Arquivo Brasileiro de Medicina Veterinária e Zootecnia (Aug 2022)
Relationship between main reproductive parameters and productivity traits in dairy cows
Abstract
ABSTRACT The objective of this study was to determine relationship between Lithuanian dairy cow breed productive and reproductive traits. The study was carried out with 586 fully completed lactation cows: 184 Lithuanian Holstein (H), 320 Lithuanian Black and White (LBW) and 82 Lithuanian Red (LR) cows (291 cows in I, 149 in II and 146 in III and older lactations). Cow productivity and reproduction traits were calculated. H cows in I lactation had a lower insemination index compared to the LR, shorter calving interval (P≤0.05) and service period (P≤0.05) than LBW cows. LBW cows produced 1440.46kg more milk (P≤0.05) with less milk fat and protein content (accordingly 0.28 and 0.22 percent) (P≤0.05) compared with the LRd. The service period of LBW older lactation cows was 21.38 days longer and the insemination index was 0.68 times higher compared to the I lactation cows (P<0.05). LR cows of III and older lactations produced 3742kg more milk (P≤0.05) compared with the I lactation. All cows from 131 and more service period days produced 1420kg more milk with 0.51 percent less fat (P≤0.05) and 0.1 percent less protein than cows with the service period from 91 till 110 days (P≤0.05).
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