ABSTRACT The objective of this study was to determine relationship between Lithuanian dairy cow breed productive and reproductive traits. carried out with 586 fully completed lactation cows: 184 Holstein (H), 320 Black White (LBW) 82 Red (LR) cows (291 in I, 149 II 146 III older lactations). Cow productivity reproduction traits were calculated. H I had a lower insemination index compared the LR...

Lethal recessive genes that cause early embryo loss are difficult to detect. Nonreturn rate at 70 d after first insemination (NR) was evaluated as a trait of the embryo using 1,739,055 first-service records from 1,251 Holstein bulls represented as both service sires and sires of cows. Effects modeled included herd-year-season, parity of cow, sire of cow, service bull, interaction of service bul...

The objective was to understand how the amount of shade (shade cloth blocking 99% of solar radiation) influenced the behavior and physiology of Holstein-Friesian dairy cattle managed on pasture. We compared behavior, body temperature, and respiration rate of cattle provided with 1 of 3 treatments for 5 d: access to 2.4m(2) or 9.6m(2) shade/cow, or no shade (n=4 groups/treatment, 10 animals/grou...

CSN1S1is one of the major genes encoding milk proteins of mammals. In this study we determined allele frequencies of CSN1S1-5` flanking region as well as exon 17 variants and their effects on milk traits in three indigenous cattle breeds Mazandarani, Golpaygani (Bos indicus) and Sarabi (Bos taurus) and Holstein cattle in Iran. CSN1S1*B variant was nearly fixed in Holstein but ranged from 0.40 t...

Effects of fetal sire on postpartum reproductive changes of the dam were studied in 21 Holstein heifers whose pregnancy had been initiated by either Angus (n = 7), Holstein (n = 7) or Brahman (n = 7) bulls. After parturition, all heifers were managed uniformly. Heifers in each service-sire-breed group were bled via jugular venipuncture thrice weekly from d 160 to 265 of pregnancy, daily thereaf...

Serotonin is known to regulate energy and calcium homeostasis in several mammalian species. The objective of this study was to determine if pre-partum infusions of 5-hydroxytryptophan (5-HTP), the immediate precursor to serotonin synthesis, could modulate energy homeostasis at the level of the hepatocyte in post-partum Holstein and Jersey dairy cows. Twelve multiparous Holstein cows and twelve ...