1,722,249 research outputs found
Socio-economic aspects of growing GM crops
No full textWhile emotional public controversies continue, there is a growing body of literature providing empirical evidence on the impacts of GM crops in different countries. This chapter reviews recent socioeconomic studies, focusing on peer-reviewed academic papers. Studies on the farm-level impacts of herbicide-tolerant and insect-resistant crops are reviewed. Moreover, some macro-level research looking at global impacts are summarized. Finally, the potential effects of future GM crop applications, including crops with other improved agronomic traits and nutritional traits, are discussed
Effect of different feeding intensity on feed intake, live weight gain, various body traits as well as the energy utilization for weight gain in female calves and heifers
No full textEighty newborn female Holstein calves were used to assess the influence of feeding intensity during the rearing period of calves and heifers on the feed intake and the growth. Throughout the first period (up to week 14) 40 animals each were provided with low and high amounts of milk replacer. Thereafter until week 24 the animals were fed on the same level with grass silage and concentrates (period 2). From the beginning of week 25 until first mating with about 400 kg of body weight each group was divided again into two subgroups receiving low and high amounts of concentrates and grass silage for ad libitum consumption. The high drinking intensity in period 1 resulted in a significantly higher dry matter intake (DMI), live weight gain (LWG), withers height and energy consumption for LWG, whereas there were no differences in these parameters at the end of period 2. The elevated concentrate level during period 3 significantly increased DMI and energy consumption independent of previous drinking intensity. Throughout the whole experiment neither the drinking intensity, nor the concentrate level did significantly influence the DMI, the growth and the energy consumption, whereas the concentrate level significantly increased the LWG
Studies on the relationship between the synchronization index and the microbial protein synthesis in the rumen of dairy cows
No full texttotal of eight Holstein cows equipped with ruminal and duodenal cannulae were used to evaluate the suitability of the synchronization index (SI) for optimizing microbial protein (MP) synthesis in the rumen in two experiments. In a preliminary study, degradation characteristics of the feedstuffs were estimated by the nylon bag technique and the quantities of organic matter (OM) and nitrogen (N) degraded per 4 It interval were calculated as difference between the cumulative amounts of OM and N degraded at successive intervals. The relationship between the sum of degraded N and the sum ofdegraded OM from the different feeds at each interval were used to calculate the SI. In the first in vivo experiment equal amounts of maize silage, grass hay, wheat grain and peas+ urea and in the second experiment grass silage, maize grain and soyabean meal were fed to seven and five cows, respectively, four times daily in three different sequences (FS): in FS-A equal amounts of the protein and energy sources were offered at each feeding time; FS-B: first and third feeding time were offered only the energy sources, second and fourth feeding time only the protein sources; FS-C: separate feeding of energy and protein sources as in "FS-B", but sequence was reversed. Mean feed intake was 14.2 and 17.0 kg DM in the first and second experiment, respectively. The ratio of N/OM release varied during the course of the day in dependence on the feeding sequences for both experiments. The variations of the ratios and the calculated SI were higher in the first compared to the second experiment. The SI was 0.76, 0.52, and 0.82 for FS-A, FS-B, and FS-C in the first experiment, respectively. In the second experiment, indices were 0.85, 0.90, and 0.72 for FS-A, FS-B, and FS-C, respectively. The means of rumen pH, ammonia-N, and total short chain fatty acids were not influenced by feeding sequences in both experiments. For both experiments, flow of non-ammonia-N at the duodenum and efficiency of microbial protein (MP) synthesis tended to be highest in FS-B where energy sources were fed at the first feeding time. This was significant only in the second experiment (187, 245, and 197 g microbial CP/kg fermented OM (FOM) for FS-A, FS-B, and FS-C, respectively). Microbial CP synthesis was not consistent with the SI parameters. Only in the second experiment, the highest SI corresponded with the highest microbial CP synthesis. The lowest SI in the first (0.52, FS-B) and second experiment (0.72, FS-C) was not associated with the lowest efficiencies of microbial CP synthesis (163 and 187 g microbial CP/kg FOM, FS-A in Experiments 1 and 2, respectively). (c) 2007 Elsevier B.V. All rights reserved
Effect of sire breeds in commercial pig crosses on growth, carcass composition, meat and fat quality
No full text200 weaners from a large field trial in Niedersachsen to test different German and foreign sire breeds for their ability to improve the quality of market products were put at an individual feeding trial at the FAL-Nutrition Institute in Braunschweig. It was the aim of this feeding trial to compare the effects of different fat additions to the diet, sire breeds, sexes and slaughter weights upon growth and usual carcass traits but also upon several additional meat and fat quality traits. The trial was carried out in two blocks with 96 pigs each with the sire breeds Pietrain of the two MHS-genotypes PP (stress susceptible) and NN (stress resistant), Duroc and Hamsphire Duroc (both NN) as preferrably used in Denmark. As control in both blocks the BHZP-standard boar 65 (PI HA(NN)) was used. Here only the sire breed effects will be reported. In daily gain and energy conversion only DU-progeny differed significantly from the control (+33g, -1.32 MJ/kg). The tissue dissection showed that PI(PP)-, DU- and HA DU-progeny had 0.8-1.0% higher bone and respectively lower residual components (lean, fat, tissue). In carcass measurements PI(PP) progeny were the leanest followed by PI(NN), and DU progeny had the smallest loin eye areas and carcass lean contents. This affected the carcass cuts such that PI(PP) progeny had a 1.2%(=1.08 kg) higher sum of primal cuts and DU progeny with -0,8% (400g) below the control were the poorest. In meat quality traits only the heterozygote stress susceptible PI(PP) progeny showed highly significant poorer values than all other crosses, which differed little from each other. This was confirmed by drip losses 2 and 4 days post mortem, which were 1.3-1.6% higher than the control whereas DU progeny were the best with -0.6%. Chemical analysis of a loin sample produced for both Danish sire breeds significantly higher intramuscular fat (+0.36-0.38%) and for PI(PP) progeny with -0.32% the lowest values, but the overall mean reached only 1.3% intramuscular fat. The protein and glycogen contents of loin revieled the expected large deviations of Hamsphire progeny due to the dominant RN gene (-0.8-1% protein, +10-14 mumol/g glycogen). All HA-free crossbreds did not differ much. The fatty acid composition of backfat and intramuscular fat showed much smaller differences between sire breeds than between fat supplements to the ration, but Danish sire breeds transmitted higher contents of polyunsaturated and Omega 3 fatty acids than the other sire breeds. Finally, for animals of the second trial also a sensoric test of loin samples was performed at the Federal Meat Research Institute. There subjective scores for tenderness and juiciness as well as grill losses showed significant sire breed differences. But contrary to expectation both Danish sire breeds produced inferior quality in all three traits to PI HA(NN) control sire groups
Effect of sire breeds in commercial pig crosses on growth, carcass composition, meat and fat quality
No full text200 weaners from a large field trial in Niedersachsen to test different German and foreign sire breeds for their ability to improve the quality of market products were put at an individual feeding trial at the FAL-Nutrition Institute in Braunschweig. It was the aim of this feeding trial to compare the effects of different fat additions to the diet, sire breeds, sexes and slaughter weights upon growth and usual carcass traits but also upon several additional meat and fat quality traits. The trial was carried out in two blocks with 96 pigs each with the sire breeds Pietrain of the two MHS-genotypes PP (stress susceptible) and NN (stress resistant), Duroc and Hamsphire Duroc (both NN) as preferrably used in Denmark. As control in both blocks the BHZP-standard boar 65 (PI HA(NN)) was used. Here only the sire breed effects will be reported. In daily gain and energy conversion only DU-progeny differed significantly from the control (+33g, -1.32 MJ/kg). The tissue dissection showed that PI(PP)-, DU- and HA DU-progeny had 0.8-1.0% higher bone and respectively lower residual components (lean, fat, tissue). In carcass measurements PI(PP) progeny were the leanest followed by PI(NN), and DU progeny had the smallest loin eye areas and carcass lean contents. This affected the carcass cuts such that PI(PP) progeny had a 1.2%(=1.08 kg) higher sum of primal cuts and DU progeny with -0,8% (400g) below the control were the poorest. In meat quality traits only the heterozygote stress susceptible PI(PP) progeny showed highly significant poorer values than all other crosses, which differed little from each other. This was confirmed by drip losses 2 and 4 days post mortem, which were 1.3-1.6% higher than the control whereas DU progeny were the best with -0.6%. Chemical analysis of a loin sample produced for both Danish sire breeds significantly higher intramuscular fat (+0.36-0.38%) and for PI(PP) progeny with -0.32% the lowest values, but the overall mean reached only 1.3% intramuscular fat. The protein and glycogen contents of loin revieled the expected large deviations of Hamsphire progeny due to the dominant RN gene (-0.8-1% protein, +10-14 mumol/g glycogen). All HA-free crossbreds did not differ much. The fatty acid composition of backfat and intramuscular fat showed much smaller differences between sire breeds than between fat supplements to the ration, but Danish sire breeds transmitted higher contents of polyunsaturated and Omega 3 fatty acids than the other sire breeds. Finally, for animals of the second trial also a sensoric test of loin samples was performed at the Federal Meat Research Institute. There subjective scores for tenderness and juiciness as well as grill losses showed significant sire breed differences. But contrary to expectation both Danish sire breeds produced inferior quality in all three traits to PI HA(NN) control sire groups
Studies on the biotin flow at the duodenum of dairy cows fed diets with different concentrate levels and types of forages
No full textBiotin is involved in many vital metabolic pathways and must be provided for an efficient fermentation in the rumen, as well as for the intermediary metabolism of the host animal. Factors influencing ruminal biotin metabolism and output are widely unknown at present. Therefore, dairy cows fitted with permanent cannulas in the dorsal rumen and in the proximal duodenum were fed differently composed diets, and the biotin flow at the proximal duodenum was measured. The diets (on DM basis) consisted of 8.9 kg grass hay (Diet 1), 8.9 kg corn silage plus 2.0 kg concentrate (Diet 2), or 7.3 and 7.4 kg grass silage plus 10.0 kg concentrate (Diets 3 and 4). The concentrate in Diets 3 and 4 contained 87% wheat and corn grain, respectively. The cows were pre-fed the rations for 21 days. Thereafter duodenal digesta was sampled every two h for 5 days. Cr2O3 served as a flow marker and the microbial proportion of total nitrogen at the duodenum was estimated by near infrared spectroscopy (NIRS). The duodenal flow of biotin was not related to biotin intake, but to the amount of fermented organic matter (FOM) and the amount of microbial protein (Biotin [mg/d] = 0.518.kg FOM-0.300; r = 0.85 and biotin [mg/d] = 0.012.g microbial protein + 1.478; r = 0.84), irrespective of the composition of the diet fed. Mean daily biotin flow was 0.48 +/- 0.11 mg/kg FOM without any systematic effect of diet composition. The ruminal biotin balance, calculated as the difference between biotin flow at the duodenum and biotin intake, was positive (1.4-2.0 mg/d) in cows fed the mixed roughage/concentrate diets and negative (-0.71 mg/d) when the pure hay diet was fed
Einfluss mikrobieller Phytase in Mais-Soja Diäten für Legehennen auf Leistung sowie Energie- und Nährstoffverwertung
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Wirkung verschiedener mikrobieller Phytasen in pflanzlichen Diäten von Tilapien (Oreochromis niloticus)
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