Feeding Methods for Crocodiles in the Pre-Breeding Period of Commercial Breeding

Through the above investigation of diseases, a certain degree of impressionistic diagnostic basis can be provided for the occurrence and epidemic situation of diseases, but a definitive diagnosis still requires a series of comprehensive diagnostic methods and techniques. Clinical symptom examinations of the group (individual) should also be carried out.

(1) Examination of mental state and responsiveness  Crocodiles show certain differences in behavioral performance at different ages, physiological states and rearing environments. Young crocodiles are more lively and active than adult crocodiles; breeding crocodiles are excited in mental state during the breeding and mating period; female crocodiles become more ferocious during the incubation period. Before daily feeding, when the stomach is empty, the amount of activity increases, while after being fed full, especially under comfortable rearing environment conditions, they can maintain body extension for a long time, with slowed respiratory rate and slightly closed eyes in a quiet resting posture. Crocodiles living under long-term rearing conditions become relatively dull in response to abnormal sounds and outside personnel, but still maintain relatively rapid responsiveness. After a crocodile becomes ill, abnormal mental states and decreased responsiveness will appear, such as lethargy, head and neck tremors, twisting, slow swimming and crawling speed, curved movement or circling in place, decreased response speed to feed during feeding, and even lack of sufficient responsiveness when stimulated with external objects such as wooden sticks. There are certain differences in manifestations depending on the type of disease. For crocodiles with relatively mild symptoms, careful observation can also reveal a concomitant decline in movement speed and endurance. In addition, when there is a fracture of the limb bones or spine, abnormal posture can be seen in the crocodile.

(2) Examination of foraging conditions 1. Appetite  There are certain differences among crocodiles in the types of feed they prefer according to species, age, individual, physiological state, feeding habits, etc., and the corresponding strength of appetite also differs, but healthy crocodiles generally have a strong preference for animal-based feeds such as fish, chicken, and livestock and game meat. In addition, the strength of appetite is also related to the crocodile's state of hunger and satiety. A healthy individual in a hungry state may clearly pay attention to operations related to feeding, sounds made, and the appearance of feeding personnel, can smell the odor of feed from a relatively long distance, and shows a strong food-seeking response. 2. Amount of feed intake  The digestion speed and metabolic intensity of crocodiles toward feed directly affect the amount of feed intake. Therefore, when examining the amount of feed intake, consideration should be given to factors such as the crocodile's species, age, physiological state, growth rate, environmental temperature, rearing season, and nutritional characteristics of the food (such as water content, digestibility and palatability) that may affect feed intake. In this examination, in addition to independently examining the feed intake of individuals with obvious disease symptoms, special attention should also be paid to changes in the total feed intake of each group, so as to achieve the goal of revealing diseases at an early stage. 3. Feeding speed  Crocodiles have a sturdy and long skull, and the powerful jaw muscles on the left and right sides of the nearby jawbones can quickly flatten and crush food obtained in the mouth. At the same time, the neatly arranged, conical and sharp teeth in the oral cavity can tear large pieces of food apart in water, while small pieces of food are directly swallowed, so healthy crocodiles feed very quickly. In addition to decreased appetite, sick crocodiles may also show reduced feeding speed, and may even eat only a certain part of the food. 4. Abnormal feeding  In occasional cases, sick crocodiles may show abnormal feeding, such as changes in feeding habits and feeding posture. It can also be found that young crocodiles develop diseases (such as gout) due to overeating caused by greediness.

(3) Examination of body surface appearance 1. Armor and skin  Crocodiles can be called strongly armored animals: some species of crocodiles are covered over the whole body with broad and sturdy scales that have already ossified, which can provide good protection for internal tissues and organs of the body and defend against various external injuries. Although some species of crocodiles have almost no scales over the whole body, they have complete and tough skin to prevent invasion of the body by various adverse stimuli and to meet the needs of living in water and on terraces. Therefore, complete and healthy armor and skin have a more special role for crocodiles. However, the body surface skin temperature of crocodiles is relatively low, the scales have no blood vessels, skin metabolism is relatively weak, and self-recovery function is relatively poor. When damaged, they are very prone to infection and open the door for various pathogenic microorganisms to invade the body. The skin areas of crocodiles that are susceptible to damage are mostly seen at the tip of the snout, under the abdomen, at the base of the limbs and on the soles of the feet. 2. Oral cavity  Crocodiles have an oral cavity with a very large volume. When performing an oral examination, attention should first be paid to the smoothness, color and integrity of the oral mucosa; second, the odor of the oral cavity should be smelled; in addition, it should be checked whether there is any missing or damaged teeth and whether there is inflammation of the gums. When a crocodile opens its oral cavity wide, obvious lesions in the deeper pharyngeal and laryngeal region can also be seen. 3. Eyes and nose  When suffering from certain diseases, crocodiles may show pathological changes in the eyes, usually mainly changes in both eyes, and in individual cases unilateral eye damage may also occur. Eye lesions may manifest as eyelid inflammation and orbital swelling, and in severe cases may spread to the skin around the outer side of the eyes, or even spread to the entire head. At the same time, inflammatory or purulent secretions may be seen in the eyes; in severe cases, visual impairment may lead to difficulty in feeding. Lesions in the nasal region mainly include redness and swelling of the nasal mucosa and increased nasal secretions; in severe cases, normal breathing may be affected. 4. Cloaca  The cloaca of a crocodile is located on the ventral side of the base of the tail. Under normal conditions it is almost closed, and on examination the opening is not obvious. During lesions, the skin in this area and around it may appear red and swollen. When examined by turning it open with two fingers, the cloacal mucosa may be found to be darker in color, edematous, and even have hemorrhagic spots (patches). When squeezed with slight force, a small amount of thin white or slightly pinkish pathological excrement may sometimes be seen.

(4) Examination of other clinical symptoms  After a crocodile becomes ill, in addition to the aforementioned general symptoms, it may also show related symptoms more closely associated with the disease. For example, clinical manifestations related to respiratory tract diseases include coughing, open-mouth breathing, and respiratory rales. As another example, when infected with digestive tract diseases, pathological symptoms such as watery excrement, foul odor, or excrement containing air bubbles, necrotic intestinal mucosa and incompletely digested food are often present.