ABSTRACT This study aimed to evaluate the effects of daily phase feeding (DP) and sequential feeding (SEQ) on the feeding behavior, performance, and body composition of growing-finishing pigs. Sixty barrows at 29.7 ± 2.8 kg body weight (BW) were assigned to one of four treatments: DP with a blended proportion of feeds A (high nutrient density) and B (low nutrient density) was adjusted to match 100 % of daily amino acid (AA) diet recommendations (DP100); a negative treatment, which matched 70 % of daily AA diet recommendations (DP70); and two SEQ with a blend of feeds A and B, adjusted twice a day (at 00h00 and 12h00), to match 70 or 110 % of daily AA diet recommendations during two 12 h intervals: SEQ110-70 and SEQ70-110. DP70 and SEQ showed a lower feed consumption rate compared to DP100 (p < 0.05). Compare to DP100, pigs in both SEQ programs had a similar average daily feed intake (ADFI), average daily gain (ADG), feed efficiency ratio (G:F) and body fat and lean mass ( p > 0.05). SEQ110-70 and SEQ70-110 showed similar ADFI, ADG, G:F and body lean mass (p > 0.05). However, fat gain was greater in SEQ110-70 than in SEQ70-110 (p < 0.05). Overall, the SEQ program does not improve performance and body composition. Furthermore, feeding pigs a diet with a higher AA level during the first 12 h of the day and a lower AA level during the remainder of the day increases fat deposition.
ABSTRACT A nitrogen balance test was performed to evaluate the individual responses of growing pigs to threonine intake. Eight commercial barrows were used (body weight ranging from 15 to 20 kg). A dose-response study was performed, in which the threonine supply increased in seven equidistant steps (the seven dietary threonine levels ranged from 50 to 120% of the requirements) every three days for each pig. The levels of all other amino acids were 20% higher than the tested amino acid. Nitrogen retention as a function of threonine intake was calculated per individual and per group (NLIN and NLMixed, respectively) using a linear plateau model. The highest break point value was 42.42 g of threonine intake (the most demanding individual), whereas the lowest value was 34.16 g (the least demanding individual), corresponding to a difference of 19%. In terms of N retention, the highest plateau value was 66.71 g and the lowest was 49.48 g, with a difference of 25%. There was no significant correlation between slope and plateau values or between slope and break point values. When using the model in which all parameters were random effects, the variations in threonine intake and nitrogen retention were 1.68±1.30 and 0.01±0.10 g, respectively, and no variance in the slope of the curve was detected. The average daily threonine intake values for the maximum response obtained in the group, as calculated by the NLIN and NLMixed procedures, were 13.96 and 14.02 g/day, respectively. The threonine intake for the maximum N retention between individuals ranged from 34.16 to 42.42 g, corresponding to a difference of 19%. The current recommended intake to optimize N retention is 14.02 g/day. The group responses obtained by the NLMixed procedures are very similar to those estimated by the NLIN procedure (all individuals).
ABSTRACT The intestinal health of piglets depends on the balance between diet, microflora and mucosal integrity. Disruption of this balance can compromise the digestive functions, leading to diarrhoeal frame and decline in performance of piglets. However, the level and type of fibre can limit digestive disorders. Thirty newly weaned piglets were used to evaluate the levels of neutral detergent fibre (NDF) in diets regarding performance, pH, viscosity and concentration of short chain fatty acids of digestive contents, gastrointestinal transit time, morphology of the intestinal mucosa, weights of organs and occurrence of diarrhoea. NDF level had quadratic effect on weight gain and feed conversion ratio of piglets, estimating best results at the level of 10.4%. NDF level had no effect on the pH, viscosity and concentration of short chain fatty acids. NDF levels below 10.2% or above 13.5% reduced the transit time of digesta. There was quadratic effect on villus height in the duodenum and jejunum and in the crypt depth of jejunum. There was linear increase in stomach, caecum and colon weights and linear decrease in the occurrence of diarrhoea according to increasing NDF levels. It is concluded that levels below 10.2% and above 13.5% reduce the transit time of digesta, whereas 12.2% NDF level results in better mucosa structure of the small intestinal, with an increase in the weights of the stomach, caecum and colon and a reduction in the occurrence of diarrhoea with increasing NDF level in diets, resulting in better performance of weaned piglets with 10.4% of NDF.
RESUMO A saúde intestinal em leitões depende do equilíbrio entre dieta, microflora e integridade da mucosa. Perturbações desse equilíbrio podem comprometer as funções digestivas, conduzindo a quadro diarreico e queda no desempenho dos leitões. Nesse sentido, o nível e tipo de fibra podem limitar as perturbações digestivas. Utilizou-se 30 leitões recém desmamados objetivando avaliar níveis de fibra em detergente neutro (FDN) nas dietas sobre o desempenho, pH, viscosidade concentração de ácidos graxos de cadeia curta dos conteúdos digestivos, tempo de trânsito gastrointestinal, do ceco, morfologia da mucosa intestinal, pesos dos órgãos e ocorrência de diarreia. Observou-se efeito quadrático do nível de FDN sobre o ganho de peso e conversão alimentar dos leitões, estimando-se melhores resultados no nível de 10,4%. Não houve efeito do nível de FDN sobre o pH, viscosidade e concentração de ácidos graxos de cadeia curta da digesta. Níveis de FDN abaixo 10.2 ou acima de 13,5% reduziu o tempo de trânsito da digesta. Houve efeito quadrático sobre a altura das vilosidades do duodeno e jejuno e na profundidade das criptas do jejuno. Houve aumento linear no peso do estômago e do ceco e cólon e redução linear na ocorrência de diarreia conforme houve aumento dos níveis de FDN. Concluiu-se que níveis abaixo de 10,2 e acima de 13,5% reduzem o tempo de trânsito da digesta, enquanto que o nível de 12,2% de NDF resulta na melhor estrutura da mucosa do intestino delgado, havendo aumento nos pesos de estômago, ceco e cólon e redução da ocorrência de diarréia com o aumento do nível de FDN, resultando um melhor desempenho de leitões desmamados com 10,4% de FDN.