: apparent digestibility of diets containing hybrid common corn and transgenic corn, and performance evaluation of pigs fed with diets containing hybrid common corn and transgenic corn, in the growing and finishing phases. The design of the apparent digestibility experiment was in blocks using four treatments and seven replications totaling 28 crossbred (LW x LD) animals with an initial BW of 50 ± 1.1 kg. The animal was considered the experimental unit. The performance experiment addoted was randomized block design using with three treatments and ten replications. There were 60 crossbred barrows and gilts (LW x LD) animals with an average initial weight of 30 ± 2.2 kg. The experimental unit was the pen containing two animals. The digestibility experiment treatments were: reference diet-R1 containing hybrid corn (2B587®); R2- 60% of R1 and 40% of common hybrid corn (2B587®), R3- 60% of R1 and 40% of transgenic hybrid corn (2B587Hx®), and R4- 60% of R1 and 40% of transgenic hybrid corn (2B707Hx®). Performance experiment treatments were: D1-ration containing common hybrid corn (2B587®); D2-ration containing transgenic hybrid corn (2B587Hx®) and D3-ration containing transgenic hybrid corn (2B707Hx®). The data were analyzed using the SAS statistical software. No differences were observed between common hybrid corn and transgenic hybrid corn for corn digestibility parameters and performance variables (P > 0.05). Effects were found in nitrogen balance and digestibility (P < 0.05), probably these results are not directly linked to the presence of the Cry transgenic gene. It was concluded that there was no difference in nutrient digestibility, ... / Doutor

M. Tech. Animal Sciences. / The main objective of this study is to develop an in vitro technique to determine the digestibility of high fibre pig feeds in order to improve pig feed formulation. An in vitro digestibility technique as an alternative to the costly, labour intensive, time consuming and ethically difficult in vivo method was developed to determine the digestibility of fibrous pig feeds. Effects of bag pore size, bag pretreatment, sample size, particle size, incubation time, enzyme concentration, fibrolytic enzymes' cocktail activity and buffer quantity on in vitro dry matter digestibility of selected feedstuffs were evaluated.