Influence of different dietary zinc levels on cashmere growth, plasma testosterone level and zinc status in male Liaoning Cashmere goats

Effects of rumen-protected biotin on the growth performance, nitrogen utilization and blood parameters of yearling Liaoning cashmere doelings

OBJECTIVE

This study was conducted to investigate the effects of rumen-protected biotin (RPB) on growth performance, nutrient digestibility, nitrogen utilization and plasma biochemical parameters of Liaoning cashmere goats during the cashmere fiber growing period.

METHODS

Sixteen 6-month-old Liaoning cashmere twin-doelings (24.8±1.20 kg) were allocated to 2 diet groups that were individually ad libitum fed 30% concentrate and 70% forage diet (dry matter [DM]) by a paired experimental design. Goats of the control group were fed the basal diet, while goats belonging to the RPB group were fed the basal diet with 10 mg RPB/d per animal. The duration of the experiment was 16 weeks with two 8-week periods. Digestibility was determined at weeks 7 and 15, and other measures were taken every four weeks.

RESULTS

Compared with the control group, the average daily gain of the RPB group increased by 10.94% (p<0.05), and the intake of neutral detergent fiber was increased (p = 0.045). There were some increasing tendencies for the intake of DM, acid detergent fiber and ether extract (p = 0.070, 0.088, and 0.070, respectively). The intake and digestibility of N tended to increase (p = 0.062 and 0.093, respectively), while the N fecal excretion percentage of N intake was decreased (p = 0.093) in the RPB compared with the control group. N retention tended to increase (p = 0.084) with the addition of adding RPB to the diet. Plasma total protein was increased (p = 0.037), whereas the urea-N concentration was decreased (p = 0.049) in the RPB diet group compared with the control diet group. The levels of propionyl-CoA carboxylase (p<0.001) and methylmalonyl-CoA (p = 0.013) were increased in the RPB group.

CONCLUSION

Supplementation of rumen-protected biotin in the diet of cashmere goats can enhance the utilization of N and improve daily weight gain during cashmere fiber growing period.

Effects of Rumen-Protected Methionine Supplementation on Growth Performance, Nutrient Digestion, Nitrogen Utilisation and Plasma Amino Acid Profiles of Liaoning Cashmere Goats

This study determined the effects of rumen-protected methionine (RPM) supplementation on the growth performance, nutrient digestibility, nitrogen (N) utilisation and plasma amino acid profiles of Liaoning cashmere goats during cashmere fibre growth. Twenty-four yearling male cashmere goats (body weight: 35.41 ± 1.13 kg) were randomly assigned to four dietary treatments: a corn-soybean meal basal diet deficient in methionine (negative control, NC) and a basal diet supplemented with 1, 2 and 3 g/kg of RPM. The RPM supplementation quadratically increased the average daily gain (ADG) and decreased the feed to gain ratio (p = 0.001) without affecting the final body weight and dry matter intake. In particular, compared to NC, 2 g/kg RPM supplementation increased the ADG by 35 g/d (p < 0.001) and resulted in the lowest feed to gain ratio (p < 0.001). RPM increased the apparent total tract digestibility of N and decreased the faecal N levels, both in a linear fashion (p = 0.005). Urinary N levels did not have an effect, but the N retention levels increased linearly with PRM (p = 0.032). Moreover, the RPM decreased the plasma urea N levels (p < 0.001) and increased the plasma Met levels quadratically (p < 0.001). In conclusion, RPM supplementation in the diet of cashmere goats can enhance the utilisation of N and improve ADG during the cashmere fibre growing period, and 2 g/kg of RPM in the diet is suggested.

Trace minerals for improved performance: a review of Zn and Cu supplementation effects on male reproduction in goats

Minerals are required in small amounts but play significant roles in many physiological functions related with growth, reproduction, and health of goats such as biochemical, molecular systems, and optimized enzymatic activities due to their roles as co-factors to metalloenzymes. Among them, zinc (Zn) and copper (Cu) are leading essential elements in goat nutrition, because of their role across several biological functions. The proportion of these minerals availability and absorption from the ingested feed is usually less, because of their complexities with un-degradable parts of feed resources. Hence, their exogenous supplementation is required for normal animal functions. On this background, this review presents findings associated with supplementation of these minerals in organic form as a way for improving the fertility of male goats with special focus on physico-chemical-kinetics of the semen for improving the application of reproductive technologies. This review emphasizes the organic sources of these minerals to replace the inorganic sources, based on their significance in improving semen qualities, antioxidant protection, and mediation of molecular activities. This review also discusses salient routes of Zn and Cu absorption and identifies the need for molecular exploration for positive outcomes with supplementation of these minerals as an area of the future goat nutrition-reproduction improvement strategy.

Effect of Zinc Supplementation on Semen Quality, Sperm Antioxidant Ability, and Seminal and Blood Plasma Mineral Profiles in Cashmere Goats

This study evaluated the effects of the different dietary zinc (Zn) levels on semen quality, on spermatozoa and seminal plasma antioxidant status, and on the seminal and blood plasma mineral status in mature male Cashmere goats during the breeding season. Twenty-eight mature male Liaoning Cashmere goats were divided into four groups based on body weight (56.2 ± 2.45 kg) and semen characteristics; these goats were fed with basal diet supplemented with 0, 20, 40, or 80 mg Zn/kg DM (zinc sulfate) for 3 months. Results showed that the Zn-supplemented diets linearly increased the semen volume (0.98, 1.04, 1.27, and 1.17 ml for the 0, 20, 40, and 80 mg Zn/kg DM supplementation, respectively) (P < 0.05) and the total sperm output (3.87, 4.52, 5.73, and 5.33 × 10⁹/ml for the 0, 20, 40, and 80 mg Zn/kg DM supplementation, respectively) (P < 0.05); by contrast, Zn supplementation exerted no effect on sperm concentration, motility, and abnormal sperms rate. The activities of copper zinc superoxide dismutase (CuZn-SOD) (linear P < 0.05) and glutathione peroxidase (GSH-Px) (linear P < 0.05; quadratic P < 0.01) were highest in the intermediate supplementation (40 mg Zn/kg DM). Moreover, the malondialdehyde (MDA) content of spermatozoa decreased linearly (P < 0.01) with the increase in Zn supplementation. In seminal plasma, the highest GSH-Px activity was observed in 20 mg Zn/kg DM supplementation (P < 0.05). Catalase (CAT) activities both in the spermatozoa and seminal plasma showed no difference in all treatments. Seminal plasma Zn level was highest in 40 mg Zn/kg DM (linear P = 0.068), and K increased linearly (P = 0.001) with increasing Zn level. Furthermore, blood plasma Zn (linear P < 0.01; quadratic P < 0.05), Fe (linear P < 0.05; quadratic P < 0.05), and Mg (linear P < 0.05) increased with increasing Zn supplementation. These results indicated that dietary Zn supplementation in Cashmere goats during the breeding season improved the semen quality and quantity, elevated the antioxidative indices and Zn concentration, and decreased the MDA content both in spermatozoa and seminal plasma.

Effect of Different Sources of Supplemental Zinc on Performance, Nutrient Digestibility, and Antioxidant Enzyme Activities in Lambs

Zinc (Zn) is an essential element in the growth of all animals and plays structural and catalytic roles in many enzymes and functional proteins. Two completely randomized trials were conducted to evaluate the effects of different sources of zinc on performance, nutrient digestibility, blood mineral profile, and antioxidant enzyme activities in male growing lambs on a barley-based diet. The first trial was conducted for 70 days and consisted of 30 lambs (30.8 ± 2.8 kg mean body weight, 4-5 months of age) which were randomly allocated to five treatments consisting of a basal diet (19.72 mg Zn/kg DM), or the basal diet supplemented with 30 mg Zn/kg DM, added as either zinc-sulfate (ZnSulf; inorganic), zinc-methionine (ZnMet), zinc-proteinate (ZnProt) or zinc-glycinate (ZnGly). For the second trial, to measure the effects of dietary Zn on nutrient digestibility, four lambs from each group of the first experiment were randomly allocated to individual digestibility cages for 12 days (first 7 days as an adaptation period followed by 5 days of sample collection). Among the groups, dietary Zn supplementation above basal level significantly improved average daily gain, average daily feed intake, feed/gain ratio, and superoxide dismutase activity of red blood cells (P < 0.05). Glutathione peroxidase activity of lambs supplemented with organic Zn was significantly (P < 0.05) higher than inorganic and control groups. At the end of the trial, the concentration of plasma Zn, tri-iodothyronine (T3), thyroxine (T4), and the activity of alkaline phosphatase was increased (P < 0.05) in all groups receiving Zn as compared with controls (P < 0.05). In addition, thyroxine level in animals supplemented with Zn-methionine and Zn-proteinate was greater than in animals receiving Zn-glycine and Zn-sulfate. The results of the second trial revealed that the supplementation with Zn-methionine and Zn-proteinate increased the digestibility of crude protein (CP) and acid detergent fiber (ADF) compared to groups supplemented with Zn sulfate and control (P < 0.05). All organic sources of Zn improved organic matter (OM) digestibility compared to inorganic and control (P < 0.05). Results indicated that, regardless of source, supplementation of Zn in growing lambs improved growth performance, blood antioxidants, and thyroid hormone levels. Furthermore, Zn-methionine and Zn-proteinate supplementation appeared to improve the digestibility of CP, OM, and ADF more effectively than Zn-sulfate.

Study on minerals status of dairy cows and their supplementation through area specific mineral mixture in the state of Jharkhand

Background

Deficiency of macro and micro-minerals in the ration of dairy cows adversely affects growth, milk production and reproduction efficiency. It is essential to examine mineral concentrations in feeds offered to dairy cows in practical farms.

Methods

Two villages from each taluka were selected at random for taking representative samples of feeds, forages and hair. Within the village, help was sought from village milk producers and district animal husbandry officer for identification of 4 to 5 farmers and collection of representative samples. All the samples were processed and analyzed for chemical composition as well as major macro and micro-minerals, using Inductively Coupled Plasma-Optical Emission Spectrometer.

Results

Ca content in wheat straw (0.29%), crushed maize (0.02%) and wheat bran (0.12%) was found to be below the critical level (0.30%). The P content in concentrate ingredients was high (0.26–0.96%), but low in dry roughages (0.06–0.12%). Cereal straws (0.14%) and grains (0.12%) were deficient in Mg. Feeds and forages were found to be adequate in K (1.50%). Cereals straws were found to be deficient in S (0.11%). Greens were good source of Cu (12.02 ppm). Wheat straw was found to be low in Zn (18 ppm), but high in Mn (225 ppm) and Fe (509 ppm). Local grasses and azolla green were found to be rich source of Co (>1.00 ppm). Se (0.63 ppm) was present in appreciable quantities in most of the feedstuffs.

Conclusions

From the present study, it was apparent that the feeds and forages available in the state of Jharkhand may not meet the requirements for Ca, P, Mg, Cu, Zn and Co in order to sustain a milk production of ~10 kg/day. Therefore, it is necessary to supplement these deficient minerals through area specific mineral mixture in the ration of dairy cows for improving productivity and reproduction efficiency.