- Enzootic bronchopneumonia
- Bovine viral diarrhoea — mucosal disease (BVD-MD)
- Infectious bovine rhinotracheitis — infectious pustular vulvovaginitis (IBR-IPV)
- Rota- and Coronavirus infections
- From a preliminary pathogenicity trial involving five lechwe antelope and six cattle it appeared that theMycobacterium tuberculosis strain isolated from lechwe antelope was identical to that recovered from local cattle.
- All the test lechwe and cattle died of acute tuberculosis; the symptoms and lesions being similar, irrespective whether they had been injected with the cattle isolate or the lechwe isolate.
- The lechwe population, from which the strain was isolated, is suffering from tuberculosis of bovine type.
- a method of expression which eliminates the effects of the melanin concentration and the age of the hair sample:
- a technique of washing the hair which limits as far as possible the removal of substances which are produced by the sebaceous and sweat glands and which are fixed by the hair, substances which provide very valuable and specific information;
- a means of detecting accidental contamination.
- In anaphylactic reactions the release, distribution and effects of mediators, including histamine, 5-hydroxytryptamine, dopamine, kinins, slow reacting substance of anaphylaxis (SRS-A), eosinophil chemotactic factor, neutrophil chemotactic factor, platelet activating factor and prostaglandins, vary. The distribution of H1 and H2-histamine receptors for example varies even between different species of ruminants. Successful inhibition of anaphylactic or allergic reactions necessitates the correct choice of antagonist for the affected species, e.g. antihistamines may be expected to be effective in guinea pigs and dogs but prostaglandin antagonists would be more useful in cattle.
- Sympathomimetics and α and β adrenergic receptor blocking drugs have different metabolic effects and effects on sweating in different species, e.g. horses, ruminants and rats.
- Substances, including analgesics and anaesthetics, which affect the central nervous system, may produce depression in some species but excitation in others (e.g. morphine, ketamine) due to differences in distribution of neurotransmitters. Some drug susceptibilities are genetically controlled.
- The effects of substances on the reproductive systems of different species can be more readily predicted as differences in the regulation of oestrus are appreciated.
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A signal from a detector indicating departure from normality
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The interpretation of the signal (diagnosis)
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A feed-back signal to the origin of the detection signal indicating corrective action.
The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-oestradiol concentrations were also compared in breeding and non-breeding hens.
In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females.
No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline.
Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.
- Mastitis was induced in one gland (homolateral) and MBF was recorded in the other (heterolateral) gland. During homolateral mastitis, clinical aspects, MCl? and TC in the heterolateral gland were normal. For MBF, however, 3 types of responses could be distinguished. In 66% of the experiments (expts) there was a delayed MBF peak which coincided with MBF peak II of the homolateral mastitis gland. Furthermore, in 10% of these cases, a 1st MBF peak occurred simultaneously with MBF peak I of the homolateral gland. After tying off the vasoanastomoses between both udder halves, only the heterolateral MBF peak II persisted. In 33% no heterolateral peaks were present and in most cases a MBF decrease was observed between the 3rd and the 6th hours.
- Large doses of prostaglandin E2 (PGE2) were infused intracerebroventricularly (i.c.v.) in normal, conscious lactating goats. In 58% of expts fever started quickly after infusion accompanied by a decrease in MBF. However, as soon as fever was established, MBF returned to normal and even rose above pre-infusion values.
- The i.c.v. PGE2 infusion was preceded (30 min) by i.mam. injection of LPS. In most expts fever appeared earlier than during mastitis control expts. Although symptoms of mastitis were observed, MBF peak I was lacking.
- The antipyretic effects of 3 non-steroidal anti-inflammatory drugs (N.S.A.I.D.) on the biphasic MBF pattern during LPS mastitis were tested: Suprofen, Indomethacine and Flurbiprofen abolished fever, muscular shivers, myosis and tachycardia but had only little effect on the MBF pattern during LPS mastitis. MBF peak II was partially suppressed by these drugs, but most significantly by Flurbiprofen, which also delayed the appearance of MBF peak I. The latter is probably the consequence of its anti-inflammatory properties. None of these drugs could prevent the breakdown of MBF peak I.
The aim of this study was to evaluate the tolerance of laying hens for an excessive L-valine (L-val) supply on laying performance, egg quality, serum free amino acids, immune function and antioxidant enzyme activities of laying hens.
A total of 720 HyLine Brown hens were allocated to 5 dietary treatment groups, each of which included 6 replicates of 24 hens, from 40 to 47 weeks of age. Graded amounts of L-val were added to the basal diet to achieve concentrations of 0 (control), 1, 2, 3 and 4 g/kg, respectively, in the experimental diets.
Supplementing the diet with L-val did not affect egg production, egg mass, egg weight, feed conversion ratio (FCR) or egg quality. The average daily feed intake response to supplemental L-val was quadratic and was maximised at 2.0 g L-val/kg diet. No differences were observed for total protein, total amino acids, blood urea nitrogen (BUN), uric acid, lactate dehydrogenase (LDH), alkaline phosphatase (AKP), Ca and P concentrations among the treatments.
Serum albumin concentration increased significantly in response to supplemental L-val and was also maximised at 2.0 g/kg. In addition, serum glucose increased quadratically to peak at 2.0 g L-val/kg diet. Serum free valine increased as L-val concentration increased to 2.0 g/kg diet and then decreased linearly.
Supplementation of L-val did not affect the serum concentrations of total antioxidative capability (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA). L-val supplementation did not affect the concentrations of immunoglobulins IgG, IgA, IgM and complements (C3 and C4). Serum concentration of triiodothyronine (T3) increased significantly at 2.0 g L-val/kg diet.
It is concluded that high concentrations of L-val are tolerated and can be successfully supplemented into diets without detrimental effects on laying performance or immune function of laying hens.
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A table of suitable size and strength with adequate padding.
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The table to be elevated reliably to a comfortable operating height.
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The elevation to be; rapid so that after induction of anaesthesia and elevation the horse would still be deeply anaesthetized enough to allow easy passage of the endotracheal tube.
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A safe and efficient method to move the anaesthetized post-operative patient to a recovery room.
The present study was conducted to determine the effects of α-lipoic acid supplementation on post-mortem changes in the fatty acid profile and concentrations of nucleotide-related substances, especially those of a taste-active compound, inosine 5?-monophosphate, in chicken meat.
Mixed-sex broiler chicks aged 14 d were divided into three groups of 16 birds each and were fed on diets supplemented with α-lipoic acid at levels of 0, 100 or 200 mg/kg for 4 weeks. Blood and breast muscle samples were taken at 42 d of age under the fed condition and then after fasting for 18 h. The breast muscle obtained from fasted chickens was subsequently refrigerated at 2°C for one and 3 d.
α-Lipoic acid supplementation did not affect any plasma metabolite concentration independently of feeding condition, while a slight increase in plasma glucose concentration was shown with both administration levels of α-lipoic acid. In early post-mortem breast muscle under the fed condition, α-lipoic acid had no effect on concentrations of fatty acids or nucleotides of ATP, ADP, and AMP.
In post-mortem breast tissues obtained from fasted chickens, total fatty acid concentrations were markedly increased by α-lipoic acid feeding at 200 mg/kg irrespective of length of refrigeration. This effect was dependent on stearic acid, oleic acid, linoleic acid and linolenic acid. However, among fatty acids, the only predominantly increased unsaturated fatty acid was oleic acid.
Dietary supplementation with α-lipoic acid at 200 mg/kg increased the inosine 5?-monophosphate concentration in breast meat and, in contrast, reduced the subsequent catabolites, inosine and xanthine, regardless of the length of refrigeration.
Therefore, the present study suggests that α-lipoic acid administration altered the fatty acid profile and improved meat quality by increasing taste-active substances in the post-mortem meat obtained from fasted chickens.
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? Semen and blood samples were collected from 541 rams in 40 flocks.
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? The type of antigen which has been used for a number of years in New Zealand was unsatisfactory. The CCFT using this antigen had a sensitivity of only 85% in 124 rams which gave positive semen cultures. These rams came from 16 infected flocks.
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? The CCFT using the best of the 3 antigens proved to be a remarkably reliable test. In the same group of infected animals mentioned above, 120 of the 124 infected rams had positive or suspicious CFT's. The sensitivity of the test was therefore 97%. The specificity was > 99% in 144 rams in 16 uninfected flocks. Only 1 suspicious titre was found in the uninfected group.
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? In 4 flocks in which B. ovis was never isolated, 18 of 58 sera gave positive or suspicious reactions. Recognition of this type of 'problem flock' is therefore important. A history and clinical picture which does not agree with serological results should always be thoroughly investigated. Semen should be collected from an appropriate number of cases for bacteriological examination. It is suspected that at least some ‘problem flocks’ may contain unreported vaccinated animals. Further investigation of ‘problem flocks’ will be an aim of the Animal Health Division in the future.
The pharmacokinetics of doxycycline in ducks were investigated after a single intravenous (IV), intramuscular (IM) or oral (PO) dose at 20 mg/kg body weight.
The concentrations of doxycycline in plasma samples were assayed using a high performance liquid chromatography method, and pharmacokinetic parameters were calculated using a non-compartmental model.
After IV administration, doxycycline had a mean (±SD) distribution volume (Vz) of 1761.9 ± 328.5 ml/kg and was slowly eliminated with a terminal half-life (t1/2λz) of 21.21±1.47 h and a total body clearance (Cl) of 57.51 ± 9.50 ml/h/kg. Following PO and IM administration, doxycycline was relatively slowly absorbed – the peak concentrations (Cmax) were 17.57 ± 4.66 μg/ml at 2 h and 25.01 ± 4.18 μg/ml at 1.5 h, respectively. The absolute bioavailabilities (F) of doxycycline after PO and IM administration were 39.13% and 70.71%, respectively.
The plasma profile of doxycycline exhibited favourable pharmacokinetics characteristics in Muscovy ducks, such as wide distribution, relatively slow absorption and slow elimination, though oral bioavailability was low.
LPIN1 is a Mg2+-dependent phosphatidic acid phosphatase. Variation in chicken LPIN1 exon 6 and its flanking regions were identified and three indel variants in 6 breeds and their associations with performance traits were studied.
Seven variants were detected from 6 breeds, which contained a synonymous tri-allelic variant (c.924A/T/C) and three indels. The exon 6 variants detected from chicken breeds were conserved among bird species. The indel variation frequency presented clear differences among breeds.
Two coding indels (c.1014-1018del3 and c.1125-1138del12) were multiples of three nucleotides and maintained the open reading frames of LPIN1 proteins. However, they were predicted to result in the clear change of the RNA secondary structure of chicken LPIN1 exon 6 and LPIN1 protein conformation.
The association analysis showed that c.871–15-22del6 variation had a significant effect on body weight at hatch (BW0) and 2 weeks (BW2); c. 1014-1018del3 variation had a significant effect on BW4, BW6, caecum length and gizzard weight (GW) traits; c.1125-1138del12 variation had a significant effect on BW12, shank length at 4 weeks (SL4), carcass weight, lactate dehydrogenase traits (LDH), glucose (GLU) and albumin (ALB) traits. The genotype combination for c.1014-1018del3 and c.1125-1138del12 also presented significant effects on SL4, SL8, GW, leg muscle weight, ALB, GLU and LDH.
The study demonstrated that chicken LPIN1 has an important effect on body, carcass and organ weight, serum LDH, GLU and ALB level.
- Key points
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? the variation in the post-injection interval to oestrus was influenced by the stage of the oestrous cycle at which treatment was administered;
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? this variation was suffkient to reduce pregnancy rates to set-time inseminations;
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? an accurate aid for oestrus detection, such as tail painting, should be used routinely with PGF;
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? if PGF-treated cows were detected in oestrus before being inseminated, the pregnancy rates to first insemination were usually 10% higher than in untreated herd mates.
A trial was designed to assess the effect of fat supplementation (amount and type of fatty acids) on vitamin E bioavailability in adult cockerels.
A total of 60 birds were force-fed three different diets: a semi-purified diet without added fat (Control diet) or supplemented with 3% fat as linseed (Linseed diet) or hydrogenated coconut oil (Coconut diet). The three experimental diets were also supplemented with dl-α-tocopheryl acetate to provide 40 mg vitamin E per bird.
After one week of depletion, blood was collected from the wing vein before (baseline) and 6, 12, 24 and 96 h after the gavage. Plasma samples were analysed for their α-tocopherol, cholesterol and triglycerides concentrations.
Results showed that the addition of 3% fat in the experimental diet increased post-gavage plasma α-tocopherol response by 153% for Linseed diet and by 75% for Coconut diet (P < 0.0001) compared to the Control group. Furthermore, the plasma α-tocopherol response observed with the Linseed diet was 44% greater than that observed with the Coconut diet (P < 0.0001). There was no effect of treatments on either plasma triglycerides (P = 0.91) or cholesterol (P = 0.45) responses.
In conclusion, this study shows that the addition of 3% fat to the diet significantly increases dl-α-tocopheryl acetate bioavailability in adult cockerels. Supplementation of fat rich in unsaturated fatty acids also leads to a higher dl-α-tocopheryl acetate bioavailability than fat rich in saturated fatty acids.
A 4 × 2 factorial experiment was conducted to investigate the effect of inclusion of spray-dried porcine plasma (SDPP), in lieu of meat meal, in the starter diet on performance and digestive physiology of broiler chickens between hatch and 35 d of age. Four levels of SDPP (0, 5, 10 or 20 g/kg) were included in the starter diets in lieu of meat meal on either wheat- or maize-based diets.
Over the first 10 d, and throughout the 35-d experimental period, birds gained more body weight with increasing concentrations of SDPP regardless to the type of grain used. Inclusion of SDPP in the starter diet markedly improved feed per gain in the starter phase and across the 35-d study. There was no significant effect of the type of grain and its interaction with SDPP on the body weight gain and feed per gain for the two assessed periods.
At d 10, the relative weight of the gizzard+proventriculus, spleen and liver increased with increasing concentrations of SDPP.
At 24 d of age, the grain and SDPP inclusion significantly interacted, depressing the weight of bursa and spleen in birds that received the highest concentration of SDPP in the maize-based diet. Birds fed on the maize-based diets had higher relative weight of pancreas than those on the wheat-based diets.
Increasing concentrations of SDPP in the starter diet improved the activities of maltase, sucrase and alkaline phosphatase at 24 d of age. The interaction of grain and SDPP concentration was significant for sucrase activity in birds on the wheat-based diets. Chickens on maize-based diets had higher alkaline phosphatase and maltase activities than those on wheat-based diets.
Chicks that were offered SDPP-containing starter diets had longer villi, deeper crypts and lower villi/crypt than the control at 24 d of age regardless of the grain type used. Furthermore, longer villi and larger villi/crypt were found in chicken groups fed on wheat-based diets than those on maize-based diets.
Chickens on maize-based diets had higher dressing percentage and relative breast weight than those on wheat-based diets at 35 d of age.
It can be concluded that supplementation of starter diets with SDPP would be beneficial to the long-term growth of broiler chickens. The effect of the basal grain used in the diet is minimal.
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the seasonal pattern of dry matter production from pasture, as determined primarily by species composition and the seasonal light and temperature regime;
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the varying requirements of the pasture plants at different times of the year, as determined by their morphological and physiological condition;
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the necessity to utilise a large proportion of the dry matter produced if animal production per hectare is to be maximised;
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late ‘winter calving in over 90% of the dairy herds; and
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the nutrient requirements of the herd at different stages of lactation.
The estimation of sulphur amino acid requirement is a vital key to providing appropriate nutrition in poultry. The estimation of amino acid requirement depends on what production parameter is taken into consideration for optimisation.
A complete randomised block design was performed with 5 treatments and 6 replicates of 8 Hy-line layers (W-36) each from 32 to 44 weeks of age. The blocks were made to have a replicate of each treatment. The dietary treatments were consisted of 5 concentrations of digestible sulphur amino acid (DSAA) at 5.1, 5.6, 6.1, 6.6 and 7.1 (g/kg).
Egg production, egg mass, egg weight and feed conversion ratio (FCR) were significantly affected by an increase in DSAA intake. However, feed intake, egg component yield, Haugh unit, specific gravity, eggshell thickness, egg protein and dry matter (DM) were not altered by DSAA intake.
A significant increment in plasma high-density lipoprotein was concomitant with a reduction in low-density lipoprotein when DSAA intake was increased. However, triglyceride, cholesterol, uric acid and total protein in plasma were not affected by DSAA intake.
The DSAA requirements estimated by the linear broken-line model to optimise egg production, egg mass, egg weight and FCR were 678, 673, 641 and 656 mg/bird.d in the whole experimental period, respectively.
The DSAA requirement estimated by the quadratic broken-line model to optimise egg production, egg mass, egg weight and FCR were 4.71%, 7.87%, 8.73% and 7.62% higher than those estimated by linear broken-line fit model in the whole experimental period, respectively.