Effect of different grazing pressures by lambs grazing Lolium perenne and Dactylis glomerata pastures during spring on: 2. Intake and growth

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the performance of lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed intakes and average daily live weight gains (ADG in g/day) were determined for each group. In general intakes of both L. perenne and D. glomerata pastures were higher at the end of the study than at the onset. Grazing pressure had no effect on the intake of L. perenne, but on the D. glomerata pasture, HGP resulted in a decreased intake by the lambs compared to the LGP treatment. For both pasture species the ADG of the lambs were lower on the HGP compared to the MGP treatment, though intake and ADG of the lambs were higher when grazing L. perenne compared to D. glomerata. Keywords:Cocksfoot; diet selection; pasture availability; perennial rye grass; performance South African Journal of Animal Science Vol. 36 (5) 2006: pp.50-5

Effect of different grazing pressure by lambs grazing Lolium perenne and Dactylis glomerata pastures during spring on: 1. Diet quality

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the quality of herbage consumed by lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed samples collected via oesophageal fistulae at the start and end of a six-week grazing period were analyzed for nitrogen (N), ash, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) concentrations, and in vitro digestibility of organic matter (IVDOM). In general, the quality of diets selected by lambs grazing both L. perenne and D. glomerata pastures was lower at the end than at the start of the grazing period. For both pastures the N concentration of herbage consumed by lambs in the HGP treatment was lower than for that in the LGP treatment. For L. perenne HGP resulted in the selection of a diet with higher fibre (NDF and ADF) concentrations and consequently lower IVDOM than in the LGP treatment. In the D. glomerata pasture, higher ADF and lower IVDOM were recorded in the MGP treatment compared to the other treatments. On the D. glomerata pasture the ADL concentration of the selected forage was lower in the HGP than in the MGP or LGP treatments. Forage selected on the L. perenne pasture had generally lower N, ash, ADF and ADL concentrations than those selected from the D. glomerata pasture. However, the IVDOM of the selected L. perenne was higher than that of selected D. glomerata. Keywords: Cocksfoot; chemical composition; diet selection; pasture availability; perennial rye grass South African Journal of Animal Science Vol. 36 (5) 2006: pp.46-4

Growth performance and carcass characteristics of three Ethiopian goat breeds fed grainless diets varying in concentrate to roughage ratios

Growth and carcass characteristics of three Ethiopian goat breeds, the Afar, Central Highland (CHG) and Long-eared Somali (LES) were evaluated using three grainless diets varying in concentrate:roughage ratios (diet 1 was 50:50, diet 2, 65:35 and diet 3, 80:20) under feedlot conditions. The roughage was native grass hay and the concentrate consisted of wheat bran and noug cake (Guizotia abyssinica). Seventy-two eight-month old intact male goats (24 per breed) were randomly allotted to the dietary treatments, fed for 126 days and slaughtered at an age of approximately 12 months. The LES had higher average daily gain (ADG), heavier slaughter, empty body (EBW) and carcass weights than Afar and CHG goats. Diet significantly affected ADG, but was similar on carcass traits except for dressing percentage (DP) on an EBW basis and some non-carcass components. The DP on an EBW basis was the highest on diet 1. Breed affected the DP, which ranged from 42.5 - 44.6% and 54.3 - 55.8% on slaughter weight and EBW basis, respectively. The LES had a greater buttock circumference and carcass compactness. The pH24 varied between 5.61 - 5.67 and chilling losses were between 2.5 and 3.1%. The physical carcass composition (8-10th rib-cut) ranged from 72 - 73, 6.9 - 10.9 and 17.1 - 20.2% for lean, fat and bone, respectively, and the fat content of the meat ranged from 10.3 - 14.0%. Breed affected the weights of internal fat depots. The findings indicate that breed affected the carcass characteristics of the three Ethiopian goat breeds. Keywords: Indigenous goats; carcass yield; carcass composition; primal cuts; non-carcass components South African Journal of Animal Science Vol. 37 (4) 2007: pp.221-23

Fish meal supplementation to early lactation Jersey cows grazing ryegrass pasture

This trial was conducted to test the hypothesis that early lactation cows grazing ryegrass pasture and receiving maize and mineral supplementation could respond to additional supplementation with a protein source such as fish meal. Multiparous Jersey cows in early to mid lactation that grazed annual ryegrass pasture in spring were used in a randomised complete block design experiment. In addition to the pasture, cows received 6 kg (as is) of a maize-based supplement, including minerals, fed in two equal portions in the milking parlour. Three groups of 15 cows received a control, a low fish meal or a high fish meal treatment (0, 4 or 8% fish meal replacing maize). Milk yield was measured and milk samples taken fortnightly. A simultaneous study on rumen fermentation was conducted using eight rumen cannulated cows receiving the control and high fish meal treatments in a cross-over design experiment. Ruminal pH and ammonia-N and volatile fatty acid concentrations were measured. Milk yield, 4% fat-corrected milk yield and milk fat and protein percentages of cows on the low and high fish meal treatments (21.9 and 22.1 kg milk/d, 24.1 and 24.2 kg 4% fat corrected milk/d, 4.73 and 4.67% fat and 3.49 and 3.45% protein) were higher than the control (20.5 kg milk/d, 20.4 kg 4% fat corrected milk/d, 3.97% fat and 3.25% protein). The ruminal ammonia-N concentration was higher in the cows on the high fish meal treatment than the control (16.7 vs. 14.2 mg/dL). Fish meal supplementation to cows on ryegrass proved to be profitable. Keywords: Dairy cattle, cultivated pasture, RUP, maize, milk yield, milk composition South African Journal of Animal Science Vol. 38 (4) 2008: pp. 331-34

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

The bii4africa dataset of faunal and floral population intactness estimates across Africa's major land uses

This is the final version. Available on open access from Nature Research via the DOI in this recordCode availability: R code for calculating aggregated intactness scores for a focal region (e.g., ecoregion or country) and/or taxonomic group can be downloaded with the bii4africa dataset on Figshare; see Data Records section.Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems.Jennifer Ward Oppenheimer Research Gran

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Qualitative evaluation of four subtropical grasses as standing hay: diet selection, rumen fermentation and partial digestibility by sheep

The nutritive value of four subtropical grasses (Panicum maximum, Anthephora pubescens, Digitaria eriantha and Chloris gayana) standing hay were compared in terms of qualitative intake and partial digestibility by sheep. The species differed significantly in terms of diet  quality selected by sheep grazing the standing hay. The rumen  ammonia nitrogen (NH3-N), total volatile fatty acid and propionic acid concentrations of sheep grazing P. maximum and A. pubescens were higher than those sheep grazing D. eriantha and C. gayana standing  hay. Organic matter intake (OMI) (g kg–1 W0.75 d–1), nitrogen intake (g d–1), digesta flow, the total N flow, NH3-N flow, non-ammonia  nitrogen (NAN) flow and NAN disappearance (g d–1) in the ileum were higher for sheep grazing P. maximum than for those grazing the other standing hays. The organic matter disappearance in the stomach and small intestine of sheep grazing P. maximum and D. eriantha standing hay was higher than for those sheep grazing either A. pubescens or C. gayana standing hay. The NAN flow/N intake were the highest for sheep grazing P. maximum and A. pubescens compared to C. gayana. The NAN digestibility was, however, not significantly different among  the four species. The standing hays (except for C. gayana) seemed to have the capacity to meet the N requirement of the sheep for production, but the OMI (g kg–1 W0.75 d–1) was not sufficient to support maintenance requirement of the sheep. African Journal of Range & Forage Science 2009, 26(2): 69–7