Estratégias nutricionais para redução na variabilidade de peso dos leitões ao nascimento

Abstract

The objective of the present study was to evaluate the pig birth weight variability, and was divided in two chapters, being the first about the effects of amino acid supplementation, through a systematic review and meta-analysis, and the second chapter was about the effects of the arginine supplementation. The objective of the first chapter was evaluate through a systematic review and meta-analysis the effects of the litter size and amino acids supplementation in the pig birth weight variability. The high prolificacy sows presented average weight of total born and born alive piglets, higher than the low prolificacy sows. The weight variability was affected in high prolificacy sows, there was an increase of 4.04 and 4.54 percentage point for the coefficient of variation of the total born and born alive piglets, respectively. There was an increase of 180 grams in the standard deviation of the born alive piglets of high prolificacy sows. Despite of amino acids with different functions been grouped together, there was a tendency for a reduction of the weight variation with an amino acid supplementation. The weight variability was affected by the average litter weight of low prolificacy sows, as the variability is affected by the number of born alive piglets of high prolificacy sows. The amino acid supplementation may reduce the piglet weight variation in a birth litter. The objective of the study was to evaluate the effects of a 1.0% L-arginine supplementation during gestation in three periods. About the piglet birth weight variability, for that, four experiments were conducted in Brazilians commercial farms. The 1.0% L-arginine supplementation were provided in “on top” form. Each sow of all farms and all treatments were inseminated by the same genetic group of males and after that, were selected through the reproductive index for 14 to 16 born alive piglets per birth. A total of 133 sows were used in the experiments, being distributed between gilts and seventh order birth sows. The piglets were dried and weighted individually. The litter size, the average litter weight, the standard deviation of litter weight and the coefficient of variation of the average litter weight were considered do analyze the pig birth weight variability. The standard deviation and the coefficient of variation of the average litter weight were calculated for each litter. The piglet weight variability due to L-arginine supplementation wasn´t analyzed by means of descriptive analyzes, correlation and analysis of variance, by having an effect of L-arginine supplementation (with or without supplementation) and the supplementation period (experiment 01: from 30 to 60 and 80 days of gestation until the birth, experiments 02 and 03: from 85 days of gestation until the birth, experiment 04: from 22 to 55 days of gestation), there was a stratification of piglets weight, by percentage, at birth by litter and normal distribution of weights of total born piglets. The supplementation of L-arginine reduced the standard deviation in 73.30 e 55.99 grams compared with the control group, when the supplementation was provided from the day 80 until the birth for litters of total born and born alive piglets. The L-arginine supplementation for gestating sows reduces the percentage of the total born and the born alive piglets with less than 800 grams, respectively in 2.26 and 2.05 percentage points and increased the percentage of the number of the total born and the born alive piglets, respectively, between 1601 and 1800 grams in 5,89 and 6,08 percentage points. A 1.0% L-arginine supplementation for gestating sows, regardless the period of feeding, increased the litter uniformity with a mean reduction of 4,06 percentage points in the group of piglets with less than 1180 grams, in addition increases in 4.07 percentage points in the group of piglets between 1180 and 1890 grams.