Survey of quality defects in market beef and dairy cows and bulls sold through livestock auction markets in the Western United States: I. Incidence rates

A survey was conducted to quantify incidence of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls selling at auction during 2 seasons in 2008. Twenty-three BQA-related traits were evaluated by 9 trained personnel during sales at 10 livestock auction markets in Idaho (n = 5; beef and dairy), California, (n = 4; dairy only), and Utah (n = 1; beef and dairy). Overall, 18,949 unique lots (8,213 beef cows, 1,036 beef bulls, 9,177 dairy cows, and 523 dairy bulls,) consisting of 23,479 animals (9,299 beef cows, 1,091 beef bulls, 12,429 dairy cows, and 660 dairy bulls) were evaluated during 125 sales (64 spring, 61 fall) for dairy and 79 sales (40 spring, 39 fall) for beef. The majority of market beef cows and bulls (60.9 and 71.3%, respectively) were predominantly black-hided, and the Holstein hide pattern was observed in 95.4 and 93.6% of market dairy cows and bulls, respectively. Market cattle weighed 548 ± 103.6 kg (beef cows), 751 ± 176.1 kg (beef bulls), 658 ± 129.7 kg (dairy cows), and 731 ± 150.8 kg (dairy bulls). Most beef cows (79.6%) weighed 455 to 726 kg, and most beef bulls (73.8%) weighed 545 to 954 kg, respectively. Among market beef cattle, 16.0% of cows and 14.5% of bulls weighed less than 455 and 545 kg, respectively, and 63.7% of dairy cows and 81.5% of dairy bulls weighed 545 to 817 kg or 545 to 954 kg, respectively. However, 19.5% of dairy cows and 13.1% of dairy bulls weighed less than 545 kg. Mean BCS for beef cattle (9-point scale) was 4.7 ± 1.2 (cows) and 5.3 ± 0.9 (bulls), and for dairy cattle (5-point scale) was 2.6 ± 0.8 (cows) and 2.9 ± 0.6 (bulls). Some 16.5% of beef cows and 4.1% of beef bulls had a BCS of 1 to 3, whereas 34.8% of dairy cows and 10.4% of dairy bulls had a BCS of 2 or less. Emaciation (beef BCS = 1, dairy BCS = 1.0) or near-emaciation (beef BCS = 2, dairy BCS = 1.5) was observed in 13.3% of dairy cows and 3.9% of beef cows. Among beef cattle, 15.1% of cows and 15.4% of bulls were considered lame. In contrast, 44.7% of dairy cows and 26.1% of dairy bulls were lame. Ocular neoplasia (cancer eye) was observed in only 0.6% of beef cows, 0.3% of beef bulls, 0.3% of dairy cows, and 0.0% of dairy bulls. However, among animals with ocular neoplasia, it was cancerous in 34.4% of beef bulls, 48.0% of dairy cows, and 73.3% of beef cows. In conclusion, numerous quality defects are present in market beef and dairy cattle selling at auction in the Western United States, which could influence their value at auction.     

Initiation of postpartum luteal function in primiparous restricted-suckled beef cows exposed to a bull or excretory products of bulls or cows

The objective of this study was to evaluate the influence of bull excretory products on the resumption of postpartum luteal function in primiparous, restricted-suckled cows. Hypotheses tested were that resumption of luteal function or proportions of cows that initiate luteal cycling did not differ among cows exposed to a bull (BE), exposed to excretory products of bulls (EPB), not exposed to a bull (NE), or exposed to excretory products of cows (EPC). Two-year-old Angus x Hereford cows were assigned 35 d after calving to one of the four treatments (n = 15, 16, 16, and 15 for BE, EPB, NE, and EPC, respectively). Cows in the EPB and EPC treatments were placed in enclosures for 10 to 12 h, between 1830 and 0800 daily. Each enclosure was occupied by bulls (EPB) or left empty (EPC) for 10 to 12 h (0800 to 1830) daily. All cows were restricted to suckling twice daily (0800 and 1800) beginning on d 0. Blood samples were obtained from each cow on d -1 and every third day of the study thereafter. An increase in progesterone concentrations in three consecutive samples that exceeded 1.0 ng/mL was used as evidence of resumption of luteal function. Interval from d 0 to resumption of luteal activity was less for (P < 0.05) BE and EPB cows than for NE cows, but did not differ between BE and EPB cows. Interval for EPC cows did not differ from that for NE cows; however, interval for EPC cows was greater (P = 0.06) than that for BE cows and was longer (P < 0.05) than that of EPB cows. Proportions of cows that resumed luteal function by d 40 and 50 did not differ between NE and EPC cows; however, proportions of EPB and BE cows that resumed luteal function were greater (P < 0.05) than those for NE and EPC cows by d 40 and 50. Proportions of cows that resumed luteal function by d 70 were greater (P < 0.05) for BE, EPB, and EPC cows than for NE cows; however, proportions of BE and EPC cows did not differ. The proportion of EPB cows that resumed luteal function was greater (P = 0.058) than that of EPC cows, but the proportion of BE cows that resumed luteal function did not differ from that of EPC cows by d 70. We conclude that exposing primiparous restricted-suckled cows to excretory products of bulls or crowding estrus-cycling cows in an enclosure hastened postpartum resumption of luteal function. Therefore, the biostimulatory role of bulls and the crowding effect of cows seem to be mediated by a pheromone (or pheremones) present in their excretory products.     

Genetic variation and covariation in beef cow and bull fertility

Single-sire natural mating data from a beef cattle herd in tropical Australia were used to estimate heritabilities of cow fertility (hc2), heritabilities of bull fertility (hb2) and genetic correlations between cow and bull fertility (rg) within each of six genotypes. Estimates of hc2 and hb2 were low, averaging .11 and .08, respectively. The pooled estimate of rg was 0.16, indicating that cow and bull fertility are favorably genetically correlated and therefore that cow fertility could be genetically improved by indirect selection on bull fertility, or some more heritable component of bull fertility.     

Quality defects in market beef and dairy cows and bulls sold through livestock auction markets in the Western United States: II. Relative effects on selling price

Relative effects of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls on selling price at auction was evaluated during 2008. The presence and severity of 23 BQA-related traits were determined during sales in Idaho, California, and Utah. Overall, 18,949 unique lots consisting of 23,479 animals were assessed during 125 dairy sales and 79 beef sales. Mean sale price ± SD (per 45.5 kg) for market beef cows, beef bulls, dairy cows, and dairy bulls was $45.15 ± 9.42, $56.30 ± 9.21, $42.23 ± 12.26, and $55.10 ± 9.07, respectively. When combined, all recorded traits explained 36% of the variation in selling price in beef cows, 35% in beef bulls, 61% in dairy cows, and 56% in dairy bulls. Premiums and discounts were determined in comparison with a "par" or "base" animal. Compared with a base BCS 5 beef cow (on a 9-point beef scale), BCS 1 to 4 cows were discounted (P < 0.0001), whereas premiums (P < 0.05) were estimated for BCS 6 to 8. Compared with a base BCS 3.0 dairy cow (on a 5-point dairy scale), more body condition resulted in a premium (P ≤ 0.001), whereas a less-than-desirable BCS of 2.0 or 2.5 was discounted (P < 0.0001). Emaciated or near-emaciated cows (beef BCS 1 or 2; dairy BCS 1.0 or 1.5) were discounted (P < 0.0001). Compared with base cows weighing 545 to 635 kg, lighter BW beef cows were discounted (P < 0.0001), whereas heavier beef cows received (P < 0.05) a premium. Compared with a base dairy cow weighing 636 to 727 kg, lighter BW cows were discounted (P < 0.0001), whereas heavier cows (727 to 909 kg) received a premium (P < 0.01). Beef and dairy cows with any evidence of lameness were discounted (P < 0.0001). Presence of ocular neoplasia in the precancerous stage discounted (P = 0.05) beef cows and discounted (P < 0.01) dairy cows, whereas at the cancerous stage, it discounted (P < 0.0001) all cows. Hide color influenced (P < 0.0001) selling price in beef cattle but had no effect (P = 0.17) in dairy cows. Animals that were visibly sick were discounted (P < 0.0001). Results suggest that improving BCS and BW, which producers can do at the farm or ranch level, positively affects sale price. Furthermore, animals that are visibly sick or have a defect associated with a possible antibiotic risk will be discounted. Ultimately, animals with minor quality defects should be sold in a timely manner before the defect advances and the discount increases.     

Detection of residues of foreign substances in the tissues of cows and bulls and in bull sperm]

The presence of residues of some chemical foreign substances in the tissues of cow and bull genitals and in sire sperm was investigated due to frequently occurring reproductive disorders in some large cow herds, mainly with the large-scale rearing system. Negative effects of these substances on the reproductive process of cows and bulls were supposed to be exerted. In keeping with the opinions and data mentioned by some authors in the literature there is a fact that the sperm and tissues of genitals belong to those biological materials which are the first to respond to the toxic effects of different chemicals by disorders of their physiological functions. These disorders, mainly in sperm cells, can be evaluated objectively from the recorded changes in physical and biological characteristics. The chemicals under investigation were residues of hexachlorobenzene (HCB), alpha, beta, gamma hexachlorocyclohexane isomers, sigma DDT and its metabolites and of polychlorinated biphenyls (PCB). The concentrations of the residues of these substances in the examined biological materials were very low, in some cases they were not detected at all. It is therefore supposed that these residues could not exert and significant effects on the physiological functions of examined cows and bulls with respect to their reproductive organs. These examinations should become more extensive and thorough, mainly in the herds and regions exposed to potential contamination; the residues of foreign substances should be investigated in view of ecological conditions. These postulates are very urgent, as illustrated by the literature data: in some cases negative effects of certain foreign substances (PCB) were found out and demonstrated on the reproductive functions of people and farm animals.(ABSTRACT TRUNCATED AT 250 WORDS)     

The use of beef bull semen reduced the risk of abortion in Neospora-seropositive dairy cows

There is an evidence that the epidemiology of neosporosis differs in dairy and beef cattle, such that beef cattle carry a lower risk of abortion. The aim of the present study was to establish whether artificial insemination using semen from beef bulls could reduce the risk of abortion in dairy cows seropositive for the Neospora caninum parasite. Our study was based on yearly serological screening for neosporosis and on the confirmation of Neospora infection in aborted fetuses in two high-producing dairy herds with a mean 28% seroprevalence of N. caninum antibodies. The study population comprised of 273 pregnancies in seropositive animals: 156 pregnancies monitored after insemination using Holstein-Friesian semen and 117 after insemination using beef bull semen. Abortion rates for these animals were 28.2% (77 of 273), 34.6% (54 of 156) and 19.7% (23 of 117). Logistic regression analysis indicated no significant effects of lactation number and previous abortion on the abortion rate. Based on the odds ratio, a 1-unit increase in the Neospora antibody titre yielded a 1.01-fold increase in the abortion rate. The likelihood of abortion was two times higher for cows in one of the two herds and 2.8 times lower (one of 0.36) for pregnant cows inseminated with beef bull semen rather than Holstein-Friesian semen. Our results indicate that the use of beef bull semen can reduce the risk of abortion in dairy cows, and suggest that annual screening for neosporosis, specifically the antibody titre to the protozoan, could be an useful predictor of abortion risk in reproductive health programmes.     

Influence of exposure to bulls on resumption of estrous cycles following parturition in beef cows

The effect of bull exposure on the resumption of estrous activity following parturition was studied in an experiment using mature Hereford and Hereford X Angus beef cows. In the spring of 1981 and 1982, cows were assigned by breed and calving date to one of two treatment groups. Cows were exposed to bulls either from 3 to 85 d postpartum (BE; n = 45, 1981; n = 35, 1982) or from 53 to 85 d postpartum (NE; n = 39, 1981, n = 36, 1982). Blood samples were collected from all cows once weekly from calving until 85 d postpartum to determine progesterone concentrations. The first increase in progesterone, which indicated onset of estrous cycles occurred at 43 +/- 2 vs 63 +/- 2 d (P less than .01) in 1981 and at 39 +/- 2 vs 61 +/- 3 d (P less than .01) postpartum in 1982 in BE cows and NE cows, respectively. Early postpartum exposure of cows to bulls reduced the postpartum anestrous interval.     

Abattoir survey of dental defects in cull cows.

The teeth in the severed heads of 501 cull cows, all over 30 months of age, were examined at an abattoir in the north of England in 1997/98; 80 per cent of them were Friesians or Holsteins. Seventy-three animals (14.6 per cent) had one or more missing incisors, most of which were acquired losses. Rotation and overlapping of rostral teeth were also common, as was attrition. Congenitally absent first lower premolars, other missing teeth, large and often multiple interdental spaces, and a few cases of macrodontia, cavitation, multiple defects and fractures were observed in the cheek tooth arcades. There were some unusual patterns of premolar and molar attrition, often attributable to malocclusion, one result of which was the formation of a hook at the posterior extremity of the third maxillary molar.     

Maxillary osteosarcoma in a beef suckler cow

ABSTRACT: A ten-year-old beef suckler cow was referred to the Scottish Centre for Production Animal Health & Food Safety of the University of Glasgow, because of facial swelling in the region of the right maxilla. The facial swelling was first noticed three months earlier and was caused by a slow growing oral mass which contained displaced, loosely embedded teeth. The radiographic, laboratory and clinicopathological findings are described. Necropsy, gross pathology and histological findings confirmed the mass as a maxillary osteosarcoma.     

Putative urinary pheromone of bulls involved with breeding performance of primiparous beef cows in a progestin-based estrous synchronization protocol

The objective of this study was to determine if factors associated with the biostimulatory effect of bulls alter breeding performance of primiparous, suckled beef cows using a progestin-based estrous synchronization protocol. We tested the hypotheses that the estrous synchronization response and AI pregnancy rates differ among cows exposed to bulls, continuously exposed to bull urine, and exposed to fence-line contact with bulls or cows not exposed to bulls or bull urine. Data were collected from 3 experiments performed over consecutive years. Cows were assigned to the following treatments: bull exposure (BE; n = 26) or no bull exposure (NB; n = 25) in Exp. 1, bull urine exposure (BUE; n = 19) or steer urine exposure (SUE; n = 19) in Exp. 2, and fence-line contact with bulls (BFL; n = 26) or no bull exposure (NB; n = 26) in Exp. 3. Synchronization protocols in each experiment included the use of a controlled internal drug release device (d -10), PGF(2alpha) (d -3), and GnRH and fixed-time AI (TAI; d 0). Cows that were observed in estrus by 60 h after PGF(2alpha) were inseminated 12 h later. Cows not observed in estrus by 60 h after PGF(2alpha) were TAI at 72 h and given GnRH (100 mug). Pregnancy was determined by ultrasonography 35 d after TAI. In Exp. 1, 2, and 3, cows were exposed directly to bulls, bull urine, or bull fence-line contact for 35, 64, and 42 d, respectively. Data were analyzed between treatments within each experiment. The proportion of estrous cycling cows did not differ between treatments at the beginning of each experiment; however, more (P < 0.05) BE and BFL cows were estrous cycling at the beginning of the estrous synchronization protocol than NB cows in Exp. 1 and 3. The proportion of cows that showed estrus and interval to estrus after PGF(2alpha) did not differ between treatments in Exp. 1 and 3. However, in Exp. 2, more BUE cows tended (P = 0.09) to have shorter intervals to estrus and to exhibit estrus after PGF(2alpha) than SUE cows. Overall, AI pregnancy rates were greater (P < 0.05) for BE and BUE cows than for NB and SUE cows in Exp. 1 and 2, respectively. There was no difference in AI pregnancy rates between BFL and NB cows in Exp. 3. The presence of bulls and exposure to bull urine appeared to improve breeding performance of primiparous beef cows using a progestin-based estrous synchronization protocol, whereas fence-line bull exposure was insufficient to cause this biostimulatory effect. We propose that a novel urinary pheromone of bulls may be responsible for the enhancement of fertility in the primiparous, postpartum cow.     

A survey of the selenium status of beef cows in Alberta.

An epidemiological survey was conducted in Alberta to measure the selenium status in blood of beef cows during the fall and to determine the risk of selenium deficiency among specific geographic regions of Alberta. Three census divisions of Alberta based on the Statistics Canada Census of Agriculture were chosen as the study areas for the project. Soils and plants in area A (Edmonton area) and area B (Calgary area) were known to be deficient in selenium, while soils and plants in area C (southeast corner of Alberta) were known to have adequate levels of selenium. Blood samples were collected from 335 cows on 29 farms from the 3 study areas. These samples were collected from cows that had recently been removed from pasture in October and November 1992. Answers to a short questionnaire pertaining to various herd characteristics and management practices were also obtained for each herd. The average value of selenium for all cows sampled was 2.20 mumol/L. The average value of selenium of cows in areas A and B was 1.93 mumol/L. The average value of selenium of cows in area C was significantly (P < 0.05) higher at 2.70 mumol/L. Nine percent of the cows in the study were considered marginal or deficient in selenium (< 1.27 mumol/L selenium). Herds located in area C, herds that were provided with supplemental feed on pasture, and herds that were pregnancy checked had higher average herd selenium values than did other herds. Cow-calf producers located in areas with selenium-deficient soils should pay particular attention to selenium supplementation for their cows. Some of the negative "geographic" effects on selenium values can be overcome by more progressive management practices.     

Salmonellosis in a herd of beef cows

Two postparturient beef cows in a herd of 30 developed acute enteritis, with pyrexia and bloody diarrhea containing intestinal casts. Salmonella typhimurium phage type 66 was isolated from feces of both animals; both recovered after treatment with tetracycline. A third cow had died without treatment after showing similar signs.     

Introduction of bulls at different days postpartum on resumption of ovarian cycling activity in primiparous beef cows

The objective of this study was to evaluate postpartum resumption of ovulatory cycles among primiparous, suckled beef cows that were exposed continuously to mature bulls beginning at various intervals after calving. We sought to determine whether cumulative distributions of proportions of cows resuming ovarian cycles and interval from the start of bull exposure to resumption of ovarian cycling activity differed among cows exposed continuously (BE) or not exposed (NE) to bulls beginning on d 15, 35, or 55 after calving. Angus x Hereford cows (n = 56) were assigned randomly to one of six treatments in a 2 (exposure type) x 3 (day exposed postpartum) factorial arrangement. Blood samples were collected from each cow starting on d -1, and every third day until the end of experiment. An increase in baseline progesterone concentrations that exceeded 1.0 ng/mL in three consecutive samples was used as evidence of resumption of ovarian cycling activity. More (P < 0.05) BE cows resumed cycling activity by the end of the experiment than NE cows. Proportions of cows resuming cycling activity did not differ (P = 0.30) among cows exposed to bulls on d 15, 35, or 55 postpartum. Proportions of BE cows that were exposed to bulls on d 15, 35, or 55 were greater for each 10-d interval (P < 0.05) than those for NE cows during the first 40 d after exposure. More (P < 0.05) BE cows exposed to bulls on d 55 resumed cycling activity by 30 d after exposure than BE cows exposed to bulls on either d 15 or 35. Interval from calving to resumption of cycling activity was decreased (P < 0.05) by the presence of bulls. Day of exposure did not affect (P = 0.21) interval from calving to resumption of cycling activity; however, interval from day of bull exposure to resumption of cycling activity decreased (P < 0.05) linearly as day of exposure to bulls after calving increased. We conclude that exposing primiparous beef cows to bulls decreased the postpartum anovulatory interval and increased the proportion of cows that exhibit resumption of ovarian cycling activity, independent of day of bull exposure. Furthermore, cows exposed to bulls at progressively later intervals postpartum seemed to respond more rapidly to the biostimulatory effect of bulls than when they were exposed earlier in the postpartum anestrous period.     

Postpartum interval to estrus and patterns of LH and progesterone in first-calf suckled beef cows exposed to mature bulls

Two trials were conducted in which Angus x Hereford first-calf cows were assigned randomly at calving to one of two treatments: exposure to mature penile-blocked bulls (BE) or isolation from bulls (NE). In Trial 1 (BE, n = 38; NE, n = 37), cow to bull ratio increased from 12:1 to 19:1 over a 14-d period; in Trial 2 (BE, n = 25; NE, n = 24), this ratio was maintained at 13:1. In both trials, blood samples were collected weekly for progesterone and ovaries and uteri of cows were examined rectally. Cows were observed for estrus twice daily (am:pm) beginning 10 d after calving. In Trial 2, intensive blood sampling for LH began 10 d after calving (eight cows per treatment) and continued at weekly intervals until estrus or the end of the trial. Postpartum weight change, condition score change and time to uterine involution did not differ (P greater than .10) between treatments in either trial. Interval to estrus was shorter (P less than .05) for BE cows than for NE cows in both trials. A greater proportion (P less than .05) of BE cows exhibited estrus by 60 and 90 d after calving and showed an increase in progesterone before first estrus. Mean and baseline LH concentrations and amplitude, frequency and duration of LH pulses were not altered (P greater than .10) by bull exposure. In conclusion, exposing first-calf suckled beef cows to bulls after calving hastened resumption of estrous cycles. Bull exposure did not alter patterns of LH concentrations but did increase proportions of cows that showed increased progesterone before first estrus.     

Causes of copulatory failure in beef bulls

A cow in full standing estrus is required to assess a bull's ability to copulate. Insufficient libido is not involved if the bull sniffs the cow's vulva and attempts to mount. Blood or pus exiting the penis or prepuce indicates penile or preputial lacerations or other lesions. Rear foot or stifle lesions, seminal vesiculitis, traumatic reticulitis or lumbar spinal injuries may prevent the bull from mounting. Preputial stenosis, penile adhesions, desensitization, hematomas or deviations, peripreputial abscess, cavernosal shunts, insufficient penile length and occlusions of the cavernosal canals may prevent intromission after mounting.     

不同蛋白能量水平日粮对肉牛生产性能和肉品质的影响

采用单因素随机区组设计,选择体重相近的健康肉牛40头,随机分成4组,分别饲喂低(Ⅰ)、中(Ⅱ)、较高(Ⅲ)和高(Ⅳ)能量蛋白水平日粮,研究不同能量蛋白水平对肉牛生长性能、屠宰性能、肉品质和血液指标的影响。结果表明:随着日粮能量蛋白水平的增加,试验牛的日增重不断提高,由959 g/d提高到1 181 g/d,提高21.88%(P0.05);各试验组屠宰率和净肉率差异显著(P0.05),Ⅳ组最高,分别为60.84%和49.21%;背膘厚度试验各组差异显著(P0.05),Ⅲ组最高,达到106.5 mm;各组间肉的剪切力无显著差异(P0.05);各试验组牛肉中饱和脂肪酸和单不饱和脂肪酸含量无显著差异(P0.05),但多不饱和脂肪酸存在显著差异(P0.05),其中Ⅲ组多不饱和脂肪酸含量最高,为6.7%,Ⅰ组最低为5.31%,相对提高26.18%(P0.05);每日每头经济效益最高达6.91元,最低为3.14元,相对多收入3.77元。因此,本试验条件下,在BMY育肥过程中,200~350 kg体重阶段以Ⅲ组能量和蛋白质水平较为适宜,经济效益最高。     

Growth patterns of cows sired by British and Continental beef and American dairy bulls and out of Hereford dams

Growth patterns from birth to maturity were compared for 92 straightbred Herefords (H) and 299 Hereford crossbred (XB) cows. Crossbred cows were out of Hereford dams and were sired by bulls of two British [Angus (A) and Shorthorn (Sh)], two Continental [Charolais (C) and Simmental (S)] and two American dairy breeds [Brown Swiss (B) and Holstein (F)]. British XB and H cows differed only slightly in weight but both weighed less than Continental and dairy XB cows. Body condition also differed significantly among breed types; dairy XB were thinnest. Among XB individuals SH calves were heaviest (34 kg) and AH calves were lightest (30 kg) at birth. Birth weights of Continental XB were 2.6 kg more than those of British XB and 1.7 kg more than those of dairy XB. At weaning, all XB calves were heavier than straightbred H calves, but differences among XB types were not significant. However, on the average, Continental XB and dairy XB calves were heavier (28 kg) than British XB at 19 mo. At 32 mo, Continental and dairy XB weighed 41 and 23 kg more, respectively, than British XB. Although differences between the British XB and the Continental and dairy XB at some ages were not significant, no case existed where the latter two groups weighed less than British XB. Adjusting weight to a common condition score reduced phenotypic variance at all ages and changed the ranking of some breed types for weight, primarily by increasing predicted weights of dairy XB. Differences in growth curves were reflected by differences in mature weight and maturing rate. Asymptotic weights of Continental XB were highest, followed by those of dairy XB. British XB and H weighed least at maturity (average of 509 kg). The CH cows matured more slowly but grew to a heavier mature weight (592 kg) than SH cows (552 kg). Generally animals reached 95% of their mature weight between 68 and 80 mo of age.     

Grass tetany in a herd of beef cows

Five cows in a herd of 15 cattle that had just been turned out onto lush pasture after having over-wintered on poor quality hay died suddenly. Biochemical profiles collected from the cadavers revealed reduced serum levels of magnesium, urea, and beta-hydroxybutycate. Classical grass tetany (hypomagnesemia) was diagnosed on postmortem examination.