The optimum valine: lysine ratios on performance and carcass traits of male broilers based on different regression approaches.

Three different regression approaches were applied to determine the optimal digestible (d.) and analyzed Val:Lys ratios for broiler performance and carcass yield. One-day-old male Cobb 500 broilers (n = 960) were assigned to 1 of 8 diets, with 6 pens/diet and 20 birds/pen, for 42 days. The negative control consisted of the basal diet with a d.Val:d.Lys ratio of 0.63 and with 93% of the required d.Lys. The positive control consisted of the basal diet with a d.Val:d.Lys of 0.80, with no reduction in d.Lys content. The other (test) diets contained a range of d.Val:d.Lys ratios, all with 93% of the required d.Lys. Data on feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) were submitted to regression analysis, applying quadratic polynomial (QP), exponential asymptotic (EA), and linear response plateau (LRP) models. Since Val did not affect carcass or breast meat yield, no regression was performed. Digestible and analyzed Val:Lys ratios were similar based on the regression models. The intercept between the QP and LRP models was used to determine the optimum Val:Lys ratio. Overall, the ideal d.Val:d.Lys ratio will vary according to the main goal of poultry production, i.e., BWG or FCR. For BWG, the ideal ratio was found to be 0.78 (0 to 12 d), 0.73 (0 to 28 d), and 0.76 (0 to 35 or 0 to 42 d). For FCR, the optimum d.Val:d.Lys was found to be 0.80 (0 to 12 d), 0.75 (0 to 28 d), and 0.78 (0 to 35 or 0 to 42 d). The optimum analyzed Val:Lys ratio was slightly higher. For instance, for BWG the optimum ratio was 0.80 (0 to 12 d), 0.76 (0 to 28 d), and 0.79 (0 to 35 or 0 to 42 d). For FCR, the optimum Val:Lys was 0.81 (0 to 12 d), 0.79 (0 to 28 d), and 0.81 (0 to 35 or 0 to 42 d). Valine did not affect carcass or breast meat yield.

Caracterização dos fatores de produção e uso de modelos matemáticos para estimar sua influência sobre o consumo diário de ração e a conversão alimentar de suínos nas fases de crescimento e terminação / Characterization of production factors and use of mathematical models to estimate their influence on daily feed intake and feed conversion ratio of grow-finishing pigs

O objetivo deste estudo foi identificar e quantificar os fatores de produção presentes em granjas de crescimento e terminação (CT) de suínos, em um sistema cooperativo do estado do Paraná, Brasil, e determinar a influência desses fatores no consumo diário de ração (CDR) e na conversão alimentar (CA). Foram avaliados, entre os anos de 2010 e 2013, os históricos produtivos de 538 lotes de engorda, alojados em 175 granjas comerciais, totalizando aproximadamente 404.000 animais. Foram considerados 40 fatores de produção, relacionados ao manejo, à sanidade, às instalações e aos equipamentos, à nutrição, à genética e ao ambiente. Em baias com menos de 20 suínos, o CDR diminuiu (P<0,05) e a CA melhorou (P<0,01). Nas baias com comedouros basculantes (lineares), o CDR reduziu (P<0,01) e a CA melhorou (P=0,001). Em baias com lâmina d'água, o CDR aumentou (P<0,01) e a CA piorou (P<0,01). Lotes formados apenas por fêmeas apresentaram menor CDR (P<0,001) e melhor CA (P<0,001), quando comparados aos lotes mistos. As variáveis selecionadas para os modelos finais explicaram cerca de 25% e 46% da variância total para CDR e para a CA, respectivamente. Os modelos constituem um instrumento de auxílio efetivo para tomadas de decisões técnicas dentro do setor suinícola.(AU)

The aim of this study was to identify and quantify the production factors present in growing and finishing (GF) pig farms partners of a cooperative in Paraná State, Brazil, and to determine the influence of these factors on daily feed intake (DFI) and the feed conversion ratio (FCR). From 2010 to 2013, the historical production of 538 batches of fattening pigs in 175 commercial farms were analyzed, in an amount approximately 404,000 animals. A total of 40 production factors regarding the management, sanity, plant and equipment, nutrition, genetics and environment were taken into consideration. Pens with less than 20 pigs resulted in a reduction in DFI (P<0.05) and an improved FCR (P<0.01). In pens that used linear dump feeders, the DFI was less (P<0.01) and the FCR was better (P=0.001). Pens with shallow pools had higher DFI (P<0.01) and worse FCR (P<0.01). Batches of females had lower DFI (P<0.001) and better FCR (P<0.001) compared to mixed-sex batches. The factors used for the final models explained the 25% and 46% of the total variance for the DFI and FCR, respectively. The models consist in effective aid instruments for technical decision making in the swine industry.(AU)

Comparison of methionine sources around requirement levels using a methionine efficacy method in 0 to 28 day old broilers.

The addition of methionine in the poultry feed industry is still facing the relative efficacy dilemma between DL-methionine (DLM) and hydroxy-methionine (HMTBA). The aim of this study was to compare the effect of dietary DLM and HMTBA on broiler performance at different levels of total sulfur amino acids (TSAA). The treatments consisted of a basal diet without methionine addition, and 4 increasing methionine doses for both sources resulting in TSAA/Lysine ratios from 0.62 to 0.73 in the starter phase and 0.59 to 0.82 in the grower phase. The comparison of product performance was performed by three-way ANOVA analysis and by methionine efficacy calculation as an alternative method of comparison. Growth results obtained during the starter phase with the different methionine supplementations did not show significant growth responses to TSAA levels, indicating a lower methionine requirement in the starter phase than currently assumed. However, a significant methionine dose effect was obtained for the period 10 to 28 day of age and for the entire growth period of 0 to 28 day of age. Excepting a significant gender effect, the statistical analysis did not allow for the discrimination of methionine sources, and no interaction between source and dose level was observed up to 28 days of age. A significant interaction between source and dose level was observed for methionine efficacy for the grower phase, and the total growth period showed better HMTBA efficacy at higher TSAA value. The exponential model fitted to each methionine source for body weight response depending on methionine intake or for feed conversion ratio (FCR) depending on methionine doses did not allow the methionine sources to be distinguished. Altogether, these results conclude that methionine sources lead to similar performances response when compared at TSAA values around the broiler requirement level. These results also showed that at TSAA values above requirement, HMTBA had a better methionine efficacy value than DLM, caused by the different properties of that molecule, whereas below the TSAA requirement levels, the opposite was observed in females.

Factors affecting the daily feed intake and feed conversion ratio of pigs in grow-finishing units: the case of a company.

BACKGROUND: The aim of this study was to use mathematical modeling to identify and quantify the main factors that affect daily feed intake (DFI) and feed conversion ratio (FCR) in grow-finishing (GF) pig units. We evaluated the production records of 93 GF farms between 2010 and 2013, linked to a company, working in a cooperative system, located in western Paraná State, Brazil. A total of 683 batches, consisting of approximately 495,000 animals, were used. Forty production factors related to the management, health, plant and equipment, nutrition, genetics and environment were considered. The number of pigs per pen, type of feeder, origin and sex (the last two variables were combined in the models) of the animals and initial and final body weights were included in the final models to predict DFI and FCR (dependent variables). Additionally, the duration of the GF phase was included for the parameter FCR. All factors included in the final models had significant effects for both dependent variables. RESULTS: There was a reduction in DFI (0.04 kg) (P < 0.001) and an improvement in FCR (6.0 points) (P < 0.001) in batches from pens with less than 20 animals compared with batches from pens with more than 20 animals. In barns with "other" feeder types (mostly the linear dump type) different of conical semiautomatic feeder, a reduction of DFI (0.03 kg) (P < 0.05) and improved FCR (3.0 points) (P < 0.05) were observed. Batches of barrows from units specialized for producing piglets (SPU) had higher DFI (approximately 0.02 kg) (P < 0.01) than batches of females and batches of mixed animals from SPU, and batches of mixed animals from farms not specialized for piglet production (farrow-to-finish farms). Batches of females from SPU and mixed batches from SPU had better FCR (5.0 and 3.0 points respectively) (P < 0.001 and P < 0.001, respectively) than batches of piglets originating from farrow-to-finish farms. The variables selected for the final models explained approximately 50 and 64 % of the total variance in DFI and FCR, respectively. CONCLUSIONS: The models are tools for the interpretation of the factors related to the evaluated parameters, aiding in the identification of critical aspects of production. The main parameters affecting DFI and FCR in this company during the GF period were the number of pigs per pen, the type of feeder used and the combination origin-sex of the animals.

Management factors affecting mortality, feed intake and feed conversion ratio of grow-finishing pigs.

The aim of this study was to determine the effect of animal management and farm facilities on total feed intake (TFI), feed conversion ratio (FCR) and mortality rate (MORT) of grower-finishing pigs. In total, 310 batches from 244 grower-finishing farms, consisting of 454 855 Pietrain sired pigs in six Spanish pig companies were used. Data collection consisted of a survey on management practices (season of placement, split-sex by pens, number of pig origins, water source in the farm, initial or final BW) and facilities (floor, feeder, ventilation or number of animals placed) during 2008 and 2009. Results indicated that batches of pigs placed between January and March had higher TFI (P=0.006), FCR (P=0.005) and MORT (P=0.03) than those placed between July and September. Moreover, batches of pigs placed between April and June had lower MORT (P=0.003) than those placed between January and March. Batches which had split-sex pens had lower TFI (P=0.001) and better FCR (P<0.001) than those with mixed-sex in pens; pigs fed with a single-space feeder with incorporated drinker also had the lowest TFI (P<0.001) and best FCR (P<0.001) in comparison to single and multi-space feeders without a drinker. Pigs placed in pens with <50% slatted floors presented an improvement in FCR (P<0.05) than pens with 50% or more slatted floors. Batches filled with pigs from multiple origins had higher MORT (P<0.001) than those from a single origin. Pigs housed in barns that performed manual ventilation control presented higher MORT (P<0.001) in comparison to automatic ventilation. The regression analysis also indicated that pigs which entered to grower-finisher facilities with higher initial BW had lower MORT (P<0.05) and finally pigs which were sent to slaughterhouse with a higher final BW presented higher TFI (P<0.001). The variables selected for each dependent variable explained 61.9%, 24.8% and 20.4% of the total variability for TFI, FCR and MORT, respectively. This study indicates that farms can increase growth performance and reduce mortality by improving farm facilities and/or modifying management practices.