To analyze the effects of some environmental factors such as herd, year, season of calving, stage of lactation on mastitis incidence, a total of 101147 monthly test day somatic cell counts collected from 13977 Iranian Holstein heifers calved between 2002 and 2006 in 183 herds were used. The event of mastitis in cows was coded as 1 if their somatic cell count at specific test day was greater tha...

The National Johne’s Demonstration Herd Project (NJDDHP) in the United States was initiated to evaluate the long-term feasibility and effectiveness of management-related practices designed to control Johne’s disease on dairy and beef cattle operations. The NJDDHP began in 2003 and includes 62 dairy herds and 20 beef herds in 17 states. All herds began with culture-confirmed Mycobacterium avium ...

The buffalo is considered as sluggish breeder as the reproductive efficiency of buffalo is adversely affected by certain constraints such as late maturity, poor expression of the estrous signs particularly during summer, irregular estrous cycle, silent heat, seasonality in breeding, poor conception rate/early embryonic mortality and prolonged inter-calving interval. Buffalo reproduction in trop...

Four hundred and twenty-two beef cattle of two different breeds (purebred Hereford and composite multibreed) were characterized by polymerase chain reaction-restriction fragment length polymorphism, using the restriction enzymes ApaI, AvaII, HindIII, PstI, SpeI, SspI and TaqI in two regions (the D-loop and the ND-5 gene) of mitochondrial DNA. The association between molecular haplotypes and rec...

Sea surface temperature (SST) time-series from the southwest Atlantic and the El Niño 4 region in the western Pacific were compared to an index of annual calving success of the southern right whale (Eubalaena australis) breeding in Argentina. There was a strong relationship between right whale calving output and SST anomalies at South Georgia in the autumn of the previous year and also with mea...

Mortality in dairy cattle is not only relevant with regard to economic losses but also to animal health and welfare. Thus, the aim of this investigation was to explore the genetic background of postnatal mortality in calves and replacement heifers in different age groups until first calving in Danish Holsteins. Records of Danish Holstein heifer calves born in the years 1998 to 2007 were extract...

The decision of when to calve beef females is critical to production efficiency and profitability in a cow and calf enterprise. Calf production and associated costs are affected by calving season because environmental conditions, stage of production, and season of the year interact to affect nutritional status and reproductive performance. Cow and calf producers typically choose to commence cal...

Utilizing pasture-based systems may increase cow comfort during late gestation and calving as it lacks the constraints of confinement housing. The objective of this study was to quantify lying behavior and activity of Holstein dairy cows housed on pasture during the 6 d before calving. Sixteen Holstein dairy cows were moved to pasture 3 weeks before their projected calving date. Data loggers we...

In a 7-year longitudinal study 292 Bovelder beef cows in a restricted breeding system in South Africa were observed from 1 to 2 days before their first breeding season, when reproductive tract scoring (RTS, scored from 1 to 5) was performed, until weaning their 5th calves. The objective was to determine whether pre-breeding RTS in heifers is a valid tool to predict long-term reproductive perfor...

Productive and reproductive traits have great importance in international dairy cattle breeding objectives. Production, reproduction (days open and calving interval) and pedigree data of Iranian Holstein dairy cattles were collected between 2002 and 2012 from 47 herds in Isfahan province. The data set consisted of 30179 records from 18837 registered IranianHolstein dairy cattles. Single trait r...