Meta-analysis of genetic parameters for economic traits in buffaloes

A comprehensive meta-analysis of genetic parameters for resilience and productivity indicator traits in Holstein cattle

Selection for resilience indicator (RIND) traits in Holstein cattle is becoming an important breeding objective as the worldwide population is expected to be exposed to increased environmental stressors due to both climate change and changing industry standards. However, genetic correlations between RIND and productivity indicator (PIND) traits, which are already being selected for and have the most economic value, are often unfavorable. As a result, it is necessary to fully understand these genetic relationships when incorporating novel traits into selection indices, so that informed decisions can be made to fully optimize selection for both groups of traits. In the past 2 decades, there have been many estimates of RIND traits published in the literature, albeit in small populations. To provide valuable pooled summary estimates, a random-effects meta-analysis was conducted for heritability and genetic correlation estimates for PIND and RIND traits in worldwide Holstein cattle. In total, 926 heritability estimates for 9 PIND and 27 RIND traits, along with 362 estimates of genetic correlation (PIND × RIND traits) were collected. Resilience indicator traits were grouped into the following subgroups: Metabolic Diseases, Hoof Health, Udder Health, Fertility, Heat Tolerance, Longevity, and Other. Pooled estimates of heritability for PIND traits ranged from 0.201 ± 0.05 (energy-corrected milk) to 0.377 ± 0.06 (protein content), while pooled estimates of heritability for RIND traits ranged from 0.032 ± 0.02 (incidence of lameness, incidence of milk fever) to 0.497 ± 0.05 (measures of body weight). Pooled estimates of genetic correlations ranged from -0.360 ± 0.25 (protein content vs. milk acetone concentration) to 0.535 ± 0.72 (measures of fat-to-protein ratio vs. milk acetone concentration). Additionally, out of 243 potential genetic correlations between PIND and RIND traits that could have been reported, only 40 had enough published estimates to implement the meta-analysis model. Our results confirmed that the interactions between PIND and RIND traits are complex, and all relationships should be evaluated when incorporating novel traits into selection indices. This study provides a valuable reference for breeders looking to incorporate RIND traits for Holstein cattle into selection indices.

Inheritance of body size and ultrasound carcass traits in yearling Anatolian buffalo calves

The body size and ultrasound carcass traits are related to the growth and muscling of animals. These characters promise future improvement through genetic selection in animal breeding. In breeding programs, knowing the (co)variance components serves to reveal the performance differences among animals and detection of suitable traits for selection. The research was carried out with 313 Anatolian buffalo calves born in 2019 at 36 farm operations. The least-square means for body weight (BW), wither height (WH), rump height (RH), body length (BL), chest width (CW), hip width (HW), chest circumference (CC), cannon-bone circumference (CBC), longissimus muscle area (LMA), longissimus muscle depth (LMD), and subcutaneous fat thickness (SFT) in yearling calves were 175.41 ±  2.06 kg, 108.35 ±  0.34, 111.85 ±  0.37, 103.74 ±  0.41, 33.93 ±  0.23, 30.56 ±   0.23, 135.18 ±  0.60, 15.69 ±  0.08 cm, 19.36 ±  0.45 cm2 , 3.086 ±  0.028, and 0.655 ±  0.006 cm, respectively. The direct heritabilities for BW, WH, RH, BL, CW, HW, CC, CBC, LMA, LMD, and SFT were 0.334 ±  0.032, 0.483 ±  0.044, 0.473 ±  0.043, 0.441 ±  0.041, 0.364 ±  0.034, 0.432 ±  0.040, 0.435 ±  0.040, 0.226 ±  0.021, 0.0001 ±  0.000, 0.300 ±  0.026, and 0.539 ±  0.046, respectively. The genetic and phenotypic correlations predicted in this study ranged from 0.02 to 0.90. All the genetic and phenotypic correlations among body size and ultrasound carcass traits were significant (P < 0.01 ), except for the genetic correlation between CW and HW. Some polymorphisms in PLAG1, NCAPG, LCORL, and HMGA2 genes were analyzed. Two single-nucleotide polymorphisms (SNPs) for PLAG1 and NCAPG genes were found to be monomorphic in this buffalo population. Meanwhile, the effects of two SNPs in the LCORL and HMGA2 genes were not significant but showed some tendencies in the aspects of least-square means. The results of the study indicated that the Anatolian buffaloes have the potential to improve in growth and muscling characteristics.