Sarcopenia is an age-related muscle-wasting syndrome common to all people that results in a reduction in muscle mass and strength, possibly leading to physical disability and morbidity (Cruz-Jentoft et al., 2010). Sarcopenia can be exacerbated by simultaneous obesity (sarcopenic obesity) (Thornell, 2011) and by diabetes (Srikanthan, Hevener, and Karlamangla, 2010). Timeline change for uncomplicated sarcopenia, muscle mass decreases about (0.5–1.0%) half to one percent per year beginning at the age of (40) forty (Paddon-Jones et al, 2008). Factors thought to contribute to sarcopenia are age-related changes in food intake, changes in physical exercise, and chronic inflammation (Young et al., 2013). Treatment with testosterone and growth hormone only moderately alter the course of the disease, while treatment with growth hormone-releasing hormone (GHRH) may have a more significant impact (Borst, 2004). However, a focused dietary intervention may have the most significant upside potential to counteract the onset or alter the course of sarcopenia (Young et al., 2013).

Increasing daily intake of protein above the requirement of 0.8 g/kg/d can reduce muscle loss that generally occurs with age (Paddon-Jones et al., 2008). Protein quality is also essential in this regard in that it contains large amounts of the functional amino acid leucine, which stimulates protein synthesis by mTOR signaling (Du et al., 2007). Paddon-Jones et al. (2008) reported that a moderate intake of lean beef could increase muscle protein synthesis in both young and older men and women. The most efficient intervention for reducing the effects of sarcopenia is resistance training (Young et al., 2013). Evans (2004) reported a synergistic effect of increased meat intake and resistance training allowing an increase in muscle mass in older men. In general, sarcopenia results from an imbalance in protein turnover. The mechanism underlying this synergistic effect involves the effect of the amino acid balance in meat on the activation of satellite cells resulting in muscle anabolism following resistance training (Thornell, 2011).

Conclusion

The solution is to formulate integrated meat production systems through the implementation of disruptive technologies to produce affordable meats allowing the populace to avoid frailty as they age. Cattle are available that have converted cellulosic materials (not food for people) into the meat (at least the frame for meat). EnhancedExchange greatly enhances this raw product (skinny cows) efficiently, producing both high-quality meat and large quantities of meat.

African Tropically Adapted Beef Breeds

Throughout most of the world, tropical adaptation is congruent with Bos indicus breeding. This is not only because of the well-recognized inherent behavioral and physiological adaptation traits in Bos indicus breeds but also because crossing with Bos taurus breeds provides a maximum amount of heterosis that aids the crossbred in handling stressful environments. However, as shown above, because of the excellent adaptation of Bos indicus influenced cattle to the tropics and subtropics, and because it has become evident that high Bos indicus breeding produces less tender and more variable beef (Crouse et al., 1989; Wheeler et al., 1990; and Shackelford et al., 1991). It has come to be accepted that the traits that predispose an animal to tropical adaptation also predispose the animal to produce tough beef. Indigenous southern African cattle breeds (the Sanga types) have often been misclassified as being in the Bos indicus species because of their adaptation to hot environments and because of their phenotypic resemblance (e.g., their humps) to Bos indicus breeds.

Manwell and Baker (1980) compared gene frequencies of several protein polymorphisms between African, European, and Indian breeds concluding that Sanga breeds had more in common with Bos taurus than with Bos indicus breeds. Frisch et al. (1997), using DNA markers, protein polymorphisms, and karyotypes confirmed that Sanga breeds have much in common with Bos taurus, but little in common with Bos indicus breeds. This explanation is in that Sanga breeds have a submetacentric Y chromosome typical of Bos taurus, in contrast to the Boran, an East African Zebu, showing an acrocentric Y chromosome similar to the karyotype of Bos indicus. They also reported that frequencies of four DNA markers and several protein polymorphisms for the Tuli, a Sanga breed, had much in common with Bos taurus breeds, but not with Bos indicus breeds. In contrast, the Boran is a mixture of the two species. Meyer (1984), in corroboration, reported that several Sanga breeds have a unique hemoglobin variant HbI unlike the typical indicine variants HbC and albumin C.

These variants are absent from Sanga and taurine breeds. Meyer (1984) also reported that a-lactalbumin A was absent in taurine breeds and present in Sanga and Zebu. Frisch et al. (1997) recommended that southern African Sanga breeds having cervico or cervicothoracic humps (e.g., Nguni, Tuli, and Afrikaner) be classified as Bos taurus sudafricanus. The quantification benefit is to distinguish them from other African taurine types, but also designate them as being descended from ancestors that were mostly taurine. In an analogous manner, they recommended that the African Zebu (e.g., Boran) having thoracic humps be classified as Bos taurindicus Africanus. These recommendations were supported by the evidence (karyotype and protein polymorphism) that African Zebu are mixtures of both Bos taurus and Bos indicus breeds. This clarifies the genetic basis and decries the prominent error made by cattlemen not accustomed to the Sanga phenotypes of classifying them, based on their hump, as having a predisposition toward tough meat.

On the contrary, a large body of work indicates that Sanga breeds, despite their adaptation to the tropics, produce tender beef. Strydom et al. (2000) reported that longissimus from Nguni, Afrikaner, and Bonsmara (5/8 Afrikaner, 3/8 Hereford, and Shorthorn) compared with Brown Swiss in WBSF but had lower values than Pinzgauer and Santa Gertrudis after 7 d aging (Table 18). The only histological difference detected was that Santa Gertrudis tended to have proportionally more and larger white muscle fibers as compared to those of the Nguni and Afrikaner. The myofibrillar index 7 d postmortem was the highest for Nguni followed by Afrikaner indicating that proteolysis was well underway (Strydom, 2008). Calkins et al (1981) and Crouse, Koohmaraie, and Seideman (1991) reported negative relationships between both white fiber size and density and tenderness. Strydom et al. (2008) reported that the variation in WBSF among indigenous South African breeds was small, especially when aged 21 d.

In contrast, Brahman animals produced consistently more robust and more variably tough longissimus regardless of aging time (2 or 21 d). They also reported that Brahman showed significantly lower proportions of soluble collagen, higher calpastatin/µ calpain ratios, and longer myofibril lengths at 2 d postmortem compared to the South African indigenous breeds. Wheeler et al., (2010) reported that Bonsmara and Romosinuano, Bos taurus tropically adapted germplasm when crossed with Angus and MARC III breeds produced carcasses that were lighter, leaner, and higher-yielding. The benefits include as well as having more longissimus tenderness than carcasses from Beefmaster and Brangus, tropically adapted Bos indicus influenced breeds (Table 15). Frylinck and Heinze (2003) also reported consistently lower WBSF for Bonsmara, Afrikaner, and Nguni longissimus compared to that of Brahman at 1, 3, 7, 14- and 21-d postmortem (Figure 10). WBSF for longissimus from Herefords were similar to Sanga but less than for Simmental and Brahman. In agreement with Strydom et al. (2008), advantages for Sanga breeds over Brahman in WBSF might be explained by lower in calpastatin/µ calpain ratios at 1 and 24 h postmortem (Frylinck and Heinze, 2003).