The Effects of Housing on Growth, Immune Function and Antioxidant Status of Young Female Lambs in Cold Conditions

Cold conditions in northern China during winter may reduce sheep growth and affect their health, especially if they are young, unless housing is provided. We allocated 45 two-month-old female lambs to be housed in an enclosed building, a polytunnel, or kept outdoors, for 28 days. The daily weight gain and scalp and ear skin temperature of outdoor lambs were less than those of lambs that were housed in either a house or polytunnel; however, rectal temperature was unaffected by treatment. There was a progressive change in blood composition over time, and by the end of the experiment, outdoor lambs had reduced total antioxidant capacity (T-AOC), catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) and increased malondialdehyde compared to those in the house or polytunnel. In relation to immune responses in the lambs' serum, in the polytunnel, immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) were higher and immunoglobulin G (IgG) lower compared with the concentrations in lambs that were outdoors. Over the course of the experiment, genes expressing heat shock proteins and antioxidant enzymes increased in lambs in the outdoor treatment, whereas they decreased in lambs in the indoor treatments. It is concluded that although there were no treatment effects on core body temperature, the trends for progressive changes in blood composition and gene expression indicate that the outdoor lambs were not physiologically stable; hence, they should not be kept outdoors in these environmental conditions for long periods.

Impact of cria protection strategy on post-natal survival and growth of alpacas (Vicugna pacos)

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Three management strategies (open corral, semi-open shed, cria body vest) were investigated in the Andes mountains of Perú for their impact on alpaca cria survival and body weight gain.

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The use of a cria body vest as a protection strategy for alpaca neonates improved survival to 12 weeks of age (100%) and improved cria body weight gain (0.17 kg / d) compared with a semi-open shed (76% survival; 0.14 kg/d) or an open corral (64% survival; 0.13 kd/d). Sex of the cria did not influence cria survival or body weight gain.

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Results of this study are useful because the use of a cria body vest can be implemented and semi-open sheds can be redesigned to improve survival and growth rate of crias reared in harsh environments.

The objective of this study was to evaluate the impact of different management systems on the postnatal survival and growth of alpaca crias. The study was conducted during the alpaca calving season in the Peruvian Andes. Animals were fed on native pastures; during the day they went out to graze, but at night they were brought into a corral. A total of 150 alpaca singleton neonates were randomly assigned to one of three cria protection strategies immediately after consuming colostrum. The first group consisted of 50 crias who slept in an open-corral (OC) without shelter. The second group was comprised of 50 crias fitted with body vests (BV) who stayed overnight in an open-corral without shelter. The third group spent nights in a semi-open shed (SH). Cria survival was recorded daily, and body weight was recorded weekly. Survival to 12 weeks of age was higher (P = 0.001) for BV (100%) than for SH (76%) or OC (64%) which were not different from each other. Daily body weight gain (kg/day) during the first 12 weeks of life was higher (P < 0.001) for BV (0.17 ± 0.03) than for SH (0.14 ± 0.02) or OC (0.13 ± 0.04). There was no effect (P < 0.979) of cria sex on daily body weight gain. Results of this study revealed that fitting neonatal crias with a BV is a viable management strategy to enhance cria postnatal survival and daily body weight gain.

Modelling Chinese grassland systems to improve herder livelihoods and grassland sustainability

Recent degradation of Chinese grasslands has contributed to declining herder productivity and profitability, increased incidence of dust storms and regionally reduced air quality. Overgrazing due to a doubling of stocking rates since the mid-1980s has been identified as a key contributing factor. Several pathways and strategies exist to improve grassland management; however, there remains uncertainty around the long-term sustainability of alternative systems. Nineteen years of grasslands research in China has produced a suite of models designed to improve understanding of grassland systems and investigate options for change. The StageTHREE Sustainable Grasslands Model was used to evaluate the ability of selected strategies to meet economic, production and environmental objectives. Sets of strategies that focussed on flock size, lambing and selling times, supplementary feeding rules and grazing management were simulated for a typical herder located in the desert steppe of Siziwang Banner, in the Inner Mongolia Autonomous Region of China. The results from the risk efficiency analysis indicated that no single strategy set clearly dominates across all objectives. Although the current practice of herders was found to be risk-efficient, it did not achieve the highest rate of grassland recovery, minimise soil erosion or minimise the greenhouse gas (GHG) emission intensity for sheepmeat production. Targeting further improvements in these attributes could be at the detriment of herder livelihoods. The analysis indicated that if herders adopted biomass-based grazing management and improved supplementary feeding they would be able to improve grassland resilience and maintain positive long-term economic performance under reduced flock sizes. Individual decision-making units, however, would still need to trade off the importance of different attributes to identify the strategy set, or system, that best meets their objectives and attitude to risk.

Effects of winter and spring housing on growth performance and blood metabolites of Pengbo semi-wool sheep in Tibet

Objective

Sixty Pengbo semi-wool sheep ewes (approximately 1.5-years-old; 31.33±0.43 kg) were randomly assigned to two groups, either grazing (G) or dry lot feeding (D), to examine the effects of traditional daily grazing and dry lot feeding on performance and blood metabolites during the cold season in Tibetan Plateau.

Methods

The ewes in the G group were grazed continuously each day and housed in one shed each evening, while the ewes in the D group were housed in another shed all day. All animals were fed 400 g/d of commercial concentrate, and grass hay was available freely throughout the experimental period.

Results

Compared with the G group, the ewes in the D group had higher (p<0.05) live weight and weight gain. The D group ewes had greater (p<0.05) numbers of white blood cells and platelets, while they had lower (p<0.05) platelet-large cell ratios, cholesterol, high-density lipoprotein cholesterol and glutathione peroxidase, as compared with the G group ewes. Additionally, three serum metabolites, abscisic acid, xanthoxin and 3,4-dihydroxy-5-polypren, were upregulated (p<0.05) in the G group in comparison with the D group.

Conclusion

In conclusion, a dry lot feeding regime during the winter and spring period will increase the productivity of sheep and improve blood physiological and biochemical profiles.