Does forage type (grazing vs. hay) fed to ewes before and after lambing affect suckling lambs performance, meat quality and consumer purchase intention?

The quality of meat in milk fed lambs is affected by the ewe diet: A review

Several scientific publications have highlighted the importance of feeding management practices in improving the nutritional properties of milk from dairy ewes. Meat production quality from suckling lambs is based on the use of milk as exclusive or near exclusive dietary component. There is considerable evidence that lamb meat contains many important nutrients and bioactive compounds that play an important role in consumer health. This paper examines the different quality characteristics of lamb meat from ewes fed different diets to improve milk quality. To conduct this research, we consulted different scientific databases and acquired relevant documents that studied the relationships between the dietary treatment of lactating ewes and the performance of their suckling lambs (growth and carcass traits) as well as the meat quality in terms of nutrient content (fat and protein in particular), bioactive compounds content (fatty acids, vitamins, and antioxidant molecules), color, odor and flavor. The extent of change in meat carcass traits and meat quality of suckling lambs due to different feeding strategies applied to ewes was evaluated and discussed. This overview of the knowledge on the relationship between the milk quality and suckling lamb quality can be useful for production and communication strategies development for the lamb meat industry.

Sainfoin in the Dams’ Diet as a Source of Proanthocyanidins: Effect on the Growth, Carcass and Meat Quality of Their Suckling Lambs

Sainfoin (Onobrychis viciifolia) is a forage legume with a medium content of proanthocyanidins (PAC), which may affect animal performance and product quality. The objective of the present study was to assess the effect of PAC from sainfoin fed to dams, using polyethylene glycol (PEG) as a blocking agent, on the performance and carcass and meat quality of their suckling male lambs. After lambing, twenty lactating dams were fed fresh sainfoin ad libitum plus 200 g per day of barley; ten were orally dosed with water (Sainfoin), and ten were dosed orally with a water dilution of 100 g PEG (Sainfoin + PEG). Their lambs (4.1 ± 0.64 kg at birth) suckled ad libitum until they reached the target slaughter weight of 10–12 kg. The presence of PAC in the dams’ diet did not affect the growth, blood metabolites and carcass weight and fatness of the suckling lambs but decreased the lightness of caudal fat (p < 0.05) and increased the weight of the digestive compartments (p < 0.05). Regarding the meat characteristics, PAC only decreased polyphenols content (p < 0.05). In conclusion, the presence of PAC in the dams’ diet had not significant effects on the performance and product quality of their suckling lambs.

Effect of Dams and Suckling Lamb Feeding Systems on the Fatty Acid Composition of Suckling Lamb Meat

The effects of the dams and suckling lamb feeding systems on the fatty acid (FA) profile of lamb meat are reviewed in this article. The suckling lamb can be considered a functional monogastric, and therefore, its meat FA composition is strongly influenced by the FA composition of maternal milk. The major source of variation for ewe milk FA composition is represented by pasture amount and type. In the traditional sheep breeding system of the Mediterranean area, the main lambing period occurs in late autumn-early winter, and ewes are able to exploit the seasonal availability of the natural pastures at their best. Therefore, lambs start suckling when maternal milk concentrations of vaccenic, rumenic, and n-3 long-chain polyunsaturated FA in maternal milk are the highest. When maternal diet is mainly based on hay and concentrates, the use of vegetable oils can be considered a good strategy to improve the meat FA profile of suckling lambs.

The Inclusion of Concentrate with Quebracho Is Advisable in Two Forage-Based Diets of Ewes According to the In Vitro Fermentation Parameters

Ewes receive hay or graze on fresh pastures supplemented with concentrates to fulfil their lactation requirements. Quebracho (Schinopsis balansae) can be added to change the ruminal fermentation. Fermentation parameters of forages alone and 70:30 forage:concentrate diets with control and quebracho concentrate were compared after 24 h of in vitro incubation. Fresh forage diets produced less gas (p < 0.05) and had greater IVOMD (p < 0.001), ammonia (NH₃-N) content, valeric acid, branched-chain volatile fatty acid proportions, and lower propionic acid proportion than the hay diets (p < 0.01). In the hay diets, methane production increased with control concentrate (p < 0.01) and tended to decrease with quebacho concentrate (p < 0.10). The inclusion of both concentrates increased the acetic:propionic ratio (p < 0.01), and only the inclusion of quebracho concentrate increased the IVOMD (p < 0.01). In the fresh forage diets, gas and methane production increased with the inclusion of the control concentrate (p < 0.05), but methane production decreased with quebracho concentrate (p < 0.01). The inclusion of quebracho concentrate reduced the NH₃-N content and valeric acid proportion (p < 0.05). In conclusion, the inclusion of quebracho concentrate would be advisable to reduce the CH₄ production and NH₃-N content in fresh forage diets and to increase the IVOMD in hay diets in comparison with the forages alone.

Meat quality of light lambs is more affected by the dam's feeding system during lactation than by the inclusion of quebracho in the fattening concentrate

The inclusion of natural antioxidants in the diet, through fresh forages or condensed tannins, might prolong meat shelf life and modify the meat quality. The aim of this study was to evaluate the effect of the dam's feeding system during lactation and the inclusion of quebracho in the fattening concentrate of male lambs on meat color, chemical composition, and lipid oxidation. Dams and their suckling lambs were fed indoors or allowed to graze on alfalfa or sainfoin until lambs reached 42 d old. Thereafter, the weaned lambs were fed concentrates with 5% quebracho or without quebracho until reaching 22 to 24 kg BW. Meat of suckling lambs from dam's fed indoors (Indoor lambs) presented greater intramuscular fat content and lower α-tocopherol content than meat of suckling lambs from dam's fed Alfalfa (Alfalfa lambs) and Sainfoin (Sainfoin lambs; < 0.01), independent of the fattening diet. Regarding meat color of longissimus thoracis et lumborum muscle, on average, Indoor lambs' meat presented greater lightness, yellowness, and hue angle values than Alfalfa and Sainfoin lambs' meat ( < 0.05). The redness was affected by the interaction between the feeding system during lactation and the time of storage, but, on average, Alfalfa and Sainfoin lambs had greater redness than Indoor lambs ( < 0.05). The lipid oxidation from 5 to 14 d of meat display time observed for Sainfoin lambs was lower than that for Indoor lambs ( < 0.05). The intramuscular fatty acid profile of meat from the Sainfoin and Alfalfa lambs met particularly well the Food and Agriculture Organization of the United Nations recommendation for human health, compared that of meat from the Indoor lambs. The dietary inclusion of quebracho during fattening modified meat α-tocopherol content, oxymyoglobin levels after 8 d of storage, and fatty acid profiles. In conclusion, the results indicate higher importance of the diet during suckling than during the subsequent fattening period on meat quality parameters such as color, lipid oxidation, and fatty acid profile. Dams grazing Sainfoin provide a more stable lamb meat, and it would be cheaper to feed the dams with fresh forages with a high α-tocopherol content than supplementing the concentrate of the lambs with synthetic α-tocopherol.

Consumer visual appraisal and shelf life of leg chops from suckling kids raised with natural milk or milk replacer

BACKGROUND

The use of milk replacers to feed suckling kids could affect the shelf life and appearance of the meat. Leg chops were evaluated by consumers and the instrumental color was measured. A machine learning algorithm was used to relate them. The aim of this experiment was to study the shelf life of the meat of kids reared with dam's milk or milk replacers and to ascertain which illuminant and instrumental color variables are used by consumers as criteria to evaluate that visual appraisal.

RESULTS

Meat from kids reared with milk replacers was more valuable and had a longer shelf life than meat from kids reared with natural milk. Consumers used the color of the whole surface of the leg chop to assess the appearance of meat. Lightness and hue angle were the prime cues used to evaluate the appearance of meat.

CONCLUSION

Illuminant D65 was more useful for relating the visual appraisal with the instrumental color using a machine learning algorithm. The machine learning algorithms showed that the underlying rules used by consumers to evaluate the appearance of suckling kid meat are not at all linear and can be computationally schematized into a simple algorithm. © 2017 Society of Chemical Industry.

A comparison of growth, carcass traits, and tissue composition of ‘Segureña’ lambs raised either in an extensive production system or an intensive one

The aim of this study was to determine the performance of lambs of a Segureña local breed for growth, carcass traits and tissue composition when raised either in an extensive or an intensive production system to produce carcasses of ~11 kg. In the extensive system lambs (n = 21) were raised on pasture with salt-tolerant forages (bermudagrass hybrid and ryegrass Westerwold) and were unweaned. In the intensive system lambs (n = 24) were weaned at 45 days and reared in stalls with concentrate feeding. Extensive lambs, especially twins, showed lower growth rates during the total growing period. Male extensive lambs had higher proportions of full digestive tract and stomachs and lower commercial dressing percentages. Extensive lambs had a lower percentage of valuable body parts such as liver and tenderloin. In addition they showed a higher percentage of head, shoulder and neck; and poorer conformation scores. Furthermore, their carcasses had a higher percentage of bone and a lower percentage of muscle. Nevertheless, other aspects should be taken into account, such as meat quality and meat production cost, animal welfare and taking advantage of high salinity soil and water to grow these forages. An alternative system in which grazing is supplemented with concentrates should be evaluated in future research.

Sustainable sheep production and consumer preference trends: compatibilities, contradictions, and unresolved dilemmas

There are increasing concerns of society towards the consumption of animal products which have been produced and transformed in a sustainable manner. This trend influences consumer purchasing decision making, particularly in developed countries. On the other hand, in the next years, the pressure to increase the volume and efficiency of meat production will be much higher to cope with the expected unsatisfied demand. At least in part, current and future technologies could contribute to solve this challenge. However, the use of some of these innovations could have a negative effect on consumer preferences. There is no consensus in our society about this dilemma. The objective of this paper is to review the scientific evidence related to these topics and to analyze and discuss the effect of some of the extrinsic and intrinsic factors linked with the sheep industry which could affect the acceptability of lamb meat by consumers.