Age at first calving (AFC) affects the profitability of dairy enterprises. This study examined the relationships between AFC and subsequent fertility, milk production and survival up to third calving in UK Holstein-Friesian heifers; Study 1 comprised 134 consecutively born heifers from the same herd (AFC 764 ± 8 days) and Study 2 contained 445 heifers born on 17 farms (AFC 796 ± 6 days). Growth...

Data from the first four cycles of the Germplasm Evaluation program at the U.S. Meat Animal Research Center were used to evaluate weights of Angus, Hereford, and F1 cows produced by crosses of 22 sire and 2 dam (Angus and Hereford) breeds. Four weights per year were available for cows from 2 through 8 yr of age (AY) with age in months (AM). Weights (n = 61,798) were analyzed with REML using cov...

The main reason for calving replacement heifers early is economics. Economic assessments (2) have demonstrated that heifer rearing cost increases $50.00 to $60.00 each month calving is delayed. In addition, older calving ages result in the need for more heifers for herd replacement. These classic concepts are presented in Table 1. Conceptually, as calving age is reduced there is a linear reduct...

the objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in holstein dairy cows of iran. the dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from july 2002 to september 2007 comprising 97 herds in iran. breeding values of anim...

The present study aimed to examine the productive and reproductive performance of Indigenous buffaloes in Mymensingh district Bangladesh. Buffalo husbandry plays a crucial role livelihoods numerous farmers across various upazilas Mymensingh. A total 100 indigenous were selected for study, representing four upazilas: Trishal, Haluaghat, Muktagachha, Sadar upazilla district. findings this reveale...

Poor cow fertility has been identified as a growing problem in Irish dairy herds. In this seasonal calving and the grass based production system, poor fertility results in a significant loss in farm income (Veerkamp et al., 2001) due to forced culling or a shift in calving pattern. In order to arrest this trend, subsequent calving interval (CIV) and survival to the next lactation (SUV) has been...

Twinning costs the dairy industry an estimated $96 million each year. Twin pregnancy occurrence in high-producing cows is primarily a result of multiple ovulations associated with low circulating concentrations progesterone due to high milk production. The present retrospective observational study aimed identify associations between (1) previous parity yield and subsequent twin birth prevalence...

Reproductive competence is one of the most important components in the overall management of a cow-calf operation. The ability to maintain a 365-day calving interval in a high percentage of the females influences the profitability of all breeding operations. In most cases, low reproductive efficiency can be directly linked to the nutritional status of the animal(s). Research has shown that poor...

This study was conducted to investigate the scenario of buffalo production and reproduction under different farming systems at Subarno Char, in the coastal area of Bangladesh. A total of 14 farms were randomly selected and studied for various traits live weight (LW); daily milk yield (DMY); lactation length (LL); lactation production (LP); calving interval (CI); gestation length (GL); post part...