Macromineral requirements of Dorper×thin-tailed Han crossbred female lambs

A comparative slaughter trial was conducted to determine the net mineral requirements for maintenance and growth of Dorper crossbred female lambs raised from 20 to 35 kg of body weight(BW).Thirty-five Dorper×thin-tailed Han crossbred female lambs of(20.3±1.14) kg BW were used: 7 lambs were randomly chosen and slaughtered at the beginning of the experiment as the baseline group for measuring the initial body composition; another 7 lambs were randomly chosen and offered a pelleted mixed diet ad libitum and slaughtered at(27.0±0.73) kg BW; the remaining 21 lambs were randomly divided into 3 groups of 7 animals each and subjected to the same diet either ad l ibitum or at 70 or 40% of ad libitum intake.The 21 lambs were fed in 7 slaughter groups, with each group consisting of one lamb from each treatment(ad libitum, 70 or 40% of ad libitum intake).The 3 groups were slaughtered when the sheep fed ad libitum attained(33.8±0.52) kg of BW.The body composition of five minerals(Ca, P, Na, K, and Mg) was determined.The net mineral requirements for maintenance were 35.01, 25.18, 9.30, 31.35, and 2.03 mg kg–1 empty BW(EBW) for Ca, P, Na, K, and Mg, respectively, and the net growth requirement per kg of EBW gain ranged from 9.73 to 8.87 g of Ca, 5.83 to 5.27 g of P, 1.73 to 1.63 g of Na, 3.73 to 4.08 g of K, and 0.26 to 0.25 g of Mg for Dorper crossbred lambs in China, respectively.The estimates of mineral requirements with Dorper crossbred lambs in the current study were not consistent with the recommendations from previous studies.     

Mineral requirements for weight gain in growing male Santa Inês and Morada Nova hair sheep

This study estimated the net macro and micromineral requirement from the 48 male uncastrated lambs (24 growing male Santa Inês and 24 growing male Morada Nova hair sheep), with initial weights of 21.7 ± 1.2 kg and 20.8 ± 0.8 kg using the comparative slaughter method. The experimental diet consisted of 30% forage (Buffel—Cenchrus ciliaris (L) hay) and 70% concentrate (corn grain 43.5%, soybean meal 22.0%, vegetable oil 3.0% and mineral supplement 1.5%). The experimental design was a completely randomized with two breeds, four weights, and six replicate. Mineral requirements sufficient to promote weight gain in Santa Inês sheep ranged from 1.75 to 1.03 g Ca, 1.01 to 0.61 g of P, 0.38 to 0.21 g of K, 0.38 to 0.16 of Na, 0.10 to 0.06 Mg, 28.5 to 16.0 mg of Fe, 6.14 to 3.22 mg of Cu, and Zn 23.0 to 14.0 mg/kg per unit of empty body weight (EBW) gain. In the Morada Nova breed, the requirements ranged from 1.96 to 0.84 g of Ca, 1.15 to 0.46 of P, 0.39 to 0.19 of K, 0.28 to 0.13 of Na, 0.10 to 0.05 Mg, 26.2 to 12.9 mg of Fe, 5.59 to 2.46 Cu, and Zn 23.6 to 10.3 mg/kg of EBW gain. Mineral requirements varied mainly in accordance with the proportion of bone mass and fat concentration in the carcass, which were influenced by the slaughter weight of the animals, and therefore should be used in the formulation of dietary mineral supplements.     

Mineral Concentrations of Cool Season Pasture Forages in North Florida During Winter-Spring Grazing Season. I. Macrominerals and Forage Organic Constituents

Two experimental late fall-winter-spring grazing studies, each lasting two years, were conducted at the North Florida Research and Education Center (NFREC), Marianna, Florida to evaluate the organic constituents and macromineral concentrations of annual cool season pasture forages grazed by growing beef cattle. Eight 1.32 ha fenced pastures or paddocks were divided into two pasture land preparation/planting methods, four pastures for the sod seeding treatments and four for the prepared seedbed treatments. These pastures were planted with two different forage combinations: rye/oats mix with or without ryegrass for the first two years (Study 1), and oats with ryegrass or ryegrass only for the last two years (Study 2). Each of the four forage/land preparation combination treatments was assigned to two pastures each year, thereby giving two replicates per year. Forage samples were collected at the start of grazing and twice monthly thereafter until the end of grazing season for each year, pooled by month, and were analyzed for calcium (Ca), phosphorus (P), sodium (Na), potassium (K), magnesium (Mg), dry matter (DM) yield, crude protein (CP), and in vitro organic matter digestibility (IVOMD). Blood plasma samples were also collected from the tester cattle during the spring season of year 2 of Study 2 and were analyzed for Ca, P, and Mg. Month differences were observed in forage concentrations of P and K (P < 0.0001), and Mg (P < 0.05) in both studies, Ca (P < 0.01) in Study 1 only, and Na (P < 0.05) only in Study 2. Year affected P, K, and Mg concentrations in Study 1 and Ca, P, and Na concentrations in Study 2. In Study 2, forage type by month interactions on Ca, K, and Mg concentrations were noticed (P < 0.01). Forage Ca was lower (P < 0.05) than the critical level for all months from the oat plus ryegrass pastures, and for early winter months and late spring months from ryegrass only pasture. Forage Na concentrations were consistently low throughout the grazing season and unaffected by forage type or land cultivation methods used in both studies. Low Mg concentrations of both forage types in Study 2 (also with high K concentrations) were indicative of a potential risk of grass tetany (hypomagnesemia) for grazing ruminants. Forage DM yields were highly variable with fluctuations among the experimental months and were found to be highest in the spring months, with decreasing yields towards the end of the grazing season in both studies (P < 0.0001). The CP concentrations were greater than the required levels and both CP and IVOMD decreased gradually by month in both studies (P < 0.0001). Normal blood plasma concentrations of Ca and P obtained were indicative of a good overall status of these minerals in the animal's body. Plasma Mg concentrations were slightly above the critical level for cattle from both forage types. In summary, the macrominerals most likely to be deficient in North Florida during the cool season would be Ca, Na, and Mg. Special attention should be given to supplementation of Mg since forages reflected a marginal deficiency of this mineral and high K concentrations were found.     

Macromineral status of dairy cows with concurrent left abomasal displacement and fatty liver

Abstract

AIM: To evaluate the macromineral status of field cases of dairy cows surgically treated for left abomasal displacement (LDA), with concurrent fatty liver of different severity, and compare this for animals that died or recovered.

METHODS: Sixty-eight Holstein dairy cows with LDA and 110 control cows, from 28 farms, were used in the study. Blood samples and liver biopsies were obtained during standing surgery for correction of LDA, and from control cows. The concentration of macrominerals in serum, and of total lipids (tLPD) and triglycerides (TG) in liver were determined. Liver was examined histologically, and classified for its severity of fatty liver. Cows with LDA were grouped according to severity of fatty liver. Cows in Groups 1 to 3 recovered, whereas those in Group 4 died within 4 weeks of surgery. Group 1=mild (n=4) or moderate (n=6 cows, n=4 heifers) fatty liver, Group 2 = moderate to severe fatty liver (n=13), Group 3=severe fatty liver (n=15 cows, n=5 heifers), Group 4 = severe fatty liver (n=17 cows, n=4 heifers).

RESULTS: The concentration of macrominerals in serum was affected by the concurrence of fatty liver and LDA; Ca, K and Mg were significantly (p<0.05) lower in animals that died than those that survived. For cows with severe fatty liver, concentrations of tLD and TG were higher in the animals that died compared with those that recovered (p<0.01). Cows with LDA and severe fatty liver that died were earlier in lactation (median days in milk (DIM) 13 days) compared with the other cows with LDA (median DIM 21–26 days) (p<0.05); they were also significantly older (median 6 years old) than cows in the other groups (median 4 or 5 years old) (p–0.05).

CONCLUSIONS AND CLINICAL RELEVANCE: Concentrations of macrominerals in serum were influenced by the concurrence of LDA and fatty liver. Animals with low concentrations of Ca, K and Mg had a guarded prognosis. The concentration of K should always be evaluated in cows with LDA and concurrent fatty liver when providing a prognosis. Most cows with severe fatty liver were detected in the first 4 weeks of lactation, but older animals and those that had more recently calved had a worse prognosis.     

Maturity effects on mineral concentration and uptake in Solanum nigrum L.

The revitalisation of wild vegetables by consuming and cultivating them in home gardens is one of the strategies that agriculturalists have recently identified to combat food insecurity. However, data on mineral uptake with maturity are not available for a larger majority of wild vegetables. S. nigrum, one of the popular wild vegetables consumed in the Eastern Cape Province of South Africa, was cultivated both on the field and glasshouse to gain a better understanding of the uptake of some macrominerals as the plant matures. Five treatments (control; 100 kg N/ha; 8.13 t manure/ha; 100 kg N/ha + 8.13 t manure/ha and 50 kg N/ha + 4.07 t manure/ha) were set up in a Randomised Complete Block Design in both trials. The data were subjected to analysis of variance using MINITAB statistical software package. K (%) ranged between 3.11–6.98 in the glasshouse and 3.88–6.98 on the field; Ca (%) between 1.23–3.72 in the glasshouse and 1.39–3.98 on the field; Mg (%) between 0.31–0.93 in the glasshouse and 0.48–0.82 on the field; P (mg/kg) between 0.23–0.80 in the glasshouse and 0.29–0.77 on the field and Na (mg/kg) ranged between 749–3070 in the glasshouse and 187–3070 on the field. The application of 50 kg N/ha + 4.07 t manure/ha increased the uptake of a majority of the minerals. K, P and Na decreased with maturity while Ca increased and Mg varied. Although the current results indicate that for K, P and Na nutritional interventions, the leaves of S. nigrum are best harvested during the early phase of growth and the final phase for Ca, the concentration of these minerals has the potential to supply sufficient quantities of the minerals in human physiology at all stages of the plant's growth. This wild vegetable is therefore recommended for both consumption and cultivation.