In semi-arid Mediterranean areas, small grain aftermath stubble represents an important summer source of food for grazing flocks of small ruminants. Wheat stubble is a mediocre source of forage and flocks are grazed in summer under harsh conditions of temperature and air dustiness. However, stubble grazing procedures are changing, water and shading are more frequently available between grazing sessions (“improved management”), and the biological soundness of this ancestral practice needs to be re-visited. The present study was aimed at evaluating the cost in energy of “improved” wheat stubble grazing, compared with feeding a similar diet indoors. The intake of stubble was first quantitatively and qualitatively evaluated in Awassi sheep. Ewes consumed daily 980 ± 100 g day− 1 of wheat stubble. Ewes were then housed and fed diets consisting of wheat hay, straw and grain formulated to be iso-energetic and iso-nitrogenous to diets consumed from wheat stubble. The average intake of ME was similar during the confinement and the pasture periods (6.4 ± 0.5 and 7.6 ± 0.8 MJ day− 1of ME, respectively). During 2 days of each period, animals were fitted with external electrodes and data loggers of heart rate and skin temperature. Energy expenditure (EE) was calculated from oxygen consumption estimated as the product of heart beats rate measured for the two days by the amount of oxygen delivered to body tissues at each heart beat (O2 pulse). The O2 pulse was determined by simultaneously measurement of oxygen consumption and HR twice daily on two occasions, while grazing stubble and indoors. Energy expenditure and energy balance were not different in sheep while grazing wheat stubble (11.1 and − 3.5 MJ day− 1) or fed indoors (11.1 and − 4.8 MJ day− 1). Our data show that stubble did not cover nitrogen and energy requirements for maintenance, and that the cost of summer stubble grazing carried out under conditions described here is less than thought before. 相似文献
This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models.
Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year− 1, 8.4 and 8.4 piglets weaned litter− 1, 66.6 and 93.0 kg piglets weaned sow− 1 year− 1, and 136 and 177 g day− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year− 1, 4.6 and 5.5 piglets weaned litter− 1, 20.5 and 30.9 kg piglets weaned sow− 1 year− 1, and 66 and 85 g day− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed. 相似文献
To identify the effects of field pea hay (FPH) as a supplement of rice straw (RS) on feed intake and milk production of mid‐late lactation buffaloes in Tarai, Nepal, nine multiparous Murrah were fed a concentrate at 0.6% of their bodyweight (BW) on a concentrate dry matter (DM) basis daily while having ad libitum access to RS. The buffaloes were divided into three groups, and the experiment with three levels of FPH feeding was conducted at the following rate of BW: 0% (T1), 0.5% (T2) and 1.0% (T3) on an FPH DM basis. The DM intake (DMI) was higher in T2 and T3 than in T1. As the amount of FPH was raised, the BW change, crude protein intake (CPI) and total digestible nutrient intake (TDNI) was increased. Although the yield of milk and milk composition did not differ among the treatments, the 7% fat corrected milk yield (FCMY) tended to increase as FPH feeding amount was raised. Although there were no significant differences in FCMY/DMI and FCMY/TDNI among the treatments, FCMY/CPI decreased with FPH feeding. Supplementary FPH increased DMI, CPI and TDNI that might have raised BW, and tended to improve FCMY in mid‐late lactating buffaloes as a result of an increase in TDNI. 相似文献
The objectives of this study were to evaluate the environmental impacts of a beef cow–calf system using a life cycle assessment (LCA) method and to investigate the effects of scenarios to reduce environmental impacts on the LCA results. The functional unit was defined as one marketed beef calf, and the processes associated with the cow–calf life cycle, such as feed production, feed transport, animal management, the biological activity of the animal and the treatment of cattle waste were included in the system boundary. The present results showed that the total contributions of one beef calf throughout its life cycle to global warming, acidification, eutrophication and energy consumption were 4550 kg of CO2 equivalents, 40.1 kg of SO2 equivalents, 7.0 kg of phosphate (PO4) equivalents and 16.1 GJ, respectively. The contribution of each process to the total environmental impact in each environmental impact category showed a similar tendency to the contribution of each process in each environmental category reported in the case of the beef fattening system as a whole. The results from this analysis showed that shortening calving intervals by 1 month reduced environmental impacts by 5.7–5.8% in all the environmental impact categories examined in the current study, and increasing the number of calves per cow also reduced environmental impacts in all the categories, although the effects were smaller. 相似文献