A survey of northern Victorian dairy farmers to investigate dairy calf management: colostrum feeding and management

Objectives

To describe colostrum management practices carried out in northern Victorian dairy herds and to identify weaknesses in these areas that may affect calf health and welfare by comparing the results with the current industry recommendations

Methods

A questionnaire to obtain information about colostrum management and calf‐rearing practices was sent to commercial dairy farming clients of Rochester Veterinary Practice between June and September 2013. The questionnaire consisted of a general herd overview and colostrum harvesting practices.

Results

The response rate was 39% (58/150). Many dairy producers were not meeting the current industry recommendations in the following areas: (1) time of removal calf from the dam, (2) relying on calf suckling colostrum from the dam to achieve adequate passive transfer, (3) failing to supplement calves with colostrum, (4) feeding inadequate volumes of colostrum, (5) delayed colostrum harvesting, (6) pooling of colostrum, (7) failing to objectively assess colostrum quality or relying on visual assessment and (8) storing colostrum for a prolonged periods of time at ambient temperatures.

Conclusion

The results from this survey highlight the need for greater awareness of industry standards for colostrum management and feeding hygiene.

     

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.     

Antioxidant potential of sesame (Sesamum indicum) cake extract in stabilization of sunflower and soybean oils

Recently natural antioxidants have gained increased interest because natural food ingredients are safer than synthetic ones. Antioxidant activities and protective effects of sesame cake extract (SCE) in stabilizing sunflower oil (SFO) and soybean oil (SBO) were tested. Since different antioxidant compounds have different mechanisms of action, 2,2-azinobis (3-ethylbenzthiazoline sulfonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, and β-carotene/linoleic acid test system were used to assess the antioxidant efficacy of SCE. Total phenolic, flavonoid and flavonol contents in SCE were 1.94 (mg gallic acid equivalent (GAE) g⁻¹ dry weight (DW)), 0.88 (mg quercetain equivalent (QE) g⁻¹ DW), and 0.40 (mg QE g⁻¹ DW), respectively. Protective effects of SCE in stabilizing SFO and SBO were tested, compared to synthetic antioxidants, by measuring their peroxide values (PV), conjugated dienes (CD), conjugated trienes (CT) and p-anisidine value during accelerated storage. Results indicated that SCE exhibited stronger antioxidant activity in SFO and SBO than butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), while its antioxidant activity was less than that of tert-butyl hydroquinone (TBHQ).     

Characterization of Egyptian <Emphasis Type="Italic">Phytophthora infestans</Emphasis> population using simple sequence repeat markers

The plant pathogenic oomycete, Phytophthora infestans, is the causal agent of late blight disease in tomato and potato. For characterizing Egyptian P. infestans isolates by DNA marker analysis, 40 isolates of P. infestans were collected from different locations in Egypt during two growing seasons (2012/2013 and 2013/2014). The 40 isolates were grouped into seven genotypes, in which 24 alleles were detected. The identified genotypes were not completely associated with geographic location and sample collection years. These results provide genetic and geographical information for developing a program to manage late blight disease.     

Potentiality of Soil Mulch and Sorghum Extract to Reduce the Biotic Stress of Weeds with Enhancing Yield and Nutrient Uptake of Maize Crop

Two field trials were conducted in 2018 and 2019 to develop practical and economically efficient weed control programs in corn. The experiment included six treatments (cowpea, rice straw, sorghum extract, hoeing, foramsulfuron herbicide and weedy check). The treatments were arranged in randomized complete block design with four replicates. Findings showed that reduction in total weed number was evident with application of hoeing, cowpea and rice straw in 2018 and 2019 seasons, in addition to foramsulfuron herbicide and sorghum extract in 2019. Cowpea, hoeing, foramsulfuron herbicide and rice straw recorded higher reduction in dry biomass of grassy weeds in both seasons. Reductions in N, P and K uptake by weeds because of rice straw and cowpea treatments were similar to hoeing treatment in both seasons. The increases in ear grain weight and grain yield ha^?1 due to cowpea and hoeing treatments were similar to rice straw one. In 2019 season, cowpea treatment was the superior practice for improving N, P and K uptake of maize, significantly leveling hoeing for K uptake. The values of gross returns and benefit/cost ratio of cowpea and sorghum extract, respectively, were higher than rice straw application. In conclusion, cowpea as a live mulch achieved acceptable weed control in maize by reducing weeds growth and lowering their ability to deplete the soil nutrients. Also, cowpea treatment improves growth and yield of maize with better utilization of nutrients. Thus, cowpea could be exploited as an eco-friendly method of weed management programs in maize cultivation.

     

Kinetic disposition, systemic bioavailability and tissue distribution of apramycin in broiler chickens

Apramycin was administered to chickens orally, intramuscularly and intravenously to determine blood concentration, kinetic behaviour, bioavailability and tissue residues. Single doses of apramycin at the rate of 75 mg kg⁻¹ body weight were given to broiler chickens by intracrop, i.m. and i.v. routes. The highest serum concentrations of apramycin were reached 0·20 and 0·76 hours after the oral and i.m. doses with an absorption half-life () of 0·10 and 0·19 hours and an elimination half life () of 1·22 and 2·31 hours respectively. The systemic bioavailability was 2·0 and 58 per cent after intracrop and i.m. administration, respectively, indicating poor absorption of the drug when given orally.Following i.v. injection, the kinetics of apramycin was described by a two-compartment open model with a () of 1·5 hours, () of 2·1 hours, V_d(ss) (volume of distribution) of 4·82 litre kg⁻¹ and C1_(B) (total body clearance) of 1·88 litre kg⁻¹ hour⁻¹. The serum protein-binding of apramycin was 26 per cent.The highest tissue concentrations of apramycin were present in the kidneys and liver. No apramycin residues were detected in tissues after six hours except in the liver and kidneys following intracrop dosing and kidneys following i.m. administration.     

Chronic obstructive mastitis in the camel. A clinicopathological study

Unilateral chronic mastitis in three she camels was due to obstruction of the teat canal by keratin. This lead to dilatation of the ducts, retention of milk and secondary bacterial infection. The teat canals and dilated ducts were lined by stratified squamous epithelium. There was excessive periductal fibrosis. Pasteurella hemolytica was isolated from one animal and Staphylococcus aureus from another. The fluid from the third animal was sterile. The condition was treated successfully by surgical amputation of the affected halves of the udder.     

Comparative studies on the effect of continuous intravenous infusion of some sulphonamides on blood and urine glucose levels in buffaloes

Three groups of five clinically healthy buffaloes each were injected intravenously with sulphadiazine, sulphadimidine and sulphamerazine in a dose of 100 mg/kg b. wt. (as a singly initial dose of 40 mg/kg b. wt. an subsequently the plasma level kept constant by a continuous intravenous infusion of a maintenance dose of 20 mg/kg per hour over a period of 3 hours). It was found that, 1) sulphadiazine, sulphadimidine and sulphamerazine increase the plasma glucose levels at 1, 2, 2.5 and 3.5 hours from the start of i.v. infusion. 2) The glucose concentration in urine increased in the buffaloes infused i.v. with sulphadiazine. 3) The glucose level in urine of buffaloes infused i.v. with sulphadimidine and sulphamerazine was slightly increased. 4) The concentrations of sulphadiazine, sulphadimidine and sulphamerazine in plasma reached its highest level, 2.5, 2 and 2.5 hours during the i.v. infusion, respectively, then declined rapidly. 5) The concentrations of sulphadiazine, sulphadimidine and sulphamerazine in urine reached their highest concentrations 3.5 hours after i.v. infusion.     

Effect of pantothenic acid on disposition kinetics and tissue residues of sulphadimidine in chickens

Sulphadimidine was administered to chickens via the intracrop route to determine plasma concentrations of the unchanged sulphonamide and its acetylated derivatives, kinetic disposition, tissue residues and acetylation. The sulphadimidine was given alone (group 1) at a dose of 200 mg kg-1 bodyweight. Pantothenic acid was given via the intracrop route at a dose of 100 mg kg-1 bodyweight one hour before (group 2) and six hours after (group 3) sulphadimidine administration (200 mg kg-1 bodyweight intracrop). The highest plasma concentrations of sulphadimidine in groups 1, 2 and 3 were reached in 1.73, 1.62 and 1.71 hours, respectively, following intracrop administration. In birds of groups 1, 2 and 3 no sulphadimidine was detected at 72, 24 and 48 hours, respectively, following its administration. Estimation of sulphadimidine in most of the body tissues revealed that all tissues examined had lower concentrations than plasma. In chickens given pantothenic acid (groups 2 and 3) before and after sulphadimidine administration, an increase in the concentration of N4 acetylated derivatives of sulphadimidine was observed compared with birds given sulphadimidine alone (group 1).