The effect of feeding two different supplements (perennial ryegrass or plantain baleage) on urinary nitrogen (N) excretion from dairy heifers (8 months old, 180 kg liveweight (LW)) grazing kale was examined in two successive winters. Heifers (n=90 and 80 in Years 1 and 2, respectively) were offered 2.5 kg DM kale/100 kg LW/day and approximately 3 kg DM/heifer/day of either perennial ryegrass or...

Previous research has demonstrated that extended photoperiod accelerates pubescence in dairy heifers thereby limiting time for mammary development, which could be detrimental to future milk yield. We hypothesized that the potential negative effects of rapid growth and puberty through long-day photoperiod (LDPP) exposure could be overcome with a greater supply of metabolizable protein in dairy h...

OBJECTIVE The objective of this study was to compare reproductive performance parameters for two protocols for estrus synchronization in dairy heifers in Germany. MATERIAL AND METHODS In the CIDR group (n=93) all heifers received a controlled intravaginal progesterone releasing insert (Eazi-Breed™ CIDR®; Pfizer Pharma GmbH; containing 1,38g of progesterone) on day 0. On day 7 these cows were ...

T HE reproductive performance and milk production of beef females is closely associated with nutritional status. Swanson and Hinton (1964) found that dairy heifers reared on a subnormal feeding regimen produced less milk than their twins which were fed normally. Blakely (1964) and Wiltbank, Bond and Warwick (1965) have associated anestrus and delay in puberty with a low plane of nutrition. Buch...

In a national survey of US dairy producers, only 2.7 +/- 0.5% of Holstein dairy operations reported achieving recommended target ranges of age < or = 24 months and body weight (BW) > or = 550 kg at first calving. Allowing for wider target ranges, still only 14.6 +/- 1.3% of Holstein dairy operations reported achieving age < or = 25 months and BW > or = 544.3 kg at first calving. Ages of individ...

The primary objective of this study was to improve the productive efficiency of growth via optimal use of both high fiber-low quality and high energy-high protein feeds in diets for growing dairy cattle. Twenty Holstein heifers were randomly assigned to either a control or treatment group. The control diet met the National Research Council (NRC) requirement for .45 kg/d gain, with heifers calvi...

A high incidence (about 70%) of alteration in endometrial epidermal growth factor (EGF) profile, i.e., loss of 2 peaks on days 2-4 and 13-14, has been linked to a reduced fertility in multiparous repeat breeder Holstein cows. However, the EGF profile in Holstein heifers and other breeds (types) of cattle has not been investigated. In study 1, EGF concentrations were determined using endometrial...

In a 120 day feeding trial, 8 cattle heifers (87±5 kg and 6 to 7 months) were randomly divided into two equal groups of four animals each (control and supplemented). During the trial, heifers in both the groups were offered National Research Council (NRC) recommended diet with or without yeast supplementation. The diet was formulated by adapting the small dairy breeds heifers’ nutrients require...

The transplacental transmission is the primary route of Neospora caninum infection in bovine herds around the world. This study aimed to determine the frequency of transplacental transmission of the parasite in dairy cattle of Agreste region of Pernambuco through serological tests (IFAT and ELISA). Three hundred sixteen serum samples from cows and heifers and their offspring were analyzed. The ...

The objective of the present study was to determine whether oestrous detection with the help of oestrous detection aids during the Heatsynch without timed AI protocol is equally effective with the progesterone-combined protocol in dairy heifers. A total of 148 heifers were randomly assigned to one of the two groups. A group of heifers treated with Heatsynch with heat detection aids (n = 72) rec...