Progesterone assays and rectal palpation in pre-service management of a dairy herd.

Fifty-one dairy cows were examined three times at weekly intervals during weeks 5 to 7 after calving. Rectal palpation of the ovaries and plasma progesterone assay were used to determine cyclic ovarian function. Eight of 51 cows exhibited true anoestrus by day 49 after calving. Only 23 of 43 cycling cows were served by day 77, the end of the target period for first service. In 77 per cent of 142 examinations, rectal palpation and progesterone assay gave compatible results. Most incompatibility occurred early or late inthe cycle, or in association with cystic structures in the ovaries. Eleven of the 51 cows had cysts in the ovaries but cyclicity and fertility were not adversely affected.     

Effect of colostrum intake on plasma glucose, non-esterified fatty acid and glucoregulatory hormone patterns in the neonatal pig

The effect of colostrum on endocrine and metabolic factors affecting glucose homeostasis was evaluated in 60 neonatal pigs that were fasted, fed (nursed ad libitum) or limit-fed colostrum (25% ad libitum, 4-hr interval feeding). Plasma acquired at birth (t0), and after 10, 20 and 30 hr (t10, t20 and t30, respectively) was analyzed for glucose, non-esterified fatty acids (NEFA), and the glucoregulatory hormones--insulin, glucagon, cortisol, growth hormone and catecholamines. The concentration of glucose and NEFA was similar among treatment groups at birth and increased in proportion to the quantity of colostrum consumed. Pigs fed ad libitum achieved and maintained a higher (greater than or equal to 40%; P less than .01) glucose concentration when compared to fasted neonates. Limit-fed counterparts also achieved and maintained higher levels, with glucose concentration being approximately 20% higher throughout (P less than .05). Fed pigs maintained NEFA concentrations which were approximately 2.5-fold to 4-fold greater than that of fasted pigs (P less than .05). Likewise, limit-fed pigs tended (P = .19) to have elevated NEFA concentrations and a lower (P less than .05) insulin:glucagon molar ratio. An inverse relationship was observed between colostrum intake and plasma concentrations of cortisol and growth hormone. Concentrations of epinephrine and norepinephrine tended (P greater than .10) to be elevated in fed pigs, relative to those of fasted counterparts. Provision of even limited quantities of colostrum is therefore beneficial to the glucoregulatory response in newborn pigs.     

Restoring the Sagebrush Component in Crested Wheatgrass–Dominated Communities

Monotypic stands of crested wheatgrass (Agropyron cristatum [L] Gaertm. and Agropyron desertorum [Fisch.] Schult.), an introduced grass, occupy vast expanses of the sagebrush steppe. Efforts to improve habitat for sagebrush-associated wildlife by establishing a diverse community of native vegetation in crested wheatgrass stands have largely failed. Instead of concentrating on a diversity of species, we evaluated the potential to restore the foundation species, Wyoming big sagebrush (Artemisia tridentata spp. wyomingensis [Beetle & A. Young] S. L. Welsh), to these communities. We investigated the establishment of Wyoming big sagebrush into six crested wheatgrass stands (sites) by broadcast seeding and planting seedling sagebrush across varying levels of crested wheatgrass control with glyphosate. Planted sagebrush seedlings survived at high rates (～ 70% planted sagebrush survival 3 yr postplanting), even without crested wheatgrass control. However, most attempts to establish sagebrush by broadcast seeding failed. Only at high levels of crested wheatgrass control did a few sagebrush plants establish from broadcasted seed. Sagebrush density and cover were greater with planting seedlings than broadcast seeding. Sagebrush cover, height, and canopy area were greater at higher levels of crested wheatgrass control. High levels of crested wheatgrass control also created an opportunity for exotic annuals to increase. Crested wheatgrass rapidly recovered after glyphosate control treatments, which suggests multiple treatments may be needed to effectively control crested wheatgrass. Our results suggest that planting sagebrush seedlings can structurally diversify monotypic crested wheatgrass stands to provide habitat for sagebrush-associated wildlife. Though this is not the full diversity of native functional groups representative of the sagebrush steppe, it is a substantial improvement over other efforts that have largely failed to alter these plant communities. We also hypothesize that planting sagebrush seedlings in patches or strips may provide a relatively inexpensive method to facilitate sagebrush recovery across vast landscapes where sagebrush has been lost.     

Ultrasonographic study of early embryonic loss induced by Actinomyces pyogenes in cattle.

Four cows were inoculated into the uterus with Actinomyces pyogenes between 30 and 41 days of gestation. Gross morphological changes were monitored by rectal palpation and with a realtime B-mode two-dimensional scanner with a 7.5 MHz transrectal linear transducer, shortly before infection and afterwards at three to 12 hours intervals. Two control groups of cows 27 to 50 days pregnant were used: two cows were inoculated with 6 ml of sterile saline into the uterine lumen and four cows were treated with cloprostenol (prostaglandin F2 alpha analogue). There was a change in the uterine fluid from a black, non-echogenic image before infection to a grey or cloudy echogenic image as early as 21 hours after infection. There was an increase in the thickness of the endometrium of the horns and body of the uterus. The embryonic membranes thickened and separated from the endometrium as early as four hours after infection, followed by cessation of the embryonic heart beat, opening of the cervix and abortion. Abortion was followed by an increase in the amount of echogenic intrauterine fluid leading to an increase in the size of the uterus, and the cervix remained open for at least eight days. The area of the corpus luteum remained greater than 2 cm2 throughout the whole period. Intrauterine inoculation with sterile saline had no effects, but the administration of cloprostenol was followed by the death of the embryo and abortion within 72 hours, and the regression of the corpus luteum from greater than 2 cm2 at treatment to 0.4 cm2, 24 hours after abortion.(ABSTRACT TRUNCATED AT 250 WORDS)     

A novel phenotype for Laron dwarfism in miniature Bos indicus cattle suggests that the expression of growth hormone receptor 1A in liver is required for normal growth

Mutations within the growth hormone receptor (GHR) gene that lead to an inactivated or truncated GHR protein cause abnormal growth and small adult size in a variety of species (Laron dwarfism). We studied a line of miniature Bos indicus cattle that have phenotypic (small mature size) and endocrine (increased blood growth hormone and decreased blood insulin-like growth factor-I concentrations) similarities to Laron dwarfs. Liver mRNA from miniature and control cattle was used to amplify a cDNA within the coding region of the GHR. The miniature cattle had GHR mRNA size (determined by Northern blot) and cDNA sequence that were similar to control cattle and, therefore, were unlike most Laron dwarf genotypes in which the GHR gene is mutated. Amounts of mRNA from liver as well as muscle (superficial neck and longissimus) were analyzed by ribonuclease protection assay for IGF-I, total GHR, GHR 1A (inducible, liver-specific GHR mRNA), and GHR 1B (constitutive GHR mRNA). Four control and five miniature bulls were tested. As expected, liver IGF-I mRNA was decreased in the miniature cattle (approximately 12% of control; P < 0.01). The amount of the total GHR as well as GHR 1A mRNA were also decreased in liver (17% and 19% of control, respectively; P < 0.01). Other GHR mRNA, including GHR 1B mRNA, were similar for miniature and control cattle. In muscle, there was a tendency (P < 0.10) for decreased IGF-I mRNA and increased GHR mRNA in miniature compared with control cattle. In summary, a novel phenotype for Laron dwarfism in Bos indicus cattle was associated with underexpression of GHR 1A mRNA, but not other GHR mRNA variants in liver. In addition to decreased GHR 1A mRNA, the miniature cattle had decreased liver IGF-I mRNA. Full expression of GHR 1A in liver, therefore, may be required for full liver IGF-I expression and normal growth.     

Effect of colostrum intake on hepatic gluconeogenesis and fatty acid oxidation in the neonatal pig

A total of 24 newborn pigs were used to determine 1) the relationship between the quantity of colostrum consumed and the capacity for gluconeogenesis and fatty acid oxidation and 2) whether fatty acid oxidation limits gluconeogenesis in isolated hepatocytes. Neonatal pigs were obtained prior to nursing and allotted to one of three treatment groups; fed (ad libitum), limit-fed (25% of fed group), or fasted. Hepatocytes were isolated when pigs were 24 h old. Colostrum intake altered the metabolic status of neonates such that the capacity for glucose synthesis and oxidation of octanoate increased with intake. Glucose synthesis with lactate as the substrate was greater (P less than .01) for fed pigs (10.79 mumol glucose.h-1.mg DNA-1) than for either limit-fed (6.56) or fasted counterparts (4.78), which were similar (P greater than .10). Colostrum intake failed to stimulate synthesis from alanine. The oxidation rate for octanoate was similar for fed and limit-fed pigs (.62 and .61 nmol CO2.h-1.mg DNA-1, respectively) but greater (P less than .05) than that observed for fasted counterparts (.36). Oxidation of octanoate (2 mM) was approximately 30-fold greater than for oleate (1 mM); oxidation of the latter was not affected by either colostrum intake or the addition of carnitine (1 mM). The increase in octanoate oxidation, however, did not elicit an increase in glucose synthesis by fasting pigs with either lactate or alanine as precursors. Thus, we conclude that gluconeogenesis is a function of colostrum intake and that reducing equivalents and(or) ATP may not be primary factors limiting glucose synthesis in pigs fasted from birth.     

Formation of a secondary corpus luteum after ultrasound-guided follicular aspiration in cows

This paper reports the observed formation of a secondary corpus luteum (CL) in the presence of the cyclic corpus luteum, on the ovaries of a cow after ultrasound-guided follicular aspiration for oocyte recovery. The secondary structure, although smaller and lighter (4.97 g vs. 6.02 g) than the natural one, had the typical macroscopic appearance of a corpus luteum. Histological examination of the structure using electron microscopy revealed typical structural features of a natural CL. Mean tissue progesterone concentration was significantly lower in the secondary CL (31.15 +/- 3.11 compared with 58.29 +/- 6.32 micrograms/g tissue of the cyclic CL) and oestradiol-17 beta significantly higher than in the natural CL (108 +/- 11.6 compared with 74.2 +/- 7.81 pg/g tissue). P450scc and P450(17 alpha) mRNA was detected in both structures while P450arom and full-length mRNA FSH receptor were detected only in the secondary structure.     

Evaluation of biomarkers of kidney injury following 4% succinylated gelatin and 6% hydroxyethyl starch 130/0.4 administration in a canine hemorrhagic shock model

Objective : To investigate the association between synthetic colloids and biomarkers of acute kidney injury (AKI) in dogs with hemorrhagic shock. Design : Experimental interventional study. Setting : University. Animals : Twenty‐four healthy ex‐racing Greyhounds. Interventions : Anesthetized Greyhounds subjected to hemorrhage for 60 min were resuscitated with 20 mL/kg of fresh whole blood (FWB), 6% hydroxyethyl starch (HES) 130/0.4, 4% succinylated gelatin (GELO), or 80 mL/kg of isotonic crystalloid (CRYST) over 20 min (n = 6 per treatment). Concentrations of biomarkers of AKI were measured at baseline, end of hemorrhage, and at 40 (T60), 100 (T120), and 160 (T180) min after fluid bolus. Biomarkers included neutrophil gelatinase‐associated lipocalin in urine and serum (uNGAL; sNGAL), and urine cystatin C (uCYSC), kidney injury molecule‐1 (uKIM), clusterin (uCLUST), osteopontin, gamma‐glutamyl transferase, monocyte chemoattractant protein‐1 (uMCP), interleukin‐6, interleukin‐8, protein (uPROT), hyaluronan, and F₂‐isoprostanes. Renal histology was scored for tubular injury and microvesiculation. Biomarker fold‐change from baseline was compared between groups using mixed effects models (Bonferroni–Holm corrected P<0.05). Frequencies of histology scores were compared by Fisher's exact test. Measurements and main results : In dogs treated with GELO, uNGAL fold‐change was markedly greater compared with all other groups at T60, T120, and T180 (all P<0.001), and uCYSC was greater at T60 compared with CRYST (P<0.001), and at T120 and T180 compared with all other groups (all P<0.001). Smaller, albeit significant, between‐group differences in uKIM, uCLUST, uMCP, and urine protein concentration were observed across the FWB, GELO, and HES groups, compared with CRYST. The GELO group more frequently had marked tubular microvesiculation than the other groups (P = 0.015) although tubular injury scores were comparable. Conclusion : In dogs with hemorrhagic shock, GELO was associated with greater magnitude increases in urine biomarkers of AKI and more frequent marked tubular microvesiculation, compared with FWB, CRYST, and HES.