Infertile bulls versus steers: II. Feed conversion efficiency and the effects of a high fat diet

1971 ◽  
Vol 77 (2) ◽  
pp. 313-315 ◽  
Author(s):  
M. A. Price ◽  
N. T. M. Yeates

SummaryThe feed conversion efficiency of four intensively fed, partially castrated male cattle, measured over an 11-week period from approximately 9-months of age, was found to be significantly higher (P <0·05) than that of four steers.The effect of adding 5% beef tallow to the diet during this period was also studied. Although no statistically significant result of this on feed conversion was obtained, there was an indication that fat in the diet improved the bulls' efficiency, but not that of the steers. Added dietary fat had an effect on carcass composition, increasing signifioantly (P < 0·05) the deposition of carcass fat by steers but having no such effect in bulls. It appears, therefore, that the two sex types metabolized the added dietary fat differently, the steers converting much of it to depot fat; the bulls using it (with some evidenoe of greater efficiency) for growth of non-adipose carcass components.

2015 ◽  
Vol 55 (10) ◽  
pp. 1324 ◽  
Author(s):  
Yousef Baghcheghi ◽  
Ahmad Zare Shahneh ◽  
Mahdi Ganjkhanlou ◽  
Mahdi Khodaei Motlagh ◽  
Ali Reza Yousefi

The aim of the present study was to investigate the effects of induction hypothyroidism by propylthiouracil (PTU) on the growth performance and meat quality of fat-tailed Lori-Bakhtiari lambs. Eighteen Lori-Bakhtiari male lambs were randomly assigned to one of three groups (n = 6) and received daily treatments (gavage) consisting of 0 (Control: C), 10 (Low: L) or 20 (High: H) mg PTU/kg bodyweight/day for 60 days. PTU decreased plasma triiodothyronine and thyroxine concentration in both L and H (P < 0.0001). Lambs treated with PTU (L and H) had lower feed intake (P < 0.004), feed conversion efficiency (P < 0.003), and greater intramuscular fat than C lambs (P < 0.035). Meat from the L and H lambs had lower cooking loss and shear force, and also higher L* (lightness) than C lambs (P < 0.004, P < 0.015 and P < 0.025, respectively). The meat of H and L lambs was more tender than C lambs (P < 0.032). However, the meat of H lambs required fewer chews before swallowing than C lambs (P < 0.041). Generally, induction of mild hypothyroidism appeared to improve feed conversion efficiency and meat quality of lambs.


1963 ◽  
Vol 5 (3) ◽  
pp. 251-257 ◽  
Author(s):  
D. W. Holme ◽  
K. L. Robinson

SUMMARYThree experiments were carried out to evaluate zinc bacitracin as compared with penicillin, as a feed supplement for bacon pigs. The first experiment compared pig performance on a control diet with performance on the control diet supplemented with penicillin, 5 g./ton, or with zinc bacitracin, 10 g./ton. Experiment 2 compared the control diet with penicillin at 10 g./ton and zinc bacitracin at 10 g./ton with pigs housed in a different piggery. Experiment 3 compared the control diet with penicillin at 10 g./ton and zinc bacitracin at two levels, 10 g./ton and 5 g./ton. In none of the experiments was there any significant response to penicillin in terms of rate of gain, feed conversion efficiency or carcass composition. In the first experiment there was a small but significant improvement in rate of gain up to 100 lb. live-weight and for the whole experimental period by the pigs receiving 10 g./ton of zinc bacitracin. There was no significant response in feed conversion efficiency or carcass measurements. In the other two experiments there was no response to zinc bacitracin. The implications of the results are discussed.


2020 ◽  
Vol 1 (1) ◽  
pp. 1-4
Author(s):  
Urip Santoso ◽  
Yosi Fenita ◽  
Suharyanyo Suharyanto ◽  
Agus Martono Hadi Putranto

A factorial design was used to evaluate the effect of Sauropus androgynus leaf extract (SALE) andturmeric powder (TP) on the performance of broilers fed a high-fat diet. Two dietary fat sources (6% beeftallow or 6% palm oil), and five mixtures of SALE plus TP (0 g SALE plus 0 g TP, 9 g SALE plus 0.5 g TP,18 g SALE plus 0.5 g TP, 9 g SALE plus 1 g TP, 18 g SALE plus 1 g TP) were studied. Experimentalresults showed that dietary fat sources, and SALE plus TP mixture had no effect on body weightgain, feed intake, and feed conversion ratio (P>0.05). No interaction was found between two factors(P>0.05). In conclusion, the addition of SALE plus TP to a high-fat diet did not improve broilerperformance.


1986 ◽  
Vol 66 (4) ◽  
pp. 1097-1105
Author(s):  
M. R. BEDFORD ◽  
J. D. SUMMERS

Male broilers were fed diets containing 14, 18 or 22% crude protein (CP) and 10.88, 12.13 or 13.39 MJ kg−1 metabolizable energy (ME) to 3 wk of age. For each level of CP and ME, three diets were formulated so that excess nitrogen arose mainly from nonessential amino acids (NEAA), essential amino acids (EAA) or both. The source of nitrogen excess had no effect on any of the parameters measured in birds fed the 18 and 22% CP diets. However, at 14% CP and over all energy levels, excess nitrogen in the form of EAA gave rise to superior results with regard to weight gain, feed conversion efficiency and carcass protein when compared to those diets where the excess nitrogen arose mainly from NEAA sources. Increasing dietary energy reduced the effect that source of nonessential nitrogen had on weight gain, feed conversion efficiency and carcass protein deposition at 14% CP. Key words: Amino acids, energy, protein, broilers


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 531
Author(s):  
Januarius Gobilik ◽  
Stephen Todd Morris ◽  
Cory Matthew

Metabolic energy budgeting (MEB) was used to evaluate evolution over 30 years (1980–1981 to 2010–2011) in New Zealand southern North Island ‘hill country’ sheep and beef cattle systems. MEB calculates energy required by animals for body weight maintenance, weight gain or loss, pregnancy, and lactation to estimate the system feed demand and thereby provide a basis for calculating feed conversion efficiency. Historic production systems were reconstructed and modeled using averaged data from industry surveys and data from owners’ diaries of three case-study farms and reviewed for patterns of change over time. The modeling indicated that pasture productivity was 11% lower and herbage harvested was 14% lower in 2010–2011 than in the early 1980s. This productivity decline is attributable to warmer, drier summer weather in recent years. However, primarily through increased lambing percentage, feed conversion efficiency based on industry data improved over the study period from 25 to 19 kg feed consumed per kg lamb weaned, while meat production rose from 137 to 147 kg per ha per year. Similar improvements were observed for the three case farms. The New Zealand MEB model was found effective for analysis of tropical beef production systems in Sabah, Malaysia.


Aquaculture ◽  
2021 ◽  
pp. 737207
Author(s):  
Jianfei Huang ◽  
Chuang Shi ◽  
Yanping Gao ◽  
Jingzhi Su ◽  
Yuqin Shu ◽  
...  

1997 ◽  
Vol 273 (1) ◽  
pp. R113-R120 ◽  
Author(s):  
B. Ahren ◽  
S. Mansson ◽  
R. L. Gingerich ◽  
P. J. Havel

Mechanisms regulating circulating leptin are incompletely understood. We developed a radioimmunoassay for mouse leptin to examine the influence of age, dietary fat content, and fasting on plasma concentrations of leptin in the background strain for the ob/ob mouse, the C57BL/6J mouse. Plasma leptin increased with age [5.3 +/- 0.6 ng/ml at 2 mo (n = 23) vs. 14.2 +/- 1.6 ng/ml at 11 mo (n = 15), P < 0.001]. Across all age groups (2-11 mo, n = 160), log plasma leptin correlated with body weight (r = 0.68, P < 0.0001), plasma insulin (r = 0.38, P < 0.001), and amount of intra-abdominal fat (r = 0.90, P < 0.001), as revealed by magnetic resonance imaging. Plasma leptin was increased by a high-fat diet (58% fat for 10 mo) and reduced by fasting for 48 h. The reduction of plasma leptin was correlated with the reduction of plasma insulin (r = 0.43, P = 0.012) but not with the initial body weight or the change in body weight. Moreover, the reduction in plasma leptin by fasting was impaired by high-fat diet. Thus plasma leptin in C57BL/6J mice 1) increases with age or a high-fat diet; 2) correlates with body weight, fat content, and plasma insulin; and 3) is reduced during fasting by an action inhibited by high-fat diet and related to changes of plasma insulin.


2018 ◽  
Vol 2 (4) ◽  
pp. 419-427 ◽  
Author(s):  
Noel A Claffey ◽  
Alan G Fahey ◽  
Vasiliki Gkarane ◽  
Aidan P Moloney ◽  
Frank J Monahan ◽  
...  

Abstract Rations (DM basis) for spring-born male lambs consisting of concentrates ad libitum (CON), 50:50 (50% concentrate:50% forage), and forage ad libitum (FORG) were evaluated across feeding periods of three durations (36, 54, and 72 d). Lambs on CON diets were offered ad libitum access to concentrate along with 400 g of fresh weight silage (daily), while 50:50 diets were offered 0.9 and 3.0 kg of concentrate and silage, respectively. Lambs on FORG were offered ad libitum access to 25.5% DM silage. These rations were fed to 99 spring-born male Texel cross Scottish Blackface lambs which were assigned to a 3 × 3 factorial arrangement. Lambs were slaughtered following completion of their respective treatments. Lambs fed CON diets had greater ADG, FCE, and carcass weight (P &lt; 0.001) and carcasses with greater conformation score (P &lt; 0.001) than lambs fed 50:50 or FORG diets. Duration of feeding had no effect on production variables across all three concentrate inclusion levels. It was concluded that the inclusion of concentrates is needed to adequately finish lambs fed indoors. Feeding lamb’s 50:50 diets resulted in modest responses and may be a viable option for finishing lambs or to maintain growth in lambs when the cost of concentrate feed is high relative to the financial return on the lamb meat.


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