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Anthrax is an acute zoonotic bacterial infection caused by Bacillus anthracis, a gram-positive, spore-forming bacteria that is thought to survive for as long as decades in the carcasses and burial [...]

Cows are often housed in tie-sheds for some part of the year (from 20 to 80% of adult cows in European countries). By contrast, regulations aiming at improving animal welfare generally provide for more opportunity to express behavior and so limit tethering (the European directive for sows). To inform current debate on whether cows should be tethered from an animal welfare point of view, 2 experiments were conducted to determine whether cows were motivated to walk (if their walking motivation was thwarted by tethering) and whether this frustration resulted in acute or chronic stress. In Exp. 1, fifteen cows were housed in tie-stalls for 1, 3, 9, or 27 d or loose-housed in a pen equipped with free-stalls for 27 d according to a Latin square design. On d 28, cows were observed in an 80-[m.sup.2] arena where they could walk or run for 10 min. In Exp. 2, fifteen cows were either loose-housed or tie-housed with or without 1 h of daily access to an exercise area according to a Latin square design (treatment duration of 27 d). On d 28, cows were observed in the test arena for 10 min as in Exp. 1. In addition, in Exp. 2, milk was sampled twice weekly for cortisol concentrations and cows underwent a chronic stress test (challenge with ACTH, followed by blood samples for cortisol concentrations). When they were tied with no access to exercise, cows displayed a greater locomotor activity in the test arena (time spent walking x 1.4 in Exp. 1, P < 0.05; time spent trotting x 5 in Exp. 2, P < 0.05), whatever the duration of tie-housing. Regular exercise caused locomotor activity in the arena test to revert to levels observed when cows were loose-housed. Basal cortisol concentrations in milk decreased with time whatever the housing condition (P < 0.001). This decrease was more marked when cows were tied than when they were loose-housed (P < 0.05). Cortisol responses to ACTH were similar between treatments. Adult cows are motivated to walk, and tethering thwarts this motivation. However, the frustration produced by tethering does not result in either acute or chronic physiological stress responses. We recommend that cows housed in tie-sheds be given regular access to an exercise area. Key words: behavior, dairy cow, exercise, housing, welfare

It is now widely accepted that abnormal prion proteins are the likely causative agent in bovine spongiform encephalopathy. Cellular prion proteins ([PrP.sup.c]) bind Cu, which appears to be required to maintain functional characteristics of the protein. The replacement of Cu on [PrP.sup.c] with Mn has resulted in loss of function and increased protease resistance. Twelve mature cows were used to determine the effects of Cu deficiency, alone and coupled with high dietary Mn, on brain Cu and Mn concentrations and on [PrP.sup.c] functional characteristics. Copper-adequate cows were randomly assigned to treatments: 1) control (adequate in Cu and Mn), 2) Cu-deficient (-Cu), and 3) Cu-deficient plus high dietary Mn (-Cu+Mn). Cows assigned to treatments -Cu and -Cu+Mn received no supplemental Cu and were supplemented with Mo to further induce Cu deficiency. After 360 d, Cu-deficient cows (-Cu and -Cu+Mn) tended to have lesser concentrations of Cu (P = 0.09) in the obex region of the brain stem. Brain Mn tended (P = 0.09) to be greater in -Cu+Mn cattle compared with -Cu cattle. Western blots revealed that [PrP.sup.c] relative optical densities, proteinase K degradability, elution profiles, molecular weights, and glycoform distributions were not different among treatments. The concentration of [PrP.sup.c], as determined by ELISA, was similar across treatment groups. Brain tissue (obex) Mn superoxide dismutase activity was greatest (P = 0.04) in cattle receiving -Cu+Mn, whereas immunopurified [PrP.sup.c] had similar superoxide dismutase-like activities among treatments. Immunopurified [PrP.sup.c] had similar Cu concentrations across treatments, whereas Mn was undetectable. We concluded that Cu deficiency, coupled with excessive Mn intake, in the bovine may decrease brain Cu and increase brain Mn. Copper deficiency, alone or coupled with high dietary Mn, did not cause detectable alterations in [PrP.sup.c] functional characteristics. Key words: bovine, copper, manganese, prion

The effect of early gestation maternal undernutrition followed by realimentation on placentomal vascular growth and angiogenic factor expression was determined in multiparous beef cows bred to the same bull. Cows gestating only female fetuses (n = 30) were fed in equal numbers to meet the NRC requirements (control) or were fed below the NRC requirements to lose BW (nutrient restricted; NR) from d 30 to 125 of gestation. After slaughter on d 125 of gestation, 10 control and 10 NR cows were necropsied. The remaining NR cows (n = 5) were then fed to achieve a BCS equal to their control group contemporaries (n = 5) by d 220 of gestation. All cows were fed the control diet from d 220 until 250 of gestation, when the remaining control and NR cows were slaughtered and necropsied. At necropsy, placentomes were fixed via perfusion of the caruncular and cotyledonary arteries to determine capillary vascular density. Cotyledonary (fetal placental) and caruncular (maternal placental) tissues also were snap-frozen in liquid nitrogen, and mRNA concentrations of vascular endothelial growth factor and its 2 specific receptors, fms-like tyrosine kinase and kinase insert domain containing receptor, as well as placental growth factor, were determined. There was no effect of diet or day of gestation on the percentage of proliferating caruncular cells. Although diet did not impact cotyledonary cellular proliferation, there was an increase (P < 0.05) in the percentage of proliferating cells on d 250 compared with d 125 of gestation. Nutrient restriction from d 30 to 125 increased (P < 0.10) placental mRNA concentrations of placental growth factor and fms-like tyrosine kinase; however, there was no alteration in vascularity. By d 250 of gestation, NR cows had increased (P < 0.05) caruncular capillary surface density and decreased (P < 0.05) cotyledonary capillary area density, capillary number density, and capillary surface density compared with control cows. Although nutrient restriction had little effect on placental vascularity by d 125, upon realimentation, alterations in vascularity became apparent by d 250 of gestation, suggesting a placental programming effect. Key words: cattle, placental efficiency, pregnancy

We determined whether a fixed-time AI (TAI) protocol could yield pregnancy rates similar to a protocol requiring detection of estrus, or estrous detection plus TAI, and whether adding a controlled internal device release (CIDR) to GnRH-based protocols would enhance fertility. Estrus was synchronized in 2,598 suckled beef cows at 14 locations, and AI was preceded by 1 of 5 treatments: 1) a CIDR for 7 d with 25 mg of PG [F.sub.2[alpha]] (PGF) at CIDR removal, followed by detection of estrus and AI during the 84 h after PGF; cows not detected in estrus by 84 h received 100 [micro]g of GnRH and TAI at 84 h (control; n = 506); 2) GnRH administration, followed in 7 d with PGF, followed in 60 h by a second injection of GnRH and TAI (CO-Synch; n = 548); 3) CO-Synch plus a CIDR during the 7 d between the first injection of GnRH and PGF (CO-Synch + CIDR; n = 539); 4) GnRH administration, followed in 7 d with PGF, followed by detection of estrus and AI during the 84 h after PGF; cows not detected in estrus by 84 h received GnRH and TAI at 84 h (Select Synch & TAI; n = 507); and 5) Select Synch & TAI plus a CIDR during the 7 d between the first injection of GnRH and PGF (Select Synch + CIDR & TAI; n = 498). Blood samples were collected (d -17 and -7, relative to PGF) to determine estrous cycle status. For the control, Select Synch & TAI, and Select Synch + CIDR & TAI treatments, a minimum of twice daily observations for estrus began on d 0 and continued for at least 72 h. Inseminations were performed using the AM/PM rule. Pregnancy was diagnosed by transrectal ultrasonography. Percentage of cows cycling at the initiation of treatments was 66%. Pregnancy rates (proportion of cows pregnant to AI of all cows synchronized during the synchronization period) among locations across treatments ranged from 37% to 67%. Pregnancy rates were greater (P < 0.05) for the Select Synch + CIDR & TAI (58%), CO-Synch + CIDR (54%), Select Synch & TAI (53%), or control (53%) treatments than the CO-Synch (44%) treatment. Among the 3 protocols in which estrus was detected, conception rates (proportion of cows that became pregnant to AI of those exhibiting estrus during the synchronization period) were greater (P < 0.05) for Select Synch & TAI (70%; 217 of 309) and Select Synch + CIDR & TAI (67%; 230 of 345) cows than for control cows (61%; 197 of 325). We conclude that the CO-Synch + CIDR protocol yielded similar pregnancy rates to estrous detection protocols and is a reliable TAI protocol that eliminates detection of estrus when inseminating beef cows. Key words: beef cow, synchronization, timed artificial insemination

We hypothesized that feed resources could be deferred to a later time in the production cycle without a decrease in fertility or weight of calf produced in heifers and young cows. One-hundred and thirty-one MARC III (four breed composite: 1/4 Hereford, 1/4 Angus, 1/4 Red Poll, and 1/4 Pinzgauer) heifers were divided into three treatments: M-M-M-M (n = 46), L-H-M-M (n = 41), and L-L-L-H (n = 44). The experiment consisted of four feeding periods. Period 1 was 94 to 186 d of gestation, and heifers were fed a moderate (M) or low (L) level of feed. Period 2 was 187 d of gestation to parturition, and heifers were fed moderate, high (H), or low levels of feed. Period 3 was from parturition through 27 d of lactation, and heifers were fed moderate or low levels of feed. Period 4 was from 28 d to approximately 63 d of lactation, and heifers were fed moderate or high levels of feed. Females remained within treatments through their first parity (heifers) and second parity (cows). Feed intake of L-H-M-M and M-M-M-M treatments did not differ from each other either as heifers (P = 0.23) or as second-parity cows (P > 0.59). The L-L-L-H heifers ate less feed than L-H-M-M and M-MM-M heifers (P < 0.001), and second-parity L-L-L-H cows ate less feed than second-parity L-H-M-M and M-M-M-M cows (P < 0.002). In the first parity, treatments did not differ in the percentage of calves weaned (P = 0.11), weight of calf weaned (P = 0.50), or percentage of cows diagnosed pregnant (P = 0.29) with a second calf. In the second parity, treatments did not differ in the percentage of calves weaned (P = 0.77), weight of calf weaned (P = 0.63), or percentage of cows expressing a corpus luteum at the start of breeding for their third calf (P = 0.21). Our findings suggest that timing nutrient availability to heifers and primiparous cows can be used to change the time that feed resources are used. Key Words: Cows, Lactation, Nutrition, Pregnancy

The effects of two kinds of Escherichia coli strains, wild-type E. coli W3110 or E. coli nir-Ptac, which has enhanced nitrite reduction activity, on in vitro [CH.sub.4] production and nitrate and nitrite reduction in cultures of mixed ruminal microorganisms was investigated using continuous incubation systems. Escherichia coli nir-Ptac, a derivative of wild-type E. coil W3110, was constructed by replacing self promoter of nir BD operon encoding subunits of nitrite reductase in E. coli W3110 by tac promoter to make the expression of nit BD higher and constitutive. The nitrite reductase activity of E. coli nir-Ptac was approximately twice as high as E. coli W3110. The culture media consisted of 400 mL of strained ruminal fluid taken from two nonlactating Holstein cows receiving a basal diet of orchardgrass hay at maintenance level (55 g of DM/kg of [BW.sup.0.75] daily), and 400 mL of autoclaved artificial saliva. Treatments were arranged in two separate 3 x 3 factorials consisting of nitrate (NaN[O.sub.3]; 0, 5, or 10 mM) without E. coli or inoculated with E. coil W3110 or E. coli nir-Ptac, or nitrite (NaN[O.sub.2]; 0, 1 or 2 mM) without E. coli or inoculated with E. coli W3110 or E. coli nir-Ptac. The control culture contained no chemical or microbial additives. Escherichia coli cells were inoculated into in vitro mixed ruminal cultures at approximately 2 x [10.sup.8] to [10.sup.9] cells/mL. Methane production by ruminal microorganisms was decreased markedly (P < 0.001) by the addition of nitrate and nitrite, and by the inoculation of cultures with E. coli W3110 or E. coli nir-Ptac (P < 0.01). With mixed nitrite-containing cultures, E. coli nir-Ptac inhibited (P < 0.001) in vitro nitrite accumulation and CH4 production more than E. coli W3110, which may be due to the tac promoter-enhanced nitrite reductase activity of E. coli nir-Ptac accelerating electrons to be consumed for nitrite reduction rather than CH4 biosynthesis. In conclusion, anaerobic cultures of E. coli W3110 or E. coli nir-Ptac may decrease CH4 production in the rumen. The inoculation of E. coli W3110 or, especially, E. coli nir-Ptac to mixed ruminal microorganisms may decrease nitrite toxicity when ruminants consume high-nitrate-containing forages and when nitrite is applied to abate ruminal CH4 production. Key Words: Escherichia coli nir-Ptac, Escherichia coli W3110, Methane, Nitrate, Nitrite

Teat scores from 9,598 first-parity Gelbvieh cows were used to investigate the adequacy of grouping approaches to decrease score misclassifications or inconsistencies as well as to simplify the data collection process. The procedure was tested using simulated data and then validated using teat score records of Gelbvieh cattle. First-parity cows were considered to be 4 yr of age or younger at first calving, did not have multiple records within 280 d, and were at least 50% Gelbvieh. Producers scored cows within 24 h of parturition. Teat score, a subjective measure of teat size, ranged from 0 (very large) to 50 (very small). A linear mixed model that included herd-year, month of calving, and age at calving as systematic effects; regression on the percentage of Gelbvieh; and additive breeding values (BV) and residual as random effects was used to generate the data. Simulated data were analyzed using one of three scoring methods: all values (S50), 10 classes (S10), and five classes (S5). The 10 classes were formed by subdividing every five scores into a single class starting at score zero. Similarly, the five classes were formed by combining every 10 scores into one class. The average Pearson correlations, based on five replicates, between the true and estimated BV (systematic effects) were 0.36 (0.85), 0.35 (0.89), and 0.32 (0.87) using S50, S10, and S5, respectively. Average correlations between estimated BV (systematic effects) were 0.97 (0.95), 0.89 (0.92), and 0.92 (0.97) based on S50 and S10, S50 and S5, and S10 and S5, respectively. Field data were used to validate the simulation procedure. The field data were categorized into 10 classes (Fl0) and five classes (F5) as described for the simulated data. Pearson correlations between estimated BV (systematic effects) were 0.99 (0.93), 0.93 (0.88), and 0.93 (0.96), based on F50 with F10, F50 with F5, and F10 with F5, respectively. The extremely high correlations between predicted BV based on S50, S10, S5, F50, F10, with F5 suggest that a simplified score classification method could be adopted without compromising the expected genetic progress for the trait under consideration. Furthermore, the difference in corresponding Pearson correlations across the field and simulated data might suggest the presence of some inconsistencies or misclassifications of the actual scoring system. Key Words: Beef Cattle, Data Simulation, Teat Score

Two experiments involving Brangus and Hereford x Brangus cows (3 to 10 yr) were conducted at four locations in western Texas to determine the effects of supplemental feeding interval on serum urea nitrogen (SUN) patterns, intake of supplement and forage, and winter changes in live body weight and condition score. Treatments were control (Control; no supplemental feed) and the equivalent of .91 kg/d of cottonseed meal (CSM) fed daily (Daily), three times per week (3T/WK), or one time per week (WK). At each location, one pasture group was given all four treatments (four cows/treatment) using Calan gates. In Exp. 1, conducted in 1994-95, blood samples were obtained for determining SUN during the last week of the study. Experiment 2, conducted in 1995-96, included both an individually fed herd and four additional herds at each location that were group-fed the four treatments. Experiment 2 included estimates of intakes of both CSM and forage in both individually fed and group-fed herds. A bolus containing chromium (Cr-bolus) was used to estimate fecal output in the individually fed cows. A double marker technique was used to determine total (Cr-bolus) and CSM (Yb) intakes in the group-fed cows. Data included initial and final cow weights and condition scores (Exp. 1 and 2), SUN patterns (Exp. 1), and supplement, forage, and total intakes (Exp. 2). Feeding CSM to range cows increased SUN concentrations (Exp. 1), reduced losses in live body weight and body condition score (Exp. 1 and 2), and tended to decrease forage intake by the approximate amount of the supplement (Exp. 2). Generally, providing supplement as infrequently as once per week reduced losses in live body weight and body condition score compared with control and was as effective as once daily supplementation. For the group-fed cows, supplement intake, forage intake, and live body weight change were more variable within groups with once daily feeding than when supplement was fed less frequently. These data indicate that feeding as infrequently as one time per week can be effective nutrition management for adult cows grazing native range. Key Words: Supplements, Feeding Frequency

Effects of body condition score (BCS) at parturition and postpartum weight gain on luteal activity and concentrations of glucose, insulin, and NEFA in plasma were evaluated during the breeding season in 242 primiparous beef cows over 3 yr (Y) at three locations (L). At approximately 90 d prepartum, cows were blocked by breed, expected calving date, and BCS and randomly assigned to diets so that cows would calve in BCS of 4, 5, or 6. At calving, cows were blocked by breed, calving date, and BCS and randomly allotted to gain .45 (M) or .90 (H) kg/d, from parturition to the start of breeding (postpartum nutrition; PPN). During the 60-d breeding season, weekly blood samples were obtained from cows, and progesterone, insulin, glucose, and NEFA were quantified. Progesterone concentrations greater than 1 ng/mL for more than i wk indicated luteal activity. To determine the possible value of blood constituents as predictors of luteal activity, categorical data analyses were performed. Cows with greater BCS at parturition had greater concentrations of glucose during breeding (P < .07). Similarly, PPN influenced glucose at the beginning of breeding, but the differences were minimal after d 28 (PPN x day; P < .001). Cows with greater BCS at parturition and M-PPN had greater concentrations of insulin during the breeding season (BCS x PPN; P < .02). Cows with a BCS of 6 at parturition had the lowest concentrations of NEFA; however, cows on H-PPN had greater concentrations of NEFA (BCS x PPN; P < .03). Location, BCS, PPN, and day affected luteal activity (P < .002). Location differences in luteal activity were associated with the interval from calving to the start of breeding. In general, a greater percentage of cows with BCS of 5 or 6 at calving had luteal activity by the end of the breeding season. Concentrations of metabolites in blood during breeding were not predictive of luteal activity. We conclude that BCS at parturition and postpartum nutrition influence concentrations of glucose, insulin, and NEFA in blood and the onset of luteal activity in primiparous beef cows. Key Words: Nutrition, Body Composition, Reproduction, Glucose, Insulin, Cows

Two grazing trials were conducted to determine the ruminally degradable protein requirement of gestating beef cows in the last half of pregnancy grazing winter native Sandhills range. In Trial 1, 80 crossbred cows (522 [+ or -] 9 kg) were assigned randomly to one of the following ruminally degradable protein (RDP) treatments: 50%, 75%, 100%, or 125% of the estimated supplemental requirement. In Trial 2, 80 crossbred cows (529 [+ or -] 8 kg) were assigned to 29%, 65%, 100%, or 139% of the estimated supplemental RDP requirement. In Trial 1, daily gain and condition score (CS) were not different (P > .15) among treatments. In Trial 2, gain responded quadratically, being higher (P = .14) for the 65% level than for the 29%, 100%, and 139% levels (.18, .05, .06, and .01 kg/d, respectively). Condition score was maintained at 65% and lost at 29%, 100%, and 139% (cubic effect, P = .06; 0, -.2, -.4, -.3, respectively). In both experiments, forage intake did not differ among treatments although OM digestibility increased linearly (P = .08) in Trial 1 with increasing level of RDP but not in Trial 2. Diet samples were collected in both experiments to estimate total nutrient intake. Forage RDP intake was 322 g/d in Trial 1 and 279 g/d in Trial 2. We conclude that gestating beef cows grazing native winter Sandhills range need between 62 and 140 g/d of supplemental RDP to meet their daily requirement of 340 to 430 g/d or 7.1% of the digestible OM. Key Words: Gestation Period, Beef Cows, Ruminally Degradable Protein

Four cows were fed once a day either a Cocksfoot hay diet (H) or a diet consisting of 65% hay and 35% pelleted ground barley (HB). 15[([NH.sub.4]).sub.2]S[O.sub.4] was continuously infused into the rumen as a microbial marker and ruminal digesta samples were collected during the 24-h postprandial period for the isolation of liquid-associated protozoa and bacteria (LAP, LAB) and particle-associated bacteria (PAB). There were marked differences between ruminal pH diurnal variations with diets H and HB. Irrespective of the diet and sampling time, the chemical composition (OM, N, DAPA, 15N) of the protozoa was clearly different from that of the bacteria (P [is less than] .001). The LAP contained more OM but less N and 15N than the bacterial fractions. The DAPA used to validate the isolation technique for the mixed ciliate population was not detected in protozoal fractions. The OM content of LAB was lower than that of PAB, whereas the N, DAPA, and 15N contents were higher. The observed effects of diet (P [is less than] .01) on LAP mean N contents were due to the different N contents of the LAP samples isolated 23 h after feeding and were correlated with the variation in the number of Endodiniomorphid protozoa (r = .72; P [is less than] .05). The N content of LAB was not affected (P [is greater than] .05) by diet but that of the PAB was increased on diet HB (P [is less than] .05). The diet did not affect the 15N content of any of the three microbial populations. However, the 15N content of the bacteria decreased shortly after feeding (P [is less than] .001).

Four nonlactating Holstein cows (593 kg) with ruminal cannulas were fed bromegrass hay that was fertilized with 0 or 89 kg of N/ha and harvested in the late-boot or full-head stage of maturity. Total tract apparent digestibility of N was less for full-head than for late-boot bromegrass (48 vs 64%; P < .01) and was greater for N-fertilized than for unfertilized bromegrass (60 vs 52%, P < .01). True N digestibility was greater (P < .01) by cows fed late-boot hay than by those fed full-head bromegrass (85 vs 81%). Maturity did not affect N retention. Nitrogen fertilization increased N retained, both grams per day (70 vs 20; P < .01) and as a percentage of N intake (P < .01). Nitrogen and amino acid disappearance kinetics were determined in situ. Rate constants for N disappearance within rapidly and slowly degraded pools were not different among treatments, but because late-boot had a larger proportion of N in the rapidly degraded pool, overall disappearance rate for N was faster (P < .05) for late-boot than for full-head bromegrass (12.0 vs 7.1 %/h). Treatment effects observed for individual amino acids were similar to those found for N. Both composition and kinetic data were needed to explain differences in N digestion and balance. Distribution of N within the forage had profound effects on the N economy of the cows. Key Words: Forage, Protein, Amino Acids, Ruminants, Maturity, Fertilizers, The effects of nitrogen fertilization and maturity of bromegrass on nitrogen and amino acid utilization by cows was studied by feeding four nonlactating Holstein cows with bromegrass. The hay was fertilized with 89 kilograms of nitrogen per hectare and harvested in full-head stage of maturity. Results show that fertilization and maturity of bromegrass significantly affected nitrogen utilization.

Bovine Spongiform Encephalopathy, popularly referred to as 'mad cow disease', is a disastrous result -- certainly for cattle, and possibly also for humans -- of the failure to deploy safe farming practices. The measures required to eliminate BSE altogether may need to be draconian. This is particularly deplorable, as the disease has in effect been self-inflicted by unsafe farming methods. The British government's response to the BSE epidemic has been characterized by political expediency and unwarranted platitudes, rather than concern for public health.

Byline: Saim Ozdemir, Mustafa S. Dundar, Bulent Sengorur, Ataman S. Senol This study was conducted to investigate the influence of vehicle emissions on zinc and lead content of cow's milk, grazing at 15 different locations near to roadsides in Sakarya, Turkey. The results obtained for zinc were between 1262 μg kg−1 and 6566 μg kg−1. An acceptable range of zinc content from various sides confirmed the absence of possible toxicological risks in this region. The lead levels ranged from 3.24 μg kg−1 to 80.69 μg kg−1. The levels of lead in milk samples collected from roadside pastures were higher than the regulatory limits and pose a health risk.

Two rare, inherited forms of ichthyosis are reported in cattle and both are characterized by autosomal recessive transmission. The mutations of transglutaminase 1 (TGM1) gene were investigated as a candidate for the diseases in cattle as they are associated with autosomal recessive ichthyosis in people.

Byline: Tomaz Zadnik The monitoring has been performed on lead content in the blood of cows (n = 1,279) from farms (n = 114) near a former lead mine and current smelting plant from 1975 to 2003. Early measurements showed that average lead concentration in the blood of cows was 1.25 [+ or -] 0.58 mg/kg while in 2002 it was about 10-times to 20-times lower (0.069 [+ or -] 0.005 mg/kg). Significant decrease in blood lead concentration is attributed to the sanitation of the major source of industrial emission of lead gases and dust by installation of bag filters to the plant chimneys in 1978.

The toxic perfluorooctane sulphonate (PFOS) present in the fire-fighting foam kills the cattle feeding on it. The hazards of widely used PFOS in plastic, paints and other industries to humans and other animal lives are discussed.

A study on the relationship between the Belgian Blue cow and its calf delivered by a Caesarean section is presented. The effect of the Caesarean section on the reproductive health of the cows is discussed.

The impact of various nursing strategies on the behavior and health of high yielding dairy cows and their calves is discussed.

A study comparing the behavior of cows on a grooved floor with that of cows on a slatted floor is presented. The health condition of the claws of the cows and efficacy of the two kinds of floor were examined.

Heritability of 2-yr-old heifer calving difficulty score was estimated in nine purebred and three composite populations with a total of 5,986 calving difficulty scores from 520 sires and 388 maternal grandsires. Estimates were 0.43 for direct (calf) genetic effects and 0.23 for maternal (heifer) genetic effects. The correlation between direct and maternal effects was -0.26. Direct effects were strongly positively correlated with birth weight and moderately correlated with 200-d weight and postweaning gain. Smaller negative correlations of maternal calving difficulty with direct effects of birth weight, weaning weight, and postweaning gain were estimated. Calving difficulty was scored from I to 7. Predicted heritabilities using seven optimal scores were similar to those using four scores. The predicted heritability using only two categories was reduced 23%. Phenotypic and direct genetic variance increased with increasing average population calving difficulty score. The estimated direct and maternal heritabilities for 2-yr-old calving difficulty score were larger than many literature estimates. These estimates suggested substantial variance for direct and maternal genetic effects. The direct effects of 2-yr-old calving difficulty score seemed to be much more closely tied to birth weight than were maternal effects. Key Words: Dystocia, Birth Weight, Weaning Weight, Heritability, Genetic Correlation

To the Editor: Belgium was declared free of bovine brucellosis by the European Union in 2003 (http:// eur-lex.europa.eu/LexUriServ/ LexUriServ.do?uri=OJ:L:2003:156 :0074:0078:EN:PDF). To maintain this status, the Federal Agency for the Safety [...]