Effects of level of concentrate supplementation on growth performance of Arsi-Bale and Boer?×?Arsi-Bale male goats consuming low-quality grass hay

Eighteen Arsi-Bale (local) and 18 Boer?×?Arsi-Bale (crossbred) male goats, initially approximately 10 months of age, were used in a 12-week experiment to investigate potential interactions between genotype and nutritional plane in growth performance, carcass and skin characteristics, and mass of non-carcass components. Grass hay (6.7% crude protein and 71.9% neutral detergent fiber) was consumed ad libitum supplemented with 150, 300, or 450 g/day (dry matter; low, moderate, and high, respectively) of a concentrate mixture (50% wheat bran, 49% noug seed cake, and 1% salt). Initial body weight was 20.7 and 14.0 kg for crossbred and local goats, respectively (SE = 0.36). Hay dry matter intake was greater (P < 0.05) for crossbred vs. local goats (461 and 429 g/day) and similar among concentrate levels (438, 444, and 451 g/day for high, moderate, and low, respectively; SE = 4.7). Average daily gain was greater (P < 0.05) for crossbred than for local goats (36.6 and 20.8 g) and differed (P < 0.05) among each level of concentrate (43.7, 29.6, and 12.8 g for high, moderate, and low, respectively). Dressing percentage was similar between genotypes (41.1% and 41.1% live body weight for crossbred and local goats, respectively; SE = 0.59) and greater (P < 0.05) for high vs. low (43.5% vs. 38.7% live body weight). Carcass weight differed (P < 0.05) between genotypes (9.23 and 6.23 kg for crossbred and local goats, respectively) and high and low (8.80 and 6.66 kg, respectively). Carcass concentrations of physically dissectible lean and fat were similar between genotypes and high and low concentrate levels. There were few differences between genotypes or concentrate levels in other carcass characteristics such as color and skin properties. Relative to empty body weight, the mass of most non-carcass tissues and organs did not differ between genotypes. However, the low concentrate-level mass of omental-mesenteric fat was greater (P < 0.05) for local vs. crossbred goats (1.06% vs. 0.54% empty body weight, respectively). In conclusion, growth performance and carcass weight advantages from crossing Boer and Arsi-Bale goats were similar with a low-quality basal grass hay diet regardless of level of supplemental concentrate.     

Effect of calves’ supplementation on performance, nutritional and behavioral characteristics of their dams

The effects of supplementation of beef calves on weight gain, intake and digestibility of pasture, milk production and composition of their dams, and behavior of the pair cow–calf were assessed. Fifty-five beef cows with an initial average body weight of 449?±?8 kg and their respective offspring, with an initial average body weight of 138?+?3 kg and aged between 90 and 150 days, were used. Animals were submitted to an experimental period of 112 days. The experimental treatments consisted of: control?=?mineral mixture only, plan 1?=?high protein and high carbohydrate multiple supplement, plan 2?= high protein and low carbohydrate multiple supplement, plan 3?=?low protein and high carbohydrate multiple supplement, and plan 4?=?low protein and low carbohydrate multiple supplement. About 25 and 12.5 % of the protein requirements were supplied by the high and low protein supplements, respectively, and 15 and 7.5 % of total digestible nutrient requirements by the high and low carbohydrate supplements, respectively. Grazing behavior, performance, milk production, milk composition, intake, and digestibility of the cows were not affected (P?>?0.05) by the supplementation of the calves. The supplemented calves had greater (P?<?0.05) performance (as measured by final body weight, average daily gain, and final body condition score), intake and idle time, and lower (P?<?0.05) grazing time, but supplementation did not affect (P?>?0.05) suckling time and suckling frequency. It can be concluded that supplementation affects the behavior and feed intake of calves. However, it does not affect the suckling time and suckling frequency of calves. Additionally, performance, milk production, nutritional characteristics, and behavior of their dams are not affected.     

Effects of single or combined dietary supplementation of β-glucan and kefir on growth performance,blood characteristics and meat quality in broilers

1. This study was conducted to evaluate the effects of dietary β-glucan and kefir (a fermented milk product) on growth performance, blood profiles, relative organ weight and meat quality in broilers.

2. A total of 375 day-of-hatch mixed sex ROSS 308 broilers (BW of 46 ± 0.1 g) were used in a 5-week experiment and randomly allotted to one of the following dietary treatments: (1) NC, basal diet; (2) PC, basal diet + 40 mg/kg of avilamycin; (3) B, NC + 0.1% β-glucan; (4) K, NC + 0.1% kefir; (5) BK, NC + 0.1% β-glucan + 0.1% kefir.

3. During weeks 0–3, broilers in B, K and BK treatments had higher body weight gain (BWG) than those in NC treatment. During weeks 4–5, BK treatment had a higher BWG than NC treatment. Overall, broilers given PC, K and BK diets had higher BWG than those given NC diet. The feed efficiency ratio (FCR) was improved by PC treatment.

4. Relative liver weight was increased by B treatment, whereas the relative weight of breast meat and gizzard was higher in BK group than that in NC group. Broilers given PC, B and BK diets had greater breast meat redness value and reduced drip loss at d 5 and d 7. The cooking loss was also reduced by B and BK treatments compared with NC treatment.

5. In conclusion, the results suggested that inclusion of 0.1% β-glucan and 0.1% kefir, either individually or combined, would improve growth performance and benefit meat quality in broiler chickens.     

Effect of different housing systems on fattening performance,slaughter and carcass characteristics of Akkeçi (White Goat) male kids

The aim of this study was to determine the fattening performance and the slaughter and carcass characteristics of Akkeçi (Saanen × Kilis (B₁) crossbred) male kids raised in individual crates (IC) or in group pen housing (GP). In both GP and IC groups, total 13 heads of male kids, whose initial body weights were 21.43 ± 1.03 kg and 20.61 ± 0.98 kg, respectively, evaluated for their fattening performances. After 56 days of the fattening period, the final body weights and average daily weight gains of the GP and IC kids were recorded as 30.84 ± 0.82 kg and 25.84 ± 0.76 kg; 182.42 ± 14.77 g and 92.09 ± 13.76 g, respectively (P < 0.001). Adrenal gland weights of the GP and IC groups were similar as 1.66 ± 0.25 g and 1.77 ± 0.22 g, respectively. Although, the carcass conformation of kids was similar between groups, there were significant differences between GP and IC groups for some slaughter and carcass characteristics. In general, although housing kids reared in individual crates provides opportunity to individually feed and monitor a kid, the results obtained from the individual crates in the present study were not satisfactorily from the ethological and production points of view.     

Effect of the administration program of 2 β-adrenergic agonists on growth performance and carcass and meat characteristics of feedlot ram lambs

The aim of the study was to determine the effects of 3 feeding dose programs of the β-adrenergic agonists (β-AA) ractopamine hydrochloride (RH) or zilpaterol hydrochloride (ZH) for the final 30 d before slaughter on growth performance and carcass and meat characteristics of feedlot ram lambs. Eighty-four Dorper × Katahdin ram lambs (30.0 ± 1.6 kg) were blocked by BW and randomly assigned to pens (4 lambs per pen and 3 pens per treatment). Pens within a block were assigned randomly to 1 of 7 dietary treatments: 1) control (CTL) = diet without β-AA; 2) RH constant (RHC) = 20.0 mg/kg of RH, d 1 to 30; 3) RH increasing (RHI) = 10.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 30.0 mg/kg, d 21 to 30; 4) RH decreasing (RHD) = 30.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 10.0 mg/kg, d 21 to 30; 5) ZH constant (ZHC) = 6.0 mg/kg of ZH, d 1 to 30; 6) ZH increasing (ZHI) = 3.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 9.0 mg/kg d 21 to 30; and 7) ZH decreasing (ZHD) = 9.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 3.0 mg/kg, d 21 to 30. Overall, β-AA supplementation reduced DMI (P < 0.001) compared with CTL lambs, but lambs fed RHI and ZHI programs had greater (P < 0.05) total BW gain, ADG, and G:F. Carcass weight was improved (P < 0.05) by RHI and ZHI programs, but dressing percentage was enhanced (P < 0.05) by only ZHC or ZHI treatments. Fat thickness and yield grade were reduced (P < 0.05) by ZH or RH regardless of feeding program. Most LM characteristics (pH, moisture loss, and chemical composition) were not different among treatments (P > 0.05), with the exception of fat content that was reduced (P < 0.001) in lambs fed β-AA, and diameter of muscle fibers that was increased (P < 0.05) by ZHI treatment. Constant and increasing doses of ZH reduced (P < 0.05) the a* value of LM and semitendinosus muscles, with no effects on L* or b* values. The mass of liver was reduced (P < 0.05) in ZHI-treated lambs compared with CTL lambs, and plasma urea concentration was reduced (P < 0.05) by RH or ZH administration regardless of feeding program, although there were no other differences in organ mass weight (P ≥ 0.35) or blood metabolites (P ≥ 0.16). Increasing doses of RH or ZH augmented the growth performance response without negative effects on organ mass weight or blood metabolites. Although a ZHI program improved carcass characteristics, the increased LM fiber diameter of lambs fed ZHI program could be unfavorable because of the potential negative effect on tenderness.     

Effects of different dietary energy and protein levels and sex on growth performance,carcass characteristics and meat quality of F1 Angus?×?Chinese Xiangxi yellow cattle

Background

The experiment evaluated the effect of nutrition levels and sex on the growth performance, carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.

Methods

During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a 2 × 2 × 2 factorial arrangement under two levels of - dietary energy (TDN: 70/80% DM), protein (CP: 11.9/14.3% DM) and sex (S: male/female) during the finishing phase of 146 d. The treatments were - (1) high energy/low protein (HELP), (2) high energy/high protein (HEHP), (3) low energy/low protein (LELP) and (4) low energy/high protein (LEHP). Each treatment used 6 steers and 6 heifers, except for HELP- 5 steers and 6 heifers.

Results

Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex. Compared with the LE diet group, the HE group had significantly lower dry matter intake (DMI, 6.76 vs. 7.48 kg DM/d), greater chest girth increments (46.1 vs. 36.8 cm), higher carcass fat (19.9 vs.16.3%) and intramuscular fat content (29.9 vs. 22.8% DM). The HE group also had improved yields of top and medium top grade commercial meat cuts (39.9 vs.36.5%). The dressing percentage was higher for the HP group than the LP group (53.4 vs. 54.9%). Steers had a greater length increment (9.0 vs. 8.3 cm), but lower carcass fat content (16.8 vs. 19.4%) than heifers. The meat quality traits (shear force value, drip loss, cooking loss and water holding capacity) were not affected by treatments or sex, averaging 3.14 kg, 2.5, 31.5 and 52.9%, respectively. The nutritive profiles (both fatty and amino acid composition) were not influenced by the energy or protein levels or by sex.

Conclusions

The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance, meat quality traits and nutritive profiles.     

Effect of dietary DL‐ethionine on growth and liver metabolism

1. The effects of DL‐ethionine, given in the diet or by injection, on growth, hepatic glycogen and lipids, and the activities of some cytoplasmic NAD‐linked dehydrogenases and NADPH‐producing enzymes were investigated.

2. Growth virtually ceased after feeding ethionine for 2 d.

3. Ethionine induced an accumulation of lipid, decreased the activities of malic enzyme and isocitrate dehydrogenase and increased the activity of lactate dehydrogenase.

4. The concentration of glycogen in the liver of ethionine‐fed chickens increased for 3 d in spite of a decrease in food intake, but then decreased.     

Effect of β -glucanase and xylanase supplementation of barley- and rye-based diets on caecal microbiota of broiler chickens

1. The aim was to investigate the effect of grain type (barley or rye) and exogenous enzymes (β-glucanase or xylanase) on the composition of chicken caecal microbiota as examined by classical culturing and molecular techniques (fluorescent in-situ hybridisation (FISH) and terminal-restriction fragment-length polymorphism (T-RFLP)). 2. Plate counting revealed higher total numbers of anaerobic bacteria, lactic acid bacteria and yeasts in caecal contents of birds fed with rye-based diets than in birds fed with barley-based diets. 3. As assessed by FISH analysis, the most abundant bacterial groups in the broiler caeca were Clostridium coccoides-Eubacterium rectale followed by Bacteroides sp., Lactobacillus sp./Enterococcus sp., Bifidobacterium sp. and Enterobacteriaceae. For both cereal types, the enzyme supplementation significantly decreased the relative amount of Enterobacteriaceae. 4. The T-RFLP profiles indicated that the caecal microbiota of birds receiving rye-based diets was more diverse than that of birds fed on barley-based diets. 5. Irrespective of the method applied, the results indicate that the cereal type as well as the exogenous enzyme supplementation influence the microbiota in broiler chicken caeca, and may have the effect of reducing potentially pathogenic Enterobacteriaceae populations.     

Effect of hygiene and medication on preweaning survival and growth of Djallonké sheep in Atacora, Benin

Low sheep productivity in North Benin hampers economic development, and improvement can contribute to reduction of rural poverty and food insecurity. To reduce one of the constraints to the productivity of Djallonké sheep, high mortality during suckling in full rainy and start dry season, we tested hygienic measures and medication in improved housing. The effect of the two treatments and their combination on lamb performance and the internal rate of return (IRR) were compared to a control. For each treatment, survival and growth were observed in 20 lambs, living in 38 herds. Good housing and hygiene (daily cleaning and fortnightly disinfection of stable and water and feed troughs) reduced mortality and increased growth of suckling lambs until 3 months. Good housing plus medication (unique injection of vitamins and amino acids and with ivermectine for deworming, weekly tick treatment by spraying, and in case of diarrhea, antibiotic treatment) reduced mortality, but growth was not higher than the control. Accounting labor opportunity, the IRR was about equal for both, but capital investment was lower for the hygiene treatment which is thus more accessible to poor farmers. The combination of both treatments increased growth and benefits compared with the hygiene treatment, but decreased the IRR.     

Effects of dietary concentrate level and chromium-methionine supplementation on ruminal fermentation,and ruminal bacterial and fatty acid composition in Tan lambs北大核心CSCD

This study evaluated the effects of dietary concentrate level and chromium methionine(Cr-Met)supplementation on ruminal fermentation and fatty acid composition, and ruminal bacteria abundance in Tan lambs. Forty male Tan lambs [(21.00±1.23) kg body weight, 5 months of age] were randomly assigned to four treatment groups with 10 lambs in each treatment. The treatments were: a low-concentrate (LC) diet (concentrate:forage, 35:65) without Cr-Met supplementation; a high-concentrate (HC) diet (concentrate:forage, 55:45) without Cr-Met supplementation; groups fed the HC diet with 0.75 or 1.50 g·d-1·lamb-1 Cr-Met (HCM and HCH, respectively). Ruminal fluid was collected on day 65 with an oral stomach tube about 3 h after the morning feed and samples used for fermentation analysis, fatty acid composition determination and bacterial DNA extraction. It was found that: 1) Ruminal pH, acetate proportion and acetate:propionate were greater (P<0.05) with the LC diet whereas microbial crude protein, propionate and valerate proportions were greater (P<0.05) with the HC diet. The acetate:propionate was greater (P<0.05) in the HCM group than in the HC group. 2) For the HC diet, the DNA abundances of Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) and Ruminococcus flavefaciens were decreased (P<0.05), compared with the LC diet, whereas the DNA abundance of Anaerovibrio lipolytica was increased (P<0.05). For lambs fed the HC diet, DNA abundances of B. fibrisolvens stearic acid subgroup, Butyrivibrio VA, Butyrivibrio proteoclasticus, and A. lipolytica showed a linear decrease (P<0.05) with increasing Cr-Met supplementation level; However, the DNA abundance of R. flavefaciens showed a linear increase (P<0.05). 3) Compared with the LC group, the concentrations of t11 C18:1, trans C18:1, c9t11 CLA, t10c12 CLA, C18:2n6, and C18:3n3 were decreased by the HC diet without Cr-Met supplementation whereas the concentration of C18:0 was increased. There was a linear increase in t11 C18:1 and trans C18:1 with increasing Cr-Met supplementation level in lambs fed the HC diet. The results suggest that the HC diet inhibited the growth of ruminal bacteria involved in the ruminal biohydrogenation process, and the addition of Cr-Met had a potentially positive effect on conjugated linoleic acid (CLA) synthesis in body tissue. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Effect of diets containing raw and extrusion‐cooked rice bran on growth and efficiency of food utilization of broilers

1. Meat strain chicks were fed on diets containing 600 g rice bran/kg for the 7 to 8 week period required to reach broiler weight.

2. Extrusion cooking of rice bran resulted, in improved chick weight gain and food efficiency for the first two weeks of feeding, but this advantage was lost by the end of the feeding period.

3. Addition of 10 g calcium/kg to the stabilised rice bran diet prevented the decline in performance after two weeks of age, and birds fed on this diet continued to gain at an increasing rate until the end of the experiment.

4. Calcium supplementation of stabilised rice bran diets produced significantly greater gains and superior food utilisation compared to stabilised rice bran diets without added calcium.

5. Calcium supplementation did not affect weight gain of chicks fed on diets containing raw rice bran.

6. Taste panel evaluation of meat from birds fed on diets containing raw rice bran, stabilised rice bran, or no rice bran indicated a significant preference in only one combination tested. Any ‘off flavour could not be related to dietary treatment.     

Effect of dietary supplementation of probiotic on the performance of F1 crossbred (Rhode Island red male × Fayoumi female) cockerels

A study was conducted to evaluate four different probiotic levels, using diets supplemented with 0 (control), 0.1%, 0.2%, 0.3% or 0.5% of organic-green culture-zs (probiotic). The cockerels of 6-weeks old were randomly divided into 15 separate floor pens each comprising 25 birds and three pens (replicates) per treatment group following completely randomized design. At 12 weeks of age BW and feed to gain ratio (FCR) were determined. At the end of 42 days of experiment, nine birds per treatment were sacrificed to evaluate carcass characteristics, abdominal fat contents and the internal organs. Blood haemato-biochemical parameters were also determined. Haemagglutination inhibition antibody titres against Newcastle disease virus and lymphoid organs weight/body weight ratio were also determined. The BW of birds fed 0.2-0.5% of probiotic was significantly greater than birds fed without probiotic diet. Similarly, better FCR was observed in birds those fed diets of high level of probiotic. There was no mortality recorded at higher levels of probiotics. Differences in carcass characteristics, organs weight, meat composition, haematological values and HDL and LDL concentrations among all the diets were non-significant. However, abdominal fat contents reduced significantly in supplemented groups in relation to control and cholesterol contents were reduced significantly in 0.3% or 0.5% supplemented groups in relation to control. Feeding levels of 0.2-0.5% of probiotic, did positively affect the immune system within the parameters measured. It may be concluded that performance, blood chemistry and immunity against disease in cockerels could be maintained when supplementing 0.3% or 0.5% level of probiotic incorporated in crossbred cockerel's diets.     

Effects of dietary supplementation of (β2‐adrenergic agonist clenbuterol on carcase characteristics and some metabolites in ducks

1. Ducks (622 in total) aged 25 d were given diets supplemented with clenbuterol (CL) at 0 (control), 0.5, 1, 2, 3 and 5 mg/kg for 25 d to investigate the effect of dietary CL on muscle and fat deposition and some metabolites in ducks.

2. The mass of the breast muscles was increased by 10 to 31%, while subcutaneous fat plus skin and abdominal fat pad were reduced by 8 to 23% and 20 to 37%, respectively, in the ducks supplemented 1 to 5 mg CL/kg diet.

3. Increased RNA:DNA ratios in the breast muscle, reduced uric acid and increased free fatty acid concentrations in the serum were observed in clenbuterol‐fed ducks.     

Effect of dietary supplementation of β-1,3–1,6-glucan on reproductive performance and immunity of New Zealand White does and their pups

The study was conducted to investigate the effects of dietary β-1,3–1,6-glucan supplementation on the reproductive performance and immunity of New Zealand White breeding does and their pups. Thirty pregnant multiparous New Zealand White does were randomly assigned to three dietary treatments; 0 (control), 0.064% β-1,3–1,6-glucan or 0.128% β-1,3–1,6-glucan dietary supplementation from day 14 of gestation to day 28 of lactation. The 0.128% dietary β-1,3–1,6-glucan supplementation caused reduced (P < 0.05) feed intake from day 14 to day 28 of gestation. The swelling response 24 and 48 h after injection of phytohemoagglutinin-P showed that does fed with 0.064% dietary β-1,3–1,6-glucan had lower (P < 0.05) swelling response than the control group. Serum IgG and IgM concentrations of does were significantly higher during pregnancy than during lactation. Compared to the controls, does fed with 0.128% β-1,3–1,6-glucan had reduced serum IgM concentrations at day 21 of gestation and day 3 of lactation. They had significantly reduced serum IgG at day 28 of gestation but increased serum IgG at day 3 of lactation. Serum IgM and IgG concentrations in supplemented does were higher (P < 0.05) than controls at day 28 of lactation. Both CD4⁺ and CD8⁺ T lymphocyte subsets were lowest at day 28 of gestation. There were no treatment effects on the three types of lymphocytes. Subsets of CD4⁺ in the weanling pups were higher (P < 0.05) for the 0.064% β-1,3–1,6-glucan supplementation group than the other two groups. In conclusion, dietary supplementation of β-1,3–1,6-glucan reduced feed intake during the first 14 days but had no adverse effects on the reproductive performance and body weight of does. Dietary supplementation with 0.064% β-1,3–1,6-glucan significantly inhibited delayed-type immune reaction of Th1 and significantly reduced serum IgG concentration of does at the late gestation stage but increased serum IgM and IgG concentrations at the late lactation stage.     

Effects of δ-aminolevulinic acid and vitamin C supplementation on iron status, production performance, blood characteristics and egg quality of laying hens

An experiment was conducted to evaluate the effects of laying hen diets supplemented with δ-aminolevulinic acid (ALA) and vitamin C (VC) on productive performance, iron status and egg quality. A total of 252 Hy-line brown commercial laying hens were fed two levels of VC (0 and 500 mg/kg) and three levels of ALA (0, 5 and 10 mg/kg) in a 2 × 3 factorial arrangement from 57 to 63 weeks of age. Each treatment contained seven replicates with six hens in each replicate. Supplementation of the diet with both ALA and VC resulted in a significant increase in egg production during 4-6 weeks (p < 0.05). The haematocrit (HCT), total iron-binding capacity (TIBC), white blood cell (WBC), total protein and albumin concentrations were not affected by the dietary treatments. However, ALA and interactive effect of ALA and VC were observed to increase the RBC, haemoglobin and serum iron concentrations (p < 0.05). In addition, inclusion of both ALA and VC increased blood lymphocyte percentage in relation to hens not supplemented with ALA (p < 0.05). Moreover, single effect of ALA or VC improved (p < 0.05) the yolk colour unit and albumin height from 3 to 6 weeks. The egg shell colour was increased (p < 0.05) by the effect of ALA. The addition of VC also led to an increase (p < 0.05) of the Haugh unit at the end of the experiment. However, neither ALA, nor VC exerted an effect on egg weight, egg shell breaking strength or egg shell thickness. The results demonstrate that dietary ALA and VC supplementation can improve the iron status and egg quality of laying hens.     

Effect of Early Weaning,Split-Weaning and Nursery Feeding Programmes on the Growth of Landrace×Desi Pigs

An experiment using 164 crossbred pigs born to 20 first-parity sows was conducted to evaluate the growth performance of piglets in four weaning management regimens: T1, conventional weaning at 56 days; T2, early weaning at 28 days; T3, split-weaning of the heavier half of the litter at day 28, the remaining half being weaned at 56 days; and T4, split-weaning of the lighter half of the litter at 28 days, with the animals kept on a special nutrient diet up to 56 days, and the heavier half being weaned at 56 days. Split-weaning of the lighter half in combination with feeding a special nutrient diet resulted in an increase of average daily gain of 21% from day 28 to day 140 compared to conventional weaning and of 36% compared to early weaning at day 28. Compared to the control (T1), the average weights of piglets at the 140th day in groups T4 and T3 were 19.6% and 6.16%, respectively, higher, whereas that of the T2 was 8% lower. It is concluded that feeding a special nutrient diet to lighter pigs is beneficial in overcoming the post-weaning lag and enables maximal weight gain.