Feed Planet Magazine Issue-Sayı: 45 December - Aralık 2022

54 ARTICLE • MAKALE FEED PLANET / DECEMBER 2022 • ARALIK 2022 All of these conditions are also found in poultry ani- mal husbandry and might have increased over the past years. Broiler growth has improved dramatically since the last 50+ years (roughly a factor of four since 1957). Growth was directed specifically to increased carcass (+12%) and breast meat yield (+50%). White muscle (such as chicken breast) consists almost solely of mus- cle fibers high in creatine (fast twitch type IIb fibers). Knowing that creatine not only supports myogenesis but also stabilizes cell membranes, can we speculate that the substantial carcass and breast muscle growth was supported by elevating muscle creatine? In fact, in 1956, just ~3gr creatine per kg muscle are reported in 21d broilers fed practical diets, but ~4 gr/kg muscle are found in 2018 for broilers of the same age (+33%). It seems evident that more creatine is stored in the muscle to support growth. Are these levels ad- equate? OPTIONS TO PROVIDE CREATINE TO BROILERS Dietary supplementation with creatine has proven to increase muscle creatine by roughly 20% in humans. Effects are most pronounced when natural creatine from food is low. Creamino®, a preparation contain- ing the creatine precursor guanidino- acetic acid (GAA, 96 % min), is established as a highly effi- cient source of creatine for broilers. A dose range of 600-1200 mg/ kg feed was derived from growth experi- ments whilst ~ 600 mg/kg are suggested from a facto- rial calculation. Interestingly, 1086 mg creatine/kg feed would be obtained from 5% inclusion of fish meal containing creatine as pres- ent in dry fish (21.7 g/kg), so fall- ing in the same range as derived for Creamino®. (Figure 1) COMPARISON TO FISH MEAL: CREAMINO® IMPROVES MUSCLE CREATINE, GROWTH AND BREAST YIELD Creamino® has been shown in numerous experi- ments to elevate muscle creatine in broilers. In a com- parison study (d0-39) with ROSS 308 broilers, fishmeal (PC) added at 6%, 3% and 3% in starter, grower and finisher diet respectively showed very low impact on muscle creatine (+3%) as compared to the pure plant based control (NC, corn/soy). This was expected from the poor creatine content in the fishmeal (1.7 g/kg). In Tüm bu koşullar kanatlı yetiştiricili- ğinde karşılaşılan ve son yıllarda artış göste- ren durumlardır. Broiler büyü- me hızı son 50+ yılda önemli derecede gelişme gösterdi (1957’den beri kabaca 4 kat). Bu gelişme özellikle artan karkas miktarı (+12%) ve göğüs eti verimi (+50%) olarak kendini gösterdi. Beyaz kas (örn. tavuk göğsü) tamamen kreatin bakımından yüksek kas liflerinden oluşur (hızlı ka- sılan tip IIb lifleri). Kreatin sadece miyogenez’i destekle- mekle kalmaz aynı zamanda hücre bütünlüğünü de korur. Bu bilgiler ışığında kaslarda birikimi artan kreatinin karkas ve göğüs etindeki artışları desteklediği söylenebilir mi? Aslında, 1956’da standart bir yem ile beslenmiş 21 günlük broilerin 1 kg kasında ~3gr kreatin bulunduğu ölçülmüştür, an- cak 2018’de yapılan çalışmalar aynı yaştaki 1 kg broiler kasın-