Small Ruminant Research最新文献

Rapidly increasing population size, recent breaks in production and supply chains, due to pandemics, and those further expected because of climate change emphasize the compelling importance of animal productivity. Traits associated with the productivity of ewes have a direct impact on the overall productivity, profitability and efficiency of sheep farms. Therefore, the objective of the current study was to estimate the variance components, heritabilities as well as genetic and phenotypic correlations, for traits associated with the lifetime productivity of Central Anatolian Merino ewes. Birth and weaning records of lambs for each ewe as well as environmental factors such as sex and birth type were utilized for deriving ewe lifetime productivity traits. Genetic parameter estimations involved observations from 3101 Central Anatolian Merino ewes, encompassing mean and total lamb birth weight per ewe (MBW and TBW), mean and total lamb weaning weight per ewe (MWW and TWW), and the mean and total number of lambs weaned (MNLW and TNLW). This analysis utilized a pedigree comprising 13229 animals. Average Information Restricted Maximum Likelihood (AIREML) based Animal Linear Mixed Model estimations for the decomposition of (co)variance components were implemented based on pedigree-derived numerator relationship matrix by also accounting for the number of parities as a fixed factor. Low to moderate heritability estimates, ranging between 0.29 and 0.42, were observed for the lifetime productivity traits of the breed. A wide range of genetic and phenotypic correlations (between −0.56 and 0.99) was observed among the traits of interest. The outcomes of the study are anticipated to significantly enhance the global sheep production systems by uncovering the essential parameters for incorporating ewe’s lifetime reproductive performance and productivity into the selection indices. This will also benefit Central Anatolian Merino farmers, who form a large proportion of sheep producers in Turkey.

Flavor of lamb is a major driving factor in eating satisfaction. Dry aging has been used in beef to alter flavor and tenderness. The objective of the research was to determine what affect dry aging had on flavor attributes and the volatile compounds that influence the perception of flavor. Lambs (n = 10) were fed an alfalfa-based concentrate diet for 60 d prior to harvest. Loins were obtained from both sides of the carcass and randomly assigned to an aging treatment; no age (boned and frozen day 0) or 14 d of dry age in cold storage (4°C, 55%RH). Descriptive flavor profile panel evaluated samples and volatile compounds were analyzed from cooked samples. No differences were detected by descriptive flavor panel between fresh and dry aged loin chops for most flavor attributes. However, aged loins were rated saltier than loins not aged. Additionally, aged loin chops tended to have a greater intensity score for mutton and green attributes. Aldehydes were the greatest proportion of the volatile aroma compound chemical classification recovered and identified from the lamb samples. Dry-aged lamb loins yielded greater thiobis-methane (a sulfurous, fishy aroma) than loins without ageing. As expected, muscle fiber tenderness as evaluated by sensory panel was greater for aged loin chops than no age (12.7 and 10.0, respectively). Aged loin chops tended to be juicier as well. Aging in aerobic conditions for up to 14 d can improve tenderness in lamb without significantly impacting flavor, however, there is a tendency to increase the mutton and green flavors with dry aging.

Equations to predict associative effects between basal forages and supplemental feedstuffs for goats were developed to improve diet formulation with the Langston University Interactive Nutrient Calculation system (LINC, http://40.65.112.141/). A literature survey of goat nutrition studies with ad libitum forage intake with or without supplementation was conducted, resulting in a database with 135 treatment mean observations, representing measures from 503 animals and derived from 26 publications. The database was divided into three datasets based on forage CP concentration (Low: < 6%, Moderate: 6 – 10%, and High: > 10%). The datasets were used to develop equations addressing positive and negative associative effects. Change in forage ME intake relative to metabolic BW (MEIMBWFOR; kJ/kg BW^0.75) due to supplementation was predicted based on potential variables of supplement ME intake also scaled to metabolic BW (MEIMBWSUP; kJ/kg BW^0.75), forage OM digestibility (OMDIGFOR; %), CP concentration (PTCPFOR; %), and NDF concentration (PTNDFFOR; % DM), supplement CP concentration (PTCPSUP; %) and ME concentration (MECSUP; MJ/kg), and quadratic functions of these variables (MEIMBWSUP2, OMDIGFOR2, PTCPFOR2, PTNDFFOR2, PTCPSUP2, and MECSUP2). Model development for each dataset was conducted by two analytical methods, stepwise regression and the Least Absolute Shrinkage Selection Operator (LASSO). Equations employing both methods were developed, with stepwise regression accounting for greatest variation (Low: MEIMBWFOR = 937 + 0.604 × MEIMBWSUP − 0.0018 × MEIMBWSUP2 – 0.105 × PTNDFFOR2; ARSq = 0.871, Moderate: MEIMBWFOR = 1732 − 0.579 × MEIMBWSUP + 40.9 × PTCPFOR − 62.4 × OMDIGFOR + 0.601 × OMDIGFOR2; ARSq = 0.826, and High: MEIMBWFOR = 51.0 − 0.00162 × MEIMBWSUP2 + 8.42 × PTNDFFOR; ARSq = 0.628). Similar variables were selected with both analytical methods for each dataset, but variables selected differed among datasets. Although goodness of fit measures were relatively high for each dataset, they ranked Low > Moderate > High, suggesting greatest robustness for Low and complexity in influencing factors for High. In conclusion, equations to predict associative effects between basal forages and supplements consumed by goats developed for basal forage with low, moderate, and high CP concentrations should be useful in diet formulation tools such as LINC. Future research should consider a wider array of conditions such as animal physiological status (e.g., growing and adult), type of production (e.g., milk and meat), and carbohydrate composition of supplements.

The aim of this study was to describe the morphological, macroscopic, and microscopic characteristics in term placentas of goats, nutritionally restricted in the prepubertal period and during the second and third of pregnancy gestation. Samples were collected from the placentas of goats separated into 3 treatments: control (C) n= 9; prepubertal feed restriction (PPFR) n = 5; pregnancy feed restriction (PFR) n=5. The placental cellular structure was studied using Masson's trichrome staining. The ultrastructural analysis was performed by high-resolution light microscopy and transmission electron microscopy. The present study revealed the effect of prepubertal and gestational feed restriction on macroscopic and microscopic characteristics in goat placentas with decreases in cotyledonary weight, height, and size in placentas from nutritionally restricted goats in both groups, PPFR and PFR. The smaller size and the change in the shape of the cotyledons could suggest compensatory mechanisms for prepubertal and gestational feed restriction to ensure placental and kid development.

Recent advancements in machine learning for detecting animal behaviors, particularly goat activities, have faced challenges due to their complexity and lack of explainability in practical applications. This article presents an interpretable machine-learning framework using sensor-based data to differentiate mimosa grazing from other goat activities like grazing herb, resting and walking. BORUTA, an algorithm for selecting the most relevant features, and SHAP, a technique for interpreting the decision of a machine learning model are two fundamental components of the methodology used for developing the model. The resulting model, a gradient boost algorithm with 15 selected features has shown robust performance with accuracy, sensitivity, and precision between 82% and 86%. SHAP analysis further elucidates the model’s decision-making, highlighting the impact of features like ’Standing’ and ’%HeadDown,’ along with distance-related features on discriminating grazing mimosa from grazing herb. The simplicity of the model advocates for its potential in real-time systems and underscores the importance of explainability in improving and deploying these models in real-world scenarios.

This study tested the hypothesis that Corynebacterium pseudotuberulosis strains isolated from small herds of ruminants in the state of Pará have a clonal genomic profile. Serum samples were collected from 169 animals and used in an indirect ELISA that detected specific antibodies against C. pseudotuberculsis in 24% of the animals monitored in the field. Among sheep and goats, 20 animals had a confirmed symptomatic diagnosis of Caseous Lymphadenitis Disease (CL) and caseous material from the abscesses was sampled. From these samples, seven bacterial strains were isolated and identified as C. pseudotuberculosis biovar ovis. Bacterial genomic DNA was extracted and subjected to fingerprint analysis (BOX-PCR and ERIC-PCR). The fingerprint analysis revealed the existence of two main groups of isolated strains, with one of these groups necessarily formed by strains A27 and A31 (at least 62% similarity), and the other group formed by the remaining isolated strains. The genome outline of the A27 and A31 strains was sequenced using Illumina NovaSeq 6000 technology. The preliminary genomes A27 and A31 grouped with other genomes of C. pseudotuberculosis biovar ovis when compared to 46 genomes of C. pseudotuberculosis belonging to both biovars (ovis and equi) isolated worldwide. More than 99% of similarity was observed when comparing the draft genomes A27 and A31 with other genomes of C. pseudotuberculosis biovar ovis strains isolated from the Brazilian Amazon. The mapping readouts generated with preliminary A27 and A31 genomes using the reference genome of C. pseudotuberculosis 42/02-A showed more than 99% coverage. The central genome consisted of 78% of the orthogroups in the pangenome analysis. The specific genes that encode unique proteins in the A27 and A31 genomes yield molecular information about how each species adapts to its ecological niches. This study shows that strains of C. pseudotuberculosis biovar ovis isolated from small ruminant herds in the Brazilian Amazon showed a clonal genomic profile.

In sheep production systems, diet type is an important factor affecting the eating quality of the meat produced. The objective of this study was to assess the effect of binary swards on the slaughter performance, descriptive sensory profile, consumer liking and instrumental texture of lamb meat. Five dietary treatments were investigated, perennial ryegrass (Lolium perenne L.; PRG), PRG plus white clover (Trifolium repens L.; PRG+WC), PRG plus red clover (Trifolium pratense L.; PRG+RC), PRG plus chicory (Chicorium intybus L.; PRG+Chic) and PRG plus plantain (Plantago lanceolata L.; PRG+Plan). Post – weaning sixty Texel sired crossbred lambs (n = 12 per dietary treatment) were selected from the main cohort of lambs born in 2022 and further balanced for sex and reared litter size. The M. longissimus thoracis et lumborum (LTL) was obtained from each lamb post-slaughter. Meat samples were analysed by a trained sensory panel, a consumer panel as well as Warner-Bratzler shear force (WBSF) measurements. All data were analysed using a linear mixed model PROC MIXED in SAS. Mean slaughter weights of 46.0 ± 0.36 kg and cold carcass weights of 22.2 ± 0.51 kg were achieved with no differences observed across dietary treatments (P > 0.05). On average, lambs were 217 d of age at slaughter. Lambs finished on PRG and PRG+Plan had similar growth rates, however binary mixtures containing PRG plus any one of WC, RC (P < 0.01) or Chic (P < 0.05) increased average daily gain (ADG) and reduced the number of days required for lambs to reach slaughter (P < 0.05), relative to lambs grazing the PRG monoculture. Meat from PRG+Plan lambs was scored lower by the trained sensory panel for initial tenderness (P < 0.001) and overall tenderness (P < 0.001) when compared to meat from any other dietary treatment. Consumers scored meat from PRG or PRG+WC lambs higher for tenderness (P < 0.05) and flavour (P < 0.01) in comparison to meat produced from PRG+Plan lambs. Relative to meat from PRG+Plan lambs, PRG, PRG+WC and PRG+Chic lamb meat scored higher for overall liking (P < 0.01) when assessed by the consumer panel. Results show that companion forage inclusion increased lamb growth performance in the post-weaning period thus reducing age at slaughter. However, findings suggest that the addition of plantain to the grazed sward may negatively affect the eating quality of lamb meat, highlighting the need to consider diet type in tandem with meat eating quality when selecting finishing systems for pasture fed lambs.

Housing and indoor feeding of sheep is required throughout the cold season, which can last more than half a year, in Nordic highlands and Alpine regions. This study aimed to examine and evaluate the housing costs, including labour requirements, according to type of sheep housing system and degree of mechanized feeding by investigating systems commonly used in Nordic and Alpine regions. Detailed cost data were obtained from 61 surveyed sheep farmers in Norway with sheep houses built between the years 2008 and 2015. Costs were calculated for a baseline scenario (2021-prices) as well as for five scenarios at low and high discount rates and opportunity cost of labour, and high energy prices. The median (interquartile range) flock size was 150 (100) winter-fed sheep. Houses with slatted floors were more expensive than deep-litter systems. Costs of bedding material and feed waste were however higher, and the net value of the manure were lower in houses with deep-litter systems. At the baseline assumptions, overall net housing costs per sheep was not statistically different among the main housing types studied. Multiple regression analyses showed that net housing costs per sheep were lower in larger flocks and for centrally located farms (control variables). Undertaking daily chores, such as feeding of roughages twice a day rather than once, resulted in significantly higher net housing costs. Mechanized feeding of roughages, and even more so for concentrates, were not economically justified since labour savings were not sufficient to pay for the additional capital costs. A round bale chopper lowered net housing costs, significantly at a high labour cost. None of the scenarios found slatted floors to be significantly more expensive than deep-litter systems. High costs of labour and capital favoured deep-litter systems, while slatted floor systems were more advantageous at rising prices of energy that resulted in increased values of organic manures and costs of feed wastes and bedding materials. The study was based on a decade old data from common Norwegian sheep house variants. Farmers that consider constructing a new sheep house today, still must compare these variants as their main alternatives. We encourage other researchers to include effects of housing systems and mechanized feeding on animal performance, health, and welfare. Moreover, future studies should preferably also be undertaken in other environmental or socio-economic settings to produce more general results.

Supplementing dietary betaine during pregnancy has improved vigour and post-natal survival rates to day seven in twin lambs, potentially due to improvements in the circulating metabolite profile of these animals. This study determined whether maternal betaine supplementation during late gestation would increase circulating levels of betaine, creatinine and other amino acids in ewes and their newborn lambs, leading to subsequent improvements in lamb viability and growth. Twenty-five single-bearing Merino ewes received dietary betaine at either 0 (Control, CTL), 2 (Low Betaine, LB) or 4 g/day (High Betaine, HB) from day 125 of gestation (dG 125) until parturition (150.7 ± 0.6 days). Blood samples were collected from the ewes prior to feeding (0 h), and at 2, 4, 6, 8 and 24 h post-feeding on dG 125 and dG 140 prior to feeding and from the lamb within 2 h after birth. Lamb viability measures were taken at 2, 24 and 72 h and day 7 post-partum, marking (⁓30 days of age) and weaning (⁓104 days of age). Betaine supplementation at LB and HB increased plasma betaine levels at 6, 8 and 24 h post-feeding on dG 125 (P < 0.05) and tended to increase plasma betaine on dG 140 (P = 0.085). Plasma methionine levels increased at 2 and 4 h post-feeding on dG 125 relative to baseline levels (0 h) in LB ewes, yet remained unchanged in HB ewes. On dG 125, creatinine levels were higher in CTL ewes compared with betaine-supplemented ewes at 4 and 8 h post-feeding (both P < 0.05). While plasma betaine and methionine levels were unchanged in neonatal lambs, plasma concentrations of glutamine and lysine were higher (P < 0.05) in HB lambs compared to CTL and LB lambs. HB lambs tended to be heavier at marking (P = 0.057) and were heavier at weaning compared to CTL and LB lambs (P < 0.05). This study indicated that betaine supplementation increased plasma betaine and methionine levels in ewes, but not in neonatal lambs. Further research is warranted to determine whether higher levels of betaine supplementation increase neonatal concentrations.