Studies on genetic trends of production and reproduction traits in Sahiwal and crossbred cattle
| dc.contributor.advisor | Sunil Kumar | |
| dc.contributor.author | Gahtori, Sanjay Dutt | |
| dc.date.accessioned | 2019-03-13T09:59:30Z | |
| dc.date.available | 2019-03-13T09:59:30Z | |
| dc.date.issued | 2019-01 | |
| dc.description.abstract | The present study was undertaken on Sahiwal and crossbred 568 cattle sired by 49 sires, maintained at Instructional Dairy Farm, Nagla of Govind Ballabh Pant University of Agriculture and Technology, Pantnagar (Uttarakhand). The data spread over a period of 30 years (1987-2016). The study was conducted on least squares means, genetic and phenotypic parameters and genetic and phenotypic trends of first lactation production and reproduction traits. The overall least-squares means for first lactation traits viz. FL305DMY, FLMY, FLL, FCI, FDP, FSP FLMY/FLL and FLMY/FCI were 2231±65.27 kg, 2453.39±84.33 kg, 317.33±4.15 days, 1303.80±21.06 days, 457.14±8.76 days, 137.66±6.47 days, 184.30±8.24 days, 7.59±0.21 kg and 5.51±0.19 kg, respectively. The heritability estimates for these first lactation traits were as 0.41±0.13, 0.30±0.11, 0.15±0.09, 0.33±0.12, 0.23±0.10, 0.27±0.11, 0.19±0.10, 0.31±0.11 and 0.38±0.12, respectively. The least-squares analysis of variance for the first lactation traits revealed that the effect due to genetic group was found highly significant on FL305DMY, FLMY, FLL, FLMY/FLL and FLMY/FCI. The effect due to sire was significant on all the first lactation traits. The effect due to the period of calving was also found highly significant (P_0.01) on FLL. The effect due to the season of calving on all the first lactation traits was found non-significant. The effect due to the AFC group was found highly significant (P_0.01) on FL305DMY, FLMY, FLMY/FLL and FLMY/FCI. The positive and significant genetic and phenotypic correlation among production traits viz. FL305DMY, FLMY and FLL revealed that these traits are influenced by the same genes and improvement for one trait simultaneously leads to the improvement in other traits. The negative and non-significant genetic correlation between FLL and FDP indicate that selection on the basis of one trait could be done up to a desirable limit after that selection process can be relaxed. In Sahiwal, the estimates of genetic trends for FL305DMY, FLMY, FLL, AFC, FCI, FDP, FSP, FLMY/FLL and FLMY/FCI were 6.26±8.56 kg, 2.02±9.29 kg, -1.53±0.76 days, -3.24±3.36 days, 1.08±2.00 days, 2.57±1.90 days, 0.16±1.99 days, 0.02±0.02 kg and -0.009±0.02 kg, respectively. The estimates of phenotypic trends for these traits were 7.92±8.46 kg, 4.64±9.05 kg, -1.35±0.71 days, -2.20±2.00 days, -0.22±3.54 days, 1.14±2.03 days, -1.17±2.03 days, 0.04±0.02 kg and 0.01±0.002 kg, respectively. In crossbred, cattle the estimates of genetic trends for FL305DMY, FLMY, FLL, AFC, FCI, FDP, FSP, FLMY/FLL and FLMY/FCI were 67.6±10.30 kg, 67.5±10.30 kg, 2.35±0.85 days, -12.69±2.50 days, 1.09±1.29 days, -1.08±0.83 days, 0.18±1.43 days, 0.22±0.02 kg and 0.15±0.02 kg, respectively. The estimates of phenotypic trends for all these traits were 51.75±5.50 kg, 70.30±8.78 kg, 2.36±0.83 days, -12.81±2.65 days, 1.26±1.29 days, -1.77±0.96 days, 1.03±1.43 days, 0.18±0.02 kg and 0.13±0.02 kg, respectively. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810098345 | |
| dc.keywords | genetic analysis, animal production, reproductive performance, crossbreds, cattle | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 112 | en_US |
| dc.publisher | G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand) | en_US |
| dc.research.problem | Cattle | en_US |
| dc.sub | Animal Genetics and Breeding | en_US |
| dc.subject | null | en_US |
| dc.theme | Crossbreeding | en_US |
| dc.these.type | M.Sc | |
| dc.title | Studies on genetic trends of production and reproduction traits in Sahiwal and crossbred cattle | en_US |
| dc.type | Thesis | en_US |