Effects of feeding system and pre-partum supplementation on the β-carotene status of South African Holstein cows

Abstract

The objectives were to investigate the β-carotene status of dairy cows under various production systems, and to determine the effect of pre-partum β-carotene supplementation on their post-partum β-carotene status. Ten farms were selected from each of the three production systems, namely pasture-based, hay-based total mixed ration (TMR) and silage-based TMR. Twenty cows per farm were sampled in each system, and blood plasma β-carotene concentration was determined with a portable spectrophotometer (n = 200 cows per system). Mean blood β-carotene concentrations of pasture-fed cows were 5.54 mg/L, and were higher (P <0.05) than concentrations of cows on hay-based (2.98 mg/L) and maize silage-based TMR systems (1.71 mg/L); in β-carotene status, therefore, these systems were optimal, marginal, and deficient, respectively. In the second experiment, 10 cows received a hay-based control TMR, and 10 were supplemented with 1.2 g/day of β-carotene pre-partum from day -56 to calving and monitored until day 56 postpartum. The supplemented cows were in optimal β-carotene status until calving, with a minor carry-over effect until 10 days post partum, and then declined gradually in status until they needed supplementation. The β-carotene status between the groups differed from three weeks pre-partum to two weeks post partum, with the control group being marginal to deficient from three weeks pre-partum onwards. Forage type and its β-carotene content play a major role in the β-carotene status of cows and more research is needed on the potential storage and mobilization of β-carotene in cows.

Transforming Rhodotorula sp. Biomass to Active Biologic Compounds for Poultry Nutrition

“…As the sole pigment additive used in human, fish, and poultry nutrition, canthaxanthin [170] dietary overdosage leads to residual pigment tissue deposits that expose the final consumer to a pigment intake that exceeds the Acceptable Daily Intake (ADI, 0.03 mg/kg body) [171], and might negatively affect the consumer's health (high risk of toxicity). Research concerning natural carotenoid sources as an alternative to commonly used synthetics for livestock nutrition shows that using natural resources such as maize and pasture (fresh or preserved) [172,173] and genetically modified organism (GMO) or non-GMO (plants, algae, and yeasts) could serve as superior native carotenes used pigment additives [174][175][176]. Few studies regarding the microbial piments additives on broiler meat [45,177,178].…”