Here is a longer translation of the full verse, given by Swāmī Mādhavānanda:
सा हेयमीक्षां चक्रे, कथं नु मात्मान एव जनयित्वा सम्भवति? हन्त तिरोऽसानीति; सा गौरभवत्, ऋषभ इतरः, तां समेवाभवत्, ततो गावोऽजायन्त; वडवेतराभवत्, अश्ववृष इतरः, गर्धभीतरा, गर्दभ इतरः, तां समेवाभवत्, तत एकशफमजायत; अजेतराभवत्, वस्त इतरः, अविरितरा, मेष इतरः, तां समेवाभवत्, ततोऽजावयोऽजायन्त; एवमेव यदिदं किंच मिथुनम्, आ पिपीलिकाभ्यः, तत्सर्वमसृजत ॥ ४ ॥
sā heyamīkṣāṃ cakre, kathaṃ nu mātmāna eva janayitvā sambhavati? hanta tiro'sānīti; sā gaurabhavat, ṛṣabha itaraḥ, tāṃ samevābhavat, tato gāvo'jāyanta; vaḍavetarābhavat, aśvavṛṣa itaraḥ, gardhabhītarā, gardabha itaraḥ, tāṃ samevābhavat, tata ekaśaphamajāyata; ajetarābhavat, vasta itaraḥ, aviritarā, meṣa itaraḥ, tāṃ samevābhavat, tato'jāvayo'jāyanta; evameva yadidaṃ kiṃca mithunam, ā pipīlikābhyaḥ, tatsarvamasṛjata || 4 ||
She thought, ‘How can he be united with me after producing me from himself? Well, let me hide myself.’ She became a cow, the other became a bull and was united with her; from that cows were born. The one became a mare, the other a stallion; the one became a she-ass, the other became a he-ass and was united with her; from that one-hoofed animals were born. The one became a she-goat, the other a he-goat; the one became a ewe, the other became a ram and was united with her; from that goats and sheep were born. Thus did he project everything that exists in pairs, down to the ants. 
It's not a very unpleasant tale at all. It's essentially telling the story of how Vishnu and Devi took various forms as the male and female versions of each creature, procreated, and essentially began every living animal's lineage.