Lamb Finishing Research Articles

PSIV-A-6 Effects of a yeast cell wall additive on the growth performance and fecal Eimeria load of finishing lambs

Abstract Yeast-based additives have been shown to alter the rumen environment and exhibit immunomodulatory properties that can lead to enhancements in health status and subsequent performance. The objectives of this study were to evaluate the impacts of supplementing a yeast cell wall additive (Safwallâ, Phileo by Lesaffre, Milwaukee, WI) on finishing lamb growth performance and fecal Eimeria load. A total of 44 Polypay lambs were used in a 35-dexperiment at the Kansas State University Sheep and Meat Goat Center. On d 0, a fresh fecal sample was collected from each lamb and submitted to the Kansas State University Veterinary Diagnostic Lab to determine a baseline Eimeria count via quantitative fecal float. Lambs were then randomly assigned to either a control diet or diet supplemented with 1.5 g Safwallâ. Diets were fed for 35-d and contained no coccidiostat. Lambs had ad libitum access to both feed and water for the duration of the experiment. A basal lamb finisher diet was manufactured as a control diet and Safwallâ was hand-mixed into rations daily to make the treatment diet. Lambs and feeders were individually weighed weekly to track dry matter intake (DMI) and changes in body weight (BW). Data were analyzed using the GLIMMIX procedure of SAS (v.9.4, SAS Inst., Cary, NC) with an alpha set at (P < 0.05). From d 0 to 7 there was no evidence of a difference (P = 0.19) in DMI between treatment groups; however, during the second week of the study (d 7 to 14) lambs fed the control diet had significantly greater (P = 0.02) DMI compared with those fed a diet supplemented with yeast cell wall (Table 1). There was no evidence of differences in DMI between treatments for the remainder of the study (P > 0.05). Likewise, BW did not differ significantly (P > 0.05) between treatments on d 0 or by d 35. There was no evidence that fecal Eimeria load differed significantly (P > 0.05) on d 0 or 21; however, on d 35, lambs fed the control diet had a decreased Eimeria load compared with those fed a diet with yeast cell wall, but neither group had biologically relevant levels of Eimeria present in the feces. In summary, feeding a diet containing a yeast cell wall additive did not alter finishing lamb growth performance. While lambs fed the control diet had reduced fecal Eimeria at the end of the study, there was a reduction in this variable across both treatments. Further research should be conducted with younger animals with a known Eimeria challenge.

Effect of Combining the Ionophore Monensin with Natural Antimicrobials Supplemented in the Last Phase of Finishing of Lambs: Growth Performance, Dietary Energetics, and Carcass Characteristics.

With the aim of evaluating the effect of combining an antibiotic ionophore with plant extracts and probiotics on the productive efficiency (performance and carcass) during the last phase of lamb fattening, 24 Pelibuey × Katahdin male lambs (38.47 ± 3.92 kg, initial weight) were fed with a high-energy diet during for 56 days, and assigned, under a complete randomized block design experiment to one of the following supplement treatments: (1) 28 mg of monensin/kg diet DM supplemented alone (MON), (2) combination of MON plus 2 g/kg diet of a product contained Bacillus subtilis 2.2 × 108 CFU kg diet DM (MON + BS), (3) combination of MON + BS plus 300 mg essential oils/kg diet DM (MON + BS + EO), and (4) BS alone. At the end of the feeding trial (56-d), lambs were slaughtered and carcass variables were measured. Compared to the rest of the treatments, combining MON with BS improved dietary NE by 3.4% and the efficiency of utilization of dietary energy consumed. Inclusion of EO in the MON + BS combination resulted in a similar average daily weight gain (ADG) and feed efficiency (GF) when compared with MON + BS, but showed a lower dietary net energy (NE), hot carcass weight, and dressing percentage. Lambs receiving BS alone showed greater average ADG and dry matter intake (DMI) than lambs receiving MON + BS + EO, but similar feed GF and dietary NE. There were no treatment effects on tissue composition, whole cut, or visceral organ mass. It was concluded that combining probiotics with the ionophore monensin can improve the efficiency of dietary energy utilization in the last phase of finishing. Probiotics supplemented alone result in greater ADG without a difference in dietary energy efficiency when compared with MON alone. Inclusion of EO in the MON + BS combination did not show advantages; on the contrary, it reduced carcass weight and dressing percentage. It is necessary to further research the potential complementary effects of combining diverse sources of natural additives with synthetic antibiotics.

Evaluation of pasture-based vs. concentrate-based lamb production systems regarding growth performance, wool cortisol concentration, meat quality and microbiological properties

The aim was to investigate the growth rate, log transformed wool cortisol concentration (WCC), carcass characteristics, meat quality and meat microbiological properties of Akkaraman, Karya and Kivircik lambs in pasture-based (n = 93) and concentrate-based (n = 85) systems. Production system had no influence on the lamb growth rate in Akkaraman and Kivircik lambs. Weights of Karya lambs on days 90 and 120 were lower in pasture lambs than concentrate fed lambs. In some sampling days, log WCC was higher in lambs fed concentrates. Lambs of pasture-based and concentrate-based systems had similar carcass weight, dressing percentage, meat pH and shear force values in all breeds. However, meat of pasture-based system was darker with a lower L* value. Production system had no significant influence on bacterial counts, except Pseudomonas spp. counts in Akkaraman lambs. In conclusion, pasture-based system had no disadvantage in lamb finishing compared to the concentrate-based system regarding carcass characteristics and meat quality, except meat colour.

Profit, productivity, and eco-efficiency of using Caucasian clover/ grass pastures in hill country farms

The following study was conducted to establish whether significant amounts of Caucasian clover-based pastures in hill country farms can increase eco-efficiency and profitability. Published data were used to predict the production of Caucasian clover-based pastures, based on weather data and soil moisture deficit prediction, for four sheep and beef farms with low rainfall in the South Island. Scenarios with 10, 20 or 30% of the flat and rolling areas improved with Caucasian clover/grass pastures were compared to current systems based on resident white clover-based pastures. A staged approach, to utilise the extra high-quality feed produced, used a sequentially process to improve productivity by increasing lamb finishing, higher hogget liveweight, better ewe nutrition or more beef finishing, depending on initial efficiency metrics. Timeto maximum production using an annual establishment programme of 5% of the target areas in Caucasian clover/grass mixtures took 4 to 6.5 years (10% and 30% respectively). Adding Caucasian clover/grass increased pasture production by 5.5% while product/kg DM consumed increased by 12.8% and profitability by 22% when either sheep or beef production were used to capture the extra amount and quality of pasture. Greenhouse gas (GHG) emissions were increased by only 6.3%, resulting in more efficient meat production.

Fatty acid and oxidative shelf-life profiles of meat from lambs fed finisher diets containing Acacia mearnsii leaf-meal

Five diets containing Acacia mearnsii leaf-meal (AMLM; 0, 50, 100, 150 and 200 g/kg DM) substituted for Triticum aestivum bran were fed to lambs for 42 days. The effect of diet and retail display period on meat fatty acid (FA) composition (day 1); colour, antioxidant activity, myoglobin and lipid oxidation (day 1, 3, 5, 7 and 9); protein oxidation (1, 3 and 7 d) and instrumental tenderness (day 1, 5 and 10) were evaluated. Dietary AMLM linearly decreased (P ≤ 0.05) individual (14:0, 16:0, 18:0) and total saturated FA and increased (P ≤ 0.05) trans(t)-monounsaturated FA (MUFA) mainly t10/t11–18:1, individual and total conjugated linoleic acids, n-3 and n-6 polyunsaturated FA (PUFA) contents. The contents of cis(c)-MUFA, mainly c9–18:1, exhibited a quadratic response reaching a minimum at 50 g/kg AMLM (P ≤ 0.05). Meat antioxidant on day 9 was higher (P ≤ 0.05) for diets containing ≥100 g/kg DM AMLM compared to the other diet × retail display period interactions. Relative to the other interactions, meat redness values were lowest on day 7 and 9 for AMLM diets containing ≥150 g/kg DM (P ≤ 0.05). Dietary addition of AMLM increased (P ≤ 0.05) meat lightness and oxymyoglobin, and reduced (P ≤ 0.05) TBARS and instrumental tenderness values. However, oxymyoglobin values declined (P ≤ 0.05) over the retail display period, while lightness, metmyoglobin, TBARS and carbonyls increased (P ≤ 0.05). Results indicate that AMLM up to 200 g/kg DM in lamb finisher diets, improves meat fatty acid composition, tenderness, and lipid shelf-life.

Substitution effects of Acacia mearnsii leaf-meal for Triticum aestivum bran on nutrient digestibility, rumen fermentation and nitrogen retention in lambs

The study evaluated the effects of substituting increasing levels of Acacia mearnsii leaf-meal (AMLM) for Triticum aestivum bran as the main fibre source in lamb finishing diets on nutrient digestibility, rumen fermentation and nitrogen retention. Twenty-five, three-months-old ram lambs with an average live weight of 25.2 ± 1.41 kg were allocated to one of the five dietary inclusion levels of AMLM (0, 50, 100, 150 and 200 g/kg DM; n = 5) in a completely randomised design for 28 days. Intake and digestibility of dry matter (DM), organic matter and crude protein, main individual and total volatile fatty acids, purine derivatives, supply of microbial nitrogen, and nitrogen intake, retention and utilisation efficiency exhibited quadratic (P ≤ 0.05) responses to AMLM reaching a maximum at 100 g/kg DM inclusion level. Ammonia-nitrogen linearly increased (P ≤ 0.05) with dietary addition of AMLM. Intake and digestibility of neutral detergent fibre (aNDFom) exhibited a positive linear trend (P ≤ 0.05) with graded levels of AMLM in the diet while that of ether extract showed a negative trend. In conclusion, replacement of T. aestivum bran with up to 100 g/kg DM of AMLM in lamb finisher diets can improve digestibility of nutrient, rumen fermentation and retention of nitrogen.

Timing of the outfield grazing season and finishing of lambs: A whole-farm modelling study of forage-based sheep production systems in Norway

Norwegian sheep production is based on the use of free outfield grazing resources in the mountains and forests in summer. Lamb prices are strongest at the beginning of the slaughter season in August and then begin to gradually decline, reaching a lower plateau in mid-October. Seasonal pricing provides incentives to get slaughter lambs to market early. The objective of this study was to examine how outfield summer pasture quality, time of collection from the outfields, and inclusion of annual forage crops in the diet of finishing lambs influence optimal farm plans and profitability in Norwegian forage-based sheep production systems at varying levels of farmland availability (varying from 15 to 25 ha with 20 ha as the basis). A linear programming model was developed for sheep production systems in the mountainous areas of Southern Norway. Input-output relationships incorporated into the model included data from field experiments with grasses for annual and perennial use, observed performance of lambs and ewes at pastures, a feed planning tool for the indoor season, and expert judgements. The model maximised total gross margin of farms with a housing capacity of 200 ewes. The results suggested that with more land available, drafting older and heavier lambs for slaughter was profitable. The lighter lambs at weaning were usually drafted much later and at the same or heavier carcass weights than the heavy lambs at weaning because of seasonal pricing. Higher quality outfield summer pastures increased lamb live weights at weaning. Annual profits improved considerably with rich summer pastures compared to poor summer pastures. Early collection was always less profitable than normal time of collection because greater prices for lambs sold could not offset losses from the additional feed costs incurred and a possibly smaller flock. Speeding up the growth rate of finishing lambs by offering annual forage crops in addition to grazed grass was usually more profitable than grass only. Only for rich summer pastures and normal time of collection at low land availability was use of annual forage crops unprofitable.

Production and meat quality attributes of lambs fed varying levels of Acacia mearnsii leaf-meal as replacement for Triticum aestivum bran

The study evaluated the effects of substituting increasing levels of Acacia mearnsii leaf-meal (AMLM) for Triticum aestivum bran in lamb finishing diets on growth, carcass, and meat quality attributes. Forty, 3-months-old lambs with an average live weight of 25.7 ± 1.60 kg were allocated to one of the five dietary inclusion levels of AMLM (0, 50, 100, 150 and 200 g/kg DM; n = 8) in a completely randomised design for 42 days. Dry matter intake, average daily gain, feed efficiency, carcass weights, dressing percentage and income over feed costs exhibited quadratic (P ≤ 0.05) responses to the addition of AMLM peaking at 100 g/kg DM inclusion level. Meat ultimate pH, moisture and lightness increased linearly (P ≤ 0.05) while intramuscular fat and shear force declined linearly (P ≤ 0.05) with increasing levels of AMLM. In conclusion, AMLM can replace up to 100 g/kg DM of T. aestivum bran in lamb finisher diets without impairing meat production and quality.

Fortification of diets with omega-3 long-chain polyunsaturated fatty acids enhances feedlot performance, intramuscular fat content, fat melting point, and carcass characteristics of Tattykeel Australian White MARGRA lambs.

Meat eating quality indices such as intramuscular fat content (IMF) and fat melting point (FMP) of the Longissimus thoracis et lumborum muscle and the feedlot performance, carcass traits, and commercial wholesale cuts of lot-fed Tattykeel Australian White (TAW) MARGRA lambs as a result of dietary fortification of the diet with omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) were evaluated. A total of 75 TAW MARGRA lambs at 6 months of age with an average liveweight of 30 ± 1.2 kg were used. The lambs were randomly allocated to the following three dietary treatments of 25 lambs each in a 47-day feeding trial using a completely randomized experimental design: (1) control diet of hay plus pellets without omega-3 oil, (2) hay plus commercial whole grain pellets (MSM) without omega-3 oil, and (3) hay plus pellets fortified with omega-3 oil. It was hypothesized that dietary supplementation with omega-3 fortified pellets will improve feedlot performance, meat-eating quality indices of IMF, FMP, and carcass characteristics. Lot-fed lambs on the MSM whole grain had the highest feed intake of 1.69 kg/day, followed by the control at 1.57 kg/day and the lowest in the omega-3 diet at 1.01 kg/day (p = 0.0001). However, the omega-3 diet had the highest average daily gain of 230 g/head/day (p = 0.0001), indicating the greatest feed efficiency since it had the best growth response with minimal feed intake. Post-slaughter evaluation of the Longissimus thoracis et lumborum muscle revealed significant treatment variations in IMF (p = 0.0001), FMP (p = 0.0001), pH (p = 0.0380), and wholesale French rack primal cut (p = 0.0001). Strong correlations (p < 0.05) between liveweight, temperature, pH, FMP, and IMF were observed. Similarly, significant correlations between carcass characteristics of total saleable meat yield, lean trim, fat trims, bones, and leg shank were evident (p < 0.05). However, there were no treatment differences in the final liveweight, GR fat depth, hot standard carcass weight, or dressing percentage. The findings indicate that feedlot performance, meat-eating quality traits such as IMF and FMP, and commercial wholesale French rack cuts can be further improved during feedlot finishing of TAW MARGRA lambs through dietary supplementation with omega-3 oils, and hence the tested hypothesis of improved meat quality attributes is partially confirmed.

Economic evaluation and productive performance of lambs finished with concentrate and corn stover

Objective: To evaluate the effect of two concentrates and corn stover on the productive performance and economic impact of finished hair sheep lambs.&#x0D; Design/methodology/approach: Twenty hair lambs (Dorper × Katahdin) with initial live weight of 33.3 ± 2.9 kg, were grouped into ten blocks where each block had two lambs of similar live weight that were randomly assigned to two treatments: T1) commercial concentrate + corn stover and T2) experimental concentrate + corn stover, in proportion 80 - 20%. Total weight gain (GPT), daily weight gain (GDP), dry matter intake (DMI), feed conversion (FC), feeding costs, gross value of GPT, gross profit margin and economic efficiency (EE). An analysis of variance was performed under a completely randomized block design. The means were compared with the Tukey test at α = 0.05.&#x0D; Results: There were no differences in GPT, GDP, CA and CMS (P&gt;0.05). The T1 has higher costs (US$41.91) per ton of feed. The production costs of diets and feeding costs were lower for T2, and it also showed the best economic efficiency (EE = 26.6 %).&#x0D; Limitations on study/implications: The advantage of using agro-industrial and agricultural by-products such as corn stover in integral diets for finishing sheep is their availability throughout the year.&#x0D; Findings/conclusions: The finishing of lambs is profitable when the producer formulates and elaborates his own diet, reducing production costs for feeding without affecting the productive variables.

Comparison and analysis on sheep meat quality and flavor under pasture-based fattening contrast to intensive pasture-based feeding system

ObjectiveThe objective of this study was to investigate the effect of 4-month intensive feeding on the meat quality, fatty acid profile, flavor, and growth performance of grazing Hulunbuir sheep (HBS).MethodsThe HBS were selected 4-months after birth in a pasture rearing system as the experimental animals (n = 44, female, average body weight 23.8±2.2 kg) then divided equally into pasture-based grazing fattening (PAS) and concentrate-included intensive fattening (CON) groups for another 4-month finishing. When finished fattening, all animals were slaughtered to collect musculus longissimus dorsi subcutaneous adipose tissue and to investigate the influences on meat quality, fatty acid profile, flavor and growth performance.ResultsThe results showed lambs in CON group got significantly higher live weight, hot carcass weight, and dressing percentage. The CON group had significantly higher value of redness (a*), lightness (L*) and water holding capacity (p<0.05), significantly lower value of Warner-Bratzler shear force than the PAS group (p<0.05). The subcutaneous fat from CON group lambs demonstrated a significantly higher content of C18:1 and C18:2 (p<0.05), but lower C14:0 and C16:0, indicating an increased degree of unsaturated fatty acid. The content of 4-methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid had increased 2 to 4 times, representing a more intense odor in the CON group. However, the values were still lower than most sheep breeds reported, indicating the indoor feeding system could not fundamentally deteriorate the excellent meat characteristic of HBS.ConclusionIt was evident that lambs in CON group exhibited a better meat production performance, improved in meat color, texture and healthier fatty acid profile through pasture-weaned concentrate included intensive fattening system, which offers a good alternative regimen for lamb finishing and has a wide prospection in the HBS meat industry.

Feedlot-finishing lambs with different levels of soybean pre-cleaning by-product as the roughage source

An experiment was conducted in the Sheep Farming Laboratory at the Federal University of Santa Maria to examine the effect of different levels of replacement of sorghum silage with soybean pre-cleaning by-product (SPCB) on nutrient intake, performance and feeding behavior; as well as to undertake an economic analysis of feeding finishing lambs in a feedlot system. The study involved 32 uncastrated Texel × Ile de France crossbred male lambs weaned at 60 days of age. Treatments consisted of diets in which the roughage source (sorghum silage) was replaced with SPCB at the levels of 0, 33.5, 66.5 or 100% (DM basis). A 45:55 roughage:concentrate ratio was used (DM basis). The diets were composed of a roughage feed based on sorghum silage and/or SPCB, and a concentrate consisting of crushed maize, soybean meal and limestone. In addition, mineral salt was freely available to the animals. The lambs were slaughtered upon reaching the pre-established live weight of 35 kg. Intake on a DM basis showed a quadratic response (P ≤ 0.05) in all forms it was evaluated and expressed, except for the NDF fraction, which increased linearly (P ≤ 0.05) with SPCB inclusion. Average daily weight gain was not significantly influenced (P &gt; 0.05) by the different SPCB levels, averaging 292 g/day. As regards the feeding behavior characteristics evaluated, the number of daily feeding bouts increased linearly (P ≤ 0.01) with the SPCB content of the diets. Total feed cost decreased linearly (P ≤ 0.01), whereas the profit per kilogram of gain and profit obtained per day in the feedlot period increased linearly (P ≤ 0.01) with SPCB inclusion. The use of soybean pre-cleaning by-product as the roughage source in the finishing of feedlot lambs proved to be a viable alternative in both the productive and economic terms.

158 The effect of sire muscling EBV and lamb finishing diet on the feed efficiency, carcass traits and meat quality of lambs

158 The effect of sire muscling EBV and lamb finishing diet on the feed efficiency, carcass traits and meat quality of lambs

Premium lamb production of South African sheep breed types under feedlot conditions

An increasing number of producers opt to finish their lambs in on-farm feedlots. Therefore, detailed production information is required to implement precision finishing of lambs of different genotypes. Precision finishing monitors growth, feed intake and efficiency to optimize management. In this study, feedlot production characteristics of Dohne Merino, Dormer, Dorper, Meatmaster, Merino, Namaqua Afrikaner, and South African Mutton Merino (SAMM) lambs were evaluated. The lambs were reared in a feedlot and fed a diet with 10.41 MJ metabolizable energy (ME)/kg feed and 19.06% crude protein. Feed intake and body weight were recorded weekly from an initial weight of 30 kg until they had the subcutaneous fat cover needed to produce an A2 carcass. Subcutaneous fat was measured on the Longissimus lumborum muscle with an ultrasound scanner. Dorper, Meatmaster and Namaqua Afrikaner had the shortest rearing periods in the feedlot, and were market ready at a lower live weight (P &lt;0.05). As a result, these lambs consumed less feed in the feedlot. Namaqua Afrikaner and Merino lambs were least efficient: 7.08 and 5.63 kg feed/kg gain, respectively. Dohne Merino, Dormer, Dorper, and Meatmaster rams and Dorper ewes were more efficient; approximately 3.58 kg feed/kg gain. Dohne Merino and Dormer rams had the highest growth rates: approximately 465 g/day. The end weights described in this study could be used as an indication for producers of the ideal slaughter weights for breeds of different maturity types.Keywords: average daily gain, fat deposition, feed efficiency, rearing period

Different Grass Availabilities of Tropical Pasture on Performances and Carcasses of Lambs

This study aimed to identify the best green-leaf offerings of Urochloa brizantha cv. Marandu for pasture-finished lambs receiving protein-energy supplementation at the rate of 1.6% of their body weights (BW). The animals were assigned into four treatments, which consisted of varied green-leaf offerings, namely, 105, 90, 75, or 60 g of dry matter/kg of body weight (BW). Sixty-eight contemporary Texel × mixed-breed lambs with an average initial BW of 22.6 kg were used over two years of experiment. The experiment was set up in a completely randomized design, the data were evaluated by analysis of variance and the means were compared by Tukey’s test at the 0.05 significance level. There was no significant effect of year neither interaction of year with green-leaf offer. There were significant effects of leaf offer on dry matter intake (DMI) with behavior of positively linear (p<0.05). There were significant effects of green-leaf offer on final BW and average daily gain, and lambs receiving of 75 g/kg green-leaf offer showed the highest ADG (179 g/d). There were no significant differences in the carcass, meat, and primal cuts between the groups of lambs receiving different herbage offerings. There were significant effects of leaf offer on slaughter weight, hot carcass weight, and subcutaneous fat thickness. Lambs receiving of 75 g/kg leaf offer showed the highest SFT (5.8 mm). Slaughter weight and hot carcass weight averaged 41.52 kg and 20.07 kg, respectively. We recommend the treatment with leaves offer of 75 g/kg BW of Marandu pasture for the finishing of lambs supplemented at 1.6% of BW.

Precision finishing of South African lambs in feedlots: a review.

In the intensification of sheep production systems, feedlot finishing plays a fundamental role in preparing lambs for slaughter, as well as relieving the grazing pressure on pasture. The profit margins in feedlot operations are often narrow and require the economics of scale to generate a sufficient income. In order to minimise expenses, intensive management and precision rearing of lambs to an ideal slaughter weight is needed to obtain premium carcass prices. The South African sheep industry is made up of wool, dual-purpose as well as meat type breeds, which also vary in terms of maturity. In order to implement precision finishing of South African lamb, a complete understanding of the growth, intake and fat deposition trends of growing lambs of different breed types is needed. This review outlines feedlot lamb production within the Southern African context for the major commercial breeds, while also providing insight in the considerations necessary to develop a decision support system for lamb rearing. Integrating such a decision support system into a lamb feedlot operation can then be used for precision finishing of lambs by predicting the optimal length of the feeding period and ideal slaughter weights of lambs.

Biological Control of Gastrointestinal Helminthes of Livestock

Gastrointestinal helminths cause considerable production loss in ruminants globally and constraint to optimum livestock production. Extensively managed animals often host gastrointestinal parasites. Guidelines for sustainable control of parasites in sheep (SCOPS) have been produced in the UK which include recommendations for treatments to ewes. Traditionally control has been achieved through the application of broad spectrum anthelmintic; however, resistance is the major issue. In terms of parasitic nematodes in sheep, widespread resistance has been identified to the three available broad-spectrum anthelmintic classes with reports of increasing multi-class resistance was reported. Anthelmintic treatments can reach up to eight for lamb finishing. Resistance to anthelmintic can be reached to 88%. The trend towards nonchemical parasite control methods (ecological, organic, green) farming of livestock. Biological control of nematode parasites of livestock is the rising issue of animal science. In this study, biological control of nematode parasites of livestock has been reviewed.

Reducing the level of nutrition of twin-bearing ewes during mid to late pregnancy produces leaner prime lambs at slaughter

The Australian prime lamb industry is seeking to improve lean meat yield (LMY) as a means to increasing efficiency and profitability across the whole value chain. The LMY of prime lambs is affected by genetics and on-farm nutrition from birth to slaughter and is the total muscle weight relative to the total carcass weight. Under the production conditions of south eastern Australia, many ewe flocks experience a moderate reduction in nutrition in mid to late pregnancy due to a decrease in pasture availability and quality. Correcting nutritional deficits throughout gestation requires the feeding of supplements. This enables the pregnant ewe to meet condition score (CS) targets at lambing. However, limited resources on farm often mean it is difficult to effectively manage nutritional supplementation of the pregnant ewe flock. The impact of reduced ewe nutrition in mid to late pregnancy on the body composition of finishing lambs and subsequent carcass composition remains unknown. This study investigated the effect of moderately reducing ewe nutrition in mid to late gestation on the body composition of finishing lambs and carcass composition at slaughter on a commercial scale. Multiple born lambs to CS2.5 target ewes were lighter at birth and weaning, had lower feedlot entry and exit weights with lower pre-slaughter and carcass weights compared with CS3.0 and CS3.5 target ewes. These lambs also had significantly lower eye muscle and fat depth when measured by ultrasound prior to slaughter and carcass subcutaneous fat depth measured 110 mm from the spine along the 12th rib (GR 12th) and at the C-site (C-fat). Although carcasses were ~5% lighter, results showed that male progeny born to ewes with reduced nutrition from day 50 gestation to a target CS2.5 at lambing had a higher percentage of lean tissue mass as measured by dual energy X-ray absorptiometry and a lower percentage of fat during finishing and at slaughter, with the multiple born progeny from CS3.0 and CS3.5 target ewes being similar. These data suggest lambs produced from multiple bearing ewes that have had a moderate reduction in nutrition during pregnancy are less mature. This effect was also independent of lamb finishing system. The 5% reduction in carcass weight observed in this study would have commercially relevant consequences for prime lamb producers, despite a small gain in LMY.

Glicerina bruta ou glicerol na dieta de cordeiros: Uma metánalise – Desempenho, carcaça e carne

The intensification of biodiesel production inevitably generates the crude glycerine byproduct, which has little output for other uses mainly due to its purity. The inclusion of crude glycerin (GB) or glycerol (G) as an energy source, mainly as a corn substitute, may be a viable alternative in lamb finishing. In this sense, the objective of this study was to evaluate the levels of GB and G in the diet on lamb performance, carcass characteristics and meat quality through a metanalytic study. Twenty-four high impact articles were selected from research conducted in Brazil and abroad, involving 880 lambs distributed in 86 treatments. Data from both GB and G were grouped into levels. Based on the data contained in these articles were analyzed: initial live weight (PVI), slaughter live weight (PVA), dry matter intake (CMS), average daily gain (GMD), feed conversion (CA), carcass yield (RCQ), cold carcass yield (RCF), loin eye area (AOL), fat thickness (EG), saturated fatty acids (AGS), unsaturated (AGI), monounsaturated (AGMI), polyunsaturated (AGPI) , n6: n3 ratio, crude protein (CP), ether extract (EE), final pH and shear force in relation to control treatment (0% GB or G in MS). The obtained data were submitted to analysis of variance for linear and quadratic effect in each of the variables within all levels and, in the case of significance, regression analysis was performed. The performance, carcass characteristics and meat quality of lambs up to 36.0% of inclusion in the DM of GB and 32.4% of lambs diet did not have deleterious effect on them, and can be considered safe for human consumption. GB and G are presented as an alternative in the diet of finishing lambs, however, the strategy of use as energy substitute should come together with the study of the economic viability based on the price of corn, crude glycerin and demand of finished lambs in the region in question.

Effect of grape (Vitis vinifera L. cv. Pinotage) pomace supplementation on nutrient utilization in finisher lambs

The objective of the study was to evaluate the effects of feeding varying levels of sun–dried red grape pomace (DGP; Vitis vinifera L. cultivar Pinotage) on nutrient digestibility, rumen fermentation, microbial nitrogen (N) supply, N retention and efficiency of N utilization in lambs. Twenty-one Dohne Merino wether lambs (6.0 ± 1.0 months and 51.6 ± 4.70 kg initial body weight) were randomly assigned to three diets containing 0, 100 and 200 g DGP per kg of diet dry matter in pelleted total mixed rations (TMR). The experiment consisted of 14 days for adaptation to the diets and 7 days for data collection. Intake of neutral detergent fiber (aNDFom) and starch decreased linearly (P ≤ 0.05) while ether extract intake increased linearly (P ≤ 0.05) with the addition of DGP. Apparent total tract aNDFom digestibility decreased linearly (P ≤ 0.05) with increasing levels of DGP. Total volatile fatty acids (VFA) production was quadratically (P ≤ 0.05) influenced by DGP addition. Increasing levels of DGP led to a linear decrease (P ≤ 0.05) in concentrations of butyrate and valerate. Allantoin, microbial N supply, total purine derivatives excreted linearly declined (P ≤ 0.05) with DGP addition. Nitrogen retention and the efficiency of N utilization were not influenced by diet (P > 0.05). Overall, addition of DGP in the lamb finisher diets reduced carbohydrate intake, microbial N yield, total purine derivatives excreted and increased total VFA concentration but did not have adverse effect of DGP on N retention and the efficiency of N utilization.