A survey of infectious bovine keratoconjunctivitis in the Gisborne and Hunterville regions of New Zealand

A postal survey of 400 beef farmers in the Hunterville and Gisborne districts sought to identify features of farms or management procedures that might influence the occurrence, transmission or severity of infectious bovine keratoconjunctivitis (IBK). The overall response rate was 72%. The annual incidence of IBK outbreaks rose from 10% to 28% between the years 1977 to 1981 and was similar for both districts. Prevalence was highest during mid-summer and lowest in mid-winter. Larger properties were more prone to outbreaks. In both districts, farmers of IBK-free properties purchased fewer cattle than those who had experienced IBK and this distinction was more evident in the Hunterville area. Only in the Gisborne district did a Hereford breed predisposition to infection become apparent. All age groups were affected with IBK but the attack rate was highest in the younger cattle. Eleven percent of farmers routinely treated their cattle for IBK and that produced an earlier resolution of lesions and fewer cattle in which healing extended longer than four weeks. Most farmers considered IBK to be an inconvenience which limited livestock production through reducing growth rates and lowering monetary returns when stock had to be sold at unsuitable times. Eye disfigurement caused loss of value in stud and export stock.     

The molecular epidemiology of Mycobacterium bovis infections in Tanzania

A molecular epidemiological study to determine the zoonotic importance of bovine tuberculosis was carried out in Tanzania. Specimens from human cases of tuberculosis as well as from slaughtered cattle were collected from regions with a high proportion of extrapulmonary tuberculosis. In order to determine the similarity of strains from the two sources, molecular typing techniques, namely RFLP and spoligotyping, were used to determine the genetic profile of the strains involved. The results of pTBN12 typing of M. bovis from cattle and man has shown a rather heterogeneous population of this species spread all over Tanzania, assuming that the present sample is representative. There were 13 different pTBN12 RFLP types encountered. The genetic relatedness between the pTBN12 RFLP patterns indicated a high degree of relatedness (86%) between the dominant pTBN12 genotypes existing in Tanzania. There were 13 different spoligotypes found in this study, whose genetic relatedness was also high (79%). DNA profiles were also confirmed by IS986 RFLP, which revealed that strains have 1-13 copies of IS986. Geographically, there was overlap between pTBN12 RFLP and spoligotypes amongst strains isolated from various parts of Tanzania. The diversity of the RFLP and spoligotype patterns observed in Tanzania probably reflects the extensive internal movements of cattle belonging to pastoralists. The evidence of overlap between DNA fingerprints of M. bovis from cattle and man has once more highlighted a need for synergy of veterinary and medical policies in the control of tuberculosis in Tanzania and probably in other developing countries.     

Comparative pharmacokinetics of meloxicam in clinically normal horses and donkeys

OBJECTIVE: To determine the disposition of a bolus of meloxicam (administered IV) in horses and donkeys (Equus asinus) and compare the relative pharmacokinetic variables between the species. ANIMALS: 5 clinically normal horses and 5 clinically normal donkeys. PROCEDURES: Blood samples were collected before and after IV administration of a bolus of meloxicam (0.6 mg/kg). Serum meloxicam concentrations were determined in triplicate via high-performance liquid chromatography. The serum concentration-time curve for each horse and donkey was analyzed separately to estimate standard noncompartmental pharmacokinetic variables. RESULTS: In horses and donkeys, mean +/- SD area under the curve was 18.8 +/- 7.31 microg/mL/h and 4.6 +/- 2.55 microg/mL/h, respectively; mean residence time (MRT) was 9.6 +/- 9.24 hours and 0.6 +/- 0.36 hours, respectively. Total body clearance (CL(T)) was 34.7 +/- 9.21 mL/kg/h in horses and 187.9 +/- 147.26 mL/kg/h in donkeys. Volume of distribution at steady state (VD(SS)) was 270 +/- 160.5 mL/kg in horses and 93.2 +/- 33.74 mL/kg in donkeys. All values, except VD(SS), were significantly different between donkeys and horses. CONCLUSIONS AND CLINICAL RELEVANCE: The small VD(SS) of meloxicam in horses and donkeys (attributed to high protein binding) was similar to values determined for other nonsteroidal anti-inflammatory drugs. Compared with other species, horses had a much shorter MRT and greater CL(T) for meloxicam, indicating a rapid elimination of the drug from plasma; the even shorter MRT and greater CL(T) of meloxicam in donkeys, compared with horses, may make the use of the drug in this species impractical.     

Better Laws = Better Environment the Role of the Environmental Lawyer in the Reconstruction and Modernisation of the Water Sector in Private Sector Participation

In order to secure a better environment, it is essential to ensure that the right and appropriate laws exist and are enforced. Before any major change is made to the physical environment, careful consideration should be given to the existence of the appropriate legal and organisational structure to ensure that the desired changes and improvements can be satisfactorily accomplished. Private sector participation is often seen as a catalyst for change and improvement in the economic and environmental situation, but, of itself, that will not create the desired cure. As water is a natural monopoly, it is essential to secure and maintain an effective, efficient and independent regulator. Environmental law should be kept under constant review to ensure that it is relevant and that it meets the challenges of the future, as well as securing the victories of the past.     

Can tree shelterbelts on agricultural land reduce flood risk?

Abstract. Agricultural practices in the UK have come under increased scrutiny since the heavy and widespread flooding of 2000 and 2001. Although the impact of land use on runoff and flood risk is of growing concern, there are few quantitative data available. A preliminary study was undertaken in the Nant Pontbren catchment, mid-Wales. Experimental tree shelterbelts were established in selected pastures of land used for sheep grazing. Water infiltration rates were up to 60 times higher in areas planted with young trees than in adjacent grazed pastures. This demonstrates that farm trees could represent a key landscape feature, reducing run-off even when only present as a small proportion of the land cover. This is likely to be just one of the environmental and economic benefits of planting trees to re-create a more diverse agricultural landscape.     

Effects of inclusion of whole-crop pea silages differing in their tannin content on the performance of dairy cows fed high or low protein concentrates

The effect of including high or low tannin forage peas as an alternative to soyabean meal on performance and N efficiency was investigated using 18 dairy cows in two Latin square design studies. Two varieties of forage pea; Racer (coloured flowers; high tannin) and Croma (white flowers; low tannin), were ensiled 12 weeks post sowing. The in situ degradability characteristics of the pea silages were determined using 4 cannulated sheep. The low tannin forage had a higher soluble N (a) fraction and a greater extent of degradation (a + b), resulting in a greater amount of N being predicted to be released in the rumen than the high tannin forage. In experiment 1, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/high tannin forage pea silage (0.25:0.25:0.50 respectively, DM basis) and 8 kg/d of a high protein concentrate (HTH) or 8 kg/d of a low protein supplement (HTL). The inclusion of forage peas increased (P < 0.05) DM intake by 1.2 kg DM/d, but there was no effect of dietary treatment on milk yield (average of 23.0 kg/d), composition or live weight change. The efficiency of use of dietary N (N output in milk/N intake) was highest (P < 0.001) in cows when fed GWH (0.289) and lowest in HTH (0.234). In experiment 2, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/low tannin forage pea silage (0.25:0.25:0.5 respectively, DM basis) and 8 kg/d of a high protein concentrate (LTH) or 8 kg/d of a low protein concentrate (LTL). Compared with GWH, the inclusion of forage peas increased (P < 0.05) DM intake by 2.0 kg/d, but there was no effect of dietary treatment on milk yield (average of 24.5 kg/d). Milk fat content was highest (P < 0.05) in cows when fed LTL (45.7 g/kg) and lowest in LTH (41.9 g/kg), but there was no effect (P > 0.05) of treatment on daily fat yield or any other milk component. The efficiency of dietary N use was highest (P < 0.001) in cows when fed GWH (0.300) and lowest in LTH (0.234). It is concluded that either high or low tannin forage pea silages can replace approximately 1.1 kg/d of soyabean meal in the diet of mid-late lactation dairy cows without affecting animal performance, but N efficiency for milk production is decreased.     

Effects of dietary lipid type on muscle fatty acid composition, carcass leanness, and meat toughness in lambs

Isonitrogenous amounts of two protein sources differing in rumen degradation rate and in lipid composition were fed to sheep with or without a rapidly fermentable cereal grain. The effects on intake, carcass leanness, and muscle fatty acid (FA) composition were examined. Thirty-eight crossbred wether lambs (9 mo, 35 to 48 kg) were allocated by stratified randomization to six treatment groups: 1) basal diet of alfalfa hay:oat hay (20:80) ad libitum = basal; 2) basal + lupin (358 g DM/d) = lupin; 3) basal + fish meal (168 g DM/d) = fish meal; 4) basal + barley (358 g DM/d) = barley; 5) basal + barley + lupin (179 + 179 g DM/d) = barley/lupin; or 6) basal + barley + fish meal (179 + 84 g DM/d) = barley/ fish meal. Lambs were fed individually. Dietary treatments were imposed for 8 wk, and the supplements were offered at 2-d intervals. Daily feed intake and weekly BW of lambs were recorded. At the end of the feeding period lambs were slaughtered after an overnight fast. Hot carcass weight (HCW) and fat depth (GR; total fat and muscle tissue depth at 12th rib, 110 mm from midline) were recorded. At 24 h postmortem samples of longissimus thoracis (LT) and longissimus lumborum (LL) muscles were taken from chilled (4 degrees C) carcasses for the assessment of FA composition and meat tenderness, respectively. Lambs fed lupin or fish meal with or without barley had heavier slaughter weights (P < 0.004) and HCW (P < 0.001) than lambs fed basal or barley when initial BW was included as a covariate. The lupin diet also resulted in heavier carcasses (P < 0.05) than the fish meal or barley/fish meal diets. With GR as an indicator, fish meal and barley/ fish meal diets produced leaner carcasses (P < 0.01) than lupin and barley/lupin lambs. Long-chain n-3 FA content [20:5n-3 (P < 0.001), 22:5n-3 (P < 0.003), and 22:6n-3 (P < 0.001)] in the LT muscle were substantially higher with the fish meal and barley/fish meal diets, whereas muscle total n-6 FA was increased (P < 0.003) by lupin and barley/lupin compared with all other diets. Thus, increased muscle long-chain n-3 FA content occurred without an increase in fatness measured as GR, whereas increased muscle n-6 FA content was associated with an increase in carcass fatness. Under these circumstances, a reduction in carcass fatness had no effect on meat tenderness measured as Warner-Bratzler shear force.     

Determination of optimum nutrient element ratios in plant tissue

A new approach for determining optimum nutrient element ratios in plant tissue is presented. Essential steps in the procedure involve: a) measuring patterns of response to pairs of nutrient elements in factorial fertilizer trials, b) modeling the yield response surface using a bivariate, Mitscherlich‐related response function, c) defining balanced nutrition in terms of the parameters of the response surface, d) identifying combinations of P and S fertilizer resulting in balanced nutrition, and e) determining from plant chemical analysis the ratio of nutrients in plant tissue in nutritionally balanced combinations. The approach is illustrated by data from a phosphorus (P) by sulfur (S) factorial field fertilizer trial on a mown mixed white clover (Trifolium repens cv Grasslands Huia) and ryegrass (Lolium perenne L cv Grasslands Nui) sward. Different parameters of yield [total dry matter production, clover dry matter production, clover nitrogen (N) uptake] required different ratios of S:P in fertilizer and consequently in plant tissue for nutritional balance. Also, plant tissue S:P ratios for balanced nutrition declined as the level of nutrition increased. Economic optimum S:P fertilizer ratios were higher than those ratios required for nutrient element balance due to the lower cost and higher effectiveness per kilogram of fertilizer S compared with fertilizer P. Ratios of S and P to N in clover tissue were useful indicators of the adequacy of S and P for clover which was dependent on N₂ fixation for its N supply. It is suggested that a nutrient element index system showing both relative and absolute nutrient element status might be built around N as an internal standard for legumes dependent on N₂ fixation and possibly also for non‐legumes.