Nutrient requirements of all livestock are based on the size of the animal, how active the animal is, the body growth rate, and/or the animal’s level of milk production and fat content in milk produced. Maintenance requirements are for low levels of activity as when being fed in a dry lot situation. When animals are on pasture activity increases and these the requirements may be as much as 25% higher due to this increased activity.

Nutrient Requirements of Sheep

Phosphorus partitioning during early lactation in dairy cows fed diets varying in phosphorus content.

A widely abundant and invasive forest shrub, Eupatorium adenophorum, was pyrolyzed in a cost-efficient flame curtain kiln to produce biochar. The resulting biochar fulfilled all the requirements for premium quality, according to the European Biochar Certificate. The biochar was either applied alone or mixed with fresh cow urine (1:1 volume) to test its capacity to serve as slow release fertilizer in a pumpkin field trial in Nepal. Treatments included cow-manure compost combined with (i) urine-only; (ii) biochar-only or (iii) urine-loaded biochar. All materials were applied directly to the root zone at a biochar dry matter content of 750 kg·ha−1 before seeding. The urine-biochar treatment led to a pumpkin yield of 82.6 t·ha−1, an increase of more than 300% compared with the treatment where only urine was applied, and an 85% increase compared with the biochar-only treatment. This study showed for the first time that a low-dosage root zone application of urine-enhanced biochar led to substantial yield increases in a fertile silt loam soil. This was tentatively explained by the formation of organic coating of inner pore biochar surfaces by the urine impregnation, which improved the capacity of the biochar to capture and exchange plant nutrients.

https://www.mdpi.com/2077-0472/5/3/723/pdf

Fourfold Increase in Pumpkin Yield in Response to Low-Dosage Root Zone Application of Urine-Enhanced Biochar to a Fertile Tropical Soil

Recent progress in the assessment of mineral requirements of goats

Pearl millet is a major cereal in the arid and semi-arid regions of Asia and Africa. It is primarily cultivated for grain production, but its stover is also valued as dry fodder. Pearl millet is resilient to climate change due to its inherent adaptability to drought and high temperatures. It is also tolerant of saline and acid soils, and is well adapted to marginal lands with low productivity. Pearl millet germplasm exhibits large genetic variability for yield components; and various agronomic, adaptation and nutritional traits. Open pollinated varieties and hybrids are two important cultivar options, but higher productivity is realized through hybrids. Pearl millet has fewer pest and disease problems compared to other cereals and is suited to different cropping systems. It is highly responsive to improved crop management practices, as witnessed in parts of India where it is grown as an irrigated summer crop that produces higher yields and better quality grain. Pearl millet has high nutritional value in terms of high levels of energy, dietary fibre, proteins with a balanced amino acid profile, many essential minerals, some vitamins, and antioxidants. These play a significant role in prevention of important human ailments such as diabetes, cancer, cardiovascular and neurodegenerative diseases. There is great potential for harnessing these positive attributes through genetic improvement, improved crop management, and grain processing and food products technologies. These should help to develop greater global awareness of the importance of this crop for food and nutritional security.

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Crops that feed the world 11. Pearl Millet (Pennisetum glaucum L.): an important source of food security, nutrition and health in the arid and semi-arid tropics

In Expt 1 the efficiency of absorption of phosphorus in feedingstuffs was compared within four sets of 18-month-old, chimaera-derived triplets; 12 feedingstuffs were evaluated in four balance trials with 32P. Seven diets consisted of a P-rich ingredient mixed with a low-P basic diet and five of hay or pelleted dried grass or lucerne. The P ingredients tested were the protein-rich meals, rape, soya-bean, maize gluten, fishmeal and rice bran, and the cereals, barley and wheat.Sets of triplets absorbed dietary P with different (P < 0·001) efficiencies; the mean values were 0·72, 0·63, 0·76 and 0·79. The availability of P differed (P < 0·001) between diets, highest values being seen with the fishmeal (0·80), barley (0·78) and wheat diets (0·78) and the lowest with rice bran (0·63) and a perennial ryegrass hay (0·64). There was no evidence for an age effect on efficiency of absorption.Endogenous faecal excretion was positively related to intake (P < 0·001) and negatively related to efficiency of absorption of dietary P. Plasma concentration was positively related (P < 0·001) to both intake and, between sets, to the efficiency of absorption.Significant urinary excretion of P generally occurred when the efficiency of absorption was greater than 0·70. Two members of a set which absorbed P with high efficiency and excreted low volumes of urine died from urethral obstruction caused by calculi.In Expt 2 an estimate of the variation in the concentration of P in plasma of 48 ewes on a barley-based diet was assessed and the values for three of the chimaera sets fell within the top quartile.Safety factors were calculated from the animal and plant variations in the efficiency of absorption of dietary P and used to determine dietary allowances for different classes of sheep.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0021859600047237

Animal and dietary variation in the absorption and metabolism of phosphorus by sheep

SUMMARY The isotope dilution technique was used to measure endogenous faecal excretion and absorption of dietary Ca and P by growing lambs. Groups of four lambs were given 0·8 or 1·2 kg/day of a pelleted barley and soya-bean diet containing 4·2 g P/kg D.M. and supplemented to contain 1·79, 3·52 or 4·67 g Ca/kg D.M. At the lowest dietary concentration of Ca, absorption of Ca was insufficient to meet the Ca required for deposition in the newly formed bone matrix of the skeleton; retention was 0·39, 1·16 and 1·12 g/day with increasing dietary Ca concentration. The proportion of dietary Ca absorbed decreased (P < 0·001) with increasing Ca intake, ranging from 0·85 to 0·44. Endogenous faecal excretion of Ca was independent of the absorption of dietary Ca, but increased (P < 0·05) from 17·2 at the lower to 21·1 mg/kg live weight/day at the higher D.M. intake. Plasma concentration of Ca was higher for the female (2·51) than the male (2·33 mmol/1) lambs and increased linearly (P < 0·001) with dietary concentration of Ca from 2·31 to 2·52 mmol/l. The retention of P increased with Ca and D.M. intake. On the other hand, the proportion of dietary P absorbed (0·85) was independent of Ca intake and hence of P retention. Increases in P retention were reflected by decreases in urinary P, but not in endogenous faecal excretion. Endogenous faecal excretion of P increased with D.M. or P intake from 17·9 at the lower to 33·5 mg/kg live weight/day at the higher intake. The results are discussed in relation to dietary allowances of Ca and the mechanism of P homoeostasis.

The effect of dietary intake of calcium and dry matter on the absorption and excretion of calcium and phosphorus by growing lambs

SUMMARY Phosphorus requirements for maintenance and growth were assessed by giving to growing lambs and non-pregnant ewes diets low in P and to growing lambs a diet containing the quantity of P recommended by the Agricultural Research Council (1980). Seven 14-week-old lambs were given ad libitum a pelleted diet containing 1·88 (LP) or 2·75 (NP) g P/kg D. M. for 13 weeks. There was no effect of P intake on feed intake or growth during the first 8 weeks when the P intake of the LP groups was 1·07 of Agricultural Research Council (1980) requirements. During the last 5 weeks the P intake of the LP group was only 0·87 of Agricultural Research Council (1980) requirements and growth and feed intake were higher in the male but not female lambs in the NP group. From the 3rd week the plasma concentration of P was significantly lower (P <0·001) in the LP group. Mineralization of selected bones was less in the LP group. After 14 weeks on the diet, balance trials with 32 P were carried out on the lambs from each dietary group. P intakes ranged from 1 to 3 g/day. An additional balance trial was undertaken with eight 2-year-old female sheep consuming a hay diet (1·5 g P/day). The endogenous faecal excretion of P by the growing lambs on the LP diet and ewes was 12·2 ± 0·8 and 12·7 ± 1·00 mg/kg live weight/day respectively, very close to the value (12 mg/kg live weight/day) adopted by the Agricultural Research Council (1980). The absorbability of the P in the concentrate and hay diets was 0.71 ±0·267 and 0·74 ± 0·0218 respectively, the former agreeing with and the latter higher than the corresponding value for Agricultural Research Council (1980).

R.A. Dingwall

Papers

Animal and dietary variation in the absorption and metabolism of phosphorus by sheep

The effect of dietary intake of calcium and dry matter on the absorption and excretion of calcium and phosphorus by growing lambs

The phosphorus requirements for growth and maintenance of sheep.