Effect of reduction of milking frequency and supplementation of vitamin E and selenium above requirements on milk yield and composition in Assaf ewes

Abstract

The aim of this research was to study the effect of milking frequency and supplementation with a vitamin-mineral complex above requirements on intake, body weight (BW), and milk yield and composition in high-yielding Assaf ewes. Sixteen lactating Assaf ewes were used in this study, separated into 4 groups of 4 ewes each. Animals in 2 of the groups (control groups) did not receive any extra vitamin-mineral supplement, whereas animals in the other 2 groups (supplement groups) received daily an oral dose of 1g of vitamin E (1,000 IU, DL-α-tocopherol acetate) and 0.4 mg of selenium (sodium selenite anhydrous). The experiment consisted of 2 consecutive periods of 3 wk (twice-daily milking in both mammary glands) and 8 wk (once-daily milking in one mammary gland and twice-daily milking in the other gland). Intake, BW, and milk composition were controlled weekly, and milk production was recorded 3 times a week. Administration of the vitamin-mineral supplement had no effect on dry matter intake, BW, or milk production and composition. The reduction of milking from twice to once a day caused a decrease in milk production and lactose concentration and a significant increase in protein concentration, total solids, and somatic cell count, without affecting the fat content. Administration of a vitamin E and Se supplement at the doses used in the present study does not seem to exert, in the short term, a noticeable effect on the mammary gland when milking frequency is reduced.

Effect of milking frequency and α-tocopherol plus selenium supplementation on sheep milk lipid composition and oxidative stability

“…Therefore, reduction in plasma Se concentration may be associated with an inflammatory response caused by the reduction in MF when ODM was applied to one of the glands after TDM. Data from the current study previously reported by Pulido et al (2012) showed that SCC increased in the milk from the ODM gland (4.84 vs. 5.14 log units of SCC for TDM and ODM glands, respectively; P < 0.05), which would be compatible with an inflammatory response as reported in other studies (Nudda et al, 2002;Castillo et al, 2008).…”

“…Compared with TDM, ODM did not affect milk fat content but decreased fat yield (Pulido et al, 2012). In general, milk FA profile was similar to that observed in earlier studies in Assaf dairy ewes (Gómez-Cortés et al, 2008).…”

“…As reported in our previous publication (Pulido et al, 2012), milk yield and composition (fat and protein contents) were not affected by AOX supplementation. Nevertheless, as expected, α-tocopherol concentration increased in milk of the AOX ewes, although the difference between groups in the daily output of α-tocopherol in milk (2.0 and 3.2 IU/d for periods 1 and 2, respectively) represented less than 0.3% of the dietary supplementation.…”

“…Omitting 1 milking daily reduced milk yield (Pulido et al, 2012) but had no effect on α-tocopherol or Se milk concentrations. Transfer routes from blood to milk for both α-tocopherol and Se are not completely understood (Hill et al, 2014), but our results suggest that gland uptake of both components was adjusted to milk yield.…”

“…The experiment design was described in detail by Pulido et al (2012). Sixteen high-yielding Assaf ewes in wk 4 of lactation were used in this study.…”