Physiological Response of Normal Adult Horses to a Low-Residue Liquid Diet

The anorexic or dysphagic adult horse often requires nutritional support. Providing nutrients by the enteral route is the safest and most economic choice, but the dietary options available for use in horses are somewhat limited. The objective of this study was to compare the physiologic response of normal horses with a low-residue liquid or normal diet over a 10-day feeding period. Two groups of 6 normal adult horses were maintained on 1 of 2 diets for a 10-day period. Diets were formulated to meet the caloric needs of a horse maintained in a stall. The control group was fed 70% timothy hay and 30% textured concentrate for the test period, and the experimental group received the low-residue liquid diet, similar to liquid nutritional formulas designed for human use. Clinical parameters, body weight, packed cell volume, total plasma solids, blood glucose, and serum electrolytes were recorded daily for each horse during the dietary trial period. On days 1, 5, and 10 of the study, a complete blood count, serum biochemical profile, and urinalysis were performed.Horses' serum total bilirubin concentration and pattern of weight loss differed between groups. All other physical parameters, blood chemistry, complete blood count, and urinalysis results remained within the normal reference interval for the horses regardless of diet, although some statistical differences were observed. Horses returned to pasture and free-choice grass diet without complications at the end of the dietary trial period. These results demonstrate that few differences of biologic significance were observed between horses being fed low-residue diet and horses receiving a normal diet of hay and grain over a 10-day period. (Equine Vet J 2003;23:310–317)     

Digestion of poultry manure by Musca domestica

Larvae of the house fly (Musca domestica) grew and developed normally in fresh poultry manure where the proper environmental conditions were maintained. A temperature of 27 °C and a moisture content ranging from 60 to 75% in fresh poultry manure was determined to be optimum for larval development. A moisture content of 80% or greater created anaerobic problems for larvae.

Optimum production of house fly pupae was obtained by inoculating 0.50 to 0.75 g of fly eggs per kg of fresh poultry manure. Five to eleven days were required for the eggs to be converted to pupae depending on the environmental conditions. After digestion, the poultry manure, was reduced to about half and was granular in texture. The digested residue readily dried, had less odour and contained approximately 15% protein.     

Growth and development of the ovine conceptus

This study was designed to characterize development of the ovine conceptus throughout gestation to establish the temporal relationships in metabolites, electrolytes, fluid volumes within the placenta, and hormonal changes with fetal growth. Length and weight of placentae, weight of cotyledons, and uterine weight increased between d 25 and 80 of gestation in advance of increases in fetal growth between d 80 and 140 of gestation. Allantoic fluid volumes changed (P < 0.01) between d 25 (21 mL) and 40 (91 mL), decreased to d 70 (32 mL), and then increased to d 140 (438 mL). Concentrations and total amounts of proteins in allantoic fluid were reduced between d 25 and 50, but total protein increased (P < 0.01) from d 40 (63 mg) to d 140 (2,991 mg). Concentrations of fructose in allantoic fluid varied between 2 and 6 mg/mL throughout gestation, but total fructose increased (P < 0.01) between d 25 (46 mg) and d 120 (679 mg). Concentrations of glucose ranged from 0.1 to 0.3 mg/mL, and total glucose increased (P < 0.05) from d 25 (3 mg) to d 140 (63 mg) of gestation. Amniotic fluid volume increased (P < 0.01) between d 30 and 140. Concentrations of estrogens in allantoic fluid, maternal uterine artery, and uterine vein increased (P < 0.01) with advancing pregnancy, and concentrations of progesterone in allantoic fluid (P < 0.07) and plasma (P < 0.05) were affected by day of gestation. Concentrations of glucose were greater (P < 0.05) in uterine artery than uterine vein, but concentrations of electrolytes and osmolarity of plasma were not affected by day of gestation. Increases in weights of fetal organs were proportional to increases in fetal weight during gestation. Results of the present study of conceptus growth and development highlight areas of needed research and provide benchmarks for comparisons when evaluating effects of various treatments, environmental conditions, and epigenetics on successful outcomes of pregnancy in sheep.     

关于内蒙古大兴安岭林区实施森林抚育补贴项目的探讨

文章通过对内蒙古大兴安岭林区实施森林抚育补贴项目的背景、必要性的分析,论述了森林抚育是促进林区生态、经济和社会协调发展的有力措施。     

内蒙古大兴安岭森林分类区划存在的问题及建议

森林分类区划是为了解决天然林的修养生息和恢复发展而提出的,但禁伐区、限伐区、商品林经营区划分在实施过程中存在一些问题。文章主要针对其存在的问题,提出一些可行性的建议和对策。     

Early Development and Putative Primordial Germ Cells Characterization in Dogs

Previously, three distinct populations of putative primordial germ cells (PGCs), namely gonocytes, intermediate cells and pre‐spermatogonia, have been described in the human foetal testis. According to our knowledge, these PGCs have not been studied in any other species. The aim of our study was to identify similar PGC populations in canine embryos. First, we develop a protocol for canine embryo isolation. Following our protocol, 15 canine embryos at 21–25 days of pregnancy were isolated by ovaryhysterectomy surgery. Our data indicate that dramatic changes occur in canine embryo development and PGCs specification between 21 to 25 days of gestation. At that moment, only two PGC populations with distinct morphology can be identified by histological analyses. Cell population 1 presented round nuclei with prominent nucleolus and a high nuclear to cytoplasm ratio, showing gonocyte morphology. Cell population 2 was often localized at the periphery of the testicular cords and presented typical features of PGC. Both germ cell populations were positively immunostained with anti‐human OCT‐4 antibody. However, at day 25, all cells of population 1 reacted positively with OCT‐4, whereas in population 2, fewer cells were positive for this marker. These two PGCs populations present morphological features similar to gonocytes and intermediate cells from human foetal testis. It is expected that a population of pre‐spermatogonia would be observed at later stages of canine foetus development. We also showed that anti‐human OCT‐4 antibody can be useful to identify canine PGC in vivo.     

Effects of supplement type on performance, reproductive, and physiological responses of Brahman-crossbred females

Two experiments were conducted to compare the performance and physiological responses of forage-fed beef females supplemented with either a molasses-based (ML) or a citrus pulp-based (CT) supplement. In Exp. 1, BW gain, reproductive performance, and concentrations of blood urea N (BUN), plasma glucose, insulin, IGF-I, and progesterone (P4) were assessed in 60 Brahman x Angus heifers supplemented 3 times weekly with either ML or CT. Supplement intakes were formulated to be isocaloric and isonitrogenous. Reproductive performance was not affected by treatments, but mean BW gain was greater (P < 0.01) for heifers fed CT than for those fed ML (0.40 vs. 0.30 kg/d). Mean plasma concentrations of glucose, insulin, and IGF-I were greater (P < 0.05) for heifers fed CT, whereas BUN was greater (P < 0.05) for heifers fed ML. Mean plasma P4 concentration did not differ between treatments, but both groups had lower plasma P4 concentrations during days that supplements were offered (P < 0.01). In Exp. 2, forage DMI and concentrations of BUN, plasma glucose, insulin, IGF-I, and P4 were assessed in 24 Brahman x British mature cows supplemented with the same treatments described in Exp. 1. Overall forage DMI did not differ between treatments, but a day effect and a treatment x day interaction were detected (P < 0.05). Both groups consumed less forage during the days on which the supplements were offered (P < 0.01), and forage DMI for cows fed CT was less (P < 0.05) than for cows fed ML during those days. No differences were detected in any blood or plasma measurement. In addition, no differences in concentrations of P4 were detected between CT- and ML-fed cows. We concluded that CT-supplemented heifers had greater BW gain compared with ML-supplemented heifers, but no differences in reproductive performance were observed. We also observed that CT-supplemented cows had a greater variability in forage DMI compared with ML-supplemented cows.     

Three cases of transitional cell carcinoma in the cat and a review of the literature

Only 47 cases of urinary bladder neoplasia have been reported in the cat. In this paper a further three are presented. They were received as post mortem specimens and were examined both macroscopically and microscopically. All three were transitional cell carcinomas, with squamous metaplasia in two. Dysplastic urothelial changes were a feature of two of the three tumours and one of these also showed two separate centres of malignancy. Various features of the three cases are discussed and attention is drawn to their possible aetiological significance. The authors suggest that the prevalence of transitional cell carcinoma in the cat may be greater than has hitherto been believed.     

Factors that affect ovarian follicular dynamics in cattle.

Studies of ovarian follicular dynamics in cattle may lead to methods for improving fertility, for synchronizing estrus with more precision, and for enhancing superovulatory responses. Within an estrous cycle, two or three large (> 10 mm) follicles develop during consecutive waves of follicular growth. The last wave provides the ovulatory follicle, whereas preceding wave(s) provide follicles that undergo atresia. The life span of large follicles seems to depend on the pulsatile secretion of LH; decreased frequency of LH pulses results in atresia of large follicles. Aromatase activity in the walls of the largest follicles is greatest during the first 8 d of the estrous cycle and decreases by d 12. Steroidogenesis of the largest and second-largest ovarian follicles differs on d 5, 8, and 12 of the estrous cycle. Follicular dynamics are altered by negative energy balance and lactation. The number of large follicles and concentration of estradiol during the preovulatory period differs between postpartum lactating and nonlactating cows. Dietary fats stimulate follicular growth when they are fed to increase energy balance. Administration of bovine somatotropin decreases energy balance and has a differential effect on ovarian follicular responses; growth of the largest follicle does not change, but growth of the second-largest follicle is stimulated by somatotropin. Studies of follicular dynamics in lactating cows demonstrate changes in ovarian function associated with energy balance that may be related to inefficient reproductive performance of cows producing high yields of milk.     

Systemic granulomatous disease in dairy cattle during a dicyandiamide feeding trial

CASE HISTORY: Mature, in-calf, non-lactating, Friesian or Friesian-cross cows were fed dicyandiamide (DCD) at daily doses of 0.15 g/kg (Group 1; n=31), 0.45 g/kg (Group 2; n=21) and 0.75 g/kg (Group 3; n=12), as part of a safety trial, which also included a control group (n=15). Daily health observations were carried out on each cow until Day 86 of the study. On Day 28 one cow from Group 3 was observed with signs of disease, and subsequently disease was noted in other cows.

CLINICAL FINDINGS: Clinical signs in the first case included depression, pyrexia (40.9°C), salivation and dehydration, in addition to progressive weight loss, followed by death on Day 32. Other cows from all treatment groups developed clinical signs of disease resulting in euthanasia of seven animals. Disease occurred in 10/12 (83%) cows in Group 3, 11/21 (52%) cows in Group 2, and 7/31 (23%) cows in Group 1. Clinical signs were variable and included dermatitis and pruritus of the head and neck, petechial haemorrhages, pyrexia, weight loss, thrombocytopenia, neutropenia, and regenerative anaemia.

PATHOLOGICAL FINDINGS: Gross findings included generalised lymphadenopathy, subcutaneous oedema, petechiation of mucosal and serosal surfaces, and gastrointestinal haemorrhage. Histologically, multiple organs and tissues contained inflammatory foci characterised by infiltrates of lymphocytes, plasma cells, macrophages and occasionally prominent multinucleated giant cells and eosinophils.

DIAGNOSIS: Multisystemic granulomatous and haemorrhagic syndrome resembling cell-mediated hypersensitivity, associated with DCD ingestion.

CLINICAL RELEVANCE:: This is the first report of toxicity in cattle associated with ingestion of DCD. The proportion of affected cows increased with increasing dose of DCD, but not all cattle in the high dose group developed disease, therefore additional factors may determine whether or not an individual cow will develop DCD-associated disease.