| 1. |
- Bernes, Gun, et al.
(author)
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Sheep fed only silage or silage supplemented with concentrates. 1. Effects on ewe performance and blood metabolites
- 2012
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 102, s. 108-113
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Journal article (peer-reviewed)abstract
- In Scandinavia, winter diets for sheep are forage-based, with concentrates commonly being added in the latter part of pregnancy and during lactation. In organic production, however, the level of concentrates is restricted and rations are sometimes purely forage-based. It is uncertain if feeding only forage fulfils the nutritional requirements of high producing ewes. The aim of this project was to compare the performance and nutrient status of ewes fed only silage from mid-pregnancy until the end of lactation (SIL), or silage and a maximum of 40% concentrates before lambing, and 50% afterwards (CON). The study was conducted during two consecutive indoor feeding seasons (Y1 and Y2), with 41 and 51 ewes, respectively. In Y1, the silage was of high nutrient quality, whereas the silage used in Y2 had a lower content of energy and protein and more fibres. The general level of feed intake was lower in Y2 than Y1. There were significant differences in body condition between SIL and CON ewes in both years. Blood samples from the ewes were analyzed for betahydroxybutyrate (BHB), non-esterified fatty acids (NEFA) and urea. In both years, SIL ewes had higher NEFA and BHB than CON ewes two weeks after lambing, In Y2, urea was lower in SIL ewes than in CON ewes after lambing. Litter size also had a significant impact on the blood metabolites. In conclusion, feeding only silage is not recommended for ewes with more than one lamb, unless the silage is of a very high nutritional quality. (C) 2011 Elsevier B.V. All rights reserved.
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| 2. |
- Bernes, Gun, et al.
(author)
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Sheep fed only silage or silage supplemented with concentrates 2. Effects on lamb performance and fatty acid profile of ewe milk and lamb meat
- 2012
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 102, s. 114-124
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Journal article (peer-reviewed)abstract
- Production performance of ewes fed only silage, or silage supplemented with a maximum of 50% concentrates (barley, peas, rapeseed cake), from mid-gestation until weaning was evaluated during two years. Lambs had access to the same diets as their dams while nursing. Ewe milk samples were collected at weeks 2 and 4 after lambing to evaluate the dietary influence on the fatty acid (FA) profile. After weaning, lambs from each ewe feeding programme either continued on the same diet or were switched to the other and the study continued for an additional five weeks year 1 (Y1) and seven weeks year 2 (Y2). Feed intake, weight gain and body condition of the lambs were recorded. At slaughter, muscle samples were taken to study the FA profile. The silage fed during Y2 was lower in crude protein content and contained more indigestible neutral detergent fibre and a higher amount of acids than the silage fed in Y1. The intake level of the lambs, particularly those fed only silage, was generally lower in Y2. In both years, weight gain was highest in the lamb groups fed concentrates after weaning and lowest in the group fed only silage. The FA profiles of milk and lamb muscle were influenced by the diet and nutritional status of the ewes. Milk from silage-fed ewes was higher in Cl 8:3n-3 and conjugated linoleic acid, whereas milk from concentrate-fed ewes was higher in C18:0 and C18:2n-6. In Y1 the muscle of lambs fed concentrates pre-weaning had lower C16:0 and higher C18:1c-9 levels. The influence of diet on lamb muscle FA profile was less pronounced in Y2. In both years the C18:3n-3 levels were lower in muscle from lambs fed concentrates. In conclusion, the FA profile of lamb muscle was strongly influenced by the ewe diet and milk FA profile. Lambs on the same pre-weaning diet had a more similar profile than lambs with the same post-weaning diet. Feeding intensity and duration were the factors influencing the lamb muscle FA profile. A diet with only silage produced meat with a higher proportion of n-3 FA beneficial for human health; however, the lamb nutritional requirements for optimal growth were difficult to meet even with high-nutrient-quality silage. (C) 2011 Elsevier B.V. All rights reserved.
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| 3. |
- Bett, Cheruioyt Rawlynce
(author)
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Definition of breeding objectives and optimum crossbreeding levels for goats in the smallholder production systems
- 2011
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 96, s. 16-24
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Journal article (peer-reviewed)abstract
- The objective of this study was to define breeding objectives and consequently determine optimum crossbreeding levels for goats in the smallholder production systems. Profits and economic values (EVs) were estimated for four genotypes namely (a) original stock or local goat breeds with 0% German Alpine blood level (OS), (b) F1 with 50% German Alpine blood level (F1), (c) first backcross with 75% German Alpine blood level (B1) and (d) second backcross with 87.5% German Alpine blood level (B2). The EVs were estimated for average daily milk yield (DMY, kg), average post-weaning daily gain (ADC, kg), number of kids weaned (NKW), mature weight (MW, kg) and 12-month live weight (LW, kg). Profitability in Kenyan Shilling (KES) without risk was optimal (KES 6038.02) for the B1 genotype. Economic values without risk for most traits were highest for the F1 genotype, i.e., KES 64.85 (ADG), 24.02 (NKW), -27.55 (MW) and 84.51 (LW). There was, however, a 23% reduction in profits in the F1 genotype. It was evident that crossbreeding would improve the profitability of the smallholder farms, but not beyond the 75% grade level. A similar trend was observed when risk was incorporated. Differences in profitability with and without risk were less than 0.005% for all the genotypes. However, differences in EVs were large, ranging from -28% to +19%; DMY had the largest differences. Therefore, incorporation of risk in estimation of EVs for traits of importance is necessary. This study has also demonstrated that crossbreeding to a higher grade level is not necessarily compensated for by a high performance in most traits. Therefore, a crossbreeding program targeting B1 (75%) crossbreds would be desirable for implementation in the smallholder production systems. (C) 2010 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Fonseca Rodriguez, Osvaldo, PhD, 1982-, et al.
(author)
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Spatial modeling of oestrosis in sheep in Guantánamo province, Cuba
- 2018
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488 .- 1879-0941. ; 164, s. 32-38
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Journal article (peer-reviewed)abstract
- Oestrosis is a myiasis caused by larvae of the fly Oestrus ovis (Linné 1761, Diptera: Oestridae) that occurs worldwide. Oestrosis was first reported in Cuba in the middle of the 1990s in the municipality of Imías, Guantánamo province. Determining the spatial pattern and risk factors for the disease might be useful to help explain the disease occurrence and select options for disease surveillance and control. In the present study, the number and distribution of affected premises was shown to have been similar throughout the period studied (2006–2010). The disease was found to occur mostly in the southern and western parts of the province with high dispersion in an east-west direction over the period of study. Three “hotspots” (Getis-Ord Gi*) were identified in the province in which there was an increased risk of disease occurrence. Geographically Weighted Logistic Regression was used to test associations between environmental variables and disease occurrence. Results demonstrated that areas with lower mean annual rainfall, higher mean temperature, and higher sheep density had the highest risk of disease occurrence. High risk areas are mostly located in the western zone (El Salvador, Niceto Pérez and Guantánamo municipalities) and also in the central zone (coast of San Antonio del Sur and Imías). The associations between oestrosis cases and local environmental characteristics varied geographically within the study area. These results might be useful to improve disease surveillance and control. Treatment of animals in these “hotspots”, as well as in other places where the risk is higher should be prioritized to more efficiently reduce the harmful impact of this disease.
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| 6. |
- Helander, Carl, et al.
(author)
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Effects of chopping grass silage and of mixing silage with concentrate on feed intake and performance in pregnant and lactating ewes and in growing lambs
- 2014
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 116, s. 78-87
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Journal article (peer-reviewed)abstract
- The effects of chopping grass silage and of mixing grass silage with concentrate on feed intake and performance in pregnant and lactating ewes, and in growing lambs were studied in two experiments (Exp. 1 and Exp. 2). The three experimental diets used in both experiments were: (1) unchopped grass silage and 0.8 kg/d concentrate, fed separately (US); (2) chopped grass silage and 0.8 kg/d concentrate, fed separately (CS); and (3) chopped grass silage mixed with concentrate to the same forage:concentrate ratio as in the CS treatment (CM). Twin bearing/suckling ewes (n = 7 per treatment) were individually penned and individually fed during the experiments. The lambs were penned and fed in twin pairs after weaning. The silages used in Experiments 1 and 2 contained 583 and 353 g dry matter (DM) per kg, and 10.9 and 11.4 MJ ME, 139 and 193 g CP, and 580 and 483 g NDF per kg DM, respectively. In Exp. 1, daily DM intake (DMI) by ewes and LWG of lambs were unaffected by chopping silage or mixing silage and concentrate (P > 0.05). In Exp. 2, the daily DMI by lactating ewes was 0.6 kg higher in the mixed diet compared with the separate diets (4.4 vs. 3.8 kg; P < 0.05). Suckling lambs on the chopped diets in Exp. 2, had 38 g higher daily live weight gain (LWG) than those on the unchopped diet (424 vs. 386 g; P < 0.05), whereas suckling lambs on the mixed diet had 63 g higher daily LWG than those on the separate diets (454 vs. 391 g; P < 0.001) resulting in 11 days younger age at slaughter (P < 0.01). Weaned lambs fed the chopped diets in Exp. 2, had 71 g higher daily LWG than those on the unchopped diets (444 vs. 373 g; P < 0.01) resulting in 9 days younger age at slaughter (P < 0.05). Averaged over treatments, the daily silage DMI of ewes increased from 1.9 to 2.8 kg in Exp. 1 and from 2.0 to 3.3 kg in Exp. 2 from late pregnancy to lactation. It was concluded that chopping highly digestible grass silage and mixing it with concentrate can increase the DMI of ewes and improve the performance of their lambs. (C) 2013 Elsevier B.V. All rights reserved.
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| 7. |
- Högberg, Madeleine, et al.
(author)
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Can vasopressin induce milk ejection in the dairy goat?
- 2014
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 121, s. 111-115
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Journal article (peer-reviewed)abstract
- Suckling increases plasma levels of both oxytocin (OT) and vasopressin (AVP) and intravenous infusions of AVP increase milk flow and milk fat concentration in goats. We hypothesized that vasopressin can cause contraction of the myoepithelial cells and thereby milk ejection. Eight goats were used in each of two series. They were kept together with their kids and were both suckled and hand milked. At experiments, one teat was first emptied by hand and after 3 min the same teat was milked again. On control days, cisternal milk (CM) was achieved at the first milking and at the second milking only a small volume of alveolar milk (AM) with modest fat content was received. On experimental days the goats were milked and immediately thereafter OT (10 mg) or AVP at the low dose 125 ng (AVPL) was injected intravenously followed by the second milking 3 min after the first (series I). In series II saline (0.9% NaCl) or vasopressin at the high dose 250 ng (AVPH) was injected. The plasma OT concentrations were unchanged after AVP injections. The CM volume did not differ between treatments within each series. Injections of AVPH or OT increased volume and fat content of AM. The proportion of AM to total milk volume was 15% in control experiments, 21% after saline and 29% after AVPL. However, after AVPH and OT the AM proportions were 56 and 57%, respectively, accompanied by an increased fat content. In conclusion, the high dose of AVP elicited a milk ejection reflex similar to that of OT. (C) 2014 Elsevier B.V. All rights reserved.
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| 8. |
- Jonas, Elisabeth
(author)
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Association of polymorphisms in leptin and leptin receptor genes with circulating leptin concentrations, production and efficiency traits in sheep
- 2016
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 136, s. 78-86
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Journal article (peer-reviewed)abstract
- The relationships among nucleotide sequence polymorphisms in the genes for leptin (LEP) and leptin receptor (LEPR) and circulating concentrations of leptin and variables related to energy turnover were investigated in a Awassi-Merino crossbred sheep population. Blood sampled at several times during gestation and lactation was used for the assay of circulating leptin and for DNA extraction. Parts of the ovine LEP and LEPR genes were sequenced and, of a total of seven polymorphisms identified, two for each gene were used for genotyping. Feed intake and body weight were recorded for 199 ewes (age 2.9-9.4 years) daily and milk yield and composition were measured. The data were used for association studies between single nucleotide polymorphisms (SNPs), circulating leptin concentration and production traits. Both polymorphisms identified in the ovine LEP gene were associated with circulating leptin concentration (P<0.05) and one SNP was associated with feed intake per unit milk production (P<0.05). For the SNPs in the LEPR gene, there were significant effects for residual feed intake during lactation (P<0.05) and for feed intake and residual feed intake at defined times during gestation (P<0.05). We conclude that polymorphisms in the LEP and LEPR genes are associated with production and efficiency traits. The interaction between body condition, milk production, energy efficiency and leptin concentrations should be investigated in detail in future studies. Further studies are also needed to identify the specific roles played by LEP and LEPR in the regulation of circulating leptin concentrations and energy metabolism. (C) 2016 Elsevier B.V. All rights reserved.
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| 9. |
- Kumm, Karl-Ivar
(author)
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Profitable Swedish lamb production by economies of scale
- 2009
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 81, s. 63-69
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Journal article (peer-reviewed)abstract
- Economic sustainability assumes profitability (revenues >= costs including annual cash expenses as well as family labor and investments). Calculations Suggest that sheep flocks of more than 500 ewes can be profitable under Swedish conditions whereas smaller flocks are unprofitable unless they are managed by cheap existing resources including buildings, fences, machinery and family labor with low or no opportunity costs. Despite these economies of scale less than 1% of the Swedish sheep flocks have 500 or more ewes. Possible reasons are, according to interviews with lamb producers which have built up for Swedish conditions large sheep flocks of 90-900 ewes (average 380), growth sacrifices when developing large flocks and lack of accessible cheap land for providing large flocks with pasture and winter forage. The growth sacrifices reducing revenues or increasing costs during or immediately after the growth period include low production of primiparous ewes, reclamation of additional land and capital costs of new buildings before the Hock has been expanded to the intended number. The cash-flow is another problem for expanding sheep operations. Profitable lamb production presupposes large areas of land with zero or low opportunity costs. In fertile flatlands the opportunity costs are too high and in forest-dominated regions it is difficult to get hold of large enough areas near the farm centre for pasture and winter feed production. The latter problem can be solved by leasing cheap land further away and transporting feed and grazing animals, and by extending present pastures by incorporating adjacent overgrown pastures, marginal arable land and forest land. Another requirement for long-term profitable lamb production is to reduce the costs of new sheep sheds below what is a common cost level in Sweden. (C) 2008 Elsevier B.V. All rights reserved.
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| 10. |
- Nadeau, Elisabet, et al.
(author)
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Relationship between energy intake and chewing index of diets fed to pregnant ewes
- 2015
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In: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 130, s. 108-116
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Journal article (peer-reviewed)abstract
- The objective was to determine whether a linear relationship exists between the metabolizable energy (ME) intake of pregnant ewes and a dietary chewing index (CI). The relationship was studied using five feeding trials with intake data from 108 pregnant ewes, 4 to 1 weeks before lambing, giving a total of 324 observations. All ewes were fed grass silage ad libitum, supplemented with concentrates either separately or in a total mixed ration (TMR). The ewes were of different breeds, were between 2 and 7 years old, had a mean body weight (BW) in the 4th week before lambing of 95.1kg (SD=9.64), and gave birth to an average of 2.2 lambs (SD=0.37). The average daily ME intake was 29.4MJ/d (SD=5.26). The NorFor CI (min/MJ ME) of the feeds was estimated from the neutral detergent fibre (NDF) (g/kg DM), indigestible NDF (g/kg NDF) and the theoretical chopping length (mm) of the forage. The CI values were adjusted for the BW of the ewes and for NDF intake higher than 0.7% of forage NDF per kg of BW. The mean corrected CI (CIcor) was 27.2min/MJ ME (SD=5.10). The relationship between ME intake (MEI) and CIcor was analysed using nonlinear mixed effects modelling, using the equation MEI=ME0-k×ME02×CIcor, where MEI is the daily metabolizable energy intake, ME0 is considered the theoretical maximum intake capacity of the animal in a theoretical situation with no physical constraint on intake, and parameter k represents the decline in MEI with the increasing CIcor of the ration. The model includes random variation of week within experiment on the intercept and linear fixed effect of week before lambing on parameter k. The maximum daily chewing time, CTmax, for the pregnant ewes was predicted to be 1/(4×k). The MEI declined linearly with increasing dietary CI (P<0.001), with different within-experiment intercepts in relation to week before lambing (P<0.001), supporting the existence of a linear relationship between MEI and CIcor for pregnant ewes in the last 4 weeks before lambing. CTmax could be calculated for the ewes and had a mean of 1066min/d. The model appears to have a potential for predicting MEI in pregnant ewes fed forages ad libitum with concentrates restrictively or TMR diets, based on BW, energy value of feeds, NDF and iNDF concentration of forage.
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