Dressed Carcass Weight Research Articles

Use of probiotics instead of antibiotics in broiler production

Effects of different available commercial probiotics on growth performance and blood parameters were evaluated. To achieve the objectives, a total of 198 one-day-old Hubbard Isa Starbro broiler chicks were raised over 28 days. Chicks were wing-banded, weighed individually and randomly allocated into six equally major groups each having three replicates. Broilers of group T1 (control group) were fed the starter and finisher diets. The broilers of groups T2 was fed the control starter and finisher diets supplemented with antibiotic and groups T3-T5 were fed 4 different commercially available probiotics (T3-Guardizen-M, T4-Protexin and T5-Poultry star sol in drinking water. Weekly body weight, feed consumption and feed conversion were recorded during experimental period. Blood parameters at 4 weeks of age including packed cell volume (PCV), haemoglobin (Hb), total protein, albumin, triglycerides, high density lipoprotein (HDL), uric acid, cholesterol, glucose, intestinal microflora, pH and color properties of meat were determined. All birds were kept under similar environmental, managerial and hygienic conditions. Probiotic supplementation significantly increased the body weight and daily weight gain of broiler chicks at 28 days (p<0.05). Improved feed conversion was noticed in birds fed a diet supplemented with probiotic. The effects of probiotics on carcass and some internal organs were measured and results shows that feeding broilers with probiotics have significant effects (P < 0.05) on dressed carcass weight, abdominal fat, breast, thigh and liver while it appeared insignificant on gizzard (P> 0.05). The lower percent of abdominal fat and the higher percent of dressed carcass, breast and thigh were observed in experimental probiotic(s) groups. pH and meat color did not affect among treatments. There was lower mortality rate in probiotics among groups. Moreover, there was no significant change for Hb, PCV, total protein and albumin concentrations among different groups. Also, total protein, lipids and albumin concentrations were not affected by probiotic(s) supplementation. In addition, different probiotics showed a significant decrease (p<0.05) in triglycerides, cholesterol and uric acid concentration compared to control group. Birds supplemented with probiotics had higher number of lactobacilli but lower number of colibacilli compared to the control. It can be concluded that use of selected commercial probiotic(s) resulted in improved growth performance and carcass yields, and reduced serum cholesterol and uric acid in broiler chickens. Moreover, supplementation of the probiotic(s) to broilers had no detrimental effect on their growth performance and blood parameters. Therefore, usage of these probiotic(s) bacteria as antibiotic alternatives in poultry nutrition can be recommended.
 Progressive Agriculture 29 (4): 359-370, 2018

Implementation of different feeding regimes and flashing light in broiler chicks

A 3 × 2 factorial arrangement was implemented to determine the performance of 450 Cobb broilers subjected to different feeding regimes with and without lighting programs. The chicks were divided into 3 groups according to the feeding regime (ad libitum, restricted, or intermittent), and each group was reared under one of two lighting programs (100% continuous light or 50% continuous light and 50% flashing light). The results showed that the broilers under the ad libitum and intermittent feeding regimes had superior body weight (BW) and average daily gain (ADG) values and the lowest feed conversion ratio (FCR) at 3 and 6 wk of age. Broilers exposed to flashing light and an intermittent feeding regime had the highest BW and ADG values and the lowest FCR. Birds exposed to intermittent feeding had the highest dressed carcass weight and the lowest heart weight. Broilers reared with flashing light had higher tenderness and juiciness values than the other groups. Broilers subjected to a restricted feeding regime and flashing light had the lowest abdominal fat values of all the groups. Tenderness and juiciness were significantly higher in broilers subjected to the ad libitum feeding regime × flashing light and the intermittent feeding regime × flashing light. Broilers fed an intermittent regime had the lowest spleen %, heterophil, heterophil to lymphocyte (H/L) ratio and body temperature values of all the groups, and broilers reared under the intermittent regime × flashing light had the lowest spleen %, H/L ratio and body temperature values. Non-significant differences in all health aspects (shank length, keel bone length, foot pad burns, breast blisters score, hock discoloration, and mortality) were observed among the experimental groups. In conclusion, intermittent and restricted feeding regimes and a flashing lighting program improved the FCR and did not produce any adverse effects on performance or physiological parameters. The results of this work show that intermittent feeding and flashing lighting programs are more beneficial to broiler management.

Carcass traits and value of meat and byproducts of buffalo

A study was conducted to collect data on carcass traits covering 1,005 buffaloes across India. The results indicated that the live weight and dressed carcass weight of buffaloes ranged from 174.82 to 422.83 kg and 79.08 to 213.73 kg, respectively with an average dressing percentage of 47.92%. There was a significant difference in the overall dressing percentage and overall yield of blood, skin and intestine of buffaloes of different body weight groups, viz. less than 200 kg (group 1), between > 200 to <300 kg (group 2), >300 to <400 kg (group 3) and more than 400 kg (group 4). It was also found that the majority of the buffalo slaughtered were in the weight group of >300 to >400 kg (43.08%) and >200 to <300 kg (40%). The overall average live weight of buffaloes from southern part of the country (Andhra Pradesh) was lower (278.26 kg) when compared to the northern part (Uttar Pradesh). Further, the proportion of low body weight buffaloes (below 300 kg) utilized for meat production was more in Andhra Pradesh (70%) and in Uttar Pradesh proportionately higher body weight animals (more than 300 kg) were slaughtered more (Mathura 92.33%, Bareilly 46.8%). The yield of edible (head, feet, stomach with content, heart, liver, kidney and fat) and inedible byproducts (blood, skin, intestine with content and lungs) as percentage of live buffalo weight were 27.61 and 24.45%, respectively. In terms of commercial value of buffalo carcass, major revenue comes from meat (88.66%), followed by skin (6.6%) and edible offal (5.0%).

Effects of low to moderate levels of deoxynivalenol on feed and water intake, weight gain, and slaughtering traits of broiler chickens

The aim of the study was to evaluate the effects of low to moderate oral exposure to the Fusarium toxin deoxynivalenol (DON; derived from culture material) on performance, water intake, and carcass parameters of broilers during early and late developmental phases. A total of 160 Ross 308 broilers were randomly allocated to four different feeding groups (n = 40/group) including 0 (control), 2.5, 5, and 10 mg DON/kg wheat-soybean meal-based feed. Three consecutive replicates of the experiment were performed. Half of the broilers were slaughtered in week 3 of the trial whereas the other half were slaughtered in week 5. Dry matter intake (DMI) and water intake (WI) were recorded on a daily basis and the body weight (BW) and BW gain (BWG) were determined weekly. The following carcass traits were recorded and calculated in absolute and relative data: dressed carcass weight, breast muscle weight, leg weight, and liver weight. Data showed that BW (P < 0.001), BWG (P = 0.005), and DMI (P < 0.001) were reduced by DON-feeding during the entire feeding period. The ratio of DMI to body weight gain (DMI/BWG) was not affected by the treatment. However, the ratio of water to DMI (WI/DMI) increased in DON-treated birds (P = 0.021). Contrast analysis showed that DON tendentially reduced slaughter weight (P = 0.082) and decreased leg yield (P = 0.037) in DON-fed chickens in week 5 of the experiment. Liver organ weight decreased in the 3-week-old DON-fed broilers compared to that in the control-fed birds (P = 0.037). In conclusion, the study suggests that DMI and BW were negatively affected under the experimental conditions at DON levels lower than the current guidance value in the European Union of 5 mg/kg feed. The study also indicates that broilers fed on low to moderate level DON-contaminated diets showed increased WI/DMI ratio which might have negative influence on wet litter syndrome.

Effect of Acacia angustissima Leaf Meal on the Physiology of Broiler Intestines

The effect of A. angustissima leaf meal based diets on intestinal physiology and dressed carcass weight was investigated on 150 day old chicks. Three diets, 0, 5 and 10% A. angustissima were used in a three phase feeding programme. At days 14, 28 and 42, two birds from each replicate were slaughtered, dressed and weighed. The weights and lengths of the duodenum, jejunum and colon were measured. Approximately 1 cm specimen was taken from each organ, fixed in formalin and stained for histological analysis. Using a light microscopy, the digestive and absorptive properties of the tissues were assessed. Inclusion of A. angustissima leaf meal increased intestinal wall thickness, epithelial thickness, and villus height of the duodenum (P &lt; 0.05). There was no effect on the proportional weight and length of the jejunum, jejunum villi height and villi width (P &gt; 0.05) but jejunum wall thickness decreased with increasing levels of the leaf meal (P &lt; 0.05). Leaf meal inclusion resulted in an increase in weight, intestinal wall and mucosal thickness of the colon (P &lt; 0.05) and a decline in sub-mucosal fold height and haustra coli width of the colon (P &lt; 0.05). Dressed weight was the same across diets at two weeks (P &gt; 0.05). At four and six weeks, broilers on the control and 5% diet had superior dressed weights to the 10% fed broilers (P &lt; 0.05). It was concluded that for intestinal physiological adaptation that will not compromise weight gain in broilers, up to 5% A. angustissima could be included in broiler diets.

Effect of dietary protein level and length of fattening period on dressing percentage and carcass conformation in broiler chickens

This study analyses the effect of different protein levels in broiler feeds (supplemented with protease) and different lengths of fattening period on some parameters related to dressed carcass quality. Medium-growing Master Gris broiler chickens were used in a fattening trial lasting 63 days. At slaughter, dressing percentages and abdominal fat percentages were determined based on traditionally dressed carcass weights and abdominal fat weights of broilers at 49 and 63 days, and conformation indices were calculated based on absolute conformation measurements. Results showed that dietary treatment had an effect only on one relative conformation measurement - body weight/shank length in chickens at 49 days, as control broilers had higher values of this index compared to chickens receiving feeds containing reduced levels of crude protein and protease supplementation (0.2% or 0.3%). Length of fattening period affected almost all studied parameters, except breast angle, dressing percentage of traditionally dressed carcass and abdominal fat percentage.

Identification of leptin gene polymorphisms associated with carcass traits and fatty acid composition in Japanese Black cattle.

Previous studies have indicated that some leptin gene polymorphisms were associated with economically important traits in cattle breeds. However, polymorphisms in the leptin gene have not been reported thus far in Japanese Black cattle. Here, we aimed to identify the leptin gene polymorphisms which are associated with carcass traits and fatty acid composition in Japanese Black cattle. We sequenced the full-length coding sequence of leptin gene for eight Japanese Black cattle. Sequence comparison revealed eight single nucleotide polymorphisms (SNPs). Three of these were predicted to cause amino acid substitutions: Y7F, R25C and A80V. Then, we genotyped these SNPs in two populations (JB1 with 560 animals and JB2 with 450 animals) and investigated the effects on the traits. Y7F in JB1 and A80V in JB2 were excluded from statistical analysis because the minor allele frequencies were low (< 0.1). Association analysis revealed that Y7F had a significant effect on the dressed carcass weight in JB2; R25C had a significant effect on C18:0 and C14:1 in JB1 and JB2, respectively; and A80V had a significant effect on C16:0, C16:1, C18:1, monounsaturated fatty acid and saturated fatty acid in JB1. The results suggested that these SNPs could be used as an effective marker for the improvement of Japanese Black cattle.

Milk Replacer Acidification for Free-Access Feeding: Effects on the Performance and Health of Veal Calves

Objectives of this study were to investigate the effects of milk replacer (MR) acidification for free- access feeding on pre- and post-weaning performance, morbidity and mortality of calves. Calves were randomly assigned to free-access feeding of acidified (ACID, n = 31) or non-acidified (NON, n = 31) MR, and weaned at 42 days. ACIDMR was prepared to pH 4.0 - 4.5 using formic acid. Intakes were measured daily and weights weekly. Samples of ACID and NON MR were analyzed for coliform and aerobic bacterial growth. After weaning, calves transitioned to a grain-fed veal diet, weighed every 2 weeks. At slaughter (approximately 6 months of age), lungs were evaluated for gross pathological changes and dressed carcass weights were obtained. Generalized linear mixed models were constructed to examine the effects of MR acidification. Differences by treatment group for pre- and post-weaning morbidity and mortality were tested using Pearson’s χ2 and Fisher’s exact tests. ACID calves consumed less MR than NON (10.6 vs. 11.7 L/d, P = 0.02). Acidification tended to promote earlier onset of starter ration consumption (32.0 vs. 39.5 d, hazard ratio = 1.5, P = 0.07), but did not affect average daily starter ration or water intakes across the pre-weaning period. ACID and NON calves did not differ for BW at weaning, pre- or post-weaning ADG or dressed carcass weight. ACID MR had less coliform (P < 0.001) and aerobic bacterial growth (P < 0.001) than NON MR, but odds of disease treatment and mortality did not differ. ACID calves tended to have lower odds of pulmonary lesions during post-mortem inspection than NON calves (OR = 0.3, P = 0.07). These results indicate that under free-access feeding conditions, acidification limited bacterial growth and MR intake, but there were no long-term impacts of acidification on calf performance or health. In conclusion, acidification to pH 4.0 - 4.5 will significantly reduce bacterial growth in milk fed to calves.

Growth Promoter Effects of Allium Sativum and Zingiber Officinale on Performances Haematological Parameters and Gut Microbiology of the Cameroon Kabir Chicken

The current study evaluated the effects of garlic and ginger powders against a commercial antibiotic as potential feed additives on growth performance, carcass characteristics, haematological parameters and gut microbiology of the Kabir chicken. For, 108 one-week old chicks of both sexes were divided into 6 groups (n=18), which received a commercial antibiotic (0.5g/L H2O), a basal diet alone or supplemented with 0.5% and 1.0% ginger or garlic. Growth performance was recorded weekly for 9 weeks while carcass, haematological and microbial parameters were evaluated at 45 days post-treatment. Generally, all investigated parameters were not significantly affected (P>0.05) by dietary treatments but enhanced it. Overall weight gains were better in the 1.0% garlic (1362.29g) followed by the commercial antibiotic (1338.36g) treatments as a consequence of slightly higher feed intakes (4139.5g, and 4854.3g)/bird respectively. The overall feed conversion ratio ranged from 3.03 to 4.38, and was generally poor as the chicks aged. Pre-slaughter and dressed carcass weights were higher in the antibiotic, followed by the 1.0% garlic treatment group. Blood parameters varied widely from the standard reference range, a normal phenomenon for avian species. Gut microbial analysis revealed the presence of only Shigella sp and Salmonella sp with the absence of E. coli from all the samples. It was concluded that garlic at 1.0% in feed could be used to replace antibiotics, for Kabir chicken production without deleterious effects.

Some factors influencing dressing percentage in goat meat production

This review article looks at the factors affecting dressing percentage in goats. Many factors can affect the dressing percentage (DP), therefore it is important for goat producers to understand the concept and factors influencing dressing percentage because it can equate to profitability. In general, goat genotypes that are heavier muscled have a higher dressing percent than goat genotypes that are lighter muscled. Additionally, as the goat fat thickness on the outside of a carcass increases, the dressing percent also increases. Dressing percentage is based on the relationship between the dressed goat carcass weight and the live weight after things like the hide and internal organs have been removed. Goat dressing percentage can be calculated by taking (weight of the carcass / weight of live animal) * 100. This can be determined on a hot carcass weight or a cold carcass weight. There are indication of the potentiality to manipulating some of the factors that influence dressing percentage in goat to the producer’s advantage. Better goat rearing practices can be achieved through nutritional management resulting in improvement of dressing percentage.

Influence of rice whole-crop silage diet on growth performance, carcass and meat characteristics and muscle-related gene expression in Japanese Black steers.

The present study investigated the influence of a diet largely comprising rice whole-crop silage (rWCS) on growth performance, carcass and meat characteristics, and expression of genes involved in muscle growth of Japanese Black steers. Steers were randomly separated into rWCS-fed (rWCS ad libitum and restricted feeding of concentrate) and concentrate-fed groups. Total digestible nutrient intake and daily gain (DG) decreased in rWCS-fed steers in comparison with concentrate-fed steers, whereas dressed carcass weight and final body weight did not significantly differ between the groups. Decreases in drip loss in the muscle of rWCS-fed steers may be caused by α-tocopherol and β-carotene in muscle. Feeding large amounts of rWCS to steers may maintain quantitative productivity of beef steers equally to a concentrate-based diet, and improve the qualitative productivity. Results of gene expression suggest that activation of skeletal muscle growth in rWCS-fed steers may occur at the late fattening period owing to a decrease in myostatin and increase in myosin heavy chain gene expression. Preadipocyte factor-1 and myostatin genes may be strongly involved in the control of lipid accumulation. This rearing system would allow beef production to switch to rWCS-based diets from concentrate-based diets.

Response of two broiler strains to four feeding regimens under hot climate

In total, 392 male broilers were randomly distributed in a factorial arrangement of 2 × 4, with two commercial broiler strains (Arbor Acres (AA) and Hubbard (Hub)) and four (NRC, Degussa, CVB, and strain guides) different feeding regimens (FR), totaling eight treatments and seven replicates, with seven broilers in each one. The following parameters were evaluated: bodyweight gain (BWG), feed intake (FI), feed conversion ratio (FCR), carcass yield, meat quality, nutrient intake, and its correlation with BWG. Interaction strain type × FR was significant for BWG, FI, and FCR, with the AA broilers showing higher BWG and FI and lower FCR than the Hub broilers. There was no difference in BWG, FI, and FCR of the AA broilers regardless of FR they were on, but the Hub broilers had lower BWG when they were fed according to the Degussa and CVB regimens; BWG and FCR were negatively affected. During the starter phase, BWG of the AA broilers was significantly correlated with feed, metabolisable energy (ME), lysine, and sulfur amino acids (SAA) intake. However, BWG was correlated with feed and ME intake and feed intake from 1 to 31 and from 1 to 42 days of age, respectively. In the Hub chicks, ME and crude protein intake and lysine and SAA intake were inversely correlated with BWG from 1 to 31 days and from 1 to 42 days of age, respectively. There was no significant effect of FR on dressed carcass weight or relative gizzard, pancreas, and liver weights and on intestinal weight; however, abdominal fat and spleen differed significantly with FR. Strain type significantly affected the relative weight of the intestines. There was no significant effect of FR and/or strain type on meat moisture, crude protein, lipid and ash content, or pH, colour, meat juiciness and tenderness (meat softness). In conclusion, AA strain of broiler performed better than the Hub strain under the different FR in all the evaluated production phases, but neither FR nor strain type affected carcass characteristics.

Pregnancy rates in central Yellowstone bison

Plains bison (Bison b. bison) centered on Yellowstone National Park are chronically infected with brucellosis (Brucella abortus) and culled along the park boundaries to reduce the probability of disease transmission to domestic livestock. We evaluated the relationship between pregnancy rates and age, dressed carcass weight, and serological status for brucellosis among bison culled from the central Yellowstone subpopulation during the winters of 1996–1997, 2001–2002, and 2002–2003. A model with only dressed carcass weight was the best predictor of pregnancy status for all ages with the odds of pregnancy increasing by 1.03 (95% CI = 1.02–1.04) for every 1-kg increase in weight. We found no effect of age or the serological status for brucellosis on pregnancy rates across age classes; however, we did find a positive association between age and pregnancy rates for bison ≥2 years old. Bison ≥2 years old had an overall pregnancy rate of 65% with markedly different rates in alternate ages for animals between 3 and 7 years old. Pregnancy rates were 0.50 (95% CI = 0.31–0.69) for brucellosis positive and 0.57 (95% CI = 0.34–0.78) for brucellosis negative 2- and 3-year-olds and 0.74 (95% CI = 0.60–0.85) in brucellosis positive and 0.69 (95% CI = 0.49–0.85) in brucellosis negative bison ≥4 years old. Only 1 of 21 bison <2 years old was pregnant. Our findings are important to accurately predict the effects of brucellosis on Yellowstone bison population dynamics. We review our results relative to other studies of Yellowstone bison that concluded serological status for brucellosis influences pregnancy rates. © 2013 The Wildlife Society.

Production performance of broiler chickens influenced by feed restriction systems

An experiment was conducted to evaluate the effect of feed restriction on growth performances of broiler chicken. One hundred fifty two, day old-commercial Hubbard broilers chicks were randomly distributed into 4 treatments. Each treatment included two replicates with 19 birds per replicate. For the first two weeks of life, feed and water were provided ad libitum. At the age of 3 weeks, one group was kept as control (Co) with no feed restriction while the other groups were restricted to access of feed for 4 h (T1, from 10 AM - 2 PM), 6 h (T2, from 10 AM–4 PM) and 8 h (T3 from 10 AM - 6 PM) until the age of 42 days. By restricted time feeding, body weight was significantly decreased but feed conversion ratio was significantly improved in 8 h and 6 h restricted group than control and 4 h restricted group. Restricted time feeding decreased dressed carcass weight but percentage of back, thigh and drumstick yield was significantly improved. Whereas, breast yield and abdominal fat % were decreased relative to control group. It can be concluded that restricted time feeding between 6 to 8 h may be applied in broiler managemental system without a very significant reduction in performance.

The effect of protease on productive and slaughter traits in broiler chickens

Carcass conformation is a very important parameter in assessing the overall appearance and meatiness of broilers. This study evaluates the effect of protease supplemented to reduced protein diets on production traits, dressed carcass weight and conformation measures in fast-growing Cobb 500 and slow-growing Master Gris broilers over a fattening period of 49 days. At slaughter, the following measurements were taken: pre-slaughter body weight (BW), conventionally dressed carcass weight and abdominal fat weight. Following carcass dissection into primal cuts, absolute conformation values, including metatarsus length (ML), keel length (KL), breast depth (BD), breast angle (BA) and thigh girth (TG), were determined. For carcass conformation evaluation purposes, index values of carcass conformation measures BW/ML, BW/KL, BW/BD and BW/TG were identified. Genotype and sex had a significant effect on dressed carcass weight and all conformation measures, whereas the effect of different protein levels in protease-supplemented diets was significant only in Master Gris, for metatarsus length and the following indices: BW/ML, BW/KL and BW/TG.

The Performance of Broiler Birds Fed Varying Levels of Roasted Pigeonpea (Cajanus cajan) Seed Meal

Two experiments were carried out to investigate the effect of roasted Pigeonpea Seed Meal (PSM) on growth performance of broiler birds. Two hundred and forty day-old commercial unsexed broiler chicks (Anak strain) were used in experiment 1, while 168 four-week old broiler birds from experiment 1 were used in experiment 2. Birds in experiments 1 and 2 were divided into 6 groups. Experiment 1 birds were randomly assigned to six isoenergetic and isonitrogenous broiler starter diets containing 0, 6.5, 13.0, 19.5, 26.0 and 32.5% roasted PSM. Experiment 2 birds were also randomly assigned to 6 isoenergetic and isonitrogenous broiler finisher diets containing 0, 5.5, 10.5, 16.0, 21.5 and 27.0% roasted PSM. Parameters considered were weight gain, feed intake, feed conversion ratio, protein efficiency ratio, dressed carcass weight and carcass dressing percent. Results (Experiment 1) showed that there were significant differences (p 0.05) among treatments in all the parameters considered in experiment 2. The results showed conclusively that roasted PSM can be included in broiler starter and finisher diets at 26% and 27% levels, respectively without any adverse effect on broiler birds.

Supplementation of isonitrogenous oil seed cakes in cactus ( Opuntia ficus-indica)–tef straw ( Eragrostis tef) based feeding of Tigray Highland sheep

The experiment was conducted at Maichew Agricultural Technical Vocational Education and Training College, Ethiopia. Twenty four male yearling Tigray Highland sheep with mean body weight (BW) of 21 ± 2.6 kg (mean ± S.D.) were used to investigate the effect of different protein sources on feed intake, nutrient digestibility, BW change and carcass parameters in a study comprising of 90 days feeding trial, followed by 7 days of digestibility trial and evaluation of carcass parameters. Six individually fed animals were used per treatment in a randomized complete block design. The treatments consisted of ad libitum feeding of tef ( Eragrostis tef) straw plus 172 g dry matter (DM) of cactus ( Opuntia ficus-indica) pear (T1, control) and supplementation with 145 g DM cotton seed cake (CSC) (T2), 195 g DM noug seed cake (NSC) (T3) or 149 g DM peanut cake (PNC) (T4) per head per day. The quantity of the supplements was set to supply 62.5 g crude protein (CP). Tef straw DM intake was depressed (P<0.01) as the result of NSC supplementation. Sheep supplemented with CSC and PNC had higher (P<0.001) total DM intake than the control and NSC supplemented ones. Supplementation with NSC and PNC also resulted in higher (P<0.01) apparent digestibility of DM and OM compared to the control treatment. Supplementation with CSC and PNC resulted in better daily BW gain (P<0.001), feed conversion efficiency (FCE) and dressed carcass weight (P<0.01) compared to the non-supplemented diet. Dressing percentage on slaughter weight base was higher (P<0.01) in supplemented sheep than in the non-supplemented ones. Supplementation with PNC also promoted higher (P<0.05) rib-eye muscle area than in the non-supplemented ones. It was concluded that supplementation with 145 g DM CSC and 149 g DM PNC resulted in better feed intake, BW gain and carcass traits in cactus–tef straw based feeding of sheep.

Effects of cinnamaldehyde, garlic and juniper berry essential oils on rumen fermentation, blood metabolites, growth performance, and carcass characteristics of growing lambs

The objective of this study was to examine the effects of cinnamaldehyde (CDH), garlic (GAR) and juniper berry (JUN) essential oils (200 mg/kg of DM) on performance and carcass characteristics of lambs fed a barley-based concentrate diet ad libitum. For this purpose, 40 ewes' lambs (23.5 ± 1.11 kg initial live weight, LW) were used in a random block design over a 13-week period. Feeding CDH, GAR or JUN did not affect dry matter intake (DMI) but the average daily gain (ADG) of lambs supplemented with CDH and JUN was higher ( P = 0.002) as compared to lambs fed GAR or the control diet. Feed conversion (DMI/ADG) was numerically improved when lambs were fed CDH (4.8) and JUN (4.7) compared to those fed GAR (5.2) or the control diet (5.3). There were no effects of feed additives on ruminal pH and concentrations of ammonia and total VFA. Serum concentrations of glycerol and total glycerides were lower and higher ( P ≤ 0.03) in lambs fed CDH or JUN respectively, as compared to lambs fed GAR or the control diet. Hot dressed carcass weight was similar among treatments (23.7 ± 0.75 kg; P = 0.18) whereas saleable meat tended ( P = 0.13) to increase (+ 9%) in lambs fed CDH and JUN compared to those fed GAR or the control diet. Feeding CDH, GAR or JUN had little effect on the overall fatty acid composition of back fat and liver and only minor effects on meat flavour characteristics.

Low-level parasitic worm burdens may reduce body condition in free-ranging red deer (Cervus elaphus)

Regulation of ungulate populations by parasites relies on establishing a density-dependent relationship between infection and vital demographic rates which may act through the effect of parasites on body condition. We examine evidence for parasite impacts in 285 red deer (Cervus elaphus) harvested during 1991 and 1992 on the Isle of Rum. In the abomasa, prevalence of nematodes was 100% and the most abundant genus observed were Ostertagia species, however, mean intensity of infection was low (less than 1000) relative to other studies. Additional species, also present in low numbers, included Nematodirus spp., Capillaria spp., Cooperia spp., Monieza expanza, Oesophagostomum venulosum and Trichuris ovis. Lungworm (Dictyocaulus spp.) and tissue worm (Elaphostronygylus cervi) larvae were also observed in faecal samples. There was no evidence for acquired immunity to abomasal nematodes. Despite low levels of infection, both adult male and female deer showed significant negative correlation between indices of condition (kidney fat index, dressed carcass weight and larder weight) and intensity of Ostertagia spp. infection. However, there was no evidence that pregnancy rate in females was related to intensity of infection. For calves, there was no relationship between body condition and intensity of infection. The apparent subclinical effects of low-level parasite infection on red deer performance could alternatively be due to animals in poorer nutritional state being more susceptible to infection. Either way the results suggest that further studies of wild populations are justified, in particular where high local host densities exist or alternative ungulate hosts are present, and, where experimental treatments are tractable.

The growth hormone 1 GH1:c.457C&gt;G mutation is associated with intramuscular and rump fat distribution in a large sample of Australian feedlot cattle

The GH1:c.457C>G exon 5 missense mutation in the bovine growth hormone 1 (GH1) gene that causes the replacement of leucine (L) with valine (V) was investigated in 1027 cattle with primarily Angus and Shorthorn breeding from Australian feedlots. The allele frequency of the GH1:c.457C allele was 0.77 in Angus and 0.76 in Shorthorn. The GH1:c.457C allele was associated with lower marbling (P = 0.0472), and the average effect of allele substitution was -0.22 of a phenotypic standard deviation. This allele was also associated with slightly higher rump fat (P = 0.0541) and the average effect of allele substitution was 0.11 SD. Marbling and rump fat were not strongly correlated (r = 0.097, P < 0.01) in this data set. This mutation had no significant effect on eye muscle area or hot dressed carcass weight (P > 0.1). Given these relationships, the differences between GH1 alleles could be the result of differential deposition of fat in fat depots.