Treatment of anovulatory anoestrous postpartum dairy cows with a gonadotropin-releasing hormone (GnRH), prostaglandin F2 alpha, GnRH regimen or with progesterone and oestradiol benzoate

AIM: To compare 2 treatments for anovulatory anoestrus (AA) in postpartum dairy cows. The treatments were combinations of gonadotropin-releasing hormone (GnRH) and prostaglandin F2 (PG) or progesterone (P4) and oestradiol benzoate (ODB). METHODS: Forty AA cows from each of 5 herds were blocked by age (2 or 2 years old) and randomly assigned to 1 of 2 treatments. The first group (GPG) were treated with 250 mug of a GnRH analogue, gonadorelin, followed 7 days later by 15 mg of the PG analogue, luprostiol. Two days later the cows were injected with 250 mug of gonadorelin. Cows were artificially inseminated 16-24 h after the second GnRH injection. The second group (P4+ODB) were treated with an intravaginal P4 releasing device for 6 days, followed 24 h after device removal by injection of 1 mg of ODB. Cows were pregnancy tested 35-40 days after the initial insemination and twice again at 6-8 week intervals thereafter. RESULTS: There was no significant difference between P4+ODB and GPG groups in the percentage of cows submitted for insemination in the first 7 days (94.0% vs 100% for P4+ODB vs GPG, respectively; p>0.3), in conception rate to first insemination within the first 7 days (43.6% vs 35.0% for P4+ODB vs GPG, respectively; p>0.2), in the percentage of cows conceiving in the first 28 days of the breeding period (68.0% vs 58.3%, P4+ODB vs GPG, respectively; p>0.1), or in median interval from the end of treatment to conception (20 vs 21 days; p>0.1). CONCLUSIONS: No differences in the reproductive performance of AA cows treated with either P4+ODB or GPG were detected. However, given the small number of animals enrolled, further data are required before the GPG protocol can be recommended for treatment of AA cows.     

Immunohistochemical demonstration of chromogranin A in endocrine organs of the rat and horse by use of region-specific antibodies

Chromogranin A (CgA) is an acidic glycoprotein that is co-stored with hormones or neurotransmitters in granular components of endocrine cells and neurons, and released together with them in response to adequate stimulation. In addition to acting as a packaging protein, CgA functions as a precursor molecule that yields several bioactive peptides by proteolytic cleavage. The purpose of this study is to elucidate how different the processing of CgA is among endocrine tissues by immunostaining using multiple region-specific antisera, and to evaluate the availability of region-specific antisera. When various endocrine organs of rats were immunostained with four region-specific antisera against rat CgA (CgA 1-28, 94-130, 296-314, and 359-389), all amine/peptide-secreting endocrine tissues except the pineal body were stained positively. The adrenal medulla and gastric endocrine cells were equally intensely immunoreactive to all four antisera, while the other endocrine tissues, represented by pancreatic islets, showed different staining patterns depending on the antiserum. These results suggest that the processing of CgA differs from tissue to tissue. An antiserum against horse CgA 335-365, corresponding to rat CgA 359-389 which shows the highest concentration in the plasma and urine of the rat, again stained all endocrine tissues of the horse except the pineal body. Therefore, the anti-horse CgA 335-365 serum is useful for immunohistochemical survey of horse CgA, and may make possible the establishment of a CgA assay system for the measurement of CgA in the plasma, urine and saliva.     

A novel nutritional strategy to prevent milk fever and stimulate milk production in dairy cows

AIMS: To assess the efficacy of a feed supplement designed to reduce the dietary availability of calcium when fed during the last 2-3 weeks of pregnancy, on the incidence of postparturient hypocalcaemia (milk fever) and on milksolids (MS) production in pasture-fed dairy cows in early lactation. METHODS: In Experiment 1, late-pregnant Holstein/Friesian cows, 4-10 years old, grazing pasture, were either fed the supplement (1 kg/cow/day) for 2-4 weeks prior to calving (n=11) or no supplement (n=10). Plasma calcium concentrations were measured immediately before and after a 20 h fast intended to induce hypocalcaemia at the end of this period, 1-7 days before the cows calved. In Experiment 2, mixed-breed dairy cows, 3-10 years old in 7 commercial dairy herds were fed the same supplement (1 kg/cow/day) for 1-3 weeks immediately prior to calving (n=565) or no supplement (n=614), and incidences of clinical milk fever and MS production at 6-9 weeks post calving were compared between groups. RESULTS: In Experiment 1, plasma calcium concentrations were higher (p=0.01) in supplemented than in non-supplemented cows after fasting, indicating reduced susceptibility to fasting-induced hypocalcaemia. In Experiment 2, the incidence of milk fever was lower (6.4% vs 17.1%, p=0.001) and MS production was higher (p=0.01) in supplemented than in non-supplemented cows. CONCLUSIONS: These preliminary results demonstrate that feeding a supplement designed to reduce dietary calcium availability for 2-4 weeks immediately prior to calving reduced the susceptibility of cows to fasting-induced hypocalcaemia, reduced the incidence of clinical milk fever and increased MS production in early lactation. CLINICAL RELEVANCE: The concept and product reported here have potential to provide dairy farmers with a practical means to prevent hypocalcaemia and improve milk production during early lactation.     

Farm and Personal Characteristics of the Clientele of a Community-based Animal Health Service Programme in Northern Malawi

The social background, farm characteristics, indicators of income and self-evaluation returns of 96 randomly selected users of a Basic Animal Health Service (BAHS) programme in northern Malawi were compared with those of 96 matched past-users and 96 non-users, respectively. All 288 farms were visited between July and October 1997. Data analysis was performed using univariate and multivariate techniques. The results showed that, on average, BAHS users had larger cattle herds (16.3) than part-users (14.7) or non-users (12.4). Similarly, the annual yields of crops were higher for users compared to either of the other groups. Users occupied better houses and owned a larger number of farm and household items than did part-users or non-users. A third of all farmers were engaged in additional income generation to lessen the risk of poverty. However, analysis of the livestock management and the educational background of the farmers suggested that usage of the BAHS programme was not only determined by already existing `wealth'. Improved livestock husbandry and management measures, which do not require capital investment, were more frequently applied by users compared to either of the other groups. Non-users and part-users had attained a lower level of education, were less open towards improved farming methods and felt less knowledgeable than BAHS users. The average straight-line distances from farms using BAHS to their respective village animal health worker (2.2 km) or veterinary assistant (2.9 km) were similar but varied according to ecological zone. Intensified extension and awareness meetings in villages will be required to get more non-users involved in BAHS.     

Evaluation of the Feeding Value of Palm Press Fibre Using In Vitro Digestibility Techniques

Palm press fibre (PPF) was obtained from two sources, a small-scale oil palm processing unit and a large-scale factory processing unit, and its chemical composition was determined. In vitro digestibility techniques were used to assess the feeding value of untreated, defatted and sodium hydroxide-treated PPF. For the NaOH treatment, 0.5 g oven-dried PPF was treated for 24 h with 5% NaOH in three ways: treated and not washed (NaNW); treated and washed (NaW); and treated after milling (NAD).The results indicate that, on a dry matter basis, PPF is low in nitrogen (12–13 g/kg), moisture (37–90 g/kg) and ash (53–62 g/kg), but high in ether extract (269–355 g/kg), neutral detergent fibre (532–768 g/kg), acid detergent fibre (375–548 g/kg) and lignin (219 g/kg). The in vitro dry matter digestibility values were low for the samples from both sources, but the large-scale factory-processed PPF had higher in vitro dry matter digestibility (0.215 vs 0.166) and in vitro organic matter digestibility (0.196 vs 0.145). Defatting the PPF and treating it with 5% NaOH solution significantly (p<0.01) improved both the dry matter and organic matter digestibility. Washing the NaOH-treated PPF resulted in a higher digestibility of dry matter as against NaNW or NAD. These results suggest that defatting and treatment with 5% NaOH would improve the feeding value of PPF.     

Laparoscopic surgical technique for repair of rectal and colonic tears in horses: an experimental study

OBJECTIVE: To determine the efficacy of laparoscopic surgical techniques for repair of rectal lacerations in horses. STUDY DESIGN: Experimental study. ANIMAL OR SAMPLE POPULATION: Thirty-two segments of equine bowel placed in an equine pelvitrainer, 8 equine cadavers, and 3 normal horses. METHODS: In experiment 1, 3 laparoscopic intestinal-repair techniques were evaluated in an equine pelvitrainer: suturing with needle holders, with an automatic suture device, and stapling with a hernia stapler. In experiment 2, descending colon lacerations were sutured laparoscopically using needle holders in a pelvitrainer and in equine cadavers. In experiment 3, iatrogenic rectal lacerations were sutured laparoscopically with needle holders in horses under general anesthesia. These horses were evaluated for 7 days' postoperatively by clinical examination and blood and peritoneal fluid analysis. The horses were euthanatized 7 days' postoperatively and necropsied. The repaired colonic segments were collected for determination of bursting pressures, degree of luminal narrowing, and microscopic examination of the suture line. RESULTS: For the 3 techniques, there was no significant difference in repair time or degree of luminal narrowing, but bursting pressure was higher in segments repaired by use of needle holders or with the suture device. Colonic and rectal lacerations were sutured successfully with laparoscopic needle holders. No major complications were recorded. At necropsy, adequate healing was confirmed by a high bursting strength (>140 mm Hg) and by histologic examination. CLINICAL RELEVANCE: A novel laparoscopic method can be used to repair iatrogenic rectal lacerations in horses. Whether this method may be used for clinical cases of rectal tears must be investigated.