Sensitivity of spermatogonia to irradiation varies with age in pre-pubertal ram lambs

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.

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Effect of detoxified karanja (Pongamia spp.) cake on testicular architecture and semen production in ram lambs

animal ◽

10.1017/s1751731113001316 ◽

2013 ◽

Vol 7 (10) ◽

pp. 1697-1703 ◽

Cited By ~ 5

Author(s):

D. Dineshkumar ◽

S. Selvaraju ◽

S. Parthipan ◽

Allen Thayakumar ◽

D. Rajendran ◽

...

Keyword(s):

Ram Lambs

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Effects of zilpaterol hydrochloride and soybean oil supplementation on feedlot performance and carcass characteristics of hair-breed ram lambs under heat stress conditions

Journal of Animal Science ◽

10.2527/jas.2012-6214 ◽

2014 ◽

Vol 92 (3) ◽

pp. 1184-1192 ◽

Cited By ~ 7

Author(s):

J. L. Dávila-Ramírez ◽

U. Macías-Cruz ◽

N. G. Torrentera-Olivera ◽

H. González-Ríos ◽

S. A. Soto-Navarro ◽

...

Keyword(s):

Heat Stress ◽

Soybean Oil ◽

Carcass Characteristics ◽

Stress Conditions ◽

Feedlot Performance ◽

Zilpaterol Hydrochloride ◽

Ram Lambs

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Immunization against Kisspeptin-54 perturb hypothalamic–pituitary–testicular signaling pathway in ram lambs

Theriogenology ◽

10.1016/j.theriogenology.2018.10.029 ◽

2019 ◽

Vol 125 ◽

pp. 193-202 ◽

Cited By ~ 5

Author(s):

Teketay Wassie ◽

Guiqiong Liu ◽

Xunping Jiang ◽

Birhanu Tesema ◽

Yanguo Han ◽

...

Keyword(s):

Signaling Pathway ◽

Ram Lambs

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FAT THICKNESS MEASURED WITH THREE ULTRASONIC INSTRUMENTS ON LIVE RAM LAMBS AS PREDICTORS OF CUTABILITY

Canadian Journal of Animal Science ◽

10.4141/cjas80-101 ◽

1980 ◽

Vol 60 (4) ◽

pp. 857-867 ◽

Cited By ~ 9

Author(s):

ANDRÉ FORTIN

Keyword(s):

Multiple Regression ◽

Live Weight ◽

Optimal Location ◽

Regression Equations ◽

Longissimus Muscle ◽

Fat Thickness ◽

Ram Lambs

Fat thickness at four locations over the longissimus muscle was measured ultrasonically on 33 live ram lambs ranging in live weight from 16.0 to 37.0 kg. Simple and multiple regression equations were developed to assess the effectiveness of fat thickness as measured by three different ultrasonic instruments (Krautkrämer USM #2, Scanoprobe Model 731A and Scanogram Model 722) to predict cutability. Weight of trimmed or boneless cuts (shoulder + loin + rack + leg) was predicted with more precision than percentage of cuts. Fat thickness alone or combined with weight at scanning was of no significant value (P > 0.05) in the prediction of percentage of trimmed cuts. Percentage of boneless cuts was predicted more efficiently from weight at scanning alone than from fat thickness alone or combined with weight at scanning. Weight of cuts (trimmed or boneless) was also estimated from the fat measurement (P < 0.01), the weight at scanning (P < 0.01) or a combination of both variables. For the latter, fat thickness did not contribute significantly (P > 0.05). The optimal location of the fat measurement depended on the ultrasonic instrument used. Fat thickness measured with the Krautkrämer was more efficient in its prediction of cutability than fat thickness measured with the Scanoprobe or Scanogram. However, over the range of liveweights studied, the usefulness of fat thickness measured on live ram lambs to predict cutability is questionable.

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Extending the interval between second vaccination and slaughter: I. Effects on growth, scrotal size and stress responses of immunocastrated ram lambs

animal ◽

10.1017/s1751731118003592 ◽

2019 ◽

Vol 13 (9) ◽

pp. 1952-1961

Author(s):

T. Needham ◽

H. Lambrechts ◽

L.C. Hoffman

Keyword(s):

Stress Responses ◽

Ram Lambs

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Effects of the percentage of Texel or Rouge de ľOuest genes in lambs on carcass characteristics and meat quality

Animal Science ◽

10.1017/s1357729800051110 ◽

1999 ◽

Vol 69 (1) ◽

pp. 81-92 ◽

Cited By ~ 19

Author(s):

A. F. Carson ◽

B. W. Moss ◽

R. W. J. Steen ◽

D. J. Kilpatrick

Keyword(s):

Meat Quality ◽

Subcutaneous Fat ◽

Carcass Characteristics ◽

Live Weight ◽

Fat Content ◽

Carcass Weight ◽

Ewe Lambs ◽

Bone Content ◽

Intermuscular Fat ◽

Ram Lambs

AbstractThis study investigated the effects of the percentage of Texel or Rouge de l’Ouest (Rouge) genes in lambs (0, 50, 75 or 100%; the remainder being Greyface (Border Leicester × Scottish Blackface)) on lamb carcass characteristics and meat quality. Ewe lambs were slaughtered at 34, 40, 46 and 52 kg and ram lambs were slaughtered at 40, 46, 52 and 58 kg live weight. Dressing proportion increased (P < 0·001) by 0·53 and 0·27 g carcass weight per kg live weight for each 1% increase in Texel or Rouge genes respectively. Carcass conformation classification increased (P < 0·001) by 0·016 and 0·007 units (on a five-point scale) for each 1% increase in Texel or Rouge genes respectively. Carcass fat depth measures were reduced by Texel and Rouge genes such that at a constant fat depth end point, carcass weight could be increased by 0·029 and 0·023 kg for each 1% increase in Texel or Rouge genes. Carcass lean content increased (P < 0·001) by 0·99 and 0·27 g/kg for each 1% increase in Texel or Rouge genes. Subcutaneous fat content was reduced (P < 0·001) by 0·36 and 0·29 g/kg for each 1% increase in Texel or Rouge genes. Intermuscular fat content was reduced (P < 0·01) by 0·38 g/kg per 1% increase in Texel genes, whereas Rouge genes had no effect. Similarly, bone content was reduced (P < 0·01) by Texel genes only (0·31 g/kg per 1% increase in Texel genes). Warner-Bratzler shear force values showed a quadratic effect with increasing Texel and Rouge genes, with an initial decrease from 0 to 50% followed by an increase to 100%. Cooking loss increased (P = 0·05) as the percentage of Rouge genes in lambs increased. Increasing the percentage of Texel or Rouge genes significantly increased L* values (P < 0·01 and P < 0·05 respectively), b* values (P = 0·05 and P< 0·05 respectively) and H° values (P < 0·001).

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