Pick a lament psalm (here is a portion of Ps 44):
Because of you we are being killed all day long, and accounted as sheep for the slaughter. Rouse yourself! Why do you sleep, O Lord? Awake, do not cast us off forever! Why do you hide your face? Why do you forget our affliction and oppression? For we sink down to the dust; our bodies cling to the ground. Rise up, come to our help. Redeem us for the sake of your steadfast love.
Edit the details. For example:
Because of you, factory farmed animals are being killed all day long, chickens, pigs, sheep, and cows all headed for slaughter. Rouse yourself! Why do you sleep, O Lord? Awake, do not cast your creatures off forever! Why do you hide your face? Why do you forget your animals' affliction and oppression? For they sink down in their cages; they can neither breathe fresh air nor play with their children. Rise up, come to their help. Redeem them for the sake of your steadfast love.
Add some psalmic affirmation of God's responses in the past.
Here's an edited portion of Psalm 34.
The eyes of the Lord are on the righteous, and his ears are open to their cry. The face of the Lord is against the torture of factory farming, to cut off the remembrance of it from the earth. When the righteous cry our in defence of animals, the Lord hears, and rescues suffering animals from all their troubles. The Lord is near to discarded creatures, and saves the crushed in spirit.
And some thanksgiving for the already and not yet reconciliation of creation.
Edited portion of Psalm 118.
Shouts of joy and victory resound in the gatherings of CreatureKind: 'The Lord has done mighty things! We will not die but live, and we will proclaim what the Lord has done. Creatures will not die but live, and we will proclaim what the Lord has done. The Lord has chastened us severely for our complicity in animal abuse, but he has not given us over to death. The Lord has not given animals over to death.
We give thanks to you, for you answered our prayers; we give thanks to you, for you rescued your creatures. You have become creation's salvation.
Pray all parts together, feeling the tension between the parts and offering all of your feelings to God.