Effect of exogenous porcine somatotropin administration on nitrogen and energy metabolism in three genotypes of pigs

Effects of exogenous administration of porcine recombinant somatotropin (rpST) on protein gain and metabolic rate were measured in three genotypes (castrated males) of pigs (Pietrain, Duroc and a crossbreed between Dutch Yorkshire and Dutch Landrace). Six pigs of each genotype were assigned at approximately 60 kg to receive pST doses of either 0 (C) or 14 mg (T) administered i.m. twice weekly over 10 wk. Pigs were housed in individual metabolism cages at a room temperature of 20 to 22 degrees C and received feed at 2.6 times maintenance. Protein gain (N x 6.25) was measured over the final 6 wk of the 10-wk test period. For 2 wk in the test period (wk 2 and wk 5), six pigs of each treatment x genotype group were placed in a large respiration chamber and energy balances (in protein and fat) and metabolic rate were measured. Rate of weight gain measured over the final 6 wk of the experimental period increased by 105 g/d (13%) with rpST administration (P less than .01). Daily protein gain over 6 wk was increased by 48 g/animal with application of rpST (P less than .001). There was a genotype x treatment interaction (P less than .01) for protein gain. Daily protein gain in Durocs with pST treatment was increased (39%) more than in crossbreds (31%). Daily fat gain was decreased by 42 g/animal (P less than .001) by T. Daily heat production with rpST was increased by 12 kcal/kg.75, which is comparable to a 12% increase in the maintenance energy requirement.     

Effect of Trypanosoma vivax infection on energy and nitrogen metabolism of west African dwarf goats

A study was conducted using 32 mature 22-kg West African Dwarf Goats to measure the effect of Trypanosoma vivax infection on energy and nitrogen metabolism. Sixteen goats were infected intravenously with 14 X 10(6) T. vivax. Sixteen control goats were sham-injected. Digestibility and metabolizability of energy and N balance were measured for each goat. Heat production and energy balances were measured per treatment group from 1 wk before infection to 6 wk after infection. Goats were fed alfalfa pellets (10% above maintenance). Treated goats had a reduced (P less than .05) packed cell volume (38 to 40% before infection vs 20 to 25% 6 wk after infection) and an increased (P less than .05) rectal temperature. Log parasitemia/ml was about 6.0 to 6.2. Parasitized goats showed increased urine creatinine excretion at wk 2 postinfection. After infection, feed intake was reduced (about 15%; P less than .05) and greater variability in intake was noted. Treated and control goats had similar N output and energy output in urine. Metabolizability of energy intake was similar at 42.7 vs 42.1% in treated vs control goats, respectively. Heat production in infected goats was increased by about 15%. Treated goats lost more weight and had a lower N balance than control goats (P less than .05). The calculated maintenance energy requirement for infected goats (464 kJ ME/kg.75) was 25% greater than for control goats (375 kJ ME/kg.75).     

Effects of recombinant porcine somatotropin on metabolic rate in growing pigs

Effects of recombinant porcine somatotropin (rpST) on metabolic rate were studied in two trials with 24 crossbred barrows (Yorkshire x Landrace) in each. The barrows weighed about 80 kg (SE within trials 2.2 kg) at the start of the measurements and in each trial 12 pigs received 4 mg of rpST and 12 received a placebo. The diet contained 2.57 Mcal NE/kg and 20% CP (about 1% lysine). Animals were fed approximately 2.8 times maintenance (280 kcal ME.kg-.75.d-1). Heat production (gaseous exchange of CO2 and O2) and activity were measured continuously. Heat production associated with activity was calculated from the regression of heat production on activity. Animals treated with rpST exceeded controls in rate of gain by 252 g/d (P less than .001) and in metabolic rate by 14.5 kcal.kg-.75.d-1 (P less than .01). The rpST treatment increased rectal (+ .2 degrees C) and surface (+ .8 degrees C) temperatures. Activity-related heat production in treated pigs was increased, but this was only partly related to the increase in metabolic rate with rpST. The daily patterns of total and activity-related heat production were similar between pigs in both experimental treatments.     

Western hegemony over african agriculture in Southern Rhodesia and its continuing threat to food security in independent zimbabwe

Zimbabwe's communal farmers are now less food secure than they were two generations ago. The roots of this decline lie not only in the confinement of Africans to marginal land but also in the historic forced replacement of their sustainable, indigenous farming system with one whose productivity now relies on the use of large amounts of expensive chemical inputs. Environmentally-friendly, traditional farming practices such as pyro-culture, minimum tillage, mixed cropping, and bush fallowing were completely wiped out and replaced with a highly technical western or ganic farming system based on plough cultivation and continuous monocultures of commodity crops, that were supposed to be sustained by liberal amounts of green and animal manures. This gave rise to an effective agricultural hegemony that was due, mainly, to the zealous dedication of an American Mormon missionary whose motives were evangelical rather than scientific.     

Determination of zearalenone in grains using high pressure liquid chromatography

The determination of zearalenone content in cereals (maize, wheat and barley) was performed by means of liquid chromatography using the Czechoslovak-made apparatus. This method enables to determine this mycotoxin up to the concentration of 8 micrograms per 1 kg of grain with the accuracy exceeding +/- 9%.     

Heat balance characteristics of limit-fed growing pigs of several breeds kept in groups at and below thermal neutrality

The lower critical temperature (Tcr) and thermoregulatory heat production below Tcr were studied in Norwegian Landrace (N), Finnish Landrace (F), Dutch Landrace (D), and Great Yorkshire (Y) barrows. Animals, weighing 26 kg at the start, were kept in groups for 18, 2-d periods in climate respiration chambers at environmental temperatures (Tenv) between 11 and 26 degrees C. Feeding level of animals in a group was 93 g.kg-.75.d-1 (2.5 times maintenance) and based on mean BW. Great Yorkshire pigs had a higher growth rate and a lower feed to gain ratio than Landrace pigs. Production characteristics of Landrace breeds were similar. The derived Tcr of the breeds was between 18.0 and 20.4 degrees C, the lower value associated with Y pigs and the higher value with F pigs. Thermoregulatory heat production was 6.4 to 11.9 kJ.kg-.75.d-1.degrees C-1 and did not differ between breeds. Radiant surface temperature (Trs) of pigs increased by .4C degrees (= bTrs) when Tenv was raised by 1.0 C degrees between 11 and 26 degrees C. In D pigs, bTrs was higher than in other pigs. Radiant surface temperature was related to backfat thickness; bTrs was increased with greater backfat thickness.     

Environmental Monitoring of Rock Carvings in Scandinavia

In the Scandinavian countries, Norway and Sweden, increased weathering rate of cultural property such as rock carvings, mostly dated between 4200 ? 500 BC, has become a serious problem. Observations during the last decades have shown severe deterioration due to a combination of natural and anthropogenic influences. In order to study the rate of weathering of the rock carvings an interdisciplinary group from Norway and Sweden was formed to carry out environmental monitoring on one site in each country, one of them belonging to the UNESCO World Heritage List. The results from this investigation have elucidated the problems concerning weathering of silicate rock surfaces and the different parameters causing the deterioration. Based on the obtained results some counter measures in order to preserve the rock carvings have been tested.     

The effects of Dictyocaulus viviparus infection on energy metabolism of calves

To determine the effects of lungworm infection on energy metabolism and rate of weight gain, five 3-mo-old male Friesian calves were infected orally twice each week with 640, third-stage larvae of Dictyocaulus viviparus (D.v.) over an 8-wk period. Infected calves were matched with uninfected controls on the basis of similar rates of feed consumption and weight gain during the acclimation period before infection. Infected calves were fed 2 kg of concentrates daily (88% DM), about 8.5 Mcal/d. Controls each received approximately 250 g less, about 7.5 Mcal/d. Similar amounts of hay (5.6 to 5.8 Mcal/d) were provided to all calves. Clinical, serum chemical, hematological and parasitological criteria, weight gain and utilization of energy were monitored on a weekly basis. Serum chemical and hematological analyses and clinical examinations of infected animals revealed signs typical of lungworm infection. Fecal and sputum sample examinations for infected calves were positive for D.v. larvae and ova, respectively. Control animals gained approximately 80 g.animal-1.d-1 more than infected calves. Lungworm infection had no significant effect on digestibility of energy or protein. Metabolizability of energy ingested was somewhat higher in the infected calves due to a higher dietary concentrate to roughage ratio. Utilization of metabolizable energy and protein tended to be less efficient for infected animals. Results showed that D.v.-infected calves need more feed for gain than do uninfected animals. This extra requirement is due to an increased maintenance requirement and probably to a reduced protein retention from digested protein.     

Detection of irradiated ingredients included in low quantity in non-irradiated food matrix. 1. Extraction and ESR analysis of bones from mechanically recovered poultry meat

Protocol EN 1786 for the detection of irradiated food by electron spin resonance (ESR) spectroscopy was not conceived for the detection of irradiated bone-containing ingredients included in low concentration in non-irradiated food. An enzymatic hydrolysis method, realized at 55 degrees C, has been developed for the extraction of the bone fraction. When followed by a purification of the extracts by an aqueous solution of sodium polytungstate, this method made possible the detection of irradiated mechanically recovered poultry meat at very low inclusions (0.5%, wt/wt by ESR) in various meals (quenelles and precooked meals).