TY - JOUR
T1 - Zinc supplementation improves growth performance in small ruminants
T2 - A systematic review and meta-regression analysis
AU - Angeles-Hernandez, J. C.
AU - Miranda, M.
AU - Munoz-Benitez, A. L.
AU - Vieyra-Alberto, R.
AU - Morales-Aguilar, N.
AU - Paz, E. A.
AU - Gonzalez-Ronquillo, M.
N1 - Funding Information:
We thank Mr Rodriguez-Maya, MA, for his support in the looking for research studies. Dr Angeles-Hernandez is grateful to the Mexican Ministry of Education (Secretaría de Educación Pública) for the funding of this research Project under grant UAEH-PTC-823.
Funding Information:
This project was supported by the Universidad Autonoma del Estado de Mexico. UAE 4974/2020. Funders did not have any input into study design or interpretation of the results. Results were interpreted and summarised by researcher at the Universidad Autonoma del Estado de Hidalgo, Universidad Autonoma del Estado de Mexico, Mexico and Universidad de Santiago de Compostela, Spain, and UWA Institute of Agriculture, The University of Western Australia.
Publisher Copyright:
© 2021 CSIRO.
PY - 2021/4
Y1 - 2021/4
N2 - Appropriate supplementation of trace minerals is fundamental to enhance the metabolic status of growing animals and promote an adequate expression of genetic potential. Zinc (Zn) is an essential mineral fundamental in many biological processes that are related to growth, energy balance and immunity. The aim of the present study was to analyse the effect of Zn supplementation on growth parameters in small ruminants by using a meta-analytic approach. Sources of heterogeneity were explored using a meta-regression analysis. The final database was integrated from a total of 53 trials. Only indexed articles that provided an effect size measure, variability measure, sample size and randomisation of the procedure were considered. The dependent variables considered for the study were average daily gain (ADG), dry-matter intake (DMI), feed conversion ratio (FCR), final bodyweight, and glucose blood concentration. The exploratory variables included species (sheep and goat), breed, production level, Zn source and dosage. The 'meta' package in R statistical software was used to conduct the meta-analyses. For response variables that showed substantial heterogeneity (I2 > 50%), mixed-effect models (meta-regression analysis) were constructed to explore the sources of heterogeneity using the 'Metafor' package. DMI was higher in animals supplemented with Zn (>21.08 g/day, P = 0.0001). Breed, species, production level, and dosage reduced heterogeneity of DMI response from I2 = 84.8 to I2 = 48.1%. Zn-supplemented animals showed higher ADG (17.39 g/day, P = 0.001), which was affected by species, breed dosage and Zn-source. Zn supplementation improved feed efficiency, with lower values of FCR (-1.56 g/g, P < 0.0001). There was a positive relationship between the dosage and effect size in all outcome variables (P < 0.05). Zn-proteinate showed the best response in both species to ADG, FCR and final body weight. Our findings of the systematic review concluded that dietary Zn supplementation improves growth performance in small ruminants and their level of response is influenced mainly by species, production level, and Zn-source and dosage.
AB - Appropriate supplementation of trace minerals is fundamental to enhance the metabolic status of growing animals and promote an adequate expression of genetic potential. Zinc (Zn) is an essential mineral fundamental in many biological processes that are related to growth, energy balance and immunity. The aim of the present study was to analyse the effect of Zn supplementation on growth parameters in small ruminants by using a meta-analytic approach. Sources of heterogeneity were explored using a meta-regression analysis. The final database was integrated from a total of 53 trials. Only indexed articles that provided an effect size measure, variability measure, sample size and randomisation of the procedure were considered. The dependent variables considered for the study were average daily gain (ADG), dry-matter intake (DMI), feed conversion ratio (FCR), final bodyweight, and glucose blood concentration. The exploratory variables included species (sheep and goat), breed, production level, Zn source and dosage. The 'meta' package in R statistical software was used to conduct the meta-analyses. For response variables that showed substantial heterogeneity (I2 > 50%), mixed-effect models (meta-regression analysis) were constructed to explore the sources of heterogeneity using the 'Metafor' package. DMI was higher in animals supplemented with Zn (>21.08 g/day, P = 0.0001). Breed, species, production level, and dosage reduced heterogeneity of DMI response from I2 = 84.8 to I2 = 48.1%. Zn-supplemented animals showed higher ADG (17.39 g/day, P = 0.001), which was affected by species, breed dosage and Zn-source. Zn supplementation improved feed efficiency, with lower values of FCR (-1.56 g/g, P < 0.0001). There was a positive relationship between the dosage and effect size in all outcome variables (P < 0.05). Zn-proteinate showed the best response in both species to ADG, FCR and final body weight. Our findings of the systematic review concluded that dietary Zn supplementation improves growth performance in small ruminants and their level of response is influenced mainly by species, production level, and Zn-source and dosage.
KW - goats
KW - sheep
KW - zinc
UR - http://www.scopus.com/inward/record.url?scp=85104542100&partnerID=8YFLogxK
U2 - 10.1071/AN20628
DO - 10.1071/AN20628
M3 - Review article
AN - SCOPUS:85104542100
SN - 1836-0939
VL - 61
SP - 621
EP - 629
JO - Animal Production Science
JF - Animal Production Science
IS - 7
ER -