SB 11.5.13
yad ghrana-bhakso vihitah surayas
tatha pasor alabhanam na himsa
evam vyavayah prajaya na ratya
imam visuddham na viduh sva-dharmam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
According to the Vedic injunctions, when wine is offered in sacrificial ceremonies it is later to be consumed by smelling, and not by drinking. Similarly, the sacrificial offering of animals is permitted, but there is no provision for wide-scale animal slaughter. Religious sex life is also permitted, but only in marriage for begetting children, and not for sensuous exploitation of the body. Unfortunately, however, the less intelligent materialists cannot understand that their duties in life should be performed purely on the spiritual platform.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Madhvacarya has given the following statement in regard to animal sacrifice:
yajñesv alabhanam proktam
devatoddesatah pasoh
himsa nama tad-anyatra
tasmat tam nacared budhah
yato yajñe mrta urdhvam
yanti deve ca paitrke
ato labhad alabhanam
svargasya na tu maranam
According to this statement, the Vedas sometimes prescribe animal sacrifice in ritual performances for the satisfaction of the Supreme Lord or a particular demigod. If, however, one whimsically slaughters animals without rigidly following the Vedic prescriptions, such killing is actual violence and should not be accepted by any intelligent person. If the animal sacrifice is perfectly performed, the sacrificed animal immediately goes to the heavenly planets of the demigods and the forefathers. Therefore such a sacrifice is not for killing animals but for demonstrating the potency of Vedic mantras, by the power of which the sacrificed creature is immediately promoted to a higher situation.
Caitanya Mahaprabhu, however, has forbidden such animal sacrifice in this age because there are no qualified brahmanas to chant the mantras, and the so-called sacrificial arena becomes an ordinary butcher shop. And in an earlier era, when unscrupulous persons tried to establish that animal killing and meat-eating are acceptable by misinterpreting the Vedic sacrifices, Lord Buddha personally appeared and rejected their heinous proposition. This is described by Jayadeva Gosvami:
nindasi yajña-vidher ahaha sruti-jatam
sadaya-hrdaya darsita-pasu-ghatam
kesava dhrta-buddha-sarira
jaya jagad-isa hare
Unfortunately, the conditioned souls are afflicted by four imperfections, one of which is the cheating propensity, and thus they tend to exploit the concessions that the Lord mercifully gives to them in religious scriptures for their gradual purification. Rather than follow the Vedic injunctions for simultaneously satisfying their senses and gradually elevating themselves, the conditioned souls reject the actual purpose of such apparently materialistic ceremonies and simply become more and more degraded in the ignorance of the bodily concept of life. Thus they fall down altogether from the varnasrama system and, taking birth in violent non-Vedic societies, foolishly presume the small fragments of universal religious principles prevalent there to be the exclusive religion of the soul. As a result, they fall into fanaticism, embracing merely sectarian, dogmatic views of religion. Such unfortunate persons are completely out of touch with their own eternal function in life and consider things to be vastly different than they are in reality.