Net mineral requirements for growth of Saanen goat kids in early life are similar among genders

The current mineral requirements for growing goat kids are based on sheep and cattle studies without differentiating between the stages of development or gender. The aims of this study were to determine the net requirements for growth of Ca, P, Mg, Na and K of Saanen goat kids during the initial stages of growth and to analyse the effect of gender on the net requirements for growth of these macrominerals. Eighteen female, 19 intact male and 10 castrated male Saanen goat kids were studied. The kids were selected applying a completely randomized design and slaughtered when their body weight (BW) reached approximately 5, 10 and 15 kg to determine the mineral requirements for growth at these stages. The net mineral requirements for growth were similar among genders. The goat kids had slightly increased net requirements of Ca, P and Mg for growth with increasing BW from 5 to 15 kg. The net requirements for growth of Ca, P, Mg, Na and K ranged from 9.61 to 9.67 g/kg of BW gain, 7.14 to 7.56 g/kg of BW gain, 0.34 to 0.37 g/kg of BW gain, 1.26 to 1.13 g/kg of BW gain, 1.88 to 1.82 g/kg of BW gain as the animals grew from 5 to 15 kg respectively. In conclusion, when formulating diets for Saanen goat kids in early growth stage mineral levels do not need to adjusted based on gender.     

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.     

Net requirements of calcium, magnesium, sodium, phosphorus, and potassium for growth of Nellore × Red Angus bulls, steers, and heifers

A comparative slaughter trial was conducted to assess the net requirements for gain of Ca, P, Na, K and Mg of bulls, steers and heifers of Nellore and Red Angus crossbreds. Twenty seven F1 Nellore and Red Angus crossbred calves (9 steers, 9 bulls, and 9 heifers), averaging 274 kg BW, were used. At the beginning of the trial, three animals from each gender were slaughtered to determine the initial body composition. The remaining 18 animals (3 animals of each gender) were randomly assigned to two treatments: fed 0.75 or 1.5% of BW of concentrate. The diets were based on corn silage and were isonitrogenous (2% N, DM). After three growing periods of 28 d, all animals were slaughtered. The cleaned gastrointestinal tract, organs, carcass, head, hide, tail, feet, and tissues were weighed to determine the empty BW (EBW). These parts were ground separately and subsampled for chemical analyses. The log of the contents of each mineral in the empty body was regressed on the log of the EBW to estimate the net requirement for each mineral per kg of empty body gain (EBG). There were no differences (P > 0.05) in the net requirements for growth of all macrominerals among genders. The equations of the pooled data of the net requirements for growth (g/kg EBG) were: 332.6 × EBW ^− 0.6367 for Ca, 112.1 × EBW ^− 0.5615 for P, 10.85 × EBW ^− 0.3992 for Na, 4.01 × EBW ^− 0.153 for K, and 3.589 × EBW ^− 0.462 for Mg. Our findings indicated that retained Ca and retained P were poorly related to the retained protein.     

20～35 kg杜泊羊×湖羊F_1代公羔常量元素维持和生长需要量

本研究采取比较屠宰法测定20~35 kg杜泊羊×湖羊(杜湖)F_1代公羔代常量元素[钙(Ca)、磷(P)、钾(K)、钠(Na)和镁(Mg)]的维持和生长需要量。选择35只杜湖F1代公羔[初体重为(19.20±0.36)kg]作为试验动物。随机选取7只羊,体重达约20 kg时进行屠宰以测定羊体常量元素含量的初始值。再随机选取7只羊,饲喂全混合颗粒饲粮,自由采食(AL),体重达约28 kg时进行屠宰。剩余的21只羊随机分为3个组,分别为AL组、70%AL组和40%AL组,每组7只羊。当AL组体重大约为35 kg时,这3组将被屠宰。屠宰后,测定空腹体(头+足、皮、内脏+血液和胴体)常量元素含量。结果表明:在20~35 kg体重阶段,杜湖F1代公羔的钙、磷、钾、钠和镁维持需要量[空腹体重(EBW)为基础]分别为24.01、11.70、3.20、6.60、1.20 mg/kg EBW,生长需要量[空腹体增重(EBW G)为基础]分别为11.55~11.41 g/kg EBW G、5.82~5.77 g/kg EBW G、1.47~1.69 g/kg EBW G、0.42~0.44 g/kg EBW G和0.98~0.88 g/kg EBW G。总之,20~35 kg杜湖F_1代常量元素需要量的确定将有助于此生长阶段合理饲粮的配制,有利于羔羊生长性能的提高。     

The effect of dietary protein content on calcium and phosphorus retention in the growing Iberian pig

The effects of dietary protein content (DPC) from excessive (192 g/kg DM) to marginally deficient (101 g/kg DM) upon whole-body retention of Ca and P was studied in 25 purebred Iberian pigs growing from 15 to 50 kg BW by means of a comparative slaughter experiment which included a digestibility trial. Ca and P retention related to intake remained unaffected at 0.228 ± 0.0072 and 0.184 ± 0.0052, reaching 3.64 ± 0.119 and 2.00 ± 0.057 g Ca and P per day respectively. Pigs fed on diets containing protein levels in excess of requirements had significantly higher concentrations of Ca and P (P < 0.05) in their bodies (14.41–14.99 and 7.88–8.08 g Ca and P/kg fat-free empty-body gain respectively) than those given adequate or marginally deficient amounts of dietary protein (11.80–12.72 and 6.61–7.01 g Ca and P/kg fat-free empty-body gain respectively). In a second experiment, made with 25 Iberian pigs of 21 kg initial weight, daily intakes of Ca and P to maintain zero retention were determined using five experimental diets in which the concentrations of Ca and P were varied by the addition of graded levels of Ca carbonate and inorganic phosphate to a basal diet balanced in protein-to-energy ratio (131 g CP; 13.8–14.4 MJ ME/kg DM). Growth rate and protein deposition were unaffected by the level of Ca and P in the diet and reached average values of 485 ± 15.4 and 103 ± 1.2 g/d. Increasing the dietary Ca and P levels increased the absolute amounts of Ca and P retained daily from 0.69 to 5.77 and 1.12 to 3.70 g respectively (P < 0.001). Highly significant (P < 0.001) curvilinear regressions were obtained when relating Ca and P absorption or retention (g/d) with Ca and P intake (g/d). From these equations, daily maintenance requirements of 105 and 72 mg/kg BW for Ca and P respectively were obtained. Average total net requirements of Ca and P for the Iberian pig at this stage of growth were estimated to be 5.25 and 3.10 g/d respectively, considerably lower than those reported for conventional and high-performance pig genotypes.     

Supplementation of cottonseed,linseed, and noug seed cakes on feed intake,digestibility, body weight,and carcass parameters of Sidama goats

A digestibility, feed intake, and carcass evaluation experiment using 20 yearling intact male Sidama goats weighing 16.4 ± 0.63 kg (mean ± SD) was conducted in Ethiopia with the objectives to determine feed intake, digestibility, body weight (BW) gain, and carcass parameters. The treatments included feeding natural pasture hay (T1, control) and supplementation with cottonseed cake (284 g—T2), linseed cake (250 g—T3), and noug seed cake (296 g—T4) on dry matter (DM) basis to supply 85 g crude protein (CP) per head per day. Randomized complete block design for feed intake and BW parameters and complete randomized design for digestibility and carcass parameters were used. Hay DM intake was higher (P < 0.01) for T1 than for the other treatments. T3 promoted higher (P < 0.01) DM (29.3 g/kg W^0.75/day) and CP (14.1 g/kg W^0.75/day) intake than T4 (8.9 g/kg W^0.75/day DM and 4.1 g/kg W^0.75/day CP). T3 showed better (P < 0.05) organic matter and CP digestibility than T2. Goats in T3 had higher nitrogen intake (P < 0.01) and retention (P < 0.05) than those in T1. Goats in T2 and T3 showed higher (P < 0.05) daily BW gain and final BW than those in T4 and T1. Goats in T2 and T3 had higher (P < 0.05) slaughter weight, empty BW, hot carcass weight, rib-eye muscle area, and dressing percentage on slaughter weight basis than those in T1. The results showed that T2 and T3 had similar effect on CP intake, daily BW gain, and carcass parameters for growing Sidama goats fed natural pasture hay.     

Effects of supplementing different levels of sun-dried groundnut foliage on intake,apparent digestibility and nitrogen metabolism in cattle offered a basal diet of a mixture of rice straw and para grass

Eight male Cambodian yellow cattle, initial body weight (BW) 136 ± 11.9 (±SD) kg; age 20 ± 2.5 (±SD) months, were randomly allocated to treatments in a double 4 × 4 Latin square design to investigate the effects of different levels of crude protein (CP) from sun-dried groundnut (Arachis hypogaea L.) foliage (DGF) on feed intake, apparent digestibility and nitrogen metabolism. All animals were fed a basal diet of rice straw ad libitum and para grass (Brachiaria mutica) at 1% of BW. The DGF was offered as a supplement at 0, 1, 2 and 3 g CP/kg BW, denoted DGF0, DGF1, DGF2 and DGF3, respectively. The results showed that the intake of DGF contributed 0, 25, 34 and 42% of total dry matter (DM) intake. Rice straw intake decreased when DGF intake increased. Total intake of DM, organic matter (OM), digestible OM, ash, neutral detergent fibre and acid detergent fibre increased with increased level of DGF inclusion but did not differ for the two highest DGF levels. Total DM intake as proportion of BW increased from 2.3% in DGF0 to 2.8% in DGF3. Crude protein digestibility and nitrogen retention improved as DGF intake increased. Daily weight gain of DGF1 cattle was higher than DGF0 but was not further improved at the higher levels of DGF inclusion. Microbial protein synthesis and efficiency of microbial protein production in DGF1 did not differ from DGF0 but both measures were higher in DGF2 and DGF3. The responses were diminished at higher DGF inclusion so it is suggested that DGF supplementation at 1 g CP/kg BW may be the optimal level.

     

Effect of dietary calcium level and source on mineral utilisation by piglets fed diets containing exogenous phytase

Calcium and phosphorus are essential minerals, closely linked in digestive processes and metabolism. With widespread use of low P diets containing exogenous phytase, the optimal dietary Ca level was verified. The 40‐day study evaluated the effects of Ca level (4, 7 and 10 g/kg diet) and Ca source (Ca from CaCO₃ and from Lithothamnium calcareum) on mineral utilisation in 72 piglets (7.9 ± 1.0 kg BW) fed an exogenous phytase containing diet with 2.9 g digestible P/kg. Measured parameters were growth performance, stomach mineral solubility, bone breaking strength and urinary, serum and bone mineral concentration. The apparent total tract digestibility of minerals was also assessed in the two diets with 7 g Ca/kg, using 12 additional pigs. Regardless of Ca source, increasing dietary Ca impaired feed conversion ratio, increased urinary pH, increased serum and urinary Ca, decreased serum and urinary P, decreased serum Mg and increased urinary Mg, increased serum AP activity, decreased bone Mg increased bone Zn. Bone breaking strength was improved with 7 compared to 4 g Ca/kg. Compared to CaCO₃, Ca from Lithothamnium calcareum increased serum Mg and with, 10 g Ca/kg, it limited body weight gain. The dose response of Ca in a diet with 2.9 g digestible P/kg and including exogenous phytase indicated that: (i) a low dietary Ca was beneficial for piglet growth, but was limiting the metabolic use of P; (ii) a high dietary Ca level impaired P utilisation; (iii) the optimal P utilisation and bone breaking strength was obtained with a dietary Ca‐to‐digestible P ratio of 2.1 to 2.4:1; (iv). Increasing dietary Ca reduced Mg utilisation, but not Zn status, when fed at adequate level. Finally, Ca from Lithothamnium calcareum had similar effects on Ca and P metabolism as CaCO₃, but impaired growth when fed at the highest inclusion level.     

Content and distribution of macro- and micro-elements in the body of pasture-fed young horses

OBJECTIVE: To determine the content and distribution of Na, K, Ca, P, Mg, S, Cu, Mn, Fe and Zn in the body of pasture-fed young horses and then use a factorial model to calculate the dietary mineral requirements for growth. PROCEDURE: Twenty-one foals were killed at about 150 days of age and the organs, soft tissues, skin and bones and a sample of muscle were dissected out and weighted. The mineral concentrations of elements in all soft tissues and bones were measured by inductively coupled emission spectrometry. The total mineral element composition associated with a tissue was determined from the weight of tissue and its mineral element concentration. RESULTS: Expressed as a percent of total body mineral elements, muscle contained 20% Na, 78% K, 32% Mg, 62% Cu, 36% Mn and 57% Zn, bone contained 47% Na, 99% Ca, 81% P, 62% Mg, 30% Mn and 28% Zn while the organs accounted for a smaller percentage ranging from 0.06% for Ca to 26% for Fe. In liver Cu accounted for 9.2% of total body Cu. Each kilogram of empty body weight was associated with 1.0 g Na, 2.5 g K, 17.1 g Ca, 10.1 g P, 0.4 g Mg, 1.1 mg Cu, 0.39 mg Mn, 52.5 mg Fe and 21.4 mg Zn. CONCLUSION: The mineral element content of body weight gain is a component used in the factorial model to determine dietary mineral element requirements for growth. The calculated dietary mineral requirements, expressed per kg dry matter, for a 200 kg horse gaining 1.0 kg/day were 1.0 g Na, 2.1 g K, 4.6 g Ca, 3.5 g P, 0.7 g Mg, 4.5 mg Cu and 25 mg Zn.     

Growth Performance and Serum Mineral Concentrations of Stocker Calves Grazing Wheat Pastures and Fed Different Sources of Magnesium,

Magnesium supplementation has been shown to benefit feedlot cattle and is typically added at high concentrations to mineral supplements for calves grazing wheat pasture. Two experiments were conducted to determine the effects of Mg-mica supplementation on performance and serum mineral concentrations of stocker calves grazing wheat pasture. Supplemental Mg was provided at 6.1 g/d of supplemental Mg/ animal, Monday through Friday. In Exp. 1, 36 mixed-breed stocker calves (243 ± 3.9 kg BW) were stratified by BW and gender and allocated randomly to one of nine groups of four animals for a 112-d grazing study. Weight gain, shrink percentage, and serum Mg, Ca, K, Cu, and Zn concentrations did not differ (P>0.10) among calves fed either weathered Mg-mica (WMM), unweathered Mg-mica (UMM), or MgO. All serum mineral concentrations were within normal physiological ranges. In Exp. 2, 64 mixed-breed stocker steers (275 ± 1.7 kg BW) were stratified by BW and allocated randomly to one of 16 groups of four animals. Weight gain during a 50-d grazing study and subsequent feedlot period did not differ (P>0.10) among calves fed either no added Mg source or WMM, UMM, or MgO. Serum Cu was higher (P<0.05), and serum Mg was lower (P<0.05), from steers fed MgO, but all serum mineral concentrations were within normal physiological ranges. Although Mg-mica is relatively high in Fe (4%), using it as a supplemental Mg source appeared to have no negative impact on growth performance or serum mineral concentrations of calves grazing wheat pasture.     

Determination of Pasture Dry Matter Intake Rates in Different Seasons and Their Application in Grazing Management

Eight mature horses weighing 576 ± 32 kg (mean ± SD) were used to compare differences in pasture dry matter (DM) intake rate in October (period 1), February (period 2), and May (period 3). Horses were randomly assigned to a pair of adjacent 5 m × 5 m grazing cells containing nontoxic, endophyte-infected tall fescue. Horses had access to each cell for 4 hours. Pasture DM intake rate was estimated over the entire 8-hour period by measuring the pre- and postgrazing herbage mass within each cell and was expressed as kg DM/100 kg body weight (BW)/hr. Mean 8-hour DM intake rate in period 1 (0.17 ± 0.01 kg DM/100 kg BW/hr) was greater (P < .001) than for period 2 (0.09 ± 0.01 kg DM/100 kg BW/hr) and period 3 (0.11 ± 0.01 kg DM/100 kg BW/hr), but it was not different (P = .274) between periods 2 and 3. A second experiment using the same eight horses was conducted immediately after the first experiment, within each season, to determine whether the DM intake rates derived from the first experiment could be used along with estimates of maintenance digestible energy (DE) requirements and pasture DE concentrations to predict the amount of grazing time required for a horse to consume only its maintenance DE requirement and maintain zero BW change over a 6-week period. Grazing time necessary to maintain zero BW change was accurately predicted for period 1 only.     

P and Ca requirements for Japanese quail

Four experiments were conducted to estimate the phosphorus and calcium requirements for weight maintenance and weight gain in Japanese quails during their growth phase from 16 to 36 days. Japanese quails aged 16 days were used for estimating the phosphorous and calcium requirements for weight maintenance or weight gain, with these quails composing each reference slaughter group and the others distributed in a completely randomized design, housed in cages of galvanized wire (33 × 33 × 16 cm) that were stored in acclimatized chambers with specific environmental temperatures. The light programme used during the 20‐day experimental period was 24 h of artificial light. Analysis of the data showed that the prediction equations for estimating the phosphorus and calcium requirements for weight maintenance and weight gain of Japanese quails between 16 and 36 days of age were P (g/quail/day) = P^0.75*(9.3695 + 7.7397*T) + 9.70*WG, in which P is the phosphorus requirement, and Ca (g/quail/day) = P^0.75*(363.99 – 8.0262*T) + 28.15*WG, in which Ca is the calcium requirement, P is BW (kg), T is temperature (°C) and WG (g/quail/day).     

Influence of dietary supplementation of prebiotics (mannanoligosaccharide) on the performance of crossbred calves

Thirty-six Holstein cross calves 5 days of age in their preruminant stage were used to study the effect of feeding prebiotic (mannanoligosaccharide) on their performance up to the age of 2 months. Treatment and control groups consisted of 18 calves each. Treatment group was supplemented with 4 g prebiotic (mannanoligosaccharide)/calf/day. Performance was evaluated by measuring average body weight (BW) gain, feed intake [dry matter (DM), total digestible nutrient (TDN) and crude protein(CP)], feed conversion efficiency (DM, TDN, and CP), fecal score, fecal coliform count and feeding cost. Body weight measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analyzed weekly, fecal score monitored daily and fecal coliform count done weekly. There was a significant increase in average body weight gain, feed intake and feed conversion efficiency; and a significant decrease in severity of scours as measured by fecal score and fecal coliform count in the treatment group compared with control group (P < 0.01). Feed cost/kg BW gain was significantly lower in the treatment group compared to control group (P < 0.01). The results suggest that prebiotic (mannanoligosaccharide) can be supplemented to the calves for better performance.     

Effect of supplementation of Simada sheep with graded levels of concentrate meal on feed intake,digestibility and body-weight parameters

The experiment consisting of 7 days of digestibility and 90 days of feeding trial was conducted at Wogda (Ethiopia) to determine the effect of supplementation of graded levels of concentrate mix (CM) on feed intake, digestibility, and body weight (BW) change in hay-based feeding of Simada sheep. Twenty-yearling Simada sheep with a mean initial BW of 17.9 ± 0.81 kg (mean ± SD) were used in randomized complete block design arranged into five blocks of four animals. The four dietary treatments that consisted of hay alone (T1), hay +150 g dry matter (DM; T2, low), hay +250 g DM (T3, medium), and hay +350 g DM (T4, high) CM were randomly assigned to each sheep within a block. The CM consisted of wheat bran (WB), noug seed (Guizotia abyssinica) meal and safflower (Carthamus tinctorius) seed meal at the ratio of (2:1:1), respectively. Supplementation with T2 and T3 increased (P < 0.001) total DM and organic matter intake than the control treatment. Overall, supplementation improved (P < 0.001) crude protein intake, digestibility, feed conversion efficiency, BW gain, and profitability compared to the control, whereas sheep on the high than the low and medium level of supplementation performed better in these parameters among the supplemented treatments. From the results of this study, T4 is recommended as the best level of supplementation since it resulted in better nutrient utilization, animal performance, and profitability.     

Effects of the level of sugarcane molasses on growth and carcass performance of Caribbean growing pigs reared under a ground sugarcane stalks feeding system

The influence of the level of sugarcane (SC) molasses on growth performance, carcass traits, and meat quality in Creole (CR) growing pigs fed with ground sugarcane stalks (GCS)-based diet was studied in a mixed farming system context. The aim of the study was to optimize the growth performance of CR pigs with SC-molasses as an energy source in this unconventional feeding. A total of 32 CR pigs were used from 30 to 60 kg of body weight (BW). The experimental dietary treatments consisted of four levels of inclusion of SC-molasses (200, 400, 600, and 800 g DM/d/pig) into a GCS diet, for diets 1, 2, 3 and 4 respectively. The GCS allowance was based on live BW (170 g/kg BW/d) and the diets were supplemented with a soya-bean meal supplement (350 g/d of a 49.2% CP and 16.6 MJ DE/kg). All the pigs were slaughtered at 60 kg BW. Increasing the level of molasses did not affect (p > 0.05) average BW gain (254 g/d), CP intake (154 g/d) and sugar extraction rate from the total ration (85%). A gradual inclusion of molasses in a GCS-based diet did not affect the carcass and meat quality of CR pigs. In conclusion, molasses supplementation does not allow the increase of growth performance in GCS fed pigs.     

Energy and protein requirements of weaned male and female Saanen goats

The objective of this research was to estimate the energy and protein requirements for maintenance and growth in male (castrated and intact) and female Saanen goat kids between 15 and 30 kg BW. To determine the net energy requirements for maintenance (NE_m) and the net protein requirements for maintenance (NP_m), 75 goats (25 castrated and 26 intact males and 24 females) were used. Twenty‐one goats (seven castrated and eight intact males and six females) were randomly assigned for slaughter to estimate the initial empty body composition. The 54 remaining animals (18 castrated and 18 intact males and 18 females) were randomly assigned in a split‐plot design using a 3 × 3 factorial arrangement with three sexes and three levels of intake (ad libitum and restricted feed to 75% or 50% of the ad libitum intake). Within each sex, six blocks (three goats per block) were formed and one goat was randomly assigned to each level of intake. The 75% and the 50% of ad libitum rationing were determined daily, based on the DMI of the animal fed ad libitum on the previous day. All animals within block were slaughtered when the animal fed ad libitum reached 30 kg BW. The net energy requirements for gain (NE_g) and the net protein requirements for gain (NP_g) were obtained using 58 animals (20 castrated and 20 intact males and 18 females). The animals were fed ad libitum and slaughtered at targeted BW (15, 23 or 30 kg). Sex did not affect NE_g and NP_m (277.8 kJ/kg^0.75 BW day and 2.98 g CP/kg^0.75 BW day respectively), as well as NP_g (180.9 ± 6.48 g/kg EBW gain) in Saanen goat kids. However, castrated males and females had similar NE_g (varied from 12.6 ± 0.424 to 17.9 ± 1.38 MJ/kg EBW gain), greater than intact males (varied from 9.74 ± 0.420 to 10.7 ± 0.984 MJ/kg EBW gain), as the BW increased from 15 to 30 kg.     

The effect of dietary garlic supplementation on body weight gain,feed intake,feed conversion efficiency,faecal score,faecal coliform count and feeding cost in crossbred dairy calves

Thirty-six crossbred calves (Holstein cross) of 5 days of age were used to study the effect of garlic extract feeding on their performance up to the age of 2 months (pre-ruminant stage). They were randomly allotted into treatment and control groups (18 numbers in each group). Performance was evaluated by measuring average body weight (BW) gain, feed intake (dry matter (DM), total digestible nutrient (TDN) and crude protein (CP)), feed conversion efficiency (FCE; DM, TDN and CP), faecal score, faecal coliform count and feeding cost. Diets were the same for the both groups. In addition, treatment group received garlic extract supplementation at 250 mg/kg BW per day per calf. Body weight measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analysed weekly, faecal scores monitored daily and faecal coliform count done weekly. There was significant increase in average body weight gain, feed intake and FCE and significant decrease in severity of scours as measured by faecal score and faecal coliform count in the treatment group compared to the control group (P < 0.01). Feed cost per kilogramme BW gain was significantly lower in the treatment group compared to control group (P < 0.01). The results suggest that garlic extract can be supplemented to the calves for better performance.     

35～50kg道赛特×小尾寒羊杂交公羔矿物质需要量研究

本试验旨在研究35~50 kg道赛特×小尾寒羊杂交公羔钙、磷、钾、钠、镁的维持需要量和净生长需要量。选取(34.54±0.40)kg、6月龄道赛特×小尾寒羊杂交公羔25只分为5组,初期组,中期组,末期100%组、末期60%组、末期40%组(饲喂水平分别为100%、60%、40%),初期组、中期组、末期组分别在羔羊体重为35、43和50 kg时屠宰。测定动物体组织中的钙、磷、钾、钠、镁含量,建立数学模型对矿物质的维持需要量和净生长需要量进行预测。结果显示:道寒杂交公羔在35~50 kg体重阶段,钙、磷、钾、钠、镁的维持需要量分别为0.73、0.72、0.32、0.32、0.13 g/d,基于空腹体重(EBW)的净生长需要量分别为13.47~14.00 g/kg EBW、7.18~7.41 g/kg EBW、0.13~0.17 g/kg EBW、1.20~1.73 g/kg EBW、0.45~0.58 g/kg EBW。本研究得出了35~50 kg道赛特×小尾寒羊杂交公羔矿物质维持需要量和净生长需要量的模型。     

The nutritive value of marula (Sclerocarya birrea) seed cake for broiler chickens: nutritional composition,performance, carcass characteristics and oxidative and mycotoxin status

This study was aimed at investigating the nutritive value of marula seed cake (MSC) as an alternative protein source for broilers. In a completely randomised design involving six replicate pens of five chickens assigned to each of five treatments, body weight gain (BWG), feed intake (FI), feed conversion efficiency (FCE) and carcass characteristics were measured in an experiment in which 150 28-day-old broilers were fed maize-based diets containing, respectively, 0, 5, 10, 15 and 20% MSC at finisher phase. The results showed MSC to be remarkably high in CP (470.0 g/kg DM) and EE (343.5 g/kg DM), with moderate CF (58.2 g/kg DM), ash (54.3 g/kg DM), Ca (1.1 g/kg DM) and P (11.0 g/kg DM). Whilst very poor in lysine, MSC was found to be rich in methionine, cyst(e)ine, arginine and glutamic acid; it also contains good levels of valine, glycine, threonine, isoleucine, leucine, histidine, phenylalanine, serine, proline and alanine. Also, it contained 85.24% oleic (OA), 9.65% palmitic and 5.11% stearic acids, with a high peroxide value and low levels of mycotoxins deoxynivalenol (DON) and T-2 toxin. BWG, FI and FCE of broiler chickens significantly decreased (P < 0.001) as the dietary level of MSC increased. Further, dietary MSC significantly decreased bird live weight at slaughter (P < 0.001), plucked weight (P < 0.001), dressed weight (P < 0.001) and weights of the liver (P < 0.001) and neck (P < 0.05). The results therefore demonstrate MSC to be a good source of CP, fat, Ca, P, amino acids (except lysine) and OA that can replace soya bean meal (SBM) in broiler diets. However, its use is currently limited by lipid peroxidation and presence of mycotoxins.

     

西藏那曲地区高寒草地牧草矿物元素动态变化及盈缺分析

测定了那曲地区尼玛县高寒草地不同月份围栏内和围栏外牧草矿物元素（Ca、P、Na、K、Mg、Cu和Zn）含量，并根据元素的吸收率及藏山羊矿物元素需要量，对放牧藏山羊采食牧草中矿物元素的盈缺进行了分析。结果表明：同月份围栏内与围栏外的矿物元素含量差异不显著（P〉0．05），但不同季节的变异很大。夏秋季牧草Ca、P、Na、K、Mg、Cu、Zn的含量（Ca1．25％DM，P0．1419％DM，Na0．06％DM，K1．51％DM，Mg0．28％DM，Cu8．70mg／kg，Zn27．35mg／kg）高于冬春季（Ca0．72％DM，P0．0005％DM，Na0．02％DM，K0．43％DM，Mg0．10％DM，Cu3．02mg／kg，Zn8．49mg／kg）。除Mg和青草期的K能满足藏山羊的需要外，其余元素不能满足藏山羊生长、繁殖和泌乳对矿物元素的需要量。