JAVMA, Vol 230, No. 6, March 15, 2007 T US dairy industry is moving toward fewer dairy farms with more cattle per farm. Between 1995 and 2005, the number of dairy farms decreased by 43.9% (from 139,670 to 78,295), but the total number of milk cows decreased by only 4.5% (from 9.47 to 9.04 million). Consequently, the average herd size for dairies in the United States has almost doubled during th...

Milk fever and subclinical hypocalcemia are the most important macro-mineral metabolic disorders that affect transition dairy cows. Many studies have shown that cows with subclinical hypocalcemia are also prone to many diseases and disorders. The drain of Calcium (Ca) during early lactation represents a significant increase in Ca demand over that for late fetal growth and physiological maintena...

The aims of this study were to determine the prevalence of Cryptosporidium spp in dairy cows in central Thailand and to investigate the genotype of Cryptosporidium spp in this population. A total of 200 fecal samples from dairy cows were collected and examined by the acid-fast staining technique and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The prevalence of...

BACKGROUND Downer cow syndrome (DCS) is often diagnosed in dairy cattle during the early post-partum period. The etiology of this condition is not completely understood, as it can be related to the energetic or electrolyte metabolism, as well as to infectious diseases or to trauma. HYPOTHESIS/OBJECTIVES The aim of this study is to compare energy metabolism and insulin sensitivity indices and ...

Ketosis is a common metabolic disorder frequently observed in dairy cows during the early lactation period. The objective of this study was to examine the changes in β-hydroxybutyrate (BHBA), glucose, non-esterified fatty acids (NEFA), glutathion peroxidase (GSH-Px), superoxide dismutase (SOD), xanthine oxidase (XOD), malonaldehyde, catalase and total antioxidant capacity (T-AOC) concentrations...

Lactating dairy cows have unique reproductive responses compared to when they were heifers that result in distinctly different reproductive measurements and pregnancy outcomes that can be partially overcome with pharmacological strategies. These parameters include circulating progesterone and estradiol concentrations, ovulatory follicle and corpus luteum diameter, incidence of anovulation and d...

The study was conducted on 20 Holstein X Sahiwal cross bred dairy cows, with an average milk production of 2,752±113.79 liters in 284±5.75 days during a single lactation, that were divided in to two groups of 10 animals. We investigated the oxidative stress and antioxidant status during the transition period in dairy cows. In this study, plasma level of MDA was considered as an indicator of lip...

The objective of this review article was to summarize the most recent clinical field trials that have been published evaluating the use of different types of vaccines against mastitis pathogens in dairy cows. Mastitis is one of the most common and economically important diseases in dairy cows in the world. The disease is considered an important welfare issue facing the dairy industry in additio...

calving records from april 1996 to december 2005 comprising 31863 calving events of 1173 dairy cows in a large commercial dairy herd were used to evaluate the effects of heat stress, using temperature-humidity index (thi) on milk yield and composition and reproductive performance of holstein dairy cows under humid climatic conditions of rasht in iran. thi values were grouped into six groups: 30...

BACKGROUND Tie-stall housing of dairy cows is used extensively worldwide, despite of the welfare concerns regarding the restriction of voluntary movement and limitation of expression of the cows' natural behaviour. The aim of this study was to compare the welfare quality of dairy cows kept in two types of tie-stall housing systems: with regular outdoor exercise and without access to exercise. I...