[Rachel]

Effects of low concentrations of dietary cobalt on liveweight gains, haematology, serum vitamin B12 and biochemistry of Omani goats

https://www.sciencedirect.com/science/article/abs/pii/S1090023305002583

“In contrast to the treated goats, the control animals of all breeds experienced a severe decrease in their serum vitamin B12 levels, developed pale mucous membranes, appeared scruffy and two breeds (D and B) had significantly lower weight gains from month 5. Untreated kids of all breeds had significant decreases in their red blood cell counts and erythrocyte indices after approximately four months. Controls developed low total serum protein levels whilst activities of alkaline phosphatase and aspartate aminotransferase significantly increased. Although it is widely assumed that goats are more resistant to cobalt deficiency than sheep this is apparently not true for Omani goats. Based on experimental data from previously reported studies and those from the present study it can be concluded that the reduction in weight gains in D and B goats is related to their lower digestibility coefficients for dry matter, crude protein and energy while the increase in alkaline phosphatase and aspartate aminotransferase are associated with developing hepatic lipidosis.”

[Rachel]

Dietary supplementation with Essential-oils-cobalt for improving growth performance, meat quality and skin cell capacity of goats

“Essential oils (EO) are secondary metabolites usually made up of terpenoids and phenylpropanoids and have antimicrobial properties. However, the feeding effects of EO-Cobalt (EOC) on the performance of goats are largely unknown. Herein we investigated and reported the effects of dietary EOC (0, 52, and 91 mg daily) on fiber producing cashmere goats. We determined the resulting phenotypes including live growth, carcass weight, meat quality, and cashmere fiber traits. We show that dietary supplement of EOC significantly promoted average daily gain (P < 0.05), and significantly improved carcass weight, and meat and hair fiber quality (P < 0.05). We further conducted RNA-seq using skin and liver tissues from each group to assess the molecular mechanism conferring these phenotypic changes. A total of 191 differentially expressed genes were found in the skin tissues (0 vs 91 mg), while 1,127 DEGs were found in livers. Analyses of liver samples for differential gene action and functional prediction found that EOC stimulated physiological changes in the body’s immune system at both blood and cell levels. Our results demonstrated the potential of using EO-based feed ingredient to improve animal growth performance, meat quality and fiber quality, and further illustrated the molecular basis that contribute to phenotypes at physiological levels.”

https://www.nature.com/articles/s41598-018-29897-3

[Rachel]

Ruminal metagenomic analyses of goat data reveals potential functional microbiota by supplementation with essential oil-cobalt complexes

“Background

Essential Oils (EO) are complex mixtures of plant secondary metabolites that have been proposed as promising feed additives for mitigating methane and ammonia emissions. We have previously demonstrated that Essential Oil-Cobalt (EOC) supplementation resulted in increased average daily gain and improved phenotypes (cashmere fiber traits, carcass weight, and meat quality) when cashmere goats received supplementation at approximately 2 mg/kg of body weight. However, the ruminal microbiological effects of EO remain poorly understood with regard to the extent to which ruminal populations can adapt to EO presence as feed ingredients. The effects of varying levels of EO require additional study.

Results

In this study, we conducted metagenomic analyses using ruminal fluid samples from three groups (addition of 0, 52, and 91 mg) to evaluate the influence of dietary EOC supplementation on goat rumen bacterial community dynamics. EOC addition resulted in changes of ruminal fermentation types and the EOC dose strongly impacted the stability of ruminal microbiota. The Bacteroides sp. and Succinivibrio sp. type bacterial community was positively associated with improved volatile fatty acid production when the diet was supplemented with EOC.

Conclusions

A clear pattern was found that reflected rapid fermentative improvement in the rumen, subsequent to butyrate metabolism and EOC based feed additives may affect rumen microbes to further improve feed conversion. This observation indicates that EOC can be safely used to enhance animal productivity and to reduce ammonia and waste gas emissions, thus positively impacting the environment.”

https://bmcmicrobiol.biomedcentral.com/articles/10.1186/s12866-019-1400-3

[Rachel]

Impaired antibody response and phagocytosis in goats fed a diet low in cobalt

“Cobalt (Co) is utilized by rumen microflora to produce vitamin B12. The aim of the present study was to determine whether feeding newly-weaned goats a diet containing low levels of Co results in impairment of neutrophil function, antibody production and/or lymphocyte proliferative responses. Forty, ten week old goats were fed a commercially-prepared concentrate (150 g/day) and Rhodesgrass hay ad libitum. This diet contained Co at <0.1 mg/kg dry matter. The goats were divided into a control group and a treated group (both n = 20). Goats in the treated group were supplemented with bi-monthly subcutaneous injections of 2 mg of hydroxycobalamin. Two months after weaning, the goats were immunized with keyhole limpet haemocyanin (KLH). A luminol-dependent chemiluminescence (CL) assay was employed to measure the oxidative respiratory burst of neutrophils during phagocytosis of zymosan A. The lymphocyte proliferative response to phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) was assessed. The controls goats demonstrated a significantly lower antibody (IgG) response to KLH compared with the Co-supplemented goats that was apparent 1 week post immunization and was maintained for the 8 week observation period. Neutrophils from the Co-restricted group demonstrated significantly lower CL responses to opsonized zymosan A. Lymphocytes from the control and treated goats did not differ in their mitogenic responses to PHA and PWM. These results demonstrate that goats fed a diet low in Co exhibited impaired antibody and phagocytic responses.”

https://www.sciencedirect.com/science/article/abs/pii/S0921448816301249

[Rachel]

A comparison between different concentrations and sources of cobalt in goat kid nutrition

“There have been extensive studies in sheep and cattle considering cobalt (Co) supplementation and its effects on vitamin B12 concentrations in the body. However, there are limited studies on goats. The aim of this study was to compare two different sources of Co (sulfate v. glucoheptonate) at two different concentrations (0.25 and 0.5 mg/kg dry matter) in goat kid nutrition, and to evaluate the effects of these supplements on performance, serum vitamin B12, blood biochemistry and rumen volatile fatty acids. For this purpose, 30 weaned male goat kids were randomly allotted to five treatments. Serum vitamin B12 increased during the trial in the Co-supplemented groups. Co supplementation increased serum glucose concentrations. On day 35, Co-supplemented groups had greater glucose concentrations compared with control. Propionic+iso-butyric acid concentrations increased only in the 0.5 mg Co glucoheptonate treatment (P<0.05). Our results suggest that, despite the two sources of Co proving mostly similar, the main advantage of Co glucoheptonate compared with Co sulfate was in the ruminal synthesis of vitamin B12. However, although providing Co at National Research Council recommendation levels maintained vitamin B12 above or at normal concentrations, Co supplementation of the Co sufficient basal diet increased vitamin B12 and glucose concentrations.”

https://www.sciencedirect.com/science/article/pii/S175173111600197X