Effect of days in feedlot on growth performance and carcass characteristics of Merino, South African Mutton Merino and Dorper lambs

Brand, T. S.; Westhuizen, E. J. van der; Merwe, D.A. Van Der; Hoffman, Louwrens C.

doi:10.4314/sajas.v47i1.5

Cited by 29 publications

(25 citation statements)

References 18 publications

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“…Under feedlot conditions, the lambs were supplied a finisher diet (Table 1) ad libitum and had free access to water during the trial period. The feedlot production characteristics of the lambs were described by Brand et al (2017).…”

Section: Methodsmentioning

confidence: 99%

“…A trend in South Africa over the last few years has been an increase in the rounding off of lambs in feedlot systems. The effect of this higher quality nutrition on the body or carcass development of the various sheep breeds in South Africa needs to be quantified so that the industry has an idea at what stage the lambs are slaughter ready (Brand et al, 2017). At slaughter, A2-classed lamb carcasses receive the best or highest price per kilogram (Red Meat Producers Organisation, 2017).…”

Section: Introductionmentioning

confidence: 99%

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Analysis of carcass characteristics and fat deposition of Merino, South African Mutton Merino and Dorper lambs housed in a feedlot

Brand¹,

Westhuizen²,

Merwe³

et al. 2018

SA J. An. Sci.

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The objective of this study was to determine the effect of time spent in a feedlot on the size of the various fat depots and the distribution of the main tissues (muscle, bone, and fat) of three common South African sheep breeds. Lambs were supplied with a balanced diet (16% protein, 10 MJ ME/kg feed) ad libitum and had free access to water. Lambs from each breed were divided into six groups, which were slaughtered at 21-day intervals until a production period of 105 days had been reached. During carcass dressing, visceral and renal fat was removed and expressed as a percentage of carcass weight. The subcutaneous fat (SCF) depth was measured on the longissimus lumborum at the 13th rib position using an electronic calliper. The proportion of muscle, bone and fat was determined by dissecting a three-rib cut made on the prime rib between the 9th and 11th ribs. The percentage of visceral and renal fat increased throughout the production period for all breeds. The percentage of renal fat was up to 2.9% higher than the percentage visceral fat in both SAMM production groups. Dorper lambs tended to have high SCF levels (5.6 mm fat after 42 days) due to the early maturing nature of the breed. They reached a maximum fat depth of 20.4 mm fat after 105 days. The SAMM lambs tended to deposit SCF at a slower rate and the late maturing Merino breed was found to be much leaner, and did not reach the high fat levels of the SAMM or Dorper lambs. The percentage of muscle and bone in all carcasses decreased with an increase in the number of days in the feedlot, while the percentage of carcass fat increased during this period. The increase in late maturing adipose tissue in all breeds as they become older is amplified by the restricted movement in the feedlot and high energy diet that the lambs receive.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of carcass characteristics and fat deposition of Merino, South African Mutton Merino and Dorper lambs housed in a feedlot

Brand¹,

Westhuizen²,

Merwe³

et al. 2018

SA J. An. Sci.

Self Cite

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“…Throughout the study the average live weight of lambs was 13.9 ± 0.37 kg (Table 3), the average live weight gain was 246 ± 26.3 g per day, which is less compared to the fattening of lambs of the cross of Romanov and Dorper breeds by offering concentrate in a trough (291.9 g) ( Barzdina and Kairiša, 2016). The results of fattening of Dorper purebred lambs are indicative of different lamb average daily live weight gain from 134 g to 285 g (Brand et al, 2017) and from 62 g to 166 g (Zishiri et al (2013). It shows that the genetic characteristics of ram are important too.…”

Section: Resultsmentioning

confidence: 97%

“…The analysis of the amount of concentrate intake and live weight gain indicates that the lowest amount of concentrate (2.95 kg) was needed to achieve 1 kg live weight gain during the 1st study period, but the highest amount (14.83 kg) was necessary in the 4th period of research. On the average throughout the research 5.39 kg of concentrate for 1 kg lamb live weight gain was used, which is less compared to concentrate intake (7.0-7.9 kg) necessary for Dorper purebreds 1 kg live weight gain (Brand et al, 2017). Also the results of the fattening of the lambs of the cross between Romanov and Dorper breeds offering concentrate in trough, showed a higher consumption of concentrate for 1 kg live weight gain (6.4 kg) (Barzdina and Kairiša, 2016).…”

Section: Resultsmentioning

confidence: 99%

“…This could be explained by influence of both the breed and nutritional factors that are not being analyzed in this study and indicates that in this research lambs had reached their peak productivity already at the end of the 3rd research period (27 August 2017). Also, Brand et al (2017) indicates that Dorper lambs should be slaughtered at less live weights.…”

Section: Resultsmentioning

confidence: 99%

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Automatic Concentrate Distribution for Fattening of Romanov × Dorper Lambs

Šenfelde

Kairiša

2018

Proccedings of International Scientific Conference "RURAL DEVELOPMENT 2017"

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The aim of this research was to study the possibility of using automatic concentrate feeding stations in fattening of lambs. Ten Romanov × Dorper weaned male lambs (initial live weight 21.0 ± 0.86 kg) for fattening were used. Lambs were kept indoors in separate pen and research was carried out in production conditions. Concentrate was distributed for animals individually in automatic feeding station. Adaption period were not applied, eight lambs had the concentrate intake in the automatic feeding station from first research day, one started eat concentrate from third research day and one – from eleventh day of research. The frequency of visits to automatic feeding station and daily concentrate intake was recorded and analyzed. Lamb’s were weighted before research and every fourteen days, live weight changes were analyzed. During all the research average number of daily visits to automatic feeding station of one lamb were 13 visits, average daily concentrate intake per animal was: 84 % of the average ration (1642 g) in all research period. Results shows, that average daily live weight gain was 246 ± 26.3 g, during last quarter daily live weight gain (89 ± 27.7 g) was significantly (p &amp;lt; 0.05) lover than in other quarters. For 1 kg lamb live weight gain 5.39 kg concentrate was used.

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