Pengaruh Guanidinoacetic Acid dalam Pakan Rendah Protein terhadap Produktivitas dan Ekspresi Gen Tight Junction Broiler

Anisa Aulia, Dr. Ir. Muhsin Al Anas, S.Pt., IPP. ; Dr. Ir. Asih Kurniawati, S.Pt., M.Si., IPM.

2025 | Tesis | S2 Ilmu Peternakan

Pemberian pakan rendah protein pada broiler dapat meningkatkan efesiensi pakan dan menurunkan emisi amonia, namun berpotensi menurunkan produktivitas. Penelitian ini bertujuan untuk mengevaluasi penambahan guanidinoasetat acid (GAA) dalam pakan rendah protein terhadap produktivitas, histomorfologi dan ekspresi gen tight junction. Sebanyak 360 broiler betina strain Ross 308 dibagi secara acak dalam rancangan faktorial dua level protein kasar (PK) (19,5?n 18,0%) dan tiga level GAA (0; 0,6; dan 1,2 g/kg), dengan enam ulangan dan 10 ekor per ulangan. Perlakuan pakan diberikan pada fase finisher (21-34 hari). Hasil penelitian menunjukkan penurunan PK 1,5% menurunkan produktivitas broiler (P<0>Suplementasi GAA 1,2 g/kg dalam pakan meningkatkan produktivitas dibandingkan suplementasi GAA 0,6 g/kg (P<0>Terdapat interaksi PK x GAA dengan produktivitas tertinggi pada PK 19,5% dengan suplementasi GAA 1,2 g/kg. Nilai histomorfologi menurun pada PK 18% dibandingkan PK 19,5% (P<0>Sedangkan suplementasi GAA 1,2 g/kg dalam pakan meningkatkan nilai histomorfologi dibandingkan dengan suplementasi GAA 0,6 g/kg dalam pakan (P<0>Selanjutnya terdapat interaksi PK x GAA terhadap tinggi vili dengan nilai tertinggi pada PK 19,5% dengan suplementasi GAA 1,2 g/kg. Ekspresi gen tight junction OCLDN, ZO-2, JAM 2 meningkat dan CLDN1 menurun pada PK 18% dibandingkan PK 19,5% (P<0>Ekspresi gen tight junction CLDN1, OCLDN, ZO-1, Z0-2 dan JAM 2 meningkat pada suplementasi GAA 1,2 g/kg dibandingkan GAA 0,6 g/kg (P<0>Selanjutnya terdapat interaksi PK x GAA terhadap ekspresi gen tight junction dengan ekspresi tertinggi pada PK 18% dengan suplementasi GAA 1,2 g/kg. Kesimpulan dari penelitian yang dilakukan adalah penurunan PK 1,5% menurunkan produktivitas dan nilai histomorfologi namun meningkatkan ekspresi gen tight junction. Suplementasi GAA 1,2 g/kg meningkatkan produktivitas, nilai histomorfologi dan gen tight junction. Terdapat interaksi antara penurunan protein kasar dengan suplementasi GAA dengan peningkatan tertinggi terdapat pada pakan dengan PK 19,5?n 1,2 % GAA.

Low-protein diet can improve feed efficiency and reduce NH3 emissions but may potentially impair productivity. This study aimed to evaluate the effects of guanidinoacetic acid (GAA) supplementation in a low-protein diet on productivity, intestinal histomorphology, and tight junction gene expression in broilers. A total of 360 female Ross 308 broilers were randomly assigned in a factorial arrangement of two crude protein (CP) levels (19.5% and 18.0%) and three GAA levels (0, 0.6, and 1.2 g/kg), with six replicates of 10 birds each. The dietary treatments were applied during the finisher phase (days 21–34). The results showed that reducing CP by 1.5% significantly decreased broiler productivity. Supplementation with 1.2 g/kg GAA improved productivity compared to 0.6 g/kg GAA. A significant interaction between CP x GAA was observed, with the highest productivity recorded at 19.5% CP combined with 1.2 g/kg GAA. Histomorphology parameters were reduced in broilers fed 18.0% CP compared to 19.5% CP, while supplementation with 1.2 g/kg GAA improved histomorphology compared to 0.6 g/kg GAA. An interaction between CP x GAA was also found for villus height, with the highest value observed in the 19.5% CP with 1.2 g/kg GAA level. Expression of tight junction genes OCLDN, ZO-2, and JAM2 increased, while CLDN1 decreased in broilers fed 18.0% CP compared to 19.5% CP. Supplementation with 1.2 g/kg GAA significantly upregulated CLDN1, OCLDN, ZO-1, ZO-2, and JAM 2 expression compared to 0.6 g/kg GAA. Furthermore, a significant CP × GAA interaction was observed for tight junction gene expression, with the highest expression found in broilers fed 18.0% CP with 1.2 g/kg GAA. In conclusion, reducing dietary CP by 1.5?creased productivity and histomorphology values but increased tight junction gene expression. Supplementation with 1.2 g/kg GAA improved productivity, histomorphology, and tight junction gene expression. There was an interaction between crude protein reduction and GAA supplementation, with the greatest improvement observed in feed containing 19.5% CP and 1.2% GAA.

Kata Kunci : Broiler, Guanidinoacetic acid, Pakan Rendah Protein, Produktivitas, Histomorfotologi usus, Tight junction.