Variability of piglet birth weights: A systematic review and meta‐analysis

Abstract

The objective of the study was to evaluate the effects of litter size and supplementation of functional amino acids on the piglet birth weight variability through of a systematic review and meta‐analysis. PubMed, ISI Web of Science, Science Direct, Scopus and SciELO are the main used databases and were searched in January 2019 by using the following keywords and their combinations: within‐litter birth, weight variability, piglets, litter size, sow, amino acids, gestation, uniformity, CV and/or SD. Of the 64 pre‐selected articles, only articles presenting the coefficients of variation and/or standard deviations according to the litter size and different levels of amino acid supplementation in the sow diets during gestation were selected. The average birth weights of total and live piglets were 43% lower in litters from sows with high prolificacy than those from sows with low prolificacy. The weight variability was affected by high prolificacy sows, with increases of 4.04% and 4.54% in the coefficients of variation of total and born alive piglets respectively (p = .074; p = .009). The standard deviation increased by 180 g in born alive piglets to high prolificacy sows. The coefficients of variation of total and live piglets born from high prolificacy sows showed an increase of 4.04% and 4.54% respectively (p = .07; p < .05). There was a tendency for reduced weight variability with amino acids supplementation when considering the standard deviation of total born (p = .072). However, reproductive performance was not significantly influenced (p > .05). In conclusion, the average litter weight and the number of piglets born influence weight variability. Amino acids supplementation may reduce the birth weight variability between piglets. However, this effect depends on the amino acid used, the levels of supplementation and on other factors not completely addressed in this study. Thus, more research is necessary to fully elucidate this topic.

Dietary supplementation with 0.4% L-arginine between days 14 and 30 of gestation enhances NO and polyamine syntheses and water transport in porcine placentae

“…A corn- and soybean meal-based diet containing 12% crude protein is considered optimal to provide most AAs and prevent hyperammonemia (a major factor contributing to embryonic death) in gestating pigs [ 8 ]. However, a gestation diet containing 12% crude protein does not meet dietary requirements for Arg [ 5 , 12 ]. Thus, supplementing this deficient AA to the maternal diet is an effective way to enhance the growth and development of the conceptus without any detrimental effects associated with increasing dietary crude protein intake [ 5 – 7 , 26 , 61 , 62 ].…”

“…However, a gestation diet containing 12% crude protein does not meet dietary requirements for Arg [ 5 , 12 ]. Thus, supplementing this deficient AA to the maternal diet is an effective way to enhance the growth and development of the conceptus without any detrimental effects associated with increasing dietary crude protein intake [ 5 – 7 , 26 , 61 , 62 ]. Most embryonic loss in pigs occurs before d 30 of gestation, making this time period an appropriate target for improvement in the reproductive performance of gilts and sows [ 2 – 4 , 24 ].…”

“…Pigs suffer high rates of embryonic mortality, especially during the peri-implantation period of pregnancy [ 1 , 2 ] when embryos elongate rapidly, signal for pregnancy recognition, and attach to the uterine wall [ 3 , 4 ]. Maternal nutrition plays an important role in the development and subsequent survival of conceptuses (embryo/fetus and its extra-embryonic membranes), especially the maternal dietary intake of amino acids (AAs) [ 5 – 7 ]. Both low and high dietary protein intake can contribute to problems with fetal development and embryonic death due to deficiencies and excesses of AAs, respectively [ 8 , 9 ].…”

“…Previous studies demonstrated that dietary supplementation with Arg to gilts during specific periods of gestation improved the placental expression of antioxidative genes [ 23 ], embryonic and fetal survival rates, as well as conceptus growth [ 5 , 6 , 24 – 26 ]. For example, Mateo et al [ 26 ] reported that supplementation of 0.83% Arg between d 30 and d 114 of gestation increased litter size in gilts by 2.…”

Incidence of dystocia at piglet level in cloprostenol-induced farrowings and associated risk factors

“…Moreover, moderate piglets had the lowest odds of dystocia. Therefore, it is suggested that selection for litters of high homogeneity and nutrition supplementation for increasing litter homogeneity may be approaches to reduce dystocia, which subsequently improves survivability of piglets (Moreira et al, 2019;Yuan et al, 2015) and welfare of the sows.…”