Effect of bovine somatotropin on reproductive function in lactating dairy cows.

Several recent experiments have reported that chronic treatment with bovine somatotropin (bST) increased the number of days open without affecting the services per conception. The physiological basis for these effects was examined. Eleven lactating Holstein cows received daily injections of bST (40 mg) and 10 received daily injections of vehicle. Treatment was initiated between 32 and 85 d post partum and continued for up to 180 d. Eight of 11 bST-treated cows experienced at least one period of extended ovarian acyclicity during treatment. Only 3 of 10 control cows did so (P = 0.05). Concentrations of progesterone during luteal phases were lower in bST-treated cows than in controls (P = 0.06). Baseline concentrations of LH were suppressed in bST-treated cows compared with those of controls (P < 0.04). Neither the pulse frequency of LH nor the expression of estrous behavior was affected by bST (P > 0.30). These results indicate that chronic administration of a high dose of bST can reduce reproduction performance by promoting ovarian acyclicity.

Copper status and requirement during the dry period and early lactation in multiparous Holstein cows.

Eighteen multiparous Holstein cows were assigned randomly to three treatments at the beginning of the dry period (8 wk before expected parturition). Treatments were: 1) the basal diet containing 5.5 ppm of Cu (control), 2) the basal diet supplemented with 10 ppm of Cu, and 3) the basal diet supplemented with 20 ppm of Cu. The objectives were to measure the changes of Cu and other trace mineral element concentrations in blood and liver from the onset of the dry period (approximately 8 wk prepartum) to 8 wk postpartum and to assess the requirement of Cu during this time. Liver Cu concentration in the control group declined continuously during the 8-wk dry period, and the nadir occurred at parturition. This decline was prevented by dietary Cu supplementation of 10 or 20 ppm. Liver Cu concentration in the control group started to increase slowly after the dramatic decline. Liver Zn concentration changed cubically as a function of week during the treatment period. Plasma Cu and Zn exhibited a quadratic pattern as a function of week. The plasma Cu concentration was lowest 5 wk prior to parturition.

Effect of copper status on luteinizing hormone secretion in dairy steers.

Two experiments were conducted to examine the effects of Cu status on neuroendocrine regulation of LH secretion in dairy steers. In Experiment 1, 18 Holstein steers were assigned randomly to treatment groups in a completely randomized design. Treatments consisted of basal diet alone (control) or supplemented with 5 ppm of Mo or with 20 ppm of Cu. At 8 and 16 wk, Cu concentrations in liver were higher in the group receiving Cu and lower in the group receiving Mo than in the control. Pulse frequencies of LH were not affected by any treatment. Serum LH concentration at 16 wk tended to be lower in the group receiving Mo than in either the control or the group receiving Cu. The ability of the pituitary gland to release LH in response to GnRH was not affected at 17 wk. Concentrations of LH in the pituitary glands were lower in the group receiving Mo than in that receiving Cu or in the controls. No differences in Cu or Mo concentrations were observed in pituitary, median eminence, or hypothalamic tissues. In Experiment 2, 12 Holstein steers were assigned to treatment groups receiving the basal diet supplemented with either 20 ppm or Cu or with 10 ppm of Mo. Spontaneous and GnRH-induced secretion of LH were not influenced by treatments after 8 mo of experiment. Reduction in Cu status has little effect on the endogenous secretion of LH in dairy steers.

Effects of copper status on neutrophil function, superoxide dismutase, and copper distribution in steers.

Twelve Holstein steers in a completely randomized block design were fed either a basal diet (concentrate:silage or hay at a DM ratio of 35:65) plus Cu sulfate at 20 ppm of Cu (Cu-supplemented diet) or a basal diet plus ammonium molybdate to obtain 10 ppm of Mo (Cu-depleting diet) on a DM basis in the whole diet for 8 mo. Supplemental Mo was utilized in the Cu-depleting diet to develop a Cu-deficient group. Molybdenum slowly accumulated in the liver in the group fed the Cu-depleting diet. Copper concentrations in the liver and polymorphonuclear neutrophils decreased in the Cu-deficient group compared with the Cu-sufficient group. Plasma Cu concentration did not change during the trial for the Cu-sufficient group. In the Cu-deficient group, plasma Cu concentrations increased during the first 3 mo of the trial, then declined, and remained unchanged for the last 5 mo. Superoxide dismutase activities in red blood cells, polymorphonuclear neutrophils, and whole blood decreased in the Cu-deficient group. Phagocytic capacity was not affected by Cu status, but killing capacity was decreased by low Cu status in the Cu-deficient group by the end of the trial. Glutathione peroxidase activity was unaffected by Cu status. Clinical symptoms of Cu-deficiency were not observed in this trial; there was no evidence of blood hemoglobin or BW gain difference between the two groups. In this study, Cu status affected its distribution in the tissues and related enzyme activities as well as bactericidal function of neutrophils.

Effects of copper sources and dietary cation-anion balance on copper availability and acid-base status in dairy calves.

Twenty-four Holstein and Jersey calves (14 Holstein), 4 to 11 d of age, were assigned randomly to six treatments in a 2 x 3 factorial arrangement to examine the effects of Cu sources and dietary cation-anion balance on Cu availability and acid-base balance. Treatments were cationic basal diet (20 meq of dietary cation-anion balance on a DM basis), cationic basal diet supplemented with CuO, cationic basal diet supplemented with CuSO4, anionic basal diet (-10 meq), anionic basal diet supplemented with CuO, and anionic basal diet supplemented with CuSO4. Copper sources did not show any effect on growth of calves. The cationic diet increased calf growth compared with the anionic diet at wk 12 of the experiment. Blood pH was increased by the cationic diet in comparison with the anionic diet at wk 8 and 12. Blood pH also was increased by CuSO4 compared with CuO treatment in the early period of the treatment. Blood bicarbonate concentration was decreased by CuO and the anionic diet. Interactions between Cu sources and cation-anion balance were found for blood pH and bicarbonate concentration. Liver Cu concentration was increased by CuSO4 but not by CuO supplementation compared with control. Therefore, CuSO4 was found to be highly available, whereas CuO was a very poorly available source of Cu for young calves.

Role of magnesium in the dietary cation-anion balance equation for ruminants.

Eight midlactation Holstein cows (four primiparous) were assigned to replicated 4 x 4 Latin squares with a 2 x 2 factorial arrangement of treatments. The basal diet was formulated to contain 0 milliequivalents (Na + K) - Cl/100 g of diet DM. Treatment diets of high and low dietary cation-anion balance were achieved by adding appropriate amounts of supplemental Na + K (added on an equivalent basis) or Mg to the basal diet. Milk and protein yield were increased as well as DMI and FCM for Na + K diets The high concentration of cation increased milk fat percentage. The cation-anion balance (using Mg as a cation) had no effect on any of the production parameters observed. The higher cation-anion balances increased blood bicarbonate levels and plasma Na. Urinary Ca excretion was increased for the Mg diets. Urinary pH increased with both the source of cation (Na + K) and the concentration of cation (high) in the diet. other minerals were unaffected in milk, plasma, or urine. Responses measured in this trial reflect treatments calculated using the equation milliequivalents (Na + K) - Cl/100 g diet DM or (Na + K) - (Cl + S)/100 g diet DM, suggesting that Mg plays a minor role in dietary cation-anion balance.

Role of sulfur and chloride in the dietary cation-anion balance equation for lactating dairy cattle.

Ten Holstein cows averaging 120 d in lactation were arranged in replicated 5 x 5 Latin squares with 3-wk periods to evaluate the role of sulfur (S) in the dietary cation-anion balance equation. Diets were based on corn silage in Exp. 1 and sorghum silage in Exp. 2. Supplemental S and chloride (Cl) from the double sulfate of potassium and magnesium and CaCl2 were used to manipulate dietary cation-anion balance from 0 to +30 meq when expressed as meq [(Na + K)-(Cl + S)]/100 g diet DM and from +19 to +49 meq when expressed as meq [(Na + K)-Cl]/100 g diet DM. Blood pH was not affected by cation-anion balance, although both S and Cl supplementation tended to lower pH. Blood HCO3- and urine pH decreased and plasma calcium (Ca) and urinary Ca excretion increased as anion was added to the diet. Milk fat production tended to be increased by the low S supplementation. Dietary Cl and S had similar effects on acid-base status. Therefore, we suggest that S be included with Cl in the dietary cation-anion balance equation for lactating dairy cows as follows: meq [(Na + K)-(Cl + S)]/100 g diet DM. Although response of acid-base status to S and Cl was similar, as more data comparing the acidogenicity of S vs Cl become available, it may be necessary to include a modifying coefficient for S in the equation to adjust for differences between S and Cl in acid-generating potential. This coefficient may be further dependent on the dietary source of S.

Two siblings with Tel Hashomer camptodactyly and mitral valve prolapse.

A brother and sister with Tel Hashomer camptodactyly and mitral valve prolapse are described. Mitral valve prolapse is heterogenous, but appears to occur more frequently in individuals with connective tissue disorders. The presence of mitral valve prolapse as a component manifestation of Tel Hashomer camptodactyly suggests that abnormal connective tissue is a pleiotropic effect of the mutant allele.

An apparently new syndrome of microcephalic primordial dwarfism and cataracts.

We describe two sibs with prenatal-onset growth deficiency, microcephaly, cataracts, mental retardation, enamel hypoplasia, immune deficiency, and generalized delay of ossification. The combination appears to constitute a previously undescribed autosomal recessive syndrome.

Sibs with the polyasplenia developmental field defect.

We report on two brothers each with absent spleen, multiple cardiac defects, and varying degrees of situs inversus. One brother also had omphalocele; the other also had annular pancreas. These findings are consistent with a diagnosis of polyasplenia, a complex developmental field defect affecting visceral and cardiac situs, with associated spleen and heart defects. We also discuss familial cases from a developmental field perspective.

Report of a case and further delineation of the SHORT syndrome.

We describe a boy with the manifestations of the SHORT syndrome: lipoatrophy, delayed speech development, minor facial anomalies, clinodactyly, and short stature. In addition, this boy had deafness, which was not previously reported in the SHORT syndrome.

Familial occurrence of a developmental defect of the medial nasal processes.

We report on a family in which the propositus and two distant relatives have a wide nose, broad philtrum, and short columella, a fusion defect of the medial nasal processes. This anomaly resembles potato nose [Benjamins and Stibbe, Acta Otolaryngol 11:274-284, 1927] and bifid nose [Anyane-Yeboa et al, Am J Med Genet 17:561-563, 1984], which are also fusion anomalies of the medial nasal processes. Potato nose is an autosomal dominant trait, whereas bifid nose is likely heterogeneous. In this family autosomal recessive inheritance is likely, therefore suggesting that anomalies of the medial nasal processes are causally heterogeneous and represent a developmental field defect.

X-linked syndrome of branchial arch and other defects.

We report on two brothers and their maternal first cousin who have branchial arch defects and other anomalies. Similar physical findings in all three include microcephaly, downslanting palpebral fissures, highly arched palate, apparently lowset, protruding ears, bilateral hearing loss, slightly webbed neck, and mild short stature. In addition, two boys had cryptorchidism, and one had subvalvar pulmonic stenosis and body asymmetry. We suggest that these cousins have an X-linked syndrome of which branchial arch defects are a component. Other pleiotropic manifestations of the mutant gene include microcephaly and cryptorchidism; body asymmetry and relatively short stature may be components as well.

Milking frequency as related to udder health and milk production.

Twenty-four cows each in two trials were paired on age, stage of lactation, and projected milk production to compare the incidence of mastitis with milking two or three times per day over 12 wk. Teats of all cows were dipped daily in a suspension of Streptococcus agalactiae (one of two strains). Average daily milk production for the combined trials was 24.0 kg for the thrice daily group and 22.0 kg for the twice daily group. Quarter foremilk samples were taken every 2 wk for somatic cell counts and bacterial isolations. Somatic cell counts of cows milked twice per day averaged 31 x 10(3) per milliliter compared to 26 x 10(3) for three milkings. There were no significant differences in numbers of new bacterial infections between groups. Cows milked twice per day had 41 new infections and 7 clinical infections and the three-time group had 39 new infections and 2 clinical infections. The many corynebacteria infections were related to the experimental design in which no disinfectant teat dip was used. Three milkings per day did not affect udder health.

Re-evaluation of CHANDS.

A rare ectodermal dysplasia with the acronym CHANDS (Curly Hair, Ankyloblepharon, Nail Dysplasia Syndrome) was described by Baughman (1971) as being a new autosomal dominant condition. Additional pedigree data obtained after the original report indicate that the mode of inheritance is more likely to be autosomal recessive, with an instance of quasi-dominant transmission as a result of multiple consanguineous matings in the family. These data are provided in this report.