Produção leiteira de ovelhas pantaneiras do núcleo de conservação da fazenda experimental da UFGD

Abstract

Milk from local sheep breeds are sources of food for family farmers worldwide. Ewe milk may be used to produce dairy products that present added value, such as cheese and yogurt. This study configured a preliminary appraisal focused on milk production of Pantaneiro ewes (n=94) kept in a university conservation herd (UFGD, Dourados, MS). Milk production was registered during 2015 (spring season) and 2016 (summer season). A joint evaluation of body score (ECC) and live weight (kg), after calving, was developed to establish different sheep stereotypes: I) light weight ewes with low body score (<50kg; ECC<2.5); II) light weight ewes with upper body score (<50kg; ECC>2.5); III) heavy weight ewes with low body score (>50kg; ECC<2.5); IV) heavy weight ewes with upper body score (>50kg; ECC>2.5). Milk yield was evaluated once a week (S) during eight consecutive weeks. Milk yield per week (kg) was estimated by weighing milk which was produced during four hours, after injection of oxytocin. This occurred after all udders were standardized with a previous injection of oxytocin and hand milking. Data analysis was scheduled to verify the effect of season and the effect of sheep stereotypes on milk yield. Variance and Tukey tests were developed using procedure means and glm in software SAS, version 9.4. Data quality control and exploratory analysis was developed using Minitab, version 17. The average milk yield was 0.78 kg per day. Greater average means (P<0.05) was observed during the spring (9.02±2.56) compared to the summer season (7.26±2.05). Variability of milk yield between ewes was highly expressed in the third week of lactation (S3) (1.63±0.86) and more discreet in the seventh (S7) (0.91±0.48) and the eighth week (S8) of lactation (0.79±0.36). Heavier ewes showing superior body scores (stereotype IV) presented greater means of milk yield (9.89±2.40) (P<0.05). Stereotypes I (7.44±2.15), II (8.20±2.36) and III (8.71±2.84) presented similar yields (P>0.05). Five ewes were assigned to extremely high values of milk production, comparable to specialized dairy sheep. An individual-based approach to monitor milk production of Pantaneiro ewes may enable sustainable conservation and subsidize milk production of local sheep raised in tropical pastures and low input systems in Brazil.