Cynodon plectostachyus is a valued pasture in the tropics and it is part of cattle production systems in several dry tropical areas, particularly in Eastern Africa and in Central and South America. In the drylands of South-East Kenya, in a survey of cattle farmers, Cynodon plectostachyus was frequently the top-ranked pasture, above Eragrostis superba, Cenchrus ciliaris and Megathyrsus maximus (Ndathi et al., 2012).
Cynodon plectostachyus is considered to be palatable (Bogdan, 1977; Asamoah et al., 1985), though less so than Guinea grass (Megathyrus maximus) and pangola grass (Digitaria eriantha) (Asamoah et al., 1985).
Cynodon plectostachyus may have a similar, or lower, nutritional value than other grasses available at the same period in the same area. In Kenya, the in vitro DM digestibility (35%) of Cynodon plectostachyus hay was lower than that of Eragrostis superba (45%) and similar to that of Cenchrus ciliaris and Megathyrsus maximus (37 and 34% respectively) (Ndathi et al., 2012). In Puerto Rico, its in vivo DM digestibility (50%) was lower than that of Cynodon dactylon, Cynodon nlemfuensis, Digitaria eriantha and Megathyrsus maximus (54-55%) (Randel et al., 1989). In Brazil, the in vitro DM digestibility of Cynodon plectostachyus grass (63%) was found to be similar to that of Tifton 85 (a cultivar of Cynodon dactylon) and Cynodon nlemfuensis (63%), and slightly lower than that of Cynodon cultivars Coastcross and Tifton 44 (65%) (Cecato et al., 2001). In the Philippines, giant star grass cut every 20 days had a higher in vivo DM digestibility in sheep (60%) than when cut every 30 or 40 days (Intong, 1998). In Cuba, the in vivo OM digestibility in sheep of Cynodon plectostachyus silage was identical to that of Megathyrsus maximus silage (59%), and lower than that of King grass (Pennisetum purpureum × Pennisetum glaucum) silage (63%) (Esperance et al., 1985).
Giant star grass does not have a high nutritive value, particularly during the dry season, and numerous trials have tried to determine the needs and methods for supplementing cattle and sheep grazing giant star grass. In Mexico (Colima), a traditional dual purpose cattle production system is based on maize stubble and giant star grass: this diet, though sufficient in energy, was found to be deficient in protein and dry matter, and required supplementation with other ingredients (Macedo et al., 2008). In silvopastoral systems, livestock grazing Cynodon plectostachyus had access to forage legumes such as Leucaena leucocephala or Prosopis juliflora (Nahed-Toral et al., 2010; Goldfarb et al., 1995; Mahecha et al., 2000). Supplementation of giant star grass with multinutrient blocks, and protein sources such as oil meals, animal by-products, urea and protein banks (forage legumes) is summarized in the table below.
||Steers (360 kg)
||No effect on liveweight gain but a better response could be expected either during the dry season or by using growing steers.
||Hernandez-Mendo et al., 2008
||Zebu/Swiss calves (200 kg)
||30% multinutrient blocks enriched with yeast: Saccharomyces cerevisiae
||Higher growth rate (795 g/d vs. 678 g/d) and DM intake than unsupplemented animals.
||Cabrera Nuñez et al., 2005
||Bos taurus x Bos indicus heifers
|Urea-treated sugarcane (3% of BW) + a protein supplement (blood meal, poultry litter, rice polishing and cane molasses)
||Higher daily gain than star grass alone (528 vs. 320 g/d).
||Aranda et al., 2001
|0.4 kg/d of a protein+mineral supplement
||Higher daily gain than with mineral supplementation alone
(150 g/d vs. 60 g/d).
|Moreira et al., 2004b
||Bos taurus x Bos indicus steers
|2 kg/d (DM) of supplement (0, 50 or 100% blood meal, copra meal, or sobyean meal + 100, 50 or 0% urea)
||Highest daily gain with 100% blood meal or copra meal (1210 g/d), lowest average daily gain (970 g/d) with 100% urea. Blood meal and coconut meal provided bypass protein in the supplement. The positive response to blood meal has been associated with the lysine supply in the bypass protein (Goedeken et al., 1990).
||Ramos et al., 1998
||Brahman x Holstein dry cows (453 kg)
||Multinutrient blocks containing either fish meal or whole cotton seeds
||No effect on DM intake and DM utilization in cows fed star grass hay but the effects were significant on cows fed the lower quality Trachypogon hay. The effect of the multinutrient block is more notable when fed to animal consuming fibrous feed of low digestibility and protein content.
||Mata et al., 1992
||Brahman × Brown Swiss steers
|Sugarcane silage with maize grain (10%), urea (1.5%) and mineral premix (0.5%)
||Increased DM intake, total gain and average daily gain,
with no effect on feed conversion and digestible DM.
|Gomez-Vasquez et al., 2011
||Indobrasil and Brahman x Swiss American steers (289-349 kg)
||30 or 60 min daily access to kudzu (Pueraria phaseoloides)
||Daily liveweight gain increased with 60 min access to kudzu, compared to star grass alone (836 vs. 575 g/d). However, legumes are not very effective as sources of bypass protein to improve rate of growth due to their extensive degradation in the rumen (Poppi et al., 1995).
||Pérez et al., 2001
In Mexico, a comparison between steers grazing Cynodon plectostachyus and steers fed a maize-soybean meal concentrate showed significant differences in the fatty acid composition of the meat, which was richer in stearic acid (C18:0) for grazing steers (Montero-Lagunes et al., 2011).
Literature reporting the use of Cynodon plectostachyus pastures for dairy production is scarce. In Cuba, Cynodon plectostachyus silage offered to Holstein x Zebu cows resulted in daily milk yields and DM intakes higher than those for king grass (Pennisetum purpureum x P. americanum) silage and lower than those for Guinea grass (Megathyrsus maximus) silage (milk yield 4.6 vs. 4.0 and 5.6 kg/d, respectively; DM intake 9.2 vs. 9.0 and 10.3 kg/d, respectively) (Esperance et al., 1985). In semi-arid areas of central Tanzania, combining Cenchrus ciliaris and Cynodon plectostachyus (50:50) provided good quality hay for milk production in dual purpose Mpwapwa cows and resulted in higher milk yield (5.3 kg/d) than other combinations of Cenchrus ciliaris, Megathyrsus maximus, Cynodon plectostachyus and Rottboellia exaltata (Bwire et al., 2003).