Comparison of the performance of dairy cows offered kale,swedes and perennial ryegrass herbage in situ and perennial ryegrass silage fed indoors in late pregnancy during winter in Ireland

The effects on the performance of dairy cows offered kale, swedes, and perennial ryegrass in situ and perennial ryegrass silage fed indoors to dairy cows pre‐partum during winter in Ireland was examined. Eighty‐eight spring‐calving dairy cows were randomly assigned to one of four offered treatments; (i) 8 kg of dry matter (DM) of kale leaf and stem + 4 kg DM of perennial ryegrass silage (treatment K), (ii) 8 kg DM of the root and leaf of swedes + 4 kg DM of perennial ryegrass silage (treatment S), (iii) 12 kg DM of perennial ryegrass herbage (treatment G) offered in situ and (iv) perennial ryegrass silage offered ad libitum indoors (treatment ID). Cows on treatments K, S and ID had a greater (P < 0·001) increase in body condition score (0·20, 0·14 and 0·50 units respectively) pre‐partum than cows on treatment G which lost 0·22 units. Pre‐partum treatment had no effect on variables of milk production in the following lactation. In the first 100 d of lactation, cows on treatment G pre‐partum had a lower milk fat concentration (35·6 g kg^?1) compared with cows on treatments S and ID (38·3 and 39·3 g kg^?1 respectively). There was no effect of treatment on the intervals between parturition and first insemination (mean 74·6 d) and conception (mean 96·1 d). The results suggest that offering kale and swedes to dairy cows pre‐partum resulted in a similar lactation performance to dairy cows grazing a perennial ryegrass sward or offered perennial ryegrass silage indoors.     

Chironomid abundance and consumption by juvenile channel catfish in plastic‐lined and earthen culture ponds

In 2004, research was conducted to compare chironomid larvae populations and their use by channel catfish (Ictalurus punctatus) fingerlings in two different culture systems. Over a 4‐month culture period, chironomid larvae densities in plastic‐lined ponds were significantly less than those in earthen ponds. The consumption of chironomid larvae by channel catfish fingerlings was related to chironomid abundance in earthen ponds. The significance of these findings is the possible relationship among pond type, initial consumption of commercial diets and subsequent survival rates of fingerling channel catfish.     

Leaf phosphorus and nitrogen concentrations and net photosynthesis in Eucalyptus seedlings

Seedlings of Eucalyptus grandis Hill ex Maiden, E. pilularis Smith and E. gummifera (Sol. ex Gaertner) Hochr. were grown in solution culture with 100 micromol phosphorus (P). After eight weeks, half of the seedlings were transferred to solution cultures containing 1 micromol P. After a further four weeks, growth, net photosynthesis and foliar P and nitrogen (N) concentrations were measured. The seeds of E. grandis came from a relatively fertile site and those of the other two species from phosphorus-deficient sites. Growth and net photosynthesis did not change in E. pilularis subjected to the low-P treatment, whereas in E. grandis, and to a limited extent in E. gummifera, the low-P treatment resulted in an increase in net photosynthesis that was associated with higher foliar N concentrations (especially protein-N), possibly as a result of nitrogen being retranslocated from the roots. In response to the low-P treatment, leaf phosphorus concentration was reduced by 50-60% in E. grandis and E. pilularis and by 20-30% in E. gummifera. Of the chemical fractions examined, the greatest decrease occurred in the inorganic-P pool. The data suggest that photosynthesis is not limited by leaf phosphorus concentrations typical of those found in Eucalyptus seedlings growing on phosphorus-deficient sites.     

A note on the effect of dietary proportions of kale (Brassica oleracea) and grass silage on rumen pH and volatile fatty acid concentrations in dry dairy cows

The objective of this study was to evaluate the effect of varying proportions of dietary kale on rumen pH and volatile fatty acid production. Four pregnant dry dairy cows permanently fitted with ruminal cannulae were randomly assigned to four kale: grass silage dietary proportions (0:100, K0; 60:40, K60; 85:15, K85 and 100:0, K100) on a dry matter basis in a 4 × 4 Latin Square design with four 20 day periods. Cows were acclimatised for 15 days, followed by a five-day period of experimental sampling and measurement. Internal pH meters were installed to continuously monitor rumen pH while rumen liquor collection tubes were used to sample rumen liquor for volatile fatty acid analysis at 0, 4, 8 and 12 h after feeding on each sampling day. Cows on treatment K85 had a lower (P < 0.001) ruminal pH compared to cows on treatments K100, K60 or K0 (6.26, 6.32, and 6.32 vs. 5.91, respectively). While a gradual decrease in rumen pH was observed over an eight-hour period for K85 before recovery, offering K100 did not reduce rumen pH below 6.0 or induce acidosis. Increasing the dietary proportion of kale did not affect (P > 0.05) acetate:propionate ratio production (3.71, 3.65, 3.86, 3.78 mmol L^− 1 for K0, K60, K85 and K100, respectively). Offering cows K60 had increased (P < 0.05) rumen VFA concentration (71.67 mmol L^− 1) relative to K0 (53.45 mmol L^− 1), while offering K85 and K100 had no affect on rumen VFA concentration (61.74 and 59.35 mmol L^− 1) (Table 2). Offering dry cows K100 relative to K0 reduced dry matter intake by 17.5% (7.32 vs. 8.87 kg DM day^− 1, respectively) which may be associated with the presence of S-methyl-L-cysteine sulphoxide which can cause haemolytic anaemia and depressed DM intake. The results suggest that increasing the dietary proportion of kale was associated with a progressive decrease in dry matter intake but with minimal effects on rumen pH, total volatile fatty acid concentration and individual volatile fatty acid proportions.     

Evaluation of the GrazeIn model of grass dry‐matter intake and milk production prediction for dairy cows in temperate grass‐based production systems. 1–Sward characteristics and grazing management factors

This study evaluated the prediction accuracy of grass dry‐matter intake (GDMI) and milk yield predicted by the model GrazeIn using a database representing 522 grazing herds. The GrazeIn input variables under consideration were fill value (FV), grass energy content [Unité Fourragère Lait (UFL)], grass protein value [true protein absorbable in the small intestine when rumen fermen energy is limiting microbial protein synthesis in the rumen (PDIE)], pre‐grazing herbage mass (PGHM), daily herbage allowance (DHA) and concentrate supplementation. GrazeIn was evaluated using the relative prediction error (RPE). The mean actual GDMI and milk yields of grazing herds in the database ranged from 9·9–22·0 kg DM per cow d^?1 and 8·9–41·8 kg per cow d^?1, respectively. The accuracy of predictions for the total database estimated by RPE was 12·2 and 12·8% for GDMI and milk yield, respectively. The mean bias (predicted minus actual) for GDMI was ?0·3 kg DM per cow d^?1 and for milk yield was +0·9 kg per cow d^?1. GrazeIn predicted GDMI with a level of error <13·4% RPE for spring, summer and autumn. GrazeIn predicted milk yield in autumn (RPE = 17·6%) with a larger error in comparison with spring (RPE = 10·4%) and summer (RPE = 11·0%). Future studies should focus on the adaptation of GrazeIn to correct and improve the prediction of milk yield in autumn.     

Amending reduced fish‐meal feeds with marine lecithin,but not soy lecithin,improves the growth of juvenile cobia and may attenuate heightened responses to stress challenge

Sparing of marine resources in aquafeeds can be environmentally and economically advantageous; however, fish meal (FM) replacement can affect the production performance and physiological competence. Phospholipids are increasingly understood to be involved in maintaining growth and vigour in fish and may be deficient in reduced FM formulations. Accordingly, we evaluated the growth and stress tolerance of juvenile cobia fed typical (50% FM) or reduced FM feeds (12% FM) with or without phospholipid amendment [1% marine lecithin (12% FM + Marine PL) or soy lecithin (12% FM + Soy PL)] for 6 weeks in triplicate tanks (N = 3) in a recirculation aquaculture system. The 50% FM feed yielded significantly superior growth and growth efficiency in comparison with the 12% FM and 12% FM+ Soy PL feeds, but the 12% FM+ Marine PL feed yielded comparable results to 50% FM feed. A low‐water stress challenge induced elevated plasma glucose, cortisol and lactate levels in all treatments. However, a significant interaction (diet × stress) effect suggested a lesser cortisol response among fish fed the 12% FM+ Marine PL and 50% FM diets. These findings demonstrate that growth performance and, perhaps, resilience of cobia raised on reduced FM feeds may be improved by the addition of marine‐origin phospholipid to the diet.     

Practical animal-handling classes at University College Dublin

The first two years of the veterinary program at University College Dublin (UCD) include two modules whereby students gain experience in basic animal handling. Practical Animal Husbandry uses both lectures and animal handling classes aimed at teaching students to approach, restrain, and carry out routine husbandry procedures on food-producing and companion animals humanely and competently and to be aware of the risks to human health of inappropriate animal approach and handling. Staff and students are given lists of animal-handling competencies designed to ensure that students attain relevant handling skills for beef and dairy cattle, pigs, horses, sheep, cats, dogs, and exotics (e.g., rabbits, guinea pigs). Students are allotted up to 12 weeks of Farm and Companion Animal Experience, an extramural (EMS) activity, according to their prior experience; the objectives are to become proficient in the handling and management of animals and to develop an understanding of the key husbandry factors in food-production systems (milk, beef, lamb, pork) at the farm level. Students are assessed in practical examinations at the end of the second year and cannot progress until they have achieved the required competence. In addition to the pedagogic strategies, special consideration is given to the welfare of the animals used in teaching practicals and to the health and safety of teaching staff and students.     

Optimal irrigation efficiency for maximum plant productivity and minimum water loss

Castilla-La Mancha in Central Spain is a semi-arid area of extremely high interannual and seasonal rainfall variability. Average annual rainfall for the catchment of the Upper Guadiana using data from 60 rain gauges for October 1956–September 1991 varied from a minimum of 326 mm in October 1982–October 1983 to a maximum of 642 mm in October 1968–September 1969. The mean annual rainfall for the period was 495 mm with a coefficient of variation for annual rainfall of 26.4%. In addition to this the spatial variability of rainfall is particularly high. For example total annual rainfall varied from 200 to 1200 mm for the hydrological year October 1968–September 1969 over a distance of only 50 km. The mean annual rainfall for all 60 stations for the period 1956–1991 was 460 mm with a coefficient for spatial variation of 15%. Dryland farming which relies on these uncertain precipitation inputs is a high risk activity [Tarjuelo, J.M., de Juan, J.A., Valiente, M., Garcia, P., 1996. Agric. Water Manage. 31, 145–163] and over recent decades intensive irrigation has increased dramatically in order that precipitation inputs can be supplemented as required thereby allowing more stable agricultural productivity. The paper uses a coupled hydrology and vegetation growth model – PATTERN [Mulligan, M., 1996. Modelling hydrology and vegetation change in a degraded semi-arid environment. PhD. Thesis, University of London] to explore the relationship between irrigation and productivity for different soils typical of the Upper Guadiana catchment. Analysis of the model results shows that irrigation efficiency is highly sensitive to both soil texture and irrigation volume. Optimally efficient irrigation in terms of water losses occurs at the lowest volumes of applications. Fine grained soils are better suited to irrigation than coarse grained soils as losses to recharge are minimised. Coarse grained soils have large recharge losses and irrigation is also more sensitive to small changes in texture for coarser soils. Irrigation losses through recharge are also very sensitive to the interannual and spatial variability of rainfall.     

Expression of an exogenous growth hormone gene by transplantable human epidermal cells

Retrovirus-mediated gene transfer was used to introduce a recombinant human growth hormone gene into cultured human keratinocytes. The transduced keratinocytes secreted biologically active growth hormone into the culture medium. When grafted as an epithelial sheet onto athymic mice, these cultured keratinocytes reconstituted an epidermis that was similar in appearance to that resulting from normal cells, but from which human growth hormone could be extracted. Transduced epidermal cells may prove to be a general vehicle for the delivery of gene products by means of grafting.