Separable Fat Research Articles

Lipid composition of Australian pork cuts 2005/2006

A study of the cholesterol content and fatty acid composition of fresh retail Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any compositional changes in fresh pork in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers’ stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, separable fat and separable lean, in late 2005 and early 2006. Variability was low across States for saturated and monounsaturated fatty acids, but more pronounced for polyunsaturated acids. The separable lean portions of all pork cuts contained levels of n-3 fatty acids and conjugated linoleic acid (C18:1c9t11) in measurable but not nutritionally claimable amounts, whilst total trans fatty acid levels were very low. There appeared to be some differences in fatty acid composition across States that may have resulted from feeding method. Cholesterol contents were similar to levels in the 80s and 90s for separable lean pork tissue, but presently are lower for separable fat tissue than for separable lean.

Nutrient composition of Australian retail pork cuts 2005/2006

A study of the nutrient composition of Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any changes in pork samples in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers' stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, raw and cooked, separable fat and separable lean, for nutrient composition (proximate components, minerals, vitamins) in late 2005 and early 2006. Results showed that present-day pork separable lean tissue continues to be low in fat, in line with stated objectives of practices implemented by the industry in Australia. Pork remains a good source of protein and of thiamin and other water-soluble vitamins, the latter being detected at nutritionally significant levels in fat tissue as well as lean; folate was detected in most samples, lean and fat portions. Iron content appeared to be slightly lower than in previous decades.

Relationships of fat-tail dimensions with fat-tail weight and carcass characteristics at different slaughter weights of Torki-Ghashghaii sheep

The purpose of this research was to investigate the relationship between fat-tail and carcass attributes in Torki–Ghashghaii sheep. Thirty ram lambs belonging to six weight groups (weighing from 25 to 50 kg) were used. Fat-tail measurements were recorded on the live animals before slaughter. Hot and cold (after 24 h in the cold room) carcass weights, and the weights of the tail and internal organs were recorded. The carcass was dissected into conventional cuts. Each cut was de-boned and the physically separable fat was removed from the meat. The bone, physical fat and trimmed meat were weighed separately. The weight of trimmed meat as a percentage of slaughter weight did not change significantly from 25 to 50 kg live weights (23.4–25.3%). The weights of physically separated fat and the fat-tail as a percentage of live weight varied from 6.6% to 15.5% for various weight groups. The correlation coefficients between the tail weight and dimensions were large, positive, and significant. The highest correlation coefficient was found between the tail weight and upper circumference ( r = 0.88), and the lowest one was found between the tail weight and upper thickness ( r = 0.61). The upper and lower circumferences of the tail accounted for 85% of the total variation in the tail weight. The tail weight was positively correlated with the meat chemically determined fat (ether extract; r = 0.43; P < 0.05) and with the total body fat ( r = 0.70; P < 0.01). Further studies are needed to see whether inclusion of fat-tail measurements in breeding programs would result in a decrease in body fat in this breed.

Productive performance and meat quality of Mouflon × Sarda and Sarda × Sarda suckling lambs

The objective of this study was to compare slaughtering performance, carcass characteristics, and meat quality in lambs of two different genotypes. Sixteen crossbred Mouflon×Sarda (M×S) and sixteen pure Sarda breed (S×S) suckling lambs were analysed. Chemical and fatty acid composition were determined on semitendinosus and longissimus dorsi muscles and perirenal and pelvic fats. Dressing percentage was higher (P<0.01) in M×S group and after histological dissection M×S carcasses had more muscle tissue (P<0.01) and less separable fat (P<0.05). Muscles of M×S had less cholesterol than the S×S lambs (P<0.01). Polyunsaturated/saturated and n−6/n−3 fatty acids ratios of the intramuscular lipids were optimal in both groups. Indexes of atherogenicity and of thrombogenicity in muscles varied between 0.9 and 1.1. The results indicated several good qualities in both the genotypes, but M×S lambs have some traits which could provide a higher market price.

Performance and carcass quality of Czech Fleckvieh, Charolais and Charolais × Czech Fleckvieh bulls fed diets based on different types of silages

A total of thirty-four Czech Fleckvieh (CF), Charolais (CH) and Charolais × Czech Fleckvieh (CH × CF) bulls with an average weight of 284 kg were included in the experiment and fed ad libitum two mixed diets: MS (based on maize silage) and LCS (based on legume-cereal and lucerne silages) with different concentrations of dietary energy until slaughter at the target live weight of 600 kg. The CF bulls consumed more dry matter (DM) of feed daily than the CH bulls (&lt;i&gt;P&lt;/i&gt; &lt; 0.05) and gained weight less efficiently than the CH × CF and CH animals (&lt;i&gt;P&lt;/i&gt; &lt; 0.01) during the entire experiment. The killing-out percentage was lower in the CF than in the CH × CF and CH (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). The CH bulls received a higher score for carcass conformation and a lower score for carcass fatness (&lt;i&gt;P&lt;/i&gt; &lt; 0.01) than the CF bulls, had lower proportions of kidney and cod fat (&lt;i&gt;P&lt;/i&gt; &lt; 0.01) than the CH × CF and CF bulls, and produced the highest percentage of high-priced meat (&lt;i&gt;P&lt;/i&gt; &lt; 0.05) and the lowest percentage of separable fat (&lt;i&gt;P&lt;/i&gt; &lt; 0.001). The bulls on the MS diet were younger than the others at the end of the experiment (&lt;i&gt;P&lt;/i&gt; &lt; 0.01), gained weight more rapidly (&lt;i&gt;P&lt;/i&gt; &lt; 0.001), consumed less DM (&lt;i&gt;P&lt;/i&gt; &lt; 0.001) daily, utilized nutrients more efficiently over the entire experimental period (&lt;i&gt;P&lt;/i&gt; &lt; 0.001), and had a higher proportion of internal fat than the LCS bulls. It can be concluded that purebred CH bulls were superior to the other breed groups in most of the traits observed. The intensive diet based on maize silage increased average daily gains, reduced the time needed to achieve the target slaughter weight, and improved the feed efficiency of bulls.

Carcass traits of Kheri lambs maintained on different system of feeding management

The study was conducted on 6-month-old finisher lambs of the Kheri breed raised under extensive range management (G1), grazing with ad libitum concentrate supplementation (G2) or intensive feeding (G3) to assess dressing yield, cutability of standard cuts, composition of the carcass and the efficiency of mutton production from the three defined systems. The weaning weight of the lambs in the three groups was similar while the finishing weight, total body weight gain in the experiment, average daily gain and the percent feed conversion efficiency were higher ( P < 0.01) in G2 and G3 than G1. The pre slaughter weight (PSW), empty live weight (ELW), hot carcass weight and hot carcass weight with edible offal was higher ( P < 0.01) in G2 and G3 fed on a high plane of nutrition than G1 raised under extensive range management. The dressing percent in terms of live weight (LW) and empty live weight (ELW) was also higher in G2 and G3 than G1. The loin eye area as an index of muscle growth was also higher in G2 and G3 than G1. Although the weights of standard cuts were generally higher in G2 and G3 due to higher PSW, as proportions of half carcass they were similar in the three groups, except the rack cut, which was higher in G2 and G3. The cut proportions pooled for the three groups averaged 33.2%, 12.3%, 13.3%, 24.9% and 16.3% of half carcass for leg, loin, rack, neck and shoulder and breast and fore shank, respectively. The depot fat (Caul and kidney fat) accretion was higher in G2 and G3 than G1. The composition of the half carcass indicated that lean percent was higher ( P < 0.01) in G1 and G2 than G3 while sub cutaneous and intra muscular fat content were generally higher ( P < 0.01) in G2 and G3 and KOH bone percent was higher ( P < 0.05) in G1 and G2 than G3. The results indicated that the growth performance was better, feed conversion efficiency, carcass yield and dressing percentage higher in lambs maintained under grazing with supplementation and intensive feeding than extensive range management. The carcass separable fat content was 8% under extensive range management while it was 12% and 16% in semi intensive and intensive system of feeding management indicating that the carcass was of acceptable quality. The loin eye area reflected the trends of pre slaughter weight and was higher in intensive and semi intensive than extensive range management.

Effect of breed on growth performance and carcass composition of Aberdeen Angus, Charolais,Herefordand Simmental bulls

Breed effects on live weight gain, slaughter characteristics and carcass composition were compared in Aberdeen Angus, Charolais, Hereford and Simmental bulls. The experiment extended over 2 years and involved totally 96 animals. The target slaughter live weights were determined 550 kg for earlier maturing breeds Aberdeen Angus and Hereford and 630 kg for later maturing breeds Charolais and Simmental. Charolais and Simmental gained more rapidly (P &amp;lt; 0.05) than Aberdeen Angus while Hereford were intermediate. Hereford had lower (P &amp;lt; 0.05) dressing percentage than the other breeds. Percentages of grade I meat were significantly higher (P &amp;lt; 0.05) in Charolais and Simmental. The highest percentage of separable fat was recorded in Hereford (P &amp;lt; 0.05). Charolais and Simmental had lower (P &amp;lt; 0.05) thickness of subcutaneous fat over MLLT than Aberdeen Angus andHereford. The later maturing bulls generally tended to achieve higher live weight gains during the experiment, produced less fat and had higher percentage of meat from high priced joints in comparison with earlier maturing animals. &amp;nbsp;

Nutrient retention in foods after earth-oven cooking compared to other forms of domestic cooking : 1. Proximates, carbohydrates and dietary fibre

Effects of Pacific traditional style of cooking in an earth-oven 1 1 Traditional Pacific style of cooking, lovo as it is known in Fijian, is performed in an oven in the earth prepared by digging a smooth sloping pit on the ground. The main source of heat is provided by the stones (once or twice the size of a fist), heated in an open fire (normally 1–2 h) until extremely hot. All food to be cooked is put in the pit at once on these extremely hot and dry stones (without water being poured to generate steam for cooking) and left in the pit, covered with earth, and left to cook for 1–2 h (1 h and 15 min in this research). on proximate content of chicken, lamb chops, fish, cassava, taro and palusami 2 2 A vegetable-based dish that consists of a filling, made by mixing canned meat (fish, mutton or beef) with coconut cream, wrapped by a layer of taro leaves. Depending on the taste and likings of people, onion, chilies, carrot, tomatoes and salt are also added to the filling. were investigated. Retention of proximates in earth-oven-cooked samples was compared with the retention in microwaved and oven-roasted chicken and lamb chops, microwave-cooked fish, boiled cassava and taro, and steamed-cooked palusami, the nutrient analyses of all of which were conducted during the course of this study. Water content of the samples generally decreased most upon earth-oven cooking. As much as 32.9% moisture was lost from earth-oven-cooked lean of lamb chops. Loss of water from microwave-cooked meat, ranging from 6.6 to 25.8 g/100 g, was second to the moisture loss in earth-oven-cooked meat and the least amount of moisture was lost from the gas-oven roasted meat with the values ranging from 4.4 to 22.2 g/100 g. Retention of protein ranged from 96% to 103% in all samples, the differences being not statistically significant. However, interestingly high retention values of fat were noted in separable lean of lamb chops ranging from 291% to 294%. A simple and logical explanation for this observation is adsorption of fat from separable fat, as it melted during cooking, into the muscle tissue of lamb chops. Retention of over 100% dietary fiber in all foods that had this component in the raw state was noted upon all types of cooking, except in steam-cooked palusami. This implied an increase in this component of food after cooking, whereas starch and sugars generally decreased after cooking.

A comparison of carcass proportions in Czech Pied and Montbeliarde bulls with a high carcass weight

The aim of the experiment was to compare the carcass composition of 20 Montbeliarde bulls (M) and 20 Czech Pied bulls (C). The carcass weight of the animals in one group varied minimally and was about 380 kg. The Montbeliarde bulls showed a higher growth rate, expressed by a significantly lower (P &amp;lt; 0.01) age at slaughter (562.6 vs. 626 days) while the live weight (682.9 vs. 690.6 kg) and carcass weight (380.4 vs. 382.6 kg) were comparable, which resulted in a significantly higher (P &amp;lt; 0.01) daily weight gain (1.142 vs. 1.045 kg) and net weight gain (0.676 vs. 0.615 kg). The Montbeliarde bulls showed a greater (P &amp;lt; 0.05) height at rump (144.0 vs. 140.2&amp;nbsp;cm), worse carcass conformation according to SEUROP (3.24 vs. 2.84), lower proportion of forequarter (44.7&amp;nbsp;vs. 45.7%) and higher proportion of hindquarter (55.3 vs. 54.3%). As for the carcass composition, no significant inter-breed differences were found in weights and proportions of shanks, meat trimmings, separable fat, bones, round, loin, filet, flank with rib, flank, shoulder and chuck. The Montbeliarde bulls had a significantly lower (P&amp;nbsp;&amp;lt; 0.05) weight and proportion of neck (10.1 vs. 11.1 kg and 5.4 vs. 5.9%) and weight of brisket and rib (17.6 vs. 18.7&amp;nbsp;kg) and proportion of brisket and rib (9.4 vs. 9.9%, P &amp;lt; 0.01). &amp;nbsp; &amp;nbsp;

Conformation and component parts of the carcass of Philippine native goat

Only limited work has been done to assess the potential of Philippines native goat in terms of conformation and component parts of the carcass. Thus, an experiment has been conducted at Institute of Animal Science, University of the Philippines os Banos, Philippines to determine carcass and lean-fat-bone yield of different cuts of chevon from Philippine native goat. Result showed that among the wholesale cuts of chevon, shoulder had significantly higher separable lean content (8.80% of LW) than leg, loin, rib, and neck. Based on % wholesale cuts (WC), however, the leg had significantly higher value (69.18%) than the other chevon cuts. Loin had significantly higher separable fat (1.67% of LW) than the other chevon cuts. Shoulder had significantly higher separable bone (4.62% of LW). Based on %WC, however, rib had significantly higher separable bone (53.36%) than the other cuts. The shoulder had significantly higher boneless recovery (9.39% of LW) than other chevon cuts. Key Words: Chevon, Carcass, Live Weight, Wholesale Cut

Carcass value of the progeny of tested beef bulls

In the study focused on the estimation of the efficiency of beef cattle in the conditions of the Czech Republic, 361 half-carcasses of the offspring of crossbred bulls of tested young beef sires were dissected. The bulls were fattened together and slaughtered at the age of 500 &amp;plusmn; 30 days. The tested breeds were Aberdeen Angus (AA), Blonde d&amp;rsquo;Aquitaine (BA), Belgian Blue (BB), Charolais (CH), Hereford (HE), Limousine (LI), and Piemontese (PI). The control groups were bulls of the Czech Pied (C) and Holstein (H) breeds. The best commercial class according to the SEUROP system was found in the offspring of Charolais sires (3.17). The fat content was the highest in the BB group (2.45) and the lowest (P &amp;lt; 0.01) in the PI group (1.50). The average hot carcass weight was 332.54 kg and was significantly (P &amp;lt; 0.05) the lowest in bulls of the HE group (290.50 kg). After dissection the dressing percentage of meat, bone, separable fat, and the meat/bone ratio were calculated. The average meat percentage in the carcass was 78.47%. The dressing percentage of meat of PI group was 80.33% and was the highest of all the groups (P &amp;lt; 0.01). H group showed the highest proportion of bones (19.79%), which was by 2% higher than in PI group. The content of separable fat ranged between 1.29 and 3.68%. &amp;nbsp;

Effect of sire breed, year, sex and weight on carcass characteristics of lambs

Carcass composition of 314 lambs from 300 Corriedale ewes sired by Corriedale, Southdown, Hampshire Down, Suffolk, Texel and East Friesian rams and born in 2 years were evaluated. Wether and female lambs (110–194 days of age) were slaughtered within a body weight range of 20–51 kg. The carcasses were grouped according to commercial weight class, i.e. light (8.0–12.9 kg), medium (13.0–16.9 kg) and heavy (17.0–23.5 kg). Dressing percentage and fat depth over the 12th rib (GR) were recorded. The carcasses were cut to obtain a double hind pistol cut (DHP) and ribs off without flank. The hindhalves were separated into five commercial joints (loin, steak, chump, leg and shank and deboned). Also total saleable meat yield (SMY), separable fat (SF) and bone were recorded. Moisture, ether extract and crude protein were determined in the steak. Year and sex had significant effect on several carcass measures. Effect of sex was significant for dressing percentage, GR, bone, separable fat, SMY:bone and SMY:SF ratios. Effect of carcass weight group was significant for age at slaughter, dressing percentage, GR, DHP, boned cuts, SMY, bone, fat, SMY:bone and SMY:SF ratios. Sire breed had significant influence on age at slaughter, dressing percentage, GR, DHP, boned cuts, SMY, bone, fat, SMY:bone and SMY:SF ratios. Sire breed had an influence of 3.5 units on dressing percentage, carcass weight group of 2.6 units, year 1.9 units and sex 0.47 units. The difference between the highest (East Friesian) and the lowest (Corriedale) value for the proportion of SMY in the double hind pistol was 6.1% (P<0.01). The East Friesian had the highest ratios of SMY:bone (2.06) and SMY:SF (6.22), whereas in Texel these values were 1.99 and 5.52, respectively. The remaining breeds had significantly lower values ranging from 1.87 to 1.93 (SMY:bone ratio) and 4.80 to 5.24 (SMY:SF ratio). In heavy carcasses the percentage of lambs with a GR higher than 15 mm (overfat) were: Southdown 57%, Suffolk 46%, Texel 46%, Corriedale 36%, Hampshire 21% and East Friesian 0%.

Effects of primiparity and subsequent management on carcass composition and quality of continental beef heifers

A total of 81 continental maiden heifers (1/2 Blonde d’Aquitaine, 3/8 Charolais breeding) were committed to eight experimental treatments. The experiment had a core factorial design (2×3) based on the factors, bred status (unbred and bred) and stage (fresh calved, fresh weaned, and finished namely weaned plus finishing period). Within each stage, once-bred and unbred animals were slaughtered at similar carcass weights and ages. Bred and unbred animals were individually fed restricted allowances of grass silage/concentrate mixtures with the same proportion at any specific time, and the level of feeding was manipulated to provide the same rate of carcass gain for the bred and unbred animals. The target carcass gains were 45 kg for each of the three stages. In two additional treatments maiden heifers were also slaughtered at the mid service point to provide a baseline measurement, and a further treatment group was taken to the third parity and slaughtered at weaning. The data were analysed as a (3×2)+2 experimental design. Primiparity had a consistent negative effect on killing-out yield and the difference between bred and unbred became smaller with advance in stage (interaction P<0.001). No significant interactions between bred status and stage were obtained for other carcass data. Primiparity had no significant effect on carcass fat class, but produced significant increases in weights of fat depots in the abdominal cavity. In the bred animals the proportion of separable fat in the forerib joint and the estimated separable fat in the carcass were significantly higher, while separable lean was significantly lower. Breeding also significantly reduced the cross-sectional area of the m. longissimus dorsi and the proportion of high priced joints in the carcass. There was no difference in any of the measured meat quality parameters due to gestation. Increases in stage, i.e. carcass weight, also produced reductions in the proportion of high-priced joints, together with increases in all measurements of fatness, separable fat in both the forerib joint and carcass, and reduced separable lean in the carcass. Increases in stage resulted in a decrease in cooking loss and increase in yellowness of fat, but no change in any of the other meat quality parameters. It is therefore concluded that gestation in young heifers increased fatness in both the carcass and body cavity, and reduced carcass leanness, but had no effect on ultimate pH or tenderness of muscle. Animals slaughtered at the post-calving stage were underfinished, while those slaughtered at the weaned and finished stages had acceptable levels of carcass fatness.

Effect of sire breed, year, sex and weight on carcass characteristics of lambs

Carcass composition of 314 lambs from 300 Corriedale ewes sired by Corriedale, Southdown, Hampshire Down, Suffolk, Texel and East Friesian rams and born in 2 years were evaluated. Wether and female lambs (110–194 days of age) were slaughtered within a body weight range of 20–51 kg. The carcasses were grouped according to commercial weight class, i.e. light (8.0–12.9 kg), medium (13.0–16.9 kg) and heavy (17.0–23.5 kg). Dressing percentage and fat depth over the 12th rib (GR) were recorded. The carcasses were cut to obtain a double hind pistol cut (DHP) and ribs off without flank. The hindhalves were separated into five commercial joints (loin, steak, chump, leg and shank and deboned). Also total saleable meat yield (SMY), separable fat (SF) and bone were recorded. Moisture, ether extract and crude protein were determined in the steak. Year and sex had significant effect on several carcass measures. Effect of sex was significant for dressing percentage, GR, bone, separable fat, SMY:bone and SMY:SF ratios. Effect of carcass weight group was significant for age at slaughter, dressing percentage, GR, DHP, boned cuts, SMY, bone, fat, SMY:bone and SMY:SF ratios. Sire breed had significant influence on age at slaughter, dressing percentage, GR, DHP, boned cuts, SMY, bone, fat, SMY:bone and SMY:SF ratios. Sire breed had an influence of 3.5 units on dressing percentage, carcass weight group of 2.6 units, year 1.9 units and sex 0.47 units. The difference between the highest (East Friesian) and the lowest (Corriedale) value for the proportion of SMY in the double hind pistol was 6.1% ( P<0.01). The East Friesian had the highest ratios of SMY:bone (2.06) and SMY:SF (6.22), whereas in Texel these values were 1.99 and 5.52, respectively. The remaining breeds had significantly lower values ranging from 1.87 to 1.93 (SMY:bone ratio) and 4.80 to 5.24 (SMY:SF ratio). In heavy carcasses the percentage of lambs with a GR higher than 15 mm (overfat) were: Southdown 57%, Suffolk 46%, Texel 46%, Corriedale 36%, Hampshire 21% and East Friesian 0%.

Use of external fat width to describe beef and lamb cuts in food composition tables

Variability in the amount of total separable fat of retail beef and lamb cuts as well as changes in the Australian meat supply make it difficult to select appropriate nutrient composition data from the current Australian food composition tables. A descriptor, based on a visual and easily measurable variable such as external fat width, could be useful if shown to be predictive of total separable fat. Fifteen representative retail beef and lamb cuts ( n=736) were randomly purchased from retail outlets located in different socioeconomic areas in each of Melbourne, Sydney and Brisbane. Mean external fat width (mm) was measured and the average percentage of total separable lean and total separable fat was determined for each retail cut. External fat width significantly predicted the amount of total separable fat for most beef and lamb cuts ( P<0.05), except for gravy beef and roasts and could therefore be used as a reliable descriptor for these cuts. Based on the variation observed in the retail beef and lamb samples, external fat width was categorized into 0, <2, 5 and 8 mm.

Parity-associated changes in slaughter weight and carcass characteristics of 3⁄4 Charolais crossbred cows kept on a lowland grass/grass silage feeding and management system

AbstractA total of 77 heifers (3⁄4 Charolais crossbred) completed a study which examined the effects of parity number on growth, changes in size of the carcass, carcass composition and meat quality. The experiment had a factorial design based on the factors: parity and level of finish. The parities were: 0 (maiden), 1, 3 and 5. At each parity animals were slaughtered at medium (EU fat class 3) and high (EU fat class 4H) levels of finish. All data were analysed by analysis of variance using individual animal observations, and linear, quadratic and asymptotic trends were explored. Where appropriate, regression equations were derived using individual animal values to describe the relationships between key parameters and the parity status of the finished animal. Animals calved at turn-out to grass in spring (April/May) and the cows were housed at weaning in mid October (mean lactation length of 163 days) and all pregnant animals were given a diet of grass silage without concentrate supplementation during the winter period. The medium level of finish animals were slaughtered 24 days after commencement of the breeding programme for parity 0 or at the end of lactation for the remaining parities, except for parity 1 animals which had a short finishing period. For the high level of finish treatment, parity 0 heifers had a longer finishing period, while all bred animals had a post-weaning finishing period. The high finish animals were finished on a diet of grass silage and concentrates. Birth weights of calves increased until the fourth parity, while weaning weights increased linearly until the fifth parity. Mean daily milk yield increased until the third lactation. Live weight, carcass weight and weights of saleable beef, separable lean and separable fat all followed asymptotic patterns of rapid initial increase and then tended to plateau with increase in parity. The asymptote values for live weight and carcass weight were 723·0 and 383·2 kg respectively. Statistically significant asymptotic relationships with parity number were obtained for live weight and various tissue weights. Nominal mature weight was assumed to be 0·99 of the asymptote and nominal mature weights for live weight, carcass weight, saleable beef, separable lean and separable fat were attained at parity (age, years) 4/5 (6·1), 3/4 (5·3), 4/5 (6·2), 3/4 (4·7) and 1/2 (2·7) respectively. The proportion of high-priced joints declined with increase in parity (linear trend P 0·01) thus indicating a reduction in relative growth of the main muscle groups of the hind limb. Shear value measurements on cooked muscle from the maiden and first parity animals indicated very tender meat, but tenderness declined with increase in parity (asymptotic trend P 0·001). Taking animals to the higher level of finish effected increases in carcass weight and separable fat in the carcass of 55·1 kg (P 0·001) and 72 g/kg (P 0·001) respectively, while separable lean declined by 53 g/kg (P 0·001). Cooked muscle from the high finish animals was less tender than from the medium finish animals (P 0·05). It was concluded that slaughtering cows at the third parity would enable a self replacing closed herd to be operated, while obtaining 0·97 of the potential maximum output of saleable beef from the cow, but there may be some compromise in the tenderness of the meat for some consumers by the third parity.

Dietary polyunsaturated fatty acids decrease fat deposition in separable fat depots but not in the remainder carcass

Two experiments were conducted in order to determine the effect of dietary fatty acid profile on deposition of body fat, carcass fat, and separable fat depots. Diets with four types of fat (tallow, olive, sunflower, and linseed oils) at an inclusion level of 10% were administered to female broiler chickens. In Experiment 1, total body fat, carcass fat (total body fat minus abdominal fat), and abdominal fat (AF) were determined. In Experiment 2, several separable fat depots (abdominal, neck, sartorial, and mesenteric fat) were removed and weighed. In general, the analyzed separable fat depots were reduced in broilers fed sunflower or linseed oils with respect to those fed tallow or olive oil (P < 0.05). Percentages of body and carcass fat were also slightly reduced in birds fed sunflower or linseed oil, with respect to those fed tallow; however, the differences were not statistically significant. Regression analysis showed that body fat, carcass fat, and fat depots variability were closely correlated with AF (R2 = 0.69, 0.56, and 0.81, respectively), except for birds fed tallow, in which abdominal and mesenteric fat showed a different growth pattern with respect to the other treatments and to the other fat depots. These results suggest that polyunsaturated fatty acids reduce fat deposition in separable fat depots with respect to monounsaturated and saturated fats but not in the rest of the body fat depots. The growth pattern of fat depots can be modified by dietary fatty acid profile. Broilers fed saturated fat tend to deposit more fat in abdominal and mesenteric depots.

Nutrient Content of South African Chickens

The nutrient content of South African chicken, of three genotypes (308 Ross, Cobb, 788 Ross), two treatments (fresh and frozen (spin chilled)), raw and/or cooked (dry and moist) and different portions (white and dark meat, skin and separable fat) was determined. Frozen compared to fresh chicken skin had a higher mineral and vitamin A, but lower vitamin E content. Medium-chain fatty acids were higher and long-chain unsaturated fatty acids lower in frozen versus fresh chicken tissues. Cholesterol was higher in fresh versus frozen fat. Cooked dark meat contained more nutrients than white meat. Mineral content of skin, white and dark meat was higher for the dry versus moist heat cooking method. Cooking method had a significant influence on thiamin, riboflavin and cyanocobalamin, but little effect on the fatty acid content of chicken meat.

Effects of the ratio of silage to concentrates in the diet on the performance and carcass composition of continental bulls

AbstractA total of 45 continental bulls (1/2 Blonde d'Aquitaine/3/8 Charolais) were used in a continuous design randomized-block experiment, to examine the effects of the ratio of silage to concentrates in the diet on growth and carcass parameters. The proportions of concentrates in the five diets were 0·26, 0·40, 0·55, 0·68 and 0·75 (DM basis). The basal diet was grass silage with D value 730 g/kg and ammonia nitrogen per unit total nitrogen 86 g/kg. The mean initial and final live weights were 467 and 651 kg respectively, with a mean carcass weight of 384 kg. The digestibility of energy was not affected by the proportion of concentrates in the diet. The rates of live weight, carcass and separable lean tissue gain tended to reach a plateau at the higher concentrate proportions, while the rate of separable fat tissue gain increased linearly with increase in concentrate proportion. The separable lean content of the carcass was linearly and negatively related to the proportion of concentrates, with a predicted decrease of’10 g/kg for an increase in concentrate proportion of 0·16. Separable fat content was also linearly related to the proportion of concentrates, with a predicted increase of 10 g/kg for each 0·196 increase in proportion of concentrates. The absence of any effect of concentrate proportion on the content of saleable meat in the carcass was considered to reflect the high growth potential of the animals. An important conclusion was that 0·99 of the asymptote value for lean tissue gain was attained at a concentrate proportion of 0·52 and that 0·95 of the maximum rate of gain was obtained at the relatively low concentrate proportion of 0·39, therefore indicating that finishing bulls of this type can perform to a high level on diets which are predominately based on grass silage.

Body weight and tissue gain in lambs fed an all-concentrate diet and implanted with trenbolone acetate or grazed on alfalfa.

Targhee x Hampshire lambs (average BW 23 +/- 1 kg) were used in two experiments to determine the effects of finishing on concentrate with an anabolic implant or forage grazing after concentrate feeding on growth, organ and viscera weights, and carcass tissue accretion. In Exp. 1 and 2 lambs were penned by sex and assigned for slaughter at initial (23 kg), intermediate (37 kg), or end BW (ewes, 47.7; wethers 50.4 kg). From 23 to 37 kg BW, lambs were fed all-concentrate diets in drylot (DL) or grazed on alfalfa (ALF). Experiment 1 was a 2 x 2 factorial with 28 lambs; factors were wether vs ewe lambs and unimplanted vs DL implanted with trenbolone acetate-estradiol benzoate. There were no differences in organ and viscera weights due to implant status. However, ADG (P < .03) and lean gain (P < .02) were greater for implanted than for unimplanted wethers (507 vs 357 g and 1,314 vs 656 g, respectively). Ewes did not respond to the implant. Fat accretion was not affected by implantation. Experiment 2 was a 2 x 3 factorial with 42 lambs; factors were wether vs ewe lambs and drylot during growing and finishing phases (DL-DL) vs drylot during growing and alfalfa grazing during finishing (DL-ALF) vs alfalfa grazing during growing and finishing phases (ALF-ALF). In Exp. 2, ADG of DL-DL lambs was greater (P < .01) than ADG of DL-ALF or ALF-ALF lambs. Lambs on ALF-ALF had smaller (P < .05) livers and rumen/reticulum weights but heavier (P < .04) kidney, omasum, small and large intestine, and cecum weights than those on DL. In Exp. 2, DL-ALF and ALF-ALF lambs had overall hindsaddle lean gain equal to those on DL-DL with less mesenteric fat and 100 g less separable fat. Finishing lambs on alfalfa reduced fat accretion without decreasing lean accretion, whereas trenbolone acetate implants for lambs fed concentrate increased BW gain and lean accretion without affecting fat accretion.