Rasht Branch, Islamic Azad University, Rasht, Iran: 1 (1)

Open Access Article

1 - Importance of Water Quality in Small Ruminants’ Productivity
A. Cervantes G. López F.J. Monge A. Estrada A. Plascencia

Successful breeding and raising of sheep and goats depend on appropriate sanitary and nutritional manage-ment, where water plays a crucial role. Alterations in water quality and availability might lead to alterations in animal productivity. Small ruminants are capable o More

Successful breeding and raising of sheep and goats depend on appropriate sanitary and nutritional manage-ment, where water plays a crucial role. Alterations in water quality and availability might lead to alterations in animal productivity. Small ruminants are capable of ingesting water in a wide range of qualities with little or no effect on health and performance, however; some elements and microorganisms present in high concentrations can produce a negative effect on health status and weight gain performance, being the qual-ity of water, an essential factor affecting the profitability of small ruminant production. The effects on cat-tle's productive performance of compounds like total dissolved solids, sulfates, and sulfur in drinking water have been documented. However, there needs to be more information available on the effect on sheep and goats, being necessary to increase the efforts to carry out studies to evaluate the effect of the physicochemi-cal and microbiological quality of drinking water on the health and productive performance of small rumi-nants. Water quality affects the efficiency of diet energy utilization in lambs. However, there is scares in-formation about this topic to reevaluate the qualification of water as “well water”. This review presents the effects of drinking water's different physicochemical and microbiological characteristics on the productivity of small ruminants. Also, it addresses water quality and its effect on productivity from an energy perspec-tive. Manuscript profile

Open Access Article

2 - The Developmental Competence of the Bovine Embryos Processed in IVC-Stroebech Medium vs. Mcr2aa Medium
M. Zandi A. Ghaedrahmati L. Stroebech

Fetal bovine serum (FBS) is preferred for its ability to provide a variety of molecules that can support the growth of embryos. However, the use of serum can lead to the development of large offspring syndrome, which is a significant problem. This study aimed to examine More

Fetal bovine serum (FBS) is preferred for its ability to provide a variety of molecules that can support the growth of embryos. However, the use of serum can lead to the development of large offspring syndrome, which is a significant problem. This study aimed to examine bovine embryo development derived from in vitro fertilized oocytes in two culture media: IVC-Stroebech medium, a chemically defined medium; and the modified medium of Charles Rosenkrans with amino acids (mCR2aa), an undefined medium containing serum. The process of in vitro maturation was carried out at 38.5 ˚C in IVC-Stroebech medium. The process of in vitro fertilization was carried out for 18 hours using Bracket and Oliphant's (BO) medium. As to the experiment, cumulus-free presumptive zygotes were randomly assigned to two different culture medium treatments. The first treatment was a two-step culture system using mCR2aa medium. The first step in-volved using mCR2aa medium without FBS for the first 48 hours of culture. After that, for the remaining days of culture, the second-step mCR2aa, which is composed of 10% FBS, replaced the medium. The em-bryos were incubated at 38.5 ˚C under 5% CO2 5% O2 and 90% N2 for 10 days. Statistical analysis re-vealed a significantly higher hatched blastocyst rate in the IVC-Stroebech medium in comparison with the mCR2aa medium. There was not any significant difference (P>0.05) in the formation rate of morulas and blastocysts between the IVC-Stroebech medium and the mCR2aa medium. Findings recommended the use of IVC-Stroebech medium for bovine in vitro embryo culture. Manuscript profile

Open Access Article

3 - The Effects of Feeding Iranian Propolis Extracts to Holstein Dairy Cows on Blood Metabolites, Milk Composition and Rumen Microbial Population
S. Ehtesham A.R. Vakili M. Danesh Mesgaran V. Bankova

The purpose of this study was to investigate the effect of feeding Iranian propolis extract on perform-ance of Holstein dairy cows. In this study 18 dairy postpartum Holstein cows (120 days in milk (DIM) and body weight of 577±37.54 kg) were used. The experiment was car More

The purpose of this study was to investigate the effect of feeding Iranian propolis extract on perform-ance of Holstein dairy cows. In this study 18 dairy postpartum Holstein cows (120 days in milk (DIM) and body weight of 577±37.54 kg) were used. The experiment was carried out in a period of 29 d (10 d adaptation and 19 d sample collection). The data was analyzed considering a completely randomized design by the GLM procedure of SAS 9.1. In this experiment 3 treatments [A: TMR diet, B: TMR diet + Iranian propolis extract (IPE) 50% (67.50 g/day/animal) and C: TMR diet + IPE 75% (67.50 g/day/animal)] were used. The results of this study showed that adding different concentrations of IPE to dairy cow ration did not have any significant effect (P>0.05) on ruminal pH, but significant de-crease (P0.05) change some the blood parameters while statistically changed (P<0.05) the blood concentrations of aspartate ami-notransferase, albumin, glucose and protein. The phenolic compounds in propolis changed rumen ni-trogen ammonia, rumen short chain fatty acids, rumen microbial population, some blood parameters and fatty acid composition in the milk. These changes improve fermentation process and consequently affect significantly fatty acid composition in milk. Manuscript profile

Open Access Article

4 - Strategic Protein Supplementation to Increase Milk Production in Crossbreed Cows Grazing on Tropical Pastures
J.R.M. Ruas P.R.M. Conceição D.S. Queiroz V.M. Gomes M.D. da Costa V.J.G. Mota M.A.S. Novaes G. Virginio Junior E.A. da Silva

This study aimed to evaluate the production and milk composition of crossbreed F1 Holstein × Zebu (1/2 H×Z) cows grazing on Marandu grass (Urochloa brizantha cv. Marandu) or Tifton-85 (Cynodon spp.) sup-plemented with different protein concentrate. 36 H × Z cows (±514 k More

This study aimed to evaluate the production and milk composition of crossbreed F1 Holstein × Zebu (1/2 H×Z) cows grazing on Marandu grass (Urochloa brizantha cv. Marandu) or Tifton-85 (Cynodon spp.) sup-plemented with different protein concentrate. 36 H × Z cows (±514 kg of body weight) were used. The cows had ± 65 days in milk and were distributed in a randomized block design, in a 2 × 3 factorial arrange-ment, i.e., two types of grass (Marandu and Tifton-85 grass), three types of protein supplementation (2.0 kg of concentrate with low rumen degradable protein; 2.0 kg of concentrate with high rumen degradable pro-tein; and no concentrate feed). Both grass produced similar amounts of forage mass, kg.h-1. The nutritional value for both grasses was also similar in all the variables analyzed, such as crude fat, crude protein, carbo-hydrates, non-fiber carbohydrates, neutral detergent fiber, and, acid detergent fiber. The milk yield was not affected by the different grasses used for grazing. Only the lactose content was higher in cows grazing on marandu grass than in Tifton-85 grass (P=0.032). The cows that did not receive concentrate had lower daily milk yield (P=0.010) and a lower percentage of lactose (P=0.011). In conclusion, both grasses can be used for grazing F1 ½ H × Z cows, and protein supplementation, regardless of its ruminal degradability, in this situation is necessary to increase milk production. Manuscript profile

Open Access Article

5 - Investigating the Effect of Using Vitamin AD3E on the Reproductive Performance of Afshari Sheep
M. Eisapour S. Yousefizadeh M. Shamsollahi F. Fatahnia Y. Mohammadi

Nutrition during mating is one of the most important factors affecting the reproductive performance of ewes. The aim of this experiment was to investigate the effect of vitamin AD3E injection around mating on body weight (BW), body condition score (BCS), plasma hormones More

Nutrition during mating is one of the most important factors affecting the reproductive performance of ewes. The aim of this experiment was to investigate the effect of vitamin AD3E injection around mating on body weight (BW), body condition score (BCS), plasma hormones, minerals, metabolites, vitamins, anti-oxidant enzymes and reproductive performance of Afshari ewes. Eighty-eight Afshari ewes were divided into 2 groups (n=44) based on age (2-4 years), BW (average 40 kg) and BCS (mean 2.75) and assigned randomly to one of the two experimental treatments. Experimental treatments consisted of control (C; no vitamin AD3E injection) and AD3E injection (AD3E) groups. Ewes in AD3E group received 5 mL of vita-min AD3E solution subcutaneously at the beginning of the experiment, the day of CIDR insertion, the day of CIDR removal, and one week after mating. Two weeks after the start of the experiment, the estrous cy-cles of all ewes were synchronized using intravaginal 12-day CIDRs. The BW, BCS and plasma minerals and metabolites concentrations of ewes did not influence by experimental treatments (P>0.05). Ewes re-ceived AD3E had lower estrogen (E2) and progesterone (P4) and higher testosterone concentrations at the day of CIDR removal (P0.05) between the treatment groups in reproductive outcomes including estrous response, fertility rate, lambing rate, twining rate and lamb sex and birth weight. These results indicated that vitamin AD3E injection around mating improved antioxidant enzyme status but had no significant effect on reproductive performance of Afshari ewes. Further researches are needed to evaluate the effect of different levels of vitamin AD3E injection around mating on reproductive performance of Afshari ewes. Manuscript profile

Open Access Article

6 - Effectiveness of Magnetic Bentonite Nanocomposites as Mycotoxin Binders in Dairy Baluchi Ewe's Diets: Impact on Milk Yield, Composition, Blood Chemistry, and Aflatoxin M1 Levels
E. Ibrahimi Khoram Abadi S. Heydari

Bentonite is considered the most effective adsorbent for aflatoxin (AF) decontamination, and recent studies have shown that changing its structure in nano form improves its physicochemical properties and chemical stability. This study was aimed to evaluate the effective More

Bentonite is considered the most effective adsorbent for aflatoxin (AF) decontamination, and recent studies have shown that changing its structure in nano form improves its physicochemical properties and chemical stability. This study was aimed to evaluate the effectiveness of different types of bentonites as binders on performance, plasma metabolites, and aflatoxin M1 (AFM1) levels in contaminated milk of Baluchi ewes. The study was conducted with 12 ewes randomly assigned to four different experimental diets. The experi-mental diets were: (1) control (the basal diet had no supplements and contained bakery waste naturally con-taminated with AF); (2) control diet supplemented with natural bentonite (NB) (5 g/kg DM); (3) control diet supplemented with modified bentonite (MB) (5 g/kg DM) and (4) control diet supplemented with magnetic bentonite nanocomposite (MBNC) (5 g/kg DM). The study found that adding bentonite clays to the diet of ewes resulted in increased milk yield (P0.05). The study also found that increasing aflatoxin B1 (AFB1) intake resulted in a decreased carryover of AFB1 into AFM1 (P<0.01), with MBNC having the lowest carryover compared to other treatments (P<0.01). These results suggest that modification of bentonite structure in nanocomposite form improves chemical stability, physicochemical properties, and efficiency as novel toxin binders for crops and animal products. Manuscript profile

Open Access Article

7 - Genome-Wide Scanning for Signatures of Selection Revealed Karakul Sheep Breed in Compared to other Iranian Breeds
A. Mirzapour-Abibagloo N. Hedayat R. Khalkhali-Evrigh R. Seyedsharifi H. Abdi-Benemar R. Hassanzadeh A. Tanveer Hussain

Karakul (KAR) is one of the resistant sheep breeds to harsh desert conditions, which is also known for its excelent lamb pelt quality. This study was performed to identify the signature of selections in the KAR breed using whole-genome sequencing data (WGS) compared wit More

Karakul (KAR) is one of the resistant sheep breeds to harsh desert conditions, which is also known for its excelent lamb pelt quality. This study was performed to identify the signature of selections in the KAR breed using whole-genome sequencing data (WGS) compared with five other Iranian native sheep. Three methods, including population differentiation index (Fst), nucleotide diversity (π), and cross-population extended haplotype homozygosity (XP-EHH) applied to detect the genomic signature of selection. Data analysis leads to identifying 38 shared genes among three methods as positively selected genes for the KAR breed. The most of mentioned genes were associated with coat color (KIT, DVL3, YPEL3, ERBB4, ZNF451, and CTSO), fat and energy metabolism (GDPD3, STARD13, ZNF106, MAPK3, RGS6, PHYH, AP2M1, SPAG9, DNAH9, NDUFAF6, and ARSK), muscle function (MYOCD and MCTP1), growth (CPNE4), altitude adaptation (DNAH9 and SERGEF), and reproduction (TBX6, PHYH, SPAG9, and ARSK). Based on our results, these candidate genes may have a positive effect on the adaptation of the KAR breed to a desert environment. Manuscript profile

Open Access Article

8 - Physicochemical Characteristics and Fatty Acid Profile of Meat and Adipose Tissue from Lambs Fed Diets with Different Levels of Pomegranate Seed Oil
A.R. Karampour R. Naseri Harsini F. Kafilzadeh

Twenty-one male Sanjabi lambs (body weight (BW)=27.5±2.6 kg, 3-month-old), were used to study the effects of diet supplementation with pomegranate seed oil (PSO) on the performance, carcass and meat quality, and fatty acid composition of muscle and subcutaneous fat. Lam More

Twenty-one male Sanjabi lambs (body weight (BW)=27.5±2.6 kg, 3-month-old), were used to study the effects of diet supplementation with pomegranate seed oil (PSO) on the performance, carcass and meat quality, and fatty acid composition of muscle and subcutaneous fat. Lambs were randomly distributed be-tween three treatments (0, 2, and 4% of dry matter (DM) pomegranate seed oil) and were fed for 90 days before slaughter. Average daily feed intake (g/d) increased by pomegranate seed oil inclusion in diet (P<0.05). Hot carcass weight (HCW) and cold carcass weight (CCW), weight of fat depots, subcutaneous fat depth, longissimus thoracis area and weight of carcass cuts, were not affected by pomegranate seed oil. Colour lightness (L*) index and fat content of longissimus thoracis muscle increased by 4% pomegranate seed oil supplementation (P<0.05); however, moisture, protein and ash content of muscle did not affect. Addition of pomegranate seed oil to lamb’s diet slightly affected fatty acid profile of longissimus thoracis muscle and couldn’t change the total amount of polyunsaturated fatty acids (PUFA), and the n-6/n-3 or polyunsaturated fatty acids/saturated fatty acids (SFA) ratios. Pomegranate seed oil supplementation sig-nificantly increased total polyunsaturated fatty acids n-3 and n-6 content and significantly decreased n-6/n-3 ratio in subcutaneous fat (P<0.05). In conclusion, the results obtained in current study suggest that addition of up to 4% pomegranate seed oil to fattening lambs diet have potential to increase some polyunsaturated fatty acids content and decrease n-6/n-3 ratio of carcass deposited fats without negative impact on fattening performance, carcass traits, and colour stability of meat. Manuscript profile

Open Access Article

9 - Effect of Selenium-Enriched Yeast Supplementation on Microbial Spoilage and Lambs’ Meat Quality during Shelf Life
G. Velázquez-Garduño M.D. Mariezcurrena-Berasain M.A. Mariezcurrena-Berasain E.D. Archundia-Velarde D. Giron-Orozco

The aim of the current research was to evaluate the effect of selenium-enriched yeast supplementation on microbial spoilage and the biochemical quality of lamb meat during shelf life. Nine Pelibuey lambs (Ovis aries) were randomly assigned to one of three treatments: a More

The aim of the current research was to evaluate the effect of selenium-enriched yeast supplementation on microbial spoilage and the biochemical quality of lamb meat during shelf life. Nine Pelibuey lambs (Ovis aries) were randomly assigned to one of three treatments: a control without selenium supplementation (T1), and two supplemented with selenium enriched yeast (Saccharomyces cerevisiae Selyeast 3000TM enriched yeast, LFA Lesaffre) with either 0.35 mg/kg (T2) or 0.60 mg/kg of selenium (T3), respectively, for 60 days. Microbiological spoilage and biochemical characteristics were evaluated during 0, 3, 6, and 9 days post-slaughter under refrigeration conditions (4 ˚C). Immediately after slaughter, no significant differences were found in aerobic plate count, fecal coliforms count, psychrophiles, pH, a* (Redness), and b* (Yellowness) among treatments. However, statistical differences (P<0.05) were observed within treatments in Psychro-philic, pH, L*(Lightness), and b* along the storage period; pH values decreased in all groups during stor-age, nevertheless higher doses of Se kept the highest pH values by the end of the observation period. As expected, there was a significant positive high correlation between day and b* (rxy=0.83; P<0.001), and a negative high correlation between pH and b* (rxy=-0.82; P<0.001). Selenium antioxidant and antimicrobial effect on meat did not result as expected and it’s hypothesized that an extreme care of animal and meat sanitary manipulation minimized its effect. Manuscript profile

Open Access Article

10 - Growth Performance and Energy Utilization of broilers fed High and Low Metabolizable Energy Diets Supplemented with Multi-Enzyme
S.A. Moftakharzadeh H. Janmohammadi Samira Kian S. Sadeghi S. Yousefi

This experiment was determined to investigate the effects of exogenous-enzyme addition to the high and low levels of metabolizable energy (ME), on performance, energy utilization and body composition of broiler chickens fed corn-soybean meal diets from 0 to 21 days of a More

This experiment was determined to investigate the effects of exogenous-enzyme addition to the high and low levels of metabolizable energy (ME), on performance, energy utilization and body composition of broiler chickens fed corn-soybean meal diets from 0 to 21 days of age. 240 one-d-old male Ross 308 broil-ers were used in a completely randomized 2 × 2 factorial design, with six replicate cages per treatment. Two metabolizable energy level: 3150 or 2750 kcal/kg and two enzyme (with xylanase beta-glucanase, and phy-tase activity) level: 0 and 200 mg/kg dry matter (DM) were used. There was a main effect of energy (P<0.05) on feed intake of broilers and feeding 2750 kcal/kg ME diet increased feed intake (FI) of broilers in the whole period. The addition of enzyme to 2750 kcal/kg ME diet significantly (P<0.05) improved the average daily gain (ADG) and feed conversion ratio (FCR) of broiler chickens on 0-21 days of age (P<0.05). While net energy for production (NEp), NE, ME, organic matter, and dry matter digestibility were improved (P<0.05) by supplementing both energy level diets with enzyme at 21 d, only addition of enzyme to 2750 kcal/kg ME diet reduced heat production (HP) of broilers in the total trial (P<0.05). On day 21, the amount of NE improvement by enzyme supplementation was greater than ME for 2750 and 3150 kcal/kg, respectively. This study showed that NE is a more sensitive energy utilization measure than ME for evaluating the response of broilers to enzyme supplementation, and the energy retained as fat and protein in the body carcass was higher for the birds fed lower energy diet supplemented with enzyme. Manuscript profile

Open Access Article

11 - Effects of Replacing Canola Meal with Soybean Meal in Broiler Chicken Diet on Growth Performance, Carcass Traits, and Liver Enzymes during Different Rearing Periods
M. Mohammadian Amiri B. Dastar R. Mirshekar O. Ashayerizadeh

Soybean meal is more beneficial than canola meal (CM) due to the better balance of amino acids in the nutrition of broilers. Three experiments were conducted to assess the impact of replacing soybean meal with CM at different levels during the rearing stages of Ross 308 More

Soybean meal is more beneficial than canola meal (CM) due to the better balance of amino acids in the nutrition of broilers. Three experiments were conducted to assess the impact of replacing soybean meal with CM at different levels during the rearing stages of Ross 308 male broilers on performance, carcass traits, and liver enzyme concentrations. In the first experiment, 420 one-day-old chicks received starter diets with six graded levels of CM from 0 to 15% for 10 days. In the second experiment, 360 eleven-day-old chicks were fed six experimental grower diets varying in CM from 0 to 25% over 14 days. In the third experiment, three hundred 25-day-old chicks were subjected to six finisher diets ranging in CM from 0 to 40% over 18 days. The findings revealed that the inclusion of the CM at the examined levels had no adverse effects on broilers' performance, carcass traits, and liver enzymes in the first and second experiments (P>0.05). Die-tary CM inclusion of more than 32% in the third experiment had significant adverse effects on the perform-ance, European broiler index, and liver enzymes of broilers (P<0.05). In conclusion, the CM can be in-cluded in broiler diets at levels up to 15% during the starter and 20% during the grower periods without adversely affecting growth performance and carcass traits. Nonetheless, an inclusion level of CM exceeding 32% of the diet during the finisher period resulted in decreased weight gain and harmful effects on liver function. Manuscript profile

Open Access Article

12 - Effect of Dietary L-Carnitine Supplementation on Characteristics of Cobb's Semen
A. Shadmanesh A. Fattah

Good semen quality plays a very important role in promoting poultry breeding programs; due to its antioxi-dant properties and role in fat metabolism, L-carnitine seems to be effective in improving semen quality. Therefore, this study was performed to evaluate the effect More

Good semen quality plays a very important role in promoting poultry breeding programs; due to its antioxi-dant properties and role in fat metabolism, L-carnitine seems to be effective in improving semen quality. Therefore, this study was performed to evaluate the effect of dietary L-carnitine supplementation on the motility parameters and qualitative traits in semen Cobb breed roosters. A total of twenty roosters, 24 weeks-old Cobb roosters randomly assigned to four experimental groups. The experimental design was conducted in a completely randomized design with 4 experimental treatments (T1: 0, T2: 125, T3: 250, and T4: 500 mg L-carnitine per kg diet) with 5 replications and sampling twice (semen collection) with an in-terval of 14 days. The collected semen was immediately evaluated for motility parameters and sperm qual-ity traits. The results showed that there is no significant difference between the levels of 250 and 500 mg of L-carnitine in semen parameters, but there are significant differences with other groups (P≤0.05). Semen collection time did not affect sperm parameters (P≤0.05). In conclusion, the addition of L-carnitine at a rate of 250 mg/kg diet can improve motility parameters and sperm quality traits in the Cobb rooster. Manuscript profile

Open Access Article

13 - Egg Characteristics, Blood Parameters and Tibia Mineralization of Laying Hens Fed Varying Dietary Levels of Limestone and Periwinkle Shell
N.W. Anizoba N.E. Ikeh C. Ezenwosu B.C. Amaefule A.L. Obinna S.O.C. Ugwu

The effect of feeding varying dietary levels of limestone (LS) and periwinkle shell (PS) on laying perform-ance, egg characteristics, blood parameters and bone mineralization of hens was studied. A total of 108 sixteen-weeks-old pullets (weighing 1.2±2.00 kg) were allot More

The effect of feeding varying dietary levels of limestone (LS) and periwinkle shell (PS) on laying perform-ance, egg characteristics, blood parameters and bone mineralization of hens was studied. A total of 108 sixteen-weeks-old pullets (weighing 1.2±2.00 kg) were allotted to 6 treatments with 3 replicate groups of 6 birds in each pen. The LS and PS were supplemented in the diets at three levels (3.00%, 3.75% and 4.50%) each for a period of 12 weeks. Birds fed 3.75% PS had the highest (P<0.05) feed intake and hen-day egg production with an improved feed conversion ratio. The inclusion levels of PS significantly (P<0.05) im-proved most of the external and internal egg quality parameters studied with the best result recorded among the laying hens fed 3.75% PS and 4.50% PS. Some of the blood parameters and bone mineralization were better (P<0.05) for hens fed 3.00% PS and 3.75% PS. On the other hand, the source of calcium and its lev-els had no significant effect on initial body weight, final body weight, total weight gain, average daily weight gain, egg weight, egg surface area, yolk height, yolk index, total protein, alanine aminotransferase, aspartate aminotransferase, bone phosphorus, tibia weight and dry defatted bone. Based on the results ob-tained from the present study, it was concluded that 3.75% PS was appropriate for laying hens without ad-verse effect on performance and the inclusion of PS in layer rations as calcium source is more beneficial than LS. Manuscript profile

Open Access Article

14 - Effect of Lighting Schedule during Incubation on Embryonic Development and Bone Gene (Col10a1, Spp1, Bglap, and Alp) Expression in Broiler Hatchlings
S.M. Hashemian M.J. Zamiri Z. Khaksar Z. Ansari Pirsaraei H.R. Moradi

We studied the effect of lighting during 19 days of incubation on embryonic bone characteristics, gene ex-pression, thyroid hormones, and glucose in Cobb broiler hatchlings. Eggs (2160) were incubated under darkness (control) and green and white lighting (16D:8L and 12D More

We studied the effect of lighting during 19 days of incubation on embryonic bone characteristics, gene ex-pression, thyroid hormones, and glucose in Cobb broiler hatchlings. Eggs (2160) were incubated under darkness (control) and green and white lighting (16D:8L and 12D:12L). On 19th day, tibiotarsal length in-creased under eight hours of white light, and femoral ossified length was longer under eight hours of white and green light. In femur, expression of Alp, Col10a1, and Spp1 increased by 12 h white and 8 h green lighting, and Bglap expression decreased under white. In tibiotarsus, expression of Alp decreased by 8 h lighting (green or white) while Bglap increased by 12 h lighting (green or white). Tibiotarsal expression of Col10a1 increased by 12 h lighting (white and green), and in 8 h green lighting, and Spp1 expression was higher under light illumination. The hatchling blood triiodothyronine concentration in 8 h green lighting was higher than that in control, whereas, thyroxine concentration was lower under 12 h white lighting com-pared with other treatments. Femoral organic matter to mineral (OM:M) ratio and calcium concentration were higher in the eight-hour white light group than in the control, but tibiotarsal OM:M ratio and calcium and phosphorus concentrations were higher under 12 h white light. The findings indicated that lighting dur-ing incubation may impact, both positively and negatively, bone morphology and gene expression. More studies are needed to find the most beneficial lighting system during incubation in chickens. Manuscript profile

Open Access Article

15 - Long Term Feeding Effects of a Vaccine against of Endotoxemia (ENDOVAC-Beef) on Growth Performance and Carcass Characteristics of Growing-Finishing Calf-Fed Holstein Steers
B.C. Latack P.H. Carvalho A. Plascencia R.A. Zinn

The objective was to evaluate the long-term effects of vaccination against endotoxemia on calf-fed Holstein steer growth performance, dietary energetics, and carcass characteristics. Fifty Holstein steer calves were used in a 322 d trial. Calves (134±5 kg) were randomly More

The objective was to evaluate the long-term effects of vaccination against endotoxemia on calf-fed Holstein steer growth performance, dietary energetics, and carcass characteristics. Fifty Holstein steer calves were used in a 322 d trial. Calves (134±5 kg) were randomly assigned to treatments within weight groups to 10 pens (5 steers per pen). Five pen groups received an endotoxemia vaccination on d 28 and 56 of the study (EV), and the remaining 5 pens did not receive vaccination. Calves were weighed (off-truck weight, no shrink applied) at start of the study, and on days 122 and 322 (shrunk 4% to account for gut fill). All steers were fed with a steam-flaked corn-based diet. Vaccination did not affect (P≥0.10) live weight, average daily gain, and dry matter intake during the experiment. Although vaccination increased (P=0.04) gain efficiency during the initial 112 d, differences in gain efficiency from d 112 to 322, and during the cumulative feeding period (1 to 322 d) was not appreciable (P≥0.14). Vaccination did not affect (P≥0.31) hot carcass weight, dressing percentage, or marbling score. However, vaccination increased (P<0.01) longissimus muscle area (86.5 vs. 76.8 cm2) and retail yield (51.3 vs. 50.4); but, also tended to increase (P=0.07) carcass fat thick-ness. Morbidity and pink eye rate infection were low and not affected by treatment (P≥0.18). We conclude that whereas vaccinating Holstein calves with EV at days 28 and 56 from arrival did not have an overall effect on growth-performance, it increased (13%) longissimus area and retail carcass yield (1.8%). Manuscript profile

XML

List of Articles