Brazilian researchers conducted an experiment to determine the effect of different levels of protein on parasite resistance and resilience of naturally-infected lambs. Sixty weaned Ile de France and Texel lambs (60 days of age) were divided into three groups, based on the level of protein in their concentrate ration: 1) low (8.5%); 2) moderate (15%); and 3) high (25%). The concentrate ration was fed at 3% of live weight. The lambs grazed native pasture (low protein). Evaluations were conducted bi-weekly.
Average weight and weight gain did not differ among lambs in the three groups. Fecal egg count values of the low protein group increased significantly during the course of the experiment. No such increase was observed in the moderate and high protein groups. The low protein group had higher fecal egg counts on d-98 (6765 epg) compared to the moderate and high protein groups (1618 and 3435 epg, respectively).
Hematocrit values decreased from d 0 to d 98, only in the low protein group. Sixty percent of treated lambs were from the low protein group. Lambs were treated if their fecal egg count exceeded 10,000 epg. According to recovered larvae, Haemonchus contortus was the primary worm species.
In this study, protein supplementation influenced the resistance and resilience of lambs naturally-infected with gastro-intestinal nematodes, as previously demonstrated in other studies. Lambs supplemented with a concentrate ration containing 15% CP showed increased resistance and resilience to internal parasites, but no differences were detected between the moderate (15%) and high (25%) protein groups.
Source: Semina: Ciências Agrárias
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